Western Mountainous Regions Research Articles

Dynamic response of pile–slab retaining wall structure under rockfall impact

Abstract. Pile–slab retaining walls, as innovative rockfall protection structures, have been extensively utilized in the western mountainous regions of China. With their characteristics of a small footprint, high interception height, and ease of construction, these structures demonstrate promising potential for application in mountainous regions worldwide, such as the Himalayas, Andes, and Alps. However, their dynamic response upon impact and impact resistance energy remain ambiguous due to the intricate composite nature of the structures. To elucidate this, an exhaustive dynamic analysis of a four-span pile–slab retaining wall with a cantilever section of 6 m under various impact scenarios was conducted utilizing the finite-element numerical simulation method. The rationality of the selected material constitutive models and the numerical algorithm was validated by reproducing two physical model tests. The simulation results reveal the following. (1) The lateral displacement of the pile at the ground surface and the concrete damage under the pile at the impact center are greater than those under the slab at the impact center, implying that the impact location has a significant influence on the stability of the structure. (2) There is a positive correlation between the response indexes (impact force, interaction force, lateral deformation of pile and slab, concrete damage) and the impact velocities. (3) The rockfall peak impact force, the ratio of the peak impact force to the peak interaction force, and lateral displacement of the pile at the ground surface had strong linear relationships with rockfall energy. (4) Relative to the bending moment, shear force, and damage degree, the lateral displacement of the pile at the ground surface is the first to reach its limit value. Taking the lateral displacement of the pile at the ground surface as the controlling factor, the estimated maximum impact energy that the pile–slab retaining wall can withstand is 905 kJ in this study when the structure top is taken as the impact point. In cases where the impact energy of falling rocks exceeds 905 kJ, it is recommended to optimize the mechanical properties of the cushion layer, improve the elastic modulus of concrete, increase the reinforcement ratio of longitudinal tension bars, enlarge the section size of piles at ground level, or add anchoring measures to enhance the bending resistance of the retaining structure.

Identifying and Optimizing the Ecological Security Pattern of the Beijing–Tianjin–Hebei Urban Agglomeration from 2000 to 2030

The conflict between economic development and ecological protection continues to intensify, highlighting the necessity for constructing regional ecological security patterns (ESPs) to reconcile the relationship between development and protection effectively. This study used the GMOP and PLUS model to simulate future land use changes by 2030 under the following three scenarios: natural development (ND), ecological protection (EP), and economic development (ED). Employing the MSPA model and circuit theory, it identified ecological source areas and constructed the ESP for the Beijing–Tianjin–Hebei urban agglomeration (BTH) from 2000 to 2030. The results indicate that the proportion of ecological source areas increased from 22.24% in 2000 to 23.09% in 2020, the EP scenario showing the highest proportion of ecological source areas compared with the other two scenarios. These areas are densely distributed in the northern and western mountainous regions, with sparse distributions in the southern plains. The number of ecological corridors grew from 603 in 2000 to 616 in 2020, with the EP scenario having more corridors than the other two scenarios. From 2000 to 2030, corridors in the northern and western mountainous areas were denser, shorter, and more variable, while those in the southern plains were less dense, longer, and relatively stable. Over two decades, habitat areas for species in BTH increased, while landscape connectivity decreased. Compared with 2020 and the other two scenarios, the EP scenario saw an increase in habitat areas and improved landscape connectivity. The impact on ecological corridors and improvement areas primarily arose from a combination of socio-ecological drivers (e.g., elevation, slope, population), while the influence on restoration and key areas mainly stemmed from ecological factors (e.g., elevation, temperature, NDVI, precipitation). The findings demonstrate that distinguishing different geomorphological units to improve and restore the regional environment, while considering socio-ecological drivers, is crucial for restoring the overall ESP and landscape connectivity of BTH.

Potential impacts of climate change on ecosystem services in Austria

Climate change is considered a major driver for environmental changes and impacts on human well-being. Understanding the relationships between climatic changes and ecosystem services (ES) is therefore crucial to develop effective adaption and mitigation measures. However, studies that comprehensively assess climate change impacts on ES, providing also spatially explicit information, are greatly lacking. To address this gap, this study aims at assessing and mapping potential impacts on multiple ES in Central Europe, using the example of Austria. Our analysis steps included (1) mapping provisioning, regulating, and cultural ES (n = 19) using a land use/cover-based approach, (2) deriving potential impacts on indicators (n = 58), used to assess ES, through a literature analysis, (3) mapping potential impacts on ES in qualitative terms, and (4) analysing spatial patterns across Austria. Our results indicate that, in particular, water-related ES and cultural ES will decline, while some provisioning and regulating ES will improve. The spatial analysis revealed that regions located in the south-eastern parts of Austria will be potentially affected the most by climate change impacts, while less ES will decline in western mountain regions. Our findings contribute to the knowledge base for decision-making at different governance levels, supporting the development of policies and management strategies at the national and international level, as well as fostering communication with stakeholders and the elaboration of targeted management plans at the local and regional level. Our proposed mapping approach is easily transferable to other regions, but future research should address current limitations related to uncertainties in climate projections, the clear distinction of climate-induced impacts, and the role of climate-related hazards.

Genomic and spatial analysis reveal the transmission dynamics of tuberculosis in areas with high incidence of Zhejiang, China: A prospective cohort study

In the mountainous, rural regions of eastern China, tuberculosis (TB) remains a formidable challenge; however, the long-term molecular epidemiological surveillance in these regions is limited. This study aimed to investigate molecular and spatial epidemiology of TB in two mountainous, rural counties of Zhejiang Province, China, from 2015 to 2021, to elucidate the recent transmission and drug-resistance profiles. The predominant Lineage 2 (L2) Beijing family accounted for 80.1% of total 532 sequenced Mycobacterium tuberculosis (Mtb) strains, showing consistent prevalence over seven years. Gene mutations associated with drug resistance were identified in 19.4% (103/532) of strains, including 47 rifampicin or isoniazid-resistant strains, eight multi-drug-resistant (MDR) strains, and five pre-extensively drug-resistant (pre-XDR) strains. Genomic clustering revealed 53 distinct clusters with an overall transmission clustering rate of 23.9% (127/532). Patients with a history of retreatment and those infected with L2 strains had a higher risk of recent transmission. Spatial and epidemiological analysis unveiled significant transmission hotspots, especially in densely populated urban areas, involving various public places such as medical institutions, farmlands, markets, and cardrooms. The study emphasizes the pivotal role of Beijing strains and urban-based TB transmission in the western mountainous regions in Zhejiang, highlighting the urgent requirement for specific interventions to mitigate the impact of TB in these unique communities.

Integrating Remote Sensing, GIS and Machine Learning Approaches in Evaluation of Landslide Susceptibility in Mountainous Region of Nghe An Province, Vietnam

This study applied remote sensing methods combining GIS and machine learning (ML) in landslide assessment and zonation for the western mountainous area of Nghe An province, Vietnam. Factors affecting landslide susceptibility are analyzed and included in the assessment model including terrain elevation, slope, aspect, flow accumulation, geomorphology, profile curvature, Topographic Position Index (TPI), fault density, road density, rainfall and land use. A field survey was conducted on July, 2023 to collect the ground truth data of landslide areas in Nghe An and used as input for the training and validating process of landslide model with ratios of 70 and 30 percentage. The landslide estimation algorithms which derived from the machine learning approach including Support Vector Machine, Random Forest, and Logistic Regression have been investigated with 11 input layers and field survey training data. The results indicated that among the causative parameters of landslides in the study area, the most important factor was the Standardized Precipitation Index, derived from the rainfall data. Additionally, traffic, terrain slope, and elevation were also significant factors. In terms of the landslide estimation algorithms, the Random Forest model exhibited the highest accuracy for mapping landslide susceptibility in the western mountainous region of Nghe An province, with a correlation coefficient (R2) of 0.97. The research findings demonstrate the effectiveness of integrating remote sensing, GIS, and ML techniques for landslide research in mountainous areas of Vietnam. This approach provides valuable insights on landslide susceptibility, and a better understanding of landslide dynamics in the study area.

Projected climatic drought events in drought-prone cities: Insights from high-resolution downscaled CMIP6 data

This study investigated the drought trends, frequency, and duration in three drought-prone cities in Northwest China under various Shared Socioeconomic Pathways (SSPs) climate scenarios from 2015 to 2099. Utilizing a two-step downscaling method, we generated high-resolution (1 km) temperature and precipitation projections for the cities using multiple global climate model (GCM) data. The Standardized Precipitation Evapotranspiration Index (SPEI) was then calculated to assess drought conditions. Our results revealed that under the influence of global climate change, the 12-month SPEI exhibited a significant increasing trend for all three cities, indicating a shift towards a more humid climate. The influence of climate change on drought trends was more pronounced at higher latitudes. Additionally, the occurrence and duration of severe droughts (3-month SPEI < -1.5) were higher in the near future (2015–2056) compared to the far future (2057–2099), suggesting time-lagged and cumulative effects of global climate change on drought. Spatial variations within each city were also observed, with the western mountainous regions of Xi'an showing a more pronounced decrease in drought frequency under higher emission scenarios. Under the influence of different projected scenarios, the variations in drought characteristics across cities exhibited significant spatial heterogeneity. This study highlights the importance of understanding local and inter-regional drought characteristics in the context of climate change, and the need for targeted management policies to effectively cope with climate anomalies and associated disasters in different regions.

Spatio-Temporal Changes and Habitats of Rare and Endangered Species in Yunnan Province Based on MaxEnt Model

Biodiversity is crucial for ecosystem functioning, but it is rapidly declining due to human activities and climate change. Protecting biodiversity has become a key priority for global environmental conservation actions. Rare and endangered species have a great impact on the ecosystem, yet due to their limited survival capacity, they are more prone to extinction, thus exerting a significant impact on biodiversity. However, current research reveals a lack of information concerning the potential distribution and changes of these species. This study used the maximum entropy model to predict the present and future potential habitats of rare and endangered species in Yunnan Province. After superimposing model results, four richness regions are divided by the natural breakpoint method and analyzed. Existing protected areas are compared with hotspots, and the land-use composition of hotspots is also analyzed. The results revealed that, in both current and future scenarios, rare and endangered species in Yunnan Province are primarily found in the western mountainous region, the Xishuangbanna–Wenshan high temperature area, and the Kunming–Qujing dense vegetation cover area. These species are also expanding their distribution towards the western mountainous area. However, under the low carbon emission scenario (RCP2.6), these species will spread from the high abundance regions to the low altitude hotspots by 2070. In the high carbon emissions scenario (RCP8.5), there will be fewer high abundance areas in 2070 than in 2050. The transfer matrix analysis reveals regional richness variations over time. Furthermore, the analysis revealed significant conservation gaps and found that existing hotspot areas were heavily affected by human activities. To improve conservation efficiency, it is necessary to enhance the protection of existing hotspots in Yunnan Province. Climate change plays a significant role in species migration, with precipitation levels being a key factor. The necessary actions should be taken to address the insufficient protection, resolve conflicts between human activities and land use in critical areas, and formulate effective strategies for adapting to future climate changes. Yunnan Province, with its rich species resources, has the potential to become a global innovator in biodiversity conservation by implementing improved conservation strategies.

Causal mechanisms and evolution processes of “block-burst” debris flow hazard chains in mountainous urban areas: a case study of Meilong gully in Danba county, Sichuan Province, China

The research interest in multi-hazard chains lies in the comprehension of how various hazards, such as debris flows, floods, and landslides, can interact and amplify one another, resulting in cascading or interconnected hazards. On 17 June 2020, at approximately 3:20 a.m., a debris flow occurred in Meilong gully (MLG), located in Banshanmen Town, Danba County, in southwest China’s Sichuan Province. The debris flow had a discharge volume of approximately 40 × 104 m3 and rushed out to block the Xiaojinchuan (XJC) river, subsequently forming a barrier lake. This event ultimately induced a hazard chain that included heavy rainfall, debris flow, landslides, the formation of a barrier lake, and an outburst flood. The impact of this chain resulted in the displacement of 48 households and affected 175 individuals. Furthermore, it led to the destruction of an 18 km section of National Highway G350, stretching from Xiaojin to Danba County, causing economic losses estimated at 65 million yuan. The objective of this study is to analyze the factors leading to the formation of this hazard chain, elucidate its triggering mechanisms, and provide insights for urban areas in the western mountainous region of Sichuan to prevent similar dam-break type debris flow hazard chains. The research findings, derived from field investigations, remote sensing imagery analysis, and parameter calculations, indicate that prior seismic disturbances and multiple dry-wet cycle events increased the volume of loose solid materials within the MLG watershed. Subsequently, heavy rainfall triggered the initiation of the debris flow in MLG. The cascading dam-break, resulting from three unstable slopes and boulders within the channel, amplified the scale of the hazard chain, leading to a significant amount of solid material rushing into the XJC river, thus creating a dam that constricted the river channel. With the intensification of river scouring, the reactivation and destabilization of the Aniangzhai (ANZ) paleolandslide occurred, ultimately leading to the breach of the dam and the formation of an outburst flood. The research comprehensively and profoundly reveals the causal mechanism of the MLG hazard chain, and proposes measures to disrupt the chain at various stages, which can aid in enhancing monitoring, early warning, forecasting systems, and identifying key directions for ecological environmental protection in urban areas within the western mountainous region of Sichuan. Additionally, it could also serve as a reference for mountainous urban areas such as the Tianshan, Alps, Rocky Mountains, and Andes, among others.

Occupational burnout and public stigma associated with employee mental well-being: A multi-industry, cross-sectional study during COVID-19.

While mental illness (e.g., depression, anxiety) has been examined frequently in the workplace, the COVID-19 pandemic has only increased the attention towards mental illness. Mental well-being views mental health as a continuum from ill health to thriving. Few studies have examined factors associated with mental well-being in the workplace. Public stigma for mental illness, the general population's negative attitude towards mental illness, and occupational burnout are examined. The purpose of this study was to examine the relationship between burnout and public stigma on mental well-being in a sample of employees across industries in the United States. Employees surveyed from 16 companies from various industries were assessed. Room Here, a non-profit organization whose goal is to improve employee mental fitness, gathered data from these companies located in the western mountain region of the U.S. Data were collected during the pandemic. Across this portfolio of companies, 259 employees were included in the sample. Survey assesses respondents' mental well-being, stigma towards mental illness, and occupational burnout. Ordinary least squares (OLS) regression was used in this cross-sectional study on secondary data. Results suggested occupational burnout was associated with a decrease in mental well-being, while public stigma was associated with an improvement in mental well-being. This study sought to examine the relationship between mental well-being, burnout, and public stigma. Employee burnout and public stigma were related to mental well-being. Implications for burnout and stigma reduction programs are discussed as well as future research.

Numerical simulation of the interaction between mine water drainage and recharge: A case study of Wutongzhuang coal mine in Heibei Province, China

Water inflow poses a critical safety concern in coal mining. The pressing challenge in current mine water inflow research is the need to enhance the prediction of dynamic changes in mine water inflow across different mining stages. In this study, the hydrogeological conditions and aquifer structural characteristics of the Wutongzhuang Coal Mine in Hebei Province, China were analyzed, and the results were combined with pumping test and drilling data. A numerical model of groundwater flow in the study area was established using Visual MODFLOW and the model was calibrated and verified by comparing its results with the measured values to ensure that it realistically reflected the state of groundwater movement in the study area. The results of numerical simulation indicated that: (1) The water level of the Ordovician aquifer varies significantly by season. A large exposed area of Ordovician limestone in the western mountainous region receives a large amount of rainfall infiltration recharge in the summer rainy period that raises the water level of the Ordovician aquifer in the study area. (2) The groundwater system in the study area is in an equilibrium state, with the water inflow approximately equal to the outflow. (3) The recharge of mine drainage water has a slight positive effect on the Ordovician water level and the floor water inflow, with the impact on the water level of the aquifer decreasing as the distance from the recharge well and the import of Ordovician limestone water increase. In cases in which there is mine water recharge, the water level of the Ordovician aquifer is approximately 0.33 to 1.37 m higher than in cases without recharge, resulting in an increase in water inflow of approximately 10.6 m3/d. (4) In cases in which there is recharge of all drainage water, the maximum water inflow into the fifth mining area is 3,491.3 m3/d, which is 12.5 m3/d higher than in the case without recharge. These results provide important technical references for the formulation of mining schemes and water prevention measures in mining areas.

Physalis ixocarpa: new species of genus physalis to the flora of Pakistan from mountainous region of district Shangla, Khyber Pakhtunkhwa Pakistan.

In the western mountainous region of Khyber Pakhtunkhwa Pakistan at the Shangla district, we found Physalis ixocarpa for the first time, not yet reported from Pakistan. Physalis ixocarpa was unidentified and has no ethnobotanical record in the flora of Pakistan. It is a member of family Solanaceae and having a close relation with Solanum tuberosum and Lycopersicon esculentum. The stem is prostrate with a dichotomous pattern of branches having leaves flower and fruits. Leaves are smooth, ovate and the margins of leaf blade dentation are poorly developed. The average length and width of the leaves are 6.50 and 3.61 cm respectively. P. ixocarpa grows to the length of 4-5 feet and an annual herb. The flowers of the plants are yellow in color and having purple color spots on the petals which are star-shaped. The round berry fruits are surrounded by persistent calyx and purple in color. The fruits are the 3-6cm in diameter. The plants are found in the different localities of district Shangla especially in Bar and Koz Kana. The life cycle of reporting plant is started in May and completed in November.

Validation of FY-4A/AGRI LST and High Temporal–Spatial Resolution Analysis of Surface Heat Resources in Hunan Province, Central China

Land surface temperature (LST) is a crucial parameter in climate and ecology, exerting significant influence on meteorological conditions, ecosystems, and human life. LST data sources are diverse, with remote sensing being the prevailing means of acquisition. FY-4A/AGRI offers high-quality LST products for East Asia. We conducted a comprehensive evaluation and refined analysis of surface heat resources in Hunan Province, central China, over a two-year period using the 4 km/1 h resolution product in this study. The results demonstrate that the FY-4A LST product effectively captures surface temperature (R = 0.893), albeit with a relatively high error level (Bias = −6.295 °C; RMSE = 8.58 °C), particularly in capturing high LST values. The performance of this product is superior in the eastern flat terrain area of Hunan Province compared to its performance in the western mountainous region due to environmental conditions causing systematic errors that contribute to instability in detection deviation for this product. Surface heat resources are more abundant in eastern Hunan Province than in mountainous areas located west and southwardly, and the detailed distribution of them at finer scales is mainly influenced by terrain and climate conditions. There is no obvious seasonal difference in the distribution of heat resources except in winter, and rapid urbanization within Chang–Zhu–Tan urban agglomeration over two years has significantly altered the spatial distribution pattern of surface heat resources across Hunan Province. These findings provide a quantitative baseline for assessing FY-4A satellite’s detection capability while serving as a reference for further application of its LST products and establishing foundations for divisional classification and utilization strategies pertaining to surface heat resources within Hunan Province.

Spatial-temporal pattern evolution and geological influence factors analysis of ecological vulnerability in Western Sichuan mountain region

Compared to plains, hills and basins, mountainous areas with complex topography are more prone to ecological and environment vulnerability to climate change, human interference and geological disasters. This type of region is usually located in abrupt transitional zones, which marked by active neotectonic movements, high-incidence mountain disasters, abundant available resources, slower economic development, diverse eco-environment and insufficient cultivated land resources. Therefore, it is of great significance to determ the vulnerability status and spatial–temporal change process of the eco-environment in mountainous area with complex topography. In this study, data derived from vegetation, topography, soil, meteorological and human social factors were used to develop an evaluation index system that can reflect the characteristics of the eco-environment in the mountain area. Employing the Genetic Projection Tracing Model (RAGA-PPM), we developed a framework for assessing the vulnerability of mountainous areas with complex terrains and applied it to the western Sichuan mountain region, China. In addition, the relationship between the geological factors and the vulnerability of eco-environment was quantitatively analyzed by using the geographic detector. The results indicate that (1) The overall vulnerability was medium and the spatial distribution was higher in the central and eastern parts and lower in the surrounding areas. The area with high vulnerability accounted for 27.9%. (2) The overall degree of vulnerability increased from2010 to 2020, the eco-environment experienced a rapid deterioration from 2010 to 2015, followed by a slower improvement from 2015 to 2020. (3) Correlations were minimal between vulnerability results and fault density and earthquake dynamic peak acceleration, the influence of other geological factors ranged from 10% to 25.8%, indicating a nonlinear correlation. (4) This study reveals that the ecological vulnerability of mountain areas was the effect of multiple human and natural factors, and there was a certain correlation between geological environment and vulnerability distribution. These findings can assist decision-makers in providing a scientific basis for managing and developing the ecological environment in mountainous regions.

Soil erosion and hydroclimatic hazards in major African port cities: the case study of Tangier

Land degradation and soil erosion are becoming increasingly problematic in Africa's rapidly developing urban areas, particularly in Major Port Cities. Uncontrolled expansion and human pressures are hindering planning, adaptation, and conservation efforts. To understand the extent of these issues, this study combined morphometric analysis, soil loss calculation, field monitoring, and remote sensing and GIS tools to assess soil erosion in the Metropolis of Tangier (Morocco) located at the confluence of the Mediterranean Sea and the Atlantic Ocean at the Strait of Gibraltar. The study relied on data from 13 rain gauge stations, official reports, and remote sensing acquisitions, as well as field observations. Results showed an average soil erosion rate of 24.2 t/ha/year, equivalent to an annual soil loss of 588,051 t/year. This high rate was largely due to areas with a high erosion risk (99.8%), covering only 8.3% of the territory, which were characterized by recently burned topsoil, fallow land, and steep slopes. These areas included both uncontrolled neighbourhoods and areas for planned urban and industrial expansion, posing a threat to the landscape's sustainability and socio-economic prospects. The morphometric analysis revealed its high vulnerability to erosion and degradation, with the highest soil loss rates observed in the eastern and western regions. The study also found that flash floods caused by hydroclimatic hazards can lead to significant damage to infrastructure and equipment, particularly in western sub-basins and mountainous regions. In conclusion, the use of remote sensing and GIS technologies provided valuable insights into the physical characteristics and vulnerability of the Tangier Metropolis to land degradation and soil erosion. These findings emphasize the need for effective land management practices and conservation measures to mitigate the impacts of land degradation and soil erosion in the face of climate change. This information is crucial for decision-makers and stakeholders to develop strategies to address these pressing issues.

Assessment of Rainfall Variability over Karnataka state in India

Karnataka state situated in the southern part of India is surrounded by a long coast line and western ghat mountain regions on the western side. The rainfall distribution shows a large variability in different parts of the state. North interior part in the state receives less rainfall as compared to the south interior region, which receives moderate rainfall. Although coastal Karnataka witnesses a high rainfall and is one of the most important regions in the country, in recent years the state has faced drought because of less rainfall which may be attributed to the regional climate change. Because of the decreasing trend in rainfall almost all the important sectors like agriculture and water resources have been affected a lot in Karnataka. In this work, assessment of the spatial and temporal distribution of monsoon rainfall is presented in terms of the climatology, variability, trend etc. The time series analysis also indicated the increasing trend of rainfall as a whole but the trend in recent decades is very less as compared to the long term. The El-Niño Southern Oscillation (ENSO) and the regional rainfall pattern relation is also explored. The increase in heavy rainfall in recent times is observed from the analysis. This study can be useful in addressing regional climate change, understanding the local and large scale variability impacts and in can be a good input for preparing the policy formulation and pro-active disaster management.

On the Mechanisms of a Snowstorm Associated with a Low-Level Cold Front and Low-Level Jet in the Western Mountainous Region of the Junggar Basin, Xinjiang, Northwest China

Snowstorms frequently hit large parts of the Northern Hemisphere, and their causative factors have been drawing increasing attention in recent years. As the first in-depth study on the mechanisms of a snowstorm associated with a low-level cold front (LLCF) and low-level westerly jet (LLWJ) in the western mountainous region of the Junggar Basin, Xinjiang, based on both observations and numerical simulation, the major findings of this work are as follows: At the early stage, instabilities were mainly dominated by inertial instability (II) occurring near the core region of the LLWJ, while the lower level was mainly controlled by the baroclinic component of moist potential vorticity (MPV2), which was mainly contributed by the vertical shear of the horizontal wind, which is also located near the LLWJ. At the later stage, II was released significantly, whereas the MPV2 still supported snowfall clouds. Further analysis based on the decomposition of the frontogenetical forcing required for the release of the instabilities indicated that the slantwise term was the major contributor, whereas convergence and deformation also played significant roles at low levels above the windward slope. The slantwise term resulted from the combined effects of baroclinicity due to the LLCF and the inhomogeneity of the momentum due to the LLWJ.

Ecosystem services balance and its influencing factors detection in China: A case study in Chengdu-Chongqing urban agglomerations

Rapid urbanization in China’s urban agglomerations has severely disrupted the relationship between supply and demand for ecosystem services (ESs). Exploring the spatial and temporal variation characteristics of ESs balance and its driving mechanisms is crucial for the high-quality development of urban agglomerations. However, few studies have explored the pattern of ESs balance and its driving mechanisms at multiple scales in urban agglomerations, which constrains the formulation of regional ecological protection and land use policies. In this study, we attempted to characterize the ESs balance pattern and its spatio-temporal variation from 2000 to 2020 at multiple scales in the Chengdu-Chongqing urban agglomerations (CCUA), using ESs matrix and hotspot analysis tools. We then introduced the optimal parametric geographic detector to detect the formation mechanism of the spatial differentiation pattern of ESs balance. The results show that the overall ESs supply index for CCUA was greater than the demand index. The ESs were in short supply in Chengdu and Chongqing. The pattern of ESs balance had significant scale dependence. The hot spots of the ESs balance index were mainly in the western, southern, and eastern mountainous regions, while the cold spots were concentrated in urban areas of Chengdu and Chongqing, with significant differences in characteristics at different scales. The spatial distribution of the ESs balance was mainly affected by the forest land proportion, slope, normalized difference vegetation index (NDVI), elevation, cultivated land proportion, and temperature. The interaction of natural, land use, and socio-economic factors significantly enhanced the spatial differentiation of ESs balance. The interaction of different types of factors highlights the importance of topography, NDVI, cultivated land, forest land, and population. The results of this study can provide scientific references for the sustainable management of ESs and the construction of ecological civilization in CCUA.

Hearing loss: an unusual presentation of neurobrucellosis: a case report

IntroductionBrucellosis is a zoonotic disease, caused by a Gram-negative coccobacillus of Brucella genus, transmitted to humans by animals, especially cattle. It rarely involves the nervous system (neurobrucellosis); only a few cases present with hearing loss. We report a case of neurobrucellosis, that presented with bilateral sensorineural hearing loss and mild to moderate persistent headache. To the best of our knowledge, this is the first well-documented case from Nepal.Case presentationThe patient was a 40-year-old Asian male shepherd from the western mountainous region of Nepal who came to the emergency department of Manipal Teaching Hospital, Pokhara in May, 2018 and did a follow-up for 6 months. He presented with high-grade fever, profuse sweating, headache, myalgia, and bilateral sensorineural hearing loss. His history of consuming raw milk of cattle, symptoms including persistent mild to moderate headache, bilateral hearing loss, and serological findings were suggestive of neurobrucellosis. Following treatment, the symptoms improved, including the complete recovery of hearing loss.ConclusionHearing loss may be the manifestation of neurobrucellosis. Physicians should know about such presentations in brucella endemic areas.

Deep learning mapping of surface MDA8 ozone: The impact of predictor variables on ozone levels over the contiguous United States

The limited number of ozone monitoring stations imposes uncertainty in various applications, calling for accurate approaches to capturing ozone values in all regions, particularly those with no in-situ measurements. This study uses deep learning (DL) to accurately estimate daily maximum 8-hr average (MDA8) ozone and examines the spatial contribution of several factors on ozone levels over the contiguous U.S. (CONUS) in 2019. A comparison between in-situ observations and DL-estimated MDA8 ozone values shows a correlation coefficient (R) of 0.95, an index of agreement (IOA) of 0.97, and a mean absolute bias (MAB) of 2.79 ppb, highlighting the promising performance of the deep convolutional neural network (Deep-CNN) at estimating surface MDA8 ozone. Spatial cross-validation also confirms the high spatial accuracy of the model, which obtains an R of 0.91, and IOA of 0.96 and an MAB of 3.46 ppb when it is trained and tested on separate stations. To interpret the black-box nature of our DL model, we use Shapley additive explanations (SHAP) to generate a spatial feature contribution map (SFCM), the results of which confirm an advanced ability of Deep-CNN to capture the interactions between most predictor variables and ozone. For instance, the model shows that solar radiation (SRad) SFCM, with higher values, enhances the formation of ozone, particularly in the south and southwestern CONUS. As SRad triggers ozone precursors to produce ozone via photochemical reactions, it increases ozone concentrations. The model also shows that humidity, with its low values, increases ozone concentrations in the western mountainous regions. The negative correlation between humidity and ozone levels can be attributed to factors such as higher ozone decomposition resulting from increased levels of humidity and OH radicals. This study is the first to introduce the SFCM to investigate the spatial role of predictor variables on changes in estimated MDA8 ozone levels.

Sociodemographic and Geographic Variation in Access to Neuro-Ophthalmologists in the United States.

Neuro-ophthalmologists have expertise in rare and complex disorders, but the ability of patients to access neuro-ophthalmic care has not been examined at a nationwide level. Using the 2020 directory of all 502 members of the North American Neuro-Ophthalmology Society as a reference, we found the practice locations of 461 confirmed practicing members and converted each street address to latitude and longitude coordinates. We calculated the travel distance and time from each census tract to the nearest practice location and calculated population-weighted averages by state, region, and other prespecified factors. Choropleth maps were used to visualize the distribution of travel distances and times across the United States. California had the most practicing neuro-ophthalmologists out of any state (50), whereas 4 states (DE, MT, SD, and WY) had none. Washington, DC and MA had the most neuro-ophthalmologists per capita. The average travel distance and time to the nearest neuro-ophthalmologists were found to be 40.90 miles and 46.50 minutes, respectively, although a large portion of western plains and mountain regions had travel times of over 120 minutes. Patients in rural areas had longer travel times than those in urban areas, and Native American patients had the longest travel times of any racial or ethnic group. The travel time to see a neuro-ophthalmologist varies widely by state, region, and rurality, with Native American patients and rural patients being disproportionately affected. By identifying the areas with the greatest travel burdens, future policies can work to alleviate these potential barriers to care.