Heterogeneous Spatial Distribution Research Articles

Spatial distribution, influencing factors and innovative development countermeasures of farmer cooperatives in Hunan Province, China

China’s rural reform is reliant on farmers' cooperatives as a key organization vehicle. It plays an important role in promoting rural revitalization. Such as, realizing the organic connection between small farmers and agricultural modernization. This study used the nearest neighbor index and kernel density estimation to analyze the spatial distribution and structural characteristics of farmer cooperatives in Hunan Province. It revealed the spatial differentiation law of cooperatives. Also using geographical detectors to figure out the main factors that affect the spatial distribution. The results show that: ① Hunan Farmers Cooperatives show significant spatial agglomeration. The overall spatial distribution shows the spatial characteristics of "one core, one circle, and multiple points". And the spatial distribution pattern of "large agglomeration, finger-shaped radiation distribution". Among them, the distribution of provincial demonstration cooperatives is relatively balanced. ② Cooperatives in six types of industries, such as planting, forestry, and feeding, showed agglomeration distribution. Different industrial cooperatives spread out in different ways, such as in an anti-"L" shape, a dual-core shape, or a one-center area. ③ The 24 influence factors selected from the five dimensions of the natural environment, social economic basis, production basis, output capacity, and facility basis have high, general, and weak influence on cooperatives' spatial distribution. The development and distribution of cooperatives mainly depend on resource endowment, social and economic development level, and market dependence. The spatial distribution heterogeneity of different professional cooperatives is mainly affected by slope, per capita disposable income of rural residents, road density, and other factors. ④ The progression of farmer cooperatives in Hunan Province should prioritize high-quality development, emphasizing the need for innovative approaches and transformative strategies within rural industrial organizations. It is imperative to optimize the spatial distribution of cooperatives, strategically contributing to the establishment of a novel framework for modern agricultural development in Hunan Province. Additionally, there is a critical emphasis on spearheading collaborative initiatives among cooperatives of varied industrial types, aimed at fostering the integrated development of rural primary, secondary, and tertiary industries.

Effect of particle size distribution variability on the permeability of hydrate-bearing sediments: A CFD study

Natural gas hydrates (NGH) are considered as a future clean energy in the era of carbon neutrality. The seepage behaviour of hydrate-bearing sediment (HBS) and its controlling factors are significant for developing effective production strategies. In this study, we aim to elucidate how the heterogeneous spatial distribution of clayey-silty sediment particles, particularly the non-uniform particle size distribution (PSD) affects the permeability of HBS. An algorithm was developed to generate the heterogeneous spatial distribution of sediment particles based on the PSD of hydrate-bearing cores extracted from Japan Nankai Trough (D50 = 122 μm). A series simulation of fluid flow in porous media based on CFD was conducted for the HBS with varying hydrate saturations (SH). The watershed segmentation algorithm was employed for the identification of pore structure, including pore space and pore throat with a detailed analysis on the pore structure evolution with SH. Host sediments with higher uniformity result in initial high permeability but the permeability reduction with increasing SH is more significant compared with that of lower uniformity. Pore throat width reduced to less than 5 μm with SH above 50% compared with its original width of ∼30 μm. Tortuosity exhibits a linear increase with SH, while permeability decreases exponentially with increasing tortuosity. We propose an improved permeability model (KCpro) based on the classical Kozeny-Carman model accounting for the change in specific surface area for non-uniform PSD in HBS with good agreement. This study confirmed the applicability of CFD modelling as a promising tool to study the seepage behaviour of HBS complementary to classical permeability experimental tests. Results of this study provide fundamental understanding on how permeability evolves in HBS with significant PSD variations in natural gas hydrate reservoirs in nature.

Estimating soil moisture content in citrus orchards using multi-temporal sentinel-1A data-based LSTM and PSO-LSTM models

Soil moisture content is a vital variable in agricultural, hydrological, ecological and climatological processes. However, susceptible to soil type, soil structure, topography, vegetation and human activities, soil moisture content exhibits strong spatial heterogeneity in spatial distribution, which makes it difficult to accurately estimate the soil moisture content distribution information at a large scale using conventional methods. To solve the problem, this study proposed a novel hybrid model (PSO-LSTM) based on the particle swarm optimization (PSO) and long short-term memory (LSTM) network model to accurately predict soil moisture content at a large scale. Five different input combinations were constructed based on the vertical polarization (VV) and cross-polarization (VH) of multi-phase Sentinel-1A data, and the soil moisture content at depths of 5 cm, 10 cm, 20 cm and 40 cm in citrus orchards were estimated using the standalone LSTM and hybrid PSO-LSTM models. The results showed that the estimation accuracy of the hybrid PSO-LSTM model was greater than that of the standalone LSTM model at different depths, with the normalized root mean square error (NRMSE) of 4.568–11.023 % and 18.056–30.156 %, respectively. With the VV polarization as the only inputs, the PSO-LSTM model obtained high prediction accuracy, with the normalized root mean square error (NRMSE) of 5.458–10.125 %, respectively. Therefore, the PSO-LSTM model with VV polarization input was recommended to estimate the soil moisture content at different depths in citrus orchards, which provides important data for decision-making on distributed precision irrigation at a large scale.

Ecological inferences on invasive carp survival using hydrodynamics and egg drift models

Bighead carp (Hypophthalmichthys nobilis), silver carp (H. molitrix), black carp (Mylopharyngodon piceus), and grass carp (Ctenopharyngodon idella), are invasive species in North America. However, they hold significant economic importance as food sources in China. The drifting stage of carp eggs has received great attention because egg survival rate is strongly affected by river hydrodynamics. In this study, we explored egg-drift dynamics using computational fluid dynamics (CFD) models to infer potential egg settling zones based on mechanistic criteria from simulated turbulence in the Lower Missouri River. Using an 8-km reach, we simulated flow characteristics with four different discharges, representing 45–3% daily flow exceedance. The CFD results elucidate the highly heterogeneous spatial distribution of flow velocity, flow depth, turbulence kinetic energy (TKE), and the dissipation rate of TKE. The river hydrodynamics were used to determine potential egg settling zones using criteria based on shear velocity, vertical turbulence intensity, and Rouse number. Importantly, we examined the difference between hydrodynamic-inferred settling zones and settling zones predicted using an egg-drift transport model. The results indicate that hydrodynamic inference is useful in determining the ‘potential’ of egg settling, however, egg drifting paths should be taken into account to improve prediction. Our simulation results also indicate that the river turbulence does not surpass the laboratory-identified threshold to pose a threat to carp eggs.

Polycyclic aromatic hydrocarbons and their halogenated derivatives in soil from Yellow River Delta: Distribution, source apportionment, and risk assessment

The distribution of polycyclic aromatic hydrocarbons (PAHs) and halogenated PAHs (HPAHs) in surface soils from the petroleum industrial area of the Yellow River Delta (YRD) in China were investigated. The total concentrations of 16 PAHs ranged from 19.6 to 1560 ng/g, while 22 HPAHs ranged from 2.44 to 14.9 ng/g. Moreover, a high degree of spatial distribution heterogeneity was observed for both PAHs and HPAHs, which is likely attributed to the distinct industrial activities in studied area. The combustion of biomass and petroleum were identified as primary sources of soil PAHs and HPAHs in the YRD. Furthermore, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[g,h,i]perylene exhibited high ecological risks (with risk quotients of 1.47, 1.44, and 1.02, respectively) in specific sites within the YRD. Considering the high toxicity of HPAHs and their potential joint environmental effects with PAHs, continuous attention should be directed towards the environmental risks associated with both PAHs and HPAHs.

Fruit Crop Species with Agrivoltaic Systems: A Critical Review

As the world seeks alternatives to fossil fuels, agrivoltaics offer a promising solution by integrating solar panels with farming practices. This review examines three key agrivoltaic setups—static tilted, full-sun tracking, and agronomic tracking—dissecting their engineering features’ roles in optimizing both the electricity yield and the fruit productivity of some fruit crops. We emphasize the microclimatic modifications induced by agrivoltaic systems, mainly encompassing changes in solar radiation, air temperature, humidity, and wind. The data collected in this survey reveal a strong spatial heterogeneity distribution over different locations and a significant influence on fruit crops’ growth, yield, and quality, with variations among species. Such findings on the overall performance recommend a 30% shading threshold to prevent substantial declines in fruit characteristics, i.e., fruit yield and quality. Shading conditions over this threshold influence the leaf morphophysiological characteristics, impacting the photosynthesis capacity and fruit dry matter accumulation. This emphasizes the importance of further investigation into spectral radiation quality and carbon assimilation kinetics as daily responses for different fruit species to be cultivated in such new environments. Starting from this point, this review underscores the need to extend studies on various fruit crops, particularly those cultivated in semi-arid horticultural regions (i.e., for saving water), and suggests the use of comprehensive and standardized indicators for comparability across studies. Finally, the authors conclude that engineering improvements, along with new research programs on agrivoltaic systems, could lead to agricultural, environmental, and economic sustainability, as well as their practical implementation and attractiveness to farmers in the coming years.

Urban Above-Ground Biomass Estimation Using GEDI Laser Data and Optical Remote Sensing Images

Accurate estimating of above-ground biomass (AGB) of vegetation in urbanized areas is essential for urban ecosystem services. NASA’s Global Ecosystem Dynamics Investigation (GEDI) mission can obtain precise terrestrial vegetation structure, which is very useful for AGB estimation in large forested areas. However, the spatial heterogeneity and sparse distribution of vegetation in urban areas lead to great uncertainty in AGB estimation. This study proposes a method for estimating vegetation heights by fusing GEDI laser observations with features extracted from optical images. GEDI is utilized to extract the accurate vegetation canopy height, and the optical images are used to compensate for the spatial incoherence of GEDI. The correlation between the discrete vegetation heights of GEDI observations and image features is constructed using Random Forest (RF) to obtain the vegetation canopy heights in all vegetated areas, thus estimating the AGB. The results in Xuzhou of China using GEDI observations and image features from Sentinel-2 and Landsat-8 satellites indicate that: (1) The method of combining GEDI laser observation data with optical images is effective in estimating AGB, and its estimation accuracy (R2 = 0.58) is higher than that of using only optical images (R2 = 0.45). (2) The total AGB in the shorter vegetation region is higher than the other two in the broadleaf forest and the coniferous forest, but the AGB per unit area is the lowest in the shorter vegetation area at 33.60 Mg/ha, and it is the highest in the coniferous forest at 46.60 Mg/ha. And the highest average AGB occurs in October–December at 59.55 Mg/ha in Xuzhou. (3) The near-infrared band has a greater influence on inverted AGB, followed by textural features. Although more precise information about vegetation should be considered, this paper provides a new method for the AGB estimation and also a way for the evaluation and utilization of urban vegetation space.

Spatial organization of astrocyte clones: The role of developmental progenitor timing.

Astrocytes represent a diverse and morphologically complex group of glial cells critical for shaping and maintaining nervous system homeostasis, as well as responding to injuries. Understanding the origins of astroglial heterogeneity, originated from a limited number of progenitors, has been the focus of many studies. Most of these investigations have centered on protoplasmic and pial astrocytes, while the clonal relationship of fibrous astrocytes or juxtavascular astrocytes has remained relatively unexplored. In this study, we sought to elucidate the morphological diversity and clonal distribution of astrocytes across adult cortical layers, with particular emphasis on their ontogenetic origins. Using the StarTrack lineage tracing tool, we explored the characteristics of adult astroglial clones derived from single and specific progenitors at various embryonic stages. Our results revealed a heterogeneous spatial distribution of astroglial clones, characterized by variations in location, clonal size, and rostro-caudal dispersion. While a considerable proportion of clones were confined within specific cortical layers, others displayed sibling cells crossing layer boundaries. Notably, we observed a correlation between clone location and developmental stage at earlier embryonic stages, although this relationship diminished in later stages. Fibrous astrocyte clones were exclusively confined to the corpus callosum. In contrast, protoplasmic or juxtavascular clones were located in either the upper or lower cortical layers, with certain clones displayed sibling cells distributed across both regions. Our findings underscore the developmental origins and spatial distribution of astroglial clones within cortical layers, providing new insights into the interplay between their morphology, clonal sizes, and progenitor heterogeneity.

Spatio-temporal distribution and evolution of the Tujia traditional settlements in China.

The rapid modernization in China has aggravated the reduction of the traditional settlements and aroused concern about the protection and research. This study aims to examine the spatial-temporal variations Tujia traditional settlements in China and to delineate the driving mechanism of the settlement distribution. Previous studies have focused on the characteristics of settlements in provincial or smaller areas, providing lacked information regarding spatial distribution heterogeneity of Tujia traditional settlements in China. In this study, the spatial heterogeneity and influence factors of the distribution of traditional Tujia settlements were examined using the GIS platform and statistical methods. The results reveal that the spatial distribution of settlements exhibits clustering with the pattern of "scattered distribution in a large region, while concentrated in small areas". The settlements were generally built in low hills, gentle slopes, sunny slopes and low-relief terrain areas, with elevation, relief degree of land surface (RDLS), slope and aspect were the key factors affecting the distribution. In Song, Yuan, Ming and Qing dynasties, settlements showed significant clustering all through, though the location and number of clustering center kept changing. In this process, the history of the Tujia chieftain and the transportation and marketing lines of Sichuan salt had a profound influence on the historical evolution of the settlement.

Green Transition Assessment, Spatial Correlation, and Obstacles Identification: Evidence from Urban Governance Data of 288 Cities in China

The green transition of China’s cities is crucial for ecology civilization realization. Based on the driver–pressure–state–impact–response (DPSIR) framework, an integrated technique for order preference by similarity to ideal solution (TOPSIS) model with entropy weight, this study achieved the comprehensive assessment of the green transition of 288 province-level municipalities and prefecture-level cities in China over 18 years from 2002 to 2019, in addition to the spatial correlations and obstacles analysis. The results indicate that major cities in China have a more significant green transition value, and the eastern region is developing fast, while the northeast region is relatively slow. There was heterogeneous spatial distribution for green transition, because of the disequilibrium sustainable development of 288 cities. Green transition has a significantly positive spatial autocorrelation in the cities of China, the high–high significant clusters greatly increased, and the main locations changed from the northeast to southeast of China. Frequent obstacles were also found, including road infrastructure construction, water resources, and the green coverage of urban built-up areas. Based on these results, several policy implications were put forward, including the optimization of environmental laws and regulations, the development of green transportation infrastructure, resource conservation and the circular economy, the establishment of a green financial system, and increasing the linkage for the green transition of different cities.

Distribution and diversity of elasmobranchs in the Sea of Marmara: A 2023 status report

Abstract Elasmobranchs, encompassing an array of sharks and rays, confront a threat of extinction on a global scale. The Sea of Marmara (SoM) stands out as a critical refuge for these endangered species. This study harnesses data derived from comprehensive trawl surveys, representing the first area‐based evaluation of the elasmobranchs inhabiting the SoM. Sampling protocols were carried out at 10 separate stations along the 980‐km coastline of the SoM, each bounded by different ecological characteristics and anthropogenic influences. A total of eight shark species and six ray species were caught in the towed area of the entire the SoM. Notably, Scyliorhinus canicula and near‐threatened Raja clavata constitute more than 50% of the total abundance. Additionally, rare, and critically endangered species, including the Oxynotus centrina, Squatina squatina, Dipturus batis, and Myliobatis aquila, were documented, expanding our knowledge of their presence in the region. Spatial distribution heterogeneity was pronounced within species. Size distributions were species‐specific, and the presence of both juvenile and adult individuals suggested successful reproduction and growth. Records expand the known size range in the SoM for six shark and three ray species. It also provides first‐size information based on the total length of the S. stellaris and D. batis. Additionally, the urgent need for field‐based conservation efforts is highlighted, citing a previously unidentified important sensitive areas located in the southern part of the SoM.

Geospatial and multilevel clustering of zero-dose children in Kikwit, Democratic Republic of the Congo in 2022.

Zero-dose children remain highly vulnerable to vaccine-preventable diseases and can sustain transmission even in highly vaccinated populations. The WHO Immunization Agenda 2030 has prioritised reaching out to these children. We assessed the spatial distribution of zero-dose children together with the associated risk factors in a provincial capital in the Democratic Republic of Congo. A cross sectional survey was conducted in the city of Kikwit between September 28 and October 14, 2022. Data were collected both at household and health area level. QGIS and SATscan were used to describe and identify hotspots among zero-dose children, and a mixed effect logistic regression model was used to identify risk factors. Overall, 1,863 children aged 12-23 months were enrolled. Kikwit city had a 16.3% zero-dose prevalence, with significant variation between and within health zones. Two hotspots were identified through geospatial analysis, each spanning multiple health areas. Multilevel analysis revealed significant clustering at health area level and found six associated risk factors. These include the absence of home visits by community health workers (aOR = 1.90), living more than a kilometre from a health centre (aOR = 1.95), the mother's lack of tetanus vaccination (aOR = 3.16), and inability to name a vaccine-preventable disease (aOR = 3.20). However, secondary (aOR = 0.56) or tertiary (aOR = 0.21) education of mothers/guardians and belonging to Bunda (aOR = 0.36) or Mbala (aOR = 0.52) ethnicity reduced the risk of zero-dose. We observed a high prevalence of zero-dose children with a heterogeneous spatial distribution of epidemiological importance. Due to sub-zonal diversity, a health zone approach to reduce zero-dose immunization appears very limited. Zero-dose prevalence was related to the community health workers' home visit, to the distance of residence to a health centre and to household-level factors. Geospatial results could help in targeting priority health areas and communities for vaccination.

OsEIL1 is involved in the response to heterogeneous high ammonium in rice: A split-root analysis

Ammonium (NH4+) concentrations in rice fields show heterogeneous spatial distribution under the combined influences of nitrogen fertilizer application and modern agronomic practices. However, the characteristics and mechanisms of rice roots in response to heterogeneous NH4+ supply are not well understood. Here, we found a systemic response of rice roots to heterogeneous and high (10 mM) NH4+ supply using a split-root experiment, and show root growth on the NH4+-free (NO3−) side was also inhibited by localized high-NH4+ supply. Moreover, OsEIL1 (encoding a core transcription factor in the ethylene signaling pathway) was found to be involved in the response of rice roots to heterogeneous NH4+. OsEIL1 mutation significantly increased the inhibitory effect of localized high-NH4+ on root growth of the NO3− side, as well as significantly increased NH4+ efflux there. Furthermore, our results indicate that the mitigating effect of OsEIL1 on NH4+ efflux is related to the regulated expression of OsVTC1-3 (encoding a GDP-mannose pyrophosphorylase). These findings provide insight into the mechanisms by which OsEIL1 responds to heterogeneous high NH4+ and contribute to our understanding of rice adaptation to heterogeneous NH4+ supply.

Spatial Distribution of Heterogeneity of the AB Reservoir Unit of Zubair Formation in the South Rumaila Oilfield, Southern Iraq

Reservoir heterogeneity, a critical factor in fluid flow and recovery processes, manifests at various scales and is influenced by depositional facies, diagenesis, and structural features. This study aims to quantify and map the spatial heterogeneity within Unit AB of Zubair Formation, south Rumaila oilfield, utilizing the Lorenz coefficient (Lk ) for vertical heterogeneity and ordinary kriging for spatial interpolation. Analyzing porosity and permeability data from 44 boreholes using the Lk coefficient revealed that the AB reservoir unit is primarily homogeneous, with 65% of boreholes exhibiting homogeneity. However, heterogeneity is present in the central and southeastern portions of the oilfield. Without considering the reservoir’s heterogeneity, placing injection wells along the eastern flank could lead to increased water production and reduced volumetric sweep efficiency.

Indium Iodide Additive Realizing Efficient Mixed Sn─Pb Perovskite Solar Cells

AbstractLow‐bandgap mixed tin (Sn)‐lead (Pb) perovskite solar cells promise efficiency beyond the pure‐Pb ones. However, the difference in the interaction rate of SnI2 and PbI2 with organic salts causes spatial distribution heterogeneity of Sn2+ and Pb2+ in mixed Sn─Pb perovskite layers. This causes a Sn‐rich surface, which can trigger more severe Sn2+ oxidation and nonradiative recombination. A strategy, of introducing indium ion (In3+) into the perovskite precursor solution to compete with Sn2+ when reacting with organic salts is developed. Therefore, the nucleation and crystallization of perovskite films are well‐controlled, leading to improved film quality with a more balanced Sn/Pb ratio on the film surface. Additionally, In3+ has a lower reduction potential compared to Sn2+ which can generate an extra energy barrier for Sn2+ oxidation. The improved film quality and reduced surface oxidation result in accelerated electron transfer and reduced carrier recombination rate. The modified devices achieve a power conversion efficiency (PCE) of 23.34%, representing one of the highest PCEs in mixed Sn─Pb solar cells made with PCBM.

Modern Statistical Methods for Infectious Diseases to Analyse Covid-19 Pandemic Data in Rwanda

The corona-virus ailment 2019(COVID-19) took tens of millions of lives and disrupted dwelling requirements at individual, societal, and international levels, causing penalties globally. Understanding its epidemic curve and Spatio-temporal dynamics is indispensable for the development of tremendous public fitness plans and responses and the allocation of resources. Thus, we performed the analysis of the epidemiological dynamics and spatio-temporal patterns of the COVID-19 pandemic in Rwanda. Using the surveillance bundle in R software version 4.0.2, we implemented endemic-epidemic multivariate time sequence methods for infectious diseases to analyze COVID-19 facts with the aid of Rwanda Biomedical Center, under the Ministry of Health, from March 15, 2020, to January 15, 2021. The COVID-19 pandemic came in waves in Rwanda and showed a heterogeneous spatial distribution across districts. The Rwandan authorities answered effectively and successively through the implementation of more than a few health measures and intervention policies to reduce the transmission of the disease. Analysis of the three factors of the mannequin confirmed that the most affected districts displayed epidemic elements inside the area, whereas the impact of epidemic elements from spatial neighbors had been skilled via the districts that surround the most affected districts. The contamination followed the disorder endemic vogue in other districts. The epidemiological and Spatio-temporal dynamics of COVID-19 in Rwanda show that the implementation of measures and interventions contributed appreciably to minimize COVID-19 transmission inside and between districts. This accentuates the essential name for endured intra-and inter-business enterprise and community engagement nationwide to make a certain effective and efficient response to the pandemic.

Spatial-temporal Evolution of Ecosystem Health and Its Influencing Factors in Beijing-Tianjin-Hebei Region

Exploring ecosystem health and its influencing factors is of great significance for promoting regional sustainable development. An ecosystem health assessment model was constructed, and the spatial-temporal evolution characteristics of ecosystem health in the Beijing-Tianjin-Hebei Region in 2000, 2010, and 2020 were analyzed. The geographical detector and GWR were used to identify the dominant factors affecting ecosystem health. The main conclusions were as follows:during the study period, the index of ecosystem natural health in the Beijing-Tianjin-Hebei Region was generally better in the north and west than that in the southeast, and it showed an overall upward trend. The index of ecosystem services in the Beijing-Tianjin-Hebei Region presented as a spatial differentiation pattern of high in the north and low in the south, and it showed a downward trend. The ecosystem health level in the Beijing-Tianjin-Hebei Region showed a trend of rising first and then declining, showing significant heterogeneity in spatial distribution. The ecological health level in the central urban area of large cities was mostly poor, and the ecosystem health level in the Yanshan and Taihang Mountains and Bohai Rim was better. During the study period, the spatial pattern of ecosystem health in the Beijing-Tianjin-Hebei Region remained relatively stable. The hot spots and sub-hot spots were mainly distributed in the northern mountainous areas of Hebei Province and the Taihang Mountains, and the cold spots and sub-cold spots were mainly distributed in the southeast plain and the surrounding areas of some big cities. Population density, annual average temperature, per capita cultivated land area, and urbanization level were the dominant factors of ecosystem health in the Beijing-Tianjin-Hebei Region, and they were all negatively correlated with ecosystem health.

Influence of preexisting structures on salt structures in the Kuqa Depression, Tarim Basin, Western China: Insights from seismic data and numerical simulations

AbstractThe preexisting structures that developed in the basement and subsalt strata play a key role in the salt structural deformation in the Kuqa Depression, Tarim Basin. The characteristics of preexisting structures and their controls on the salt structure are investigated via the latest three‐dimensional seismic data and numerical modelling. The results show that the preexisting structures that developed in the Kuqa Depression mainly consist of basement faults, palaeouplifts, subsalt slopes and early passive salt diapirs. Basement faults are mainly distributed in the Kelasu and Qiulitag structural belts and control the position of development and deformation style of the Miocene compressive salt structure. The differences in styles and reactivation degrees of basement faults lead to great diversity in the salt structure. The palaeouplifts mainly include the Wensu, western Qiulitag, Xinhe and Yaha‐Luntai palaeouplifts. The original sedimentary range and later deformation space of the salt layer are limited by the palaeouplift, resulting in strong salt thrusting in the Awate sag in the western part of the Kuqa Depression. The heterogeneous spatial distribution of the palaeouplift promoted the development of regional strike‐slip transform belts. Subsalt slopes are located mainly on the northern edge of the western Qiulitag low uplift and block the southward flow of the salt, causing the salt to form salt domes; the size of these domes is closely related to the subsalt slope. Early passive salt diapirs mainly developed in the Quele and Bozidun areas of the western Kuqa Depression, and they were preferentially active during the compression period, inducing the formation of a piercement salt nappe. Numerical modelling revealed that the preexisting structure strongly controlled the stress–strain distribution during the deformation of the salt structure. The spatial distribution heterogeneity of the basement structure is an important factor in the structural zonation along the north–south strike and segmentation along the west–east strike in the Kuqa Depression, as well as an important inducer of the piercement salt structure.

Shift in virus composition in honeybees (Apis mellifera) following worldwide invasion by the parasitic mite and virus vector Varroa destructor.

Invasive vectors can induce dramatic changes in disease epidemiology. While viral emergence following geographical range expansion of a vector is well known, the influence a vector can have at the level of the host's pathobiome is less well understood. Taking advantage of the formerly heterogeneous spatial distribution of the ectoparasitic mite Varroa destructor that acts as potent virus vector among honeybees Apis mellifera, we investigated the impact of its recent global spread on the viral community of honeybees in a retrospective study of historical samples. We hypothesized that the vector has had an effect on the epidemiology of several bee viruses, potentially altering their transmissibility and/or virulence, and consequently their prevalence, abundance, or both. To test this, we quantified the prevalence and loads of 14 viruses from honeybee samples collected in mite-free and mite-infested populations in four independent geographical regions. The presence of the mite dramatically increased the prevalence and load of deformed wing virus, a cause of unsustainably high colony losses. In addition, several other viruses became more prevalent or were found at higher load in mite-infested areas, including viruses not known to be actively varroa-transmitted, but which may increase opportunistically in varroa-parasitized bees.

Demographic and Economic Center of Gravity of Nepal

In this paper, an attempt has been made on determination of the Demographic Center of Gravity (DCG) and Economic Center of Gravity (ECG) of Nepal The results are then used for the study of historical demographic dynamics and present spatial heterogeneity in distribution of population and economic activities across the country. Census data from 1971-2021 shows the net shift of DCG of Nepal by about 12.5 km toward South-West direction with location in 2021 being at 84.588°E 27.648°N, Khairhani Municipality, Chitwan. Likewise, the ECG of Nepal in FY 2020/21 was at 84.780°E 27.655°N, near the tri-junction point of Chitwan, Makawanpur and Dhading districts. Due to unavailability of enough historical data of Provincial Gross Domestic Product (PGDP), the historical shift in ECG couldn’t be traced. Besides this, the Geographic Centroid (GC) of Nepal is estimated being at 83.920°E 28.277°N, Pokhara, Kaski. From these findings, it is seen that the DCG and ECG lie towards the South-East of GC of Nepal suggesting that the population and economic activities of Nepal is more concentrated on the southern Terai part of Nepal than Hills and inclined toward Eastern part of Nepal than the West.