Central Hub Research Articles

Mechanistic insights into phosphoactivation of SLAC1 in guard cell signaling

Stomata in leaves regulate gas (carbon dioxide and water vapor) exchange and water transpiration between plants and the atmosphere. SLow Anion Channel 1 (SLAC1) mediates anion efflux from guard cells and plays a crucial role in controlling stomatal aperture. It serves as a central hub for multiple signaling pathways in response to environmental stimuli, with its activity regulated through phosphorylation via various plant protein kinases. However, the molecular mechanism underlying SLAC1 phosphoactivation has remained elusive. Through a combination of protein sequence analyses, AlphaFold-based modeling and electrophysiological studies, we unveiled that the highly conserved motifs on the N- and C-terminal segments of SLAC1 form a cytosolic regulatory domain (CRD) that interacts with the transmembrane domain(TMD), thereby maintaining the channel in an autoinhibited state. Mutations in these conserved motifs destabilize the CRD, releasing autoinhibition in SLAC1 and enabling its transition into an activated state. Our further studies demonstrated that SLAC1 activation undergoes an autoinhibition-release process and subsequent structural changes in the pore helices. These findings provide mechanistic insights into the activation mechanism of SLAC1 and shed light on understanding how SLAC1 controls stomatal closure in response to environmental stimuli.

Dysregulated gene subnetworks in breast invasive carcinoma reveal novel tumor suppressor genes

Breast invasive carcinoma (BRCA) is the most malignant and leading cause of death in women. Global efforts are ongoing for improvement in early detection, prevention, and treatment. In this milieu, a comprehensive analysis of RNA-sequencing data of 1097 BRCA samples and 114 normal adjacent tissues is done to identify dysregulated genes in major molecular classes of BRCA in various clinical stages. Significantly enriched pathways in distinct molecular classes of BRCA have been identified. Pathways such as interferon signaling, tryptophan degradation, granulocyte adhesion & diapedesis, and catecholamine biosynthesis were found to be significantly enriched in Estrogen/Progesterone Receptor positive/Human Epidermal Growth Factor Receptor 2 negative, pathways such as RAR activation, adipogenesis, the role of JAK1/2 in interferon signaling, TGF-β and STAT3 signaling intricated in Estrogen/Progesterone Receptor negative/Human Epidermal Growth Factor Receptor 2 positive and pathways as IL-1/IL-8, TNFR1/TNFR2, TWEAK, and relaxin signaling were found in triple-negative breast cancer. The dysregulated genes were clustered based on their mutation frequency which revealed nine mutated clusters, some of which were well characterized in cancer while others were less characterized. Each cluster was analyzed in detail which led to the identification of NLGN3, MAML2, TTN, SYNE1, ANK2 as candidate genes in BRCA. They are central hubs in the protein–protein-interaction network, indicating their important regulatory roles. Experimentally, the Real-Time Quantitative Reverse Transcription PCR and western blot confirmed our computational predictions in cell lines. Further, immunohistochemistry corroborated the results in ~ 100 tissue samples. We could experimentally show that the NLGN3 & ANK2 have tumor-suppressor roles in BRCA as shown by cell viability assay, transwell migration, colony forming and wound healing assay. The cell viability and migration was found to be significantly reduced in MCF7 and MDA-MB-231 cell lines in which the selected genes were over-expressed as compared to control cell lines. The wound healing assay also demonstrated a significant decrease in wound closure at 12 h and 24 h time intervals in MCF7 & MDA-MB-231 cells. These findings established the tumor suppressor roles of NLGN3 & ANK2 in BRCA. This will have important ramifications for the therapeutics discovery against BRCA.

Destination selection and flight scheduling for regional airlines at slot‐constrained airports

AbstractWe present the problem of a regional airline based at a slot‐constrained airport, which must select a set of destinations to serve, how many flights per day to operate to each destination, at what time the flights take place and which aircraft operates each flight. Restricting ourselves to the special case of regional airlines, which fly round trips from a central hub, we are able to tackle the four above decisions jointly. By contrast, in the existing literature, these decisions are usually optimised separately for generic airline networks. To solve the proposed problem, we introduce two compact integer formulations: a three‐index and a two‐index formulation. This latter, however, only solves a relaxation of the original problem because it cannot guarantee that all constraints are respected. Therefore, we embed the two‐index formulation into an iterative algorithm which dynamically adds violated constraints. Computational experiments highlight the validity of this approach and provide insights into the characteristics of the solutions.

The lipid droplet assembly complex consists of seipin and four accessory factors in budding yeast

Seipin, a crucial protein for cellular lipid droplet (LD) assembly, oligomerizes at the interface between the endoplasmic reticulum (ER) and LDs to facilitate neutral lipid packaging. Using proximity labeling, we identify four proteins—Ldo45, Ldo16, Tgl4, and Pln1—that are recruited to the vicinity of yeast seipin, the Sei1-Ldb16 complex, exclusively when seipin function is intact, hence termed seipin accessory factors. Localization studies identify Tgl4 at the ER-LD contact site, in contrast to Ldo45, Ldo16 and Pln1 at the LD surface. Cells with compromised seipin function resulted in uneven distribution of these proteins with aberrant LDs, supporting a central role of seipin in orchestrating their association with the LD. Overexpression of any seipin accessory factor causes LD aggregation and affects a subset of LD protein distribution, highlighting the importance of their stoichiometry. Although single factor mutations show minor LD morphology changes, combined mutations have additive effects. Lastly, we present evidence that seipin accessory factors assemble and interact with seipin in the absence of neutral lipids and undergo dynamically rearrangements during LD formation induction, with Ldo45 acting as a central hub recruiting other factors to interact with the seipin complex.

Cultivation of novel Atribacterota from oil well provides new insight into their diversity, ecology, and evolution in anoxic, carbon-rich environments

BackgroundThe Atribacterota are widely distributed in the subsurface biosphere. Recently, the first Atribacterota isolate was described and the number of Atribacterota genome sequences retrieved from environmental samples has increased significantly; however, their diversity, physiology, ecology, and evolution remain poorly understood.ResultsWe report the isolation of the second member of Atribacterota, Thermatribacter velox gen. nov., sp. nov., within a new family Thermatribacteraceae fam. nov., and the short-term laboratory cultivation of a member of the JS1 lineage, Phoenicimicrobium oleiphilum HX-OS.bin.34TS, both from a terrestrial oil reservoir. Physiological and metatranscriptomics analyses showed that Thermatribacter velox B11T and Phoenicimicrobium oleiphilum HX-OS.bin.34TS ferment sugars and n-alkanes, respectively, producing H2, CO2, and acetate as common products. Comparative genomics showed that all members of the Atribacterota lack a complete Wood-Ljungdahl Pathway (WLP), but that the Reductive Glycine Pathway (RGP) is widespread, indicating that the RGP, rather than WLP, is a central hub in Atribacterota metabolism. Ancestral character state reconstructions and phylogenetic analyses showed that key genes encoding the RGP (fdhA, fhs, folD, glyA, gcvT, gcvPAB, pdhD) and other central functions were gained independently in the two classes, Atribacteria (OP9) and Phoenicimicrobiia (JS1), after which they were inherited vertically; these genes included fumarate-adding enzymes (faeA; Phoenicimicrobiia only), the CODH/ACS complex (acsABCDE), and diverse hydrogenases (NiFe group 3b, 4b and FeFe group A3, C). Finally, we present genome-resolved community metabolic models showing the central roles of Atribacteria (OP9) and Phoenicimicrobiia (JS1) in acetate- and hydrocarbon-rich environments.ConclusionOur findings expand the knowledge of the diversity, physiology, ecology, and evolution of the phylum Atribacterota. This study is a starting point for promoting more incisive studies of their syntrophic biology and may guide the rational design of strategies to cultivate them in the laboratory.5rnPv2dUCRDw24_qsw9GBLVideo

Transcriptomic meta-analysis and exploration of differentially expressed gene functions in wooden breast myopathy of broilers

Wooden breast (WB) myopathy is a common myopathy found in commercial broiler chickens worldwide. Although extensive research on WB has been conducted using transcriptomics, effectively screening and analyzing key target information remains a challenge. In this present study, 5 transcriptomic datasets obtained from the National Center for Biotechnology Information (NCBI) were used. A meta-analysis was conducted to identify meta-differentially expressed genes (meta-DEGs) involved in the response of broilers to WB myopathy. These meta-DEGs were further analyzed using Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and Gene Set Enrichment Analysis (GSEA), supplemented by protein-protein interaction (PPI) network construction to pinpoint hub genes. These analyses help to reveal key genes, pathways, and biological processes associated with WB myopathy. The results showed that 645 up-regulated and 99 down-regulated significant meta-DEGs (|log2FC| ≥0.6, P-Meta < 0.05, and present in at least 4 datasets) were identified. GO analysis showed that multiple fibrosis-related pathways/biological processes, such as cell adhesion, connective tissue development, and collagen-rich extracellular matrix, as well as calcium ion binding were significantly upregulated. PPI analysis identified TGFB3, COL1A1, COL1A2, and COL3A1 as central hub genes involved in the fibrotic processes. KEGG analysis revealed significant upregulation of apoptosis and lysosomal pathways, with an enrichment of Ca2+-related signals and lysosomal cathepsins within the apoptosis pathway. Additionally, GSEA indicated a suppression of the tricarboxylic acid (TCA) cycle and the mitochondrial electron transport chain (ETC) in WB myopathy, with PPI analysis also identifying specific hub genes associated with these pathways. In conclusion, our comprehensive analysis of meta-DEGs elucidated key biological processes and pathways implicated in WB myopathy, including fibrosis, apoptosis, altered calcium signaling, and metabolic disruption. The identification of specific hub genes offers avenues for further investigation into the pathogenesis of this condition, potentially guiding targeted therapeutic strategies.

The Regional Ain Shams Telemedicine Network

Abstract With the deficiency in specialized care and low resources it is vital to come up with new healthcare delivery systems that utilize available resources in an efficient way. The hub-spoke model is not new but has recently been revisited as it aids in sharing of specialized services. A central hub is able to support attached spokes through physical and virtual healthcare services. To manage such a network a strong software platform with several integral features should be in place. Using available solutions may not satisfy all required features and may fragment the patient’s health records. Ain Shams University Virtual Hospital (AVH) dedicated to healthcare transformation in Egypt and the region, manages and connects its spokes through TREAT platform (The REgional Ainshams Telemedicine network) that was funded by the Science and Technology Development Fund. The software platform supports provider-to-provider (P2P) telemedicine but for the sake of continuity of care other telemedicine modules and physical services are present. It helps utilize available resources in an efficient way with the capacity to audit user and system performance. The patient module has a seperate entry point and integrates with the rest of the system. Inpatients and outpatients from inside the system and outside can be managed physically and remotely.

ANALYSIS OF THE AVAILABILITY AND IDENTIFICATION OF PUBLIC GREEN OPEN SPACES IN GKU 1 AND GKU 2 AT INSTITUT TEKNOLOGI SUMATERA CAMPUS

Institut Teknologi Sumatera (ITERA) is a higher education institution located in the village of Way Huwi, South Lampung Regency. It was established to fulfill the educational needs centered on the island of Suamtera. ITERA campus was formerly a green area used for rubber plantations and forests which underwent transformation due to the demand for academic buildings. This transformations is ecidenced by the construction of the General Lecture Building (GKU) and Engineering Laboratory Building (Labtek) 1-4. This reserarch focuses on GKU 1 and 2, which serve as the central academic hubs for three faculties of ITERA. The aim is to identify issues related to the availability of public green open spaces in each building. Both GKU building have the potential to function as communal zones that can be utilized for discussions, relaxation, and studying due to their distinct characteristics in terms of green space forms and types. The research methodology employs both quantitative and qualitative methods, such as parameters of Responsive Environments, The Likert Scale, and interviews related to the questionnaire, with the primary target audience being ITERA’s students. The research results highlight various shortcomings and advantages in each GKU building. Recommendarions for improvemenr are expected to refine the research outcomes for ITERA.

Multi-criteria GIS-based land suitability analysis for rice cultivation: a case study in Guilan Province, Iran.

Ensuring food security and sustainable resource management has become a paramount global concern, prompting significant attention to land suitability analysis for enhancing agricultural production. In this study, an AHP-weighted overlay method was employed to delineate rice cultivation suitability in Guilan province, Iran, a central hub for rice production. Sixteen climatic, topographic, and soil variables were integrated, and individual maps were reclassified to align with the specific requisites for rice production. The results revealed three suitability classes: including 'very suitable,' 'suitable,' and 'moderately suitable', covering 91%, 6%, and 3% of the land, respectively. Soil attributes, particularly organic matter, significantly influenced suitability (weight value of 0.745), with topographic and soil factors outweighing climate in assessment. While salinity is generally absent, organic matter deficiency affects 44% of the land. Phosphorus imbalances are prevalent, with potassium toxicity observed in 10%. Microelement deficiencies, especially in iron and zinc, are noted. Additionally, the results indicated that topographic and soil attributes played a more significant role than climate-related factors in assessing land suitability for rice cultivation within the study area. This research provides a comprehensive spatial analysis of all variables in the study region, shedding light on the complexities of land suitability for rice cultivation. These findings contribute to the understanding of agricultural sustainability and resource management strategies in the context of food security.

중원지역 원삼국~삼국시대 중심취락의 변동과 지역사회

This paper is written with the aim of classifying the settlements in the Chungju area of the Central Plains region, utilizing the recently introduced Social Network Analysis (SNA) in Korean archaeology, and examining the transitions of settlements and regional characteristics during the transition from the Proto-Three Kingdoms to the Three Kingdoms Era. Settlements in the Chungju area have the disadvantage of being numerically smaller than those in Cheongju. Therefore, the periodization is based on the expansion periods of Baekje, Goguryeo, and Silla: Phase I (before the mid-4th century), PhaseⅡ(from the mid-4th century to the late 6th century), and PhaseⅢ(after the mid-6th century). During Phase I, Geumneung-dong functioned as the central settlement with Tangeumdae-Fortress and Chilgeum-dong playing significant roles in the Mahan Central Settlement. During PhaseⅡ, with the expansion of Baekje, Tappyeong-ri emerged as a central settlement, utilizing the alluvial lands and hillsides for residential and burial purposes. Tangeumdae Fortress and Chilgeum-dong continued their roles as iron production sites from Phase I. Meanwhile, Baekje left its identity in the Hwangsae-maeri tomb cluster. In PhaseⅡ, iron production by Baekje expanded east to west from Tappyeong-ri. Despite the Goguryeo expansion, Tappyeong-ri continued to serve as a central hub. Additionally, evidence of Goguryeo-related tombs and residences in Dujeong-ri and Danwol-dong suggests a prolonged Goguryeo occupation in the Chungju area. However, in PhaseⅢ, Chungju witnessed the expansion of Silla. Silla utilized Tappyeong-ri, previously occupied by Baekje and Goguryeo, as its central settlement and established a central tomb cluster in Nuam-ri and Haguam-ri. Recently reported remains at 445-1 Tappyeong-ri indicate a broader extent of settlement in Tappyeong-ri, suggesting its continued significance as a central settlement even after the Silla expansion. During this period, surrounding settlements around Tappyeong-ri, Nuam-ri, and Haguam-ri expanded even further compared to Phases I andⅡ. However, in the late 7th century of PhaseⅢ, Danwol-dong emerged prominently, indicating a shift of the central hub towards the east. In essence, the central settlements in the Chungju area evolved from Geumneung-dong, Tangeumdae, and Chilgeum-dong (East) to Tappyeong-ri, Nuam-ri, and Haguam-ri (West), and finally to Danwol-dong (East). This transformation correlates with the expansion processes of the Three Kingdoms era following the Proto-Three Kingdoms period. However, there were differences in the formation and positioning of the central settlements among the Three Kingdoms. Specifically, Baekje chose locations reflecting intentions to monitor or exploit nearby Mahan forces, while Goguryeo and Silla directly occupied Tappyeong-ri. This is interpreted as a measure to counteract the weakening and containment of previous powers.

Multispectral Imaging and Single-Cell Analysis with Genetically Encoded Biosensors Unveil Complex Interactions between Extracellular ATP and Intracellular Calcium

The dynamic interplay between extracellular ATP (eATP) and intracellular calcium ([Ca2+]i) serves as a pivotal signaling axis in cellular physiology, influencing a myriad of cellular processes. Traditionally recognized as an energy currency within the cell, ATP has emerged as a multifunctional signaling molecule that orchestrates diverse cellular responses through activation of purinergic receptors. The complex link between ATP signaling and calcium dynamics plays a central role in cellular communication and homeostasis. Advancements in imaging technologies such as development of genetically encoded biosensors have revolutionized the study of cellular signaling dynamics, enabling visualization of the spatiotemporal aspects of eATP and [Ca2+]i in real-time. The convergence of eATP signaling and [Ca2+]i dynamics serves as a central hub in cellular communication. In this study, utilizing bicistronic construct biosensors for multispectral imaging of [Ca2+]i responses to eATP, we show that distinct concentrations of eATP administration reveal complex intracellular [Ca2+]i responses, potentially attributed to receptor desensitization. Single-cell co-imaging uncovers [Ca2+]i heterogeneity, emphasizing the significance of individual cell dynamics in eATP-induced calcium signaling. Therefore, this study sheds light on the intricacies of eATP-induced calcium signaling, providing insights valuable for basic research and therapeutic applications.

The effect of preterm birth on thalamic development based on shape and structural covariance analysis

Acting as a central hub in regulating brain functions, the thalamus plays a pivotal role in controlling high-order brain functions. Considering the impact of preterm birth on infant brain development, traditional studies focused on the overall development of thalamus other than its subregions. In this study, we compared the volumetric growth and shape development of the thalamic hemispheres between the infants born preterm and full-term (Left volume: P = 0.027, Left normalized volume: P < 0.0001; Right volume: P = 0.070, Right normalized volume: P < 0.0001). The ventral nucleus region, dorsomedial nucleus region, and posterior nucleus region of the thalamus exhibit higher vulnerability to alterations induced by preterm birth. The structural covariance (SC) between the thickness of thalamus and insula in preterm infants (Left: corrected P = 0.0091, Right: corrected P = 0.0119) showed significant increase as compared to full-term controls. Current findings suggest that preterm birth affects the development of the thalamus and has differential effects on its subregions. The ventral nucleus region, dorsomedial nucleus region, and posterior nucleus region of the thalamus are more susceptible to the impacts of preterm birth.

Limited waterpower contributed to rise of steam power in British "Cottonopolis".

The Industrial Revolution precipitated a pivotal shift from waterpower to coal-fueled steam power in British textile mills. Although it is now widely accepted that steam was chosen to power factories despite the availability of sufficient waterpower resources across most of Britain, the location and suitability of that waterpower during the early 19th century remain underexplored. Here, we employ quantitative fluvial geomorphology alongside historical climate data, factory records, and a catalog of over 26,000 mill sites to reveal that waterpower was abundant for most of early 19th century Britain, except in the central hub of British cotton production: Greater Manchester in the Mersey Basin. Our findings show that surging factory mechanization and overcrowding on key waterways in the Mersey Basin compounded waterpower scarcity arising from a drier 19th century climate. Widespread adoption of coal-fueled steam engines in certain key industrial centers of Britain was a strategy aimed at ameliorating some of the reduced reliability of waterpower. The fact that steam engines were frequently used in water-powered factories in many industrial regions until the third quarter of the 19th century to recirculate water to provide that power, or as a power supplement when waterpower availability was restricted, adds further weight to our argument. Rapid adoption of coal-powered steam engines reshaped the social and structural landscape of industrial work, firmly established Britain's prominence as an industrial powerhouse, and had lasting global industrial and environmental impacts.

An innovative referral system: Bridging healthcare providers and community supports for pregnant and parenting people.

The connection between community healthcare providers and available community-based programs is often weak. For community members to be connected with services, a strong referral link between providers and programs is paramount. The Referral Express and Central Hub (REACH) project was born out of this need for Nurse-Family Partnership (NFP) program sites in the Denver Metro area of Colorado to be better connected and coordinated with local referral sources. The objective of the REACH pilot was to create a centralized referral system and determine its feasibility in practice. After a 12-month pilot, this innovative referral system supported the increase in a number of referral partners to Denver Metro area sites, an increase in clients served across the Denver Metro area, as well as an increase in the "refer to enroll" rate which increased by 37%. The success of the pilot of REACH led the developers to test the process on a second program, Child First, which was also successful. REACH has proved to be sustainable and continues to operate for both programs. Additionally, REACH acts as a consultant to NFP sites outside the Denver Metro area, in the state of Colorado, as each site works to increase its relationships with referral partners.

Transcendent thinking counteracts longitudinal effects of mid-adolescent exposure to community violence in the anterior cingulate cortex.

Adolescence involves extensive brain maturation, characterized by social sensitivity and emotional lability, that co-occurs with increased independence. Mid-adolescence is also a hallmark developmental stage when youths become motivated to reflect on the broader personal, ethical, and systems-level implications of happenings, a process we term transcendent thinking. Here, we examine the confluence of these developmental processes to ask, from a transdisciplinary perspective, how might community violence exposure (CVE) impact brain development during mid-adolescence, and how might youths' dispositions for transcendent thinking be protective? Fifty-five low-SES urban youth with no history of delinquency (32 female; 27 Latinx, 28 East Asian) reported their CVE and underwent structural MRI first at age 14-18, and again 2 years later. At the study's start, participants also discussed their feelings about 40 minidocumentaries featuring other teens' compelling situations in a 2-h private interview that was transcribed and coded for transcendent thinking. Controlling for CVE and brain structure at the start: (1) New CVE during the 2-year inter-scan interval was associated with greater gray matter volume (GMV) reduction over that interval in the anterior cingulate cortex (ACC), a central network hub whose reduced volume has been associated with posttraumatic stress disorder, and across multiple additional cortical and subcortical regions; (2) participants' transcendent thinking in the interview independently predicted greater GMV increase during the 2-year inter-scan interval in the ACC. Findings highlight the continued vulnerability of mid-adolescents to community violence and the importance of supporting teens' dispositions to reflect on the complex personal and systems-level implications and affordances of their civic landscape.

Hub stability in the calcium calmodulin-dependent protein kinase II

The calcium calmodulin protein kinase II (CaMKII) is a multi-subunit ring assembly with a central hub formed by the association domains. There is evidence for hub polymorphism between and within CaMKII isoforms, but the link between polymorphism and subunit exchange has not been resolved. Here, we present near-atomic resolution cryogenic electron microscopy (cryo-EM) structures revealing that hubs from the α and β isoforms, either standalone or within an β holoenzyme, coexist as 12 and 14 subunit assemblies. Single-molecule fluorescence microscopy of Venus-tagged holoenzymes detects intermediate assemblies and progressive dimer loss due to intrinsic holoenzyme lability, and holoenzyme disassembly into dimers upon mutagenesis of a conserved inter-domain contact. Molecular dynamics (MD) simulations show the flexibility of 4-subunit precursors, extracted in-silico from the β hub polymorphs, encompassing the curvature of both polymorphs. The MD explains how an open hub structure also obtained from the β holoenzyme sample could be created by dimer loss and analysis of its cryo-EM dataset reveals how the gap could open further. An assembly model, considering dimer concentration dependence and strain differences between polymorphs, proposes a mechanism for intrinsic hub lability to fine-tune the stoichiometry of αβ heterooligomers for their dynamic localization within synapses in neurons.

Mitochondria and cell death.

Mitochondria are cellular factories for energy production, calcium homeostasis and iron metabolism, but they also have an unequivocal and central role in intrinsic apoptosis through the release of cytochrome c. While the subsequent activation of proteolytic caspases ensures that cell death proceeds in the absence of collateral inflammation, other phlogistic cell death pathways have been implicated in using, or engaging, mitochondria. Here we discuss the emerging complexities of intrinsic apoptosis controlled by the BCL-2 family of proteins. We highlight the emerging theory that non-lethal mitochondrial apoptotic signalling has diverse biological roles that impact cancer, innate immunity and ageing. Finally, we delineate the role of mitochondria in other forms of cell death, such as pyroptosis, ferroptosis and necroptosis, and discuss mitochondria as central hubs for the intersection and coordination of cell death signalling pathways, underscoring their potential for therapeutic manipulation.

The border tourism hotspots network based on travelogues

This study applies the Apriori algorithm and social network analysis to analyze travelogue data from the Qinghai-Tibet Plateau, effectively mapping significant border tourism hotspots and their interconnections within defined networks. Our findings distinctly partition the region into two principal sub-networks: Xinjiang and Tibet, highlighting the geographical segmentation that potentially impedes comprehensive regional tourism integration. The analysis underscores a pronounced reliance on transportation, reflecting the inherently multi-destination nature of border tourism in the area. Key nodes within these networks include Kashgar City and Lhasa City, serving as central hubs in their respective sub-networks, while Gar County and Hotan County act as pivotal connectors bridging the two distinct areas. Additionally, Gyirong County, Nyalam County, and Tashkurgan Tajik Autonomous County are identified as well-developed border tourism destinations, with Gyirong County and Tashkurgan Tajik Autonomous County possessing substantial potential to evolve into core border tourism hubs. Drawing on these insights, the study proposes targeted development strategies to enhance the structure and efficacy of border tourism on the Qinghai-Tibet Plateau.

Urban biodiversity conservation: A framework for ecological network construction and priority areas identification considering habit differences within species

The construction of ecological networks within the context of urbanization is an effective approach to cope with the challenges of urban biodiversity decline, representing a crucial goal in urban planning and development. However, existing studies often overlook the richness and uniqueness within species communities by homogenizing traits of species in the same class. This study proposes a framework for constructing and optimizing ecological networks focused on differential conservation within the same class. By classifying birds into three groups (specialists of water, forest or urban areas) based on their ecological requirements and urbanization tolerance, we constructed an ecological network tailored to their distinct migratory dispersal patterns. We then identified strategic areas including pinch points, barriers, and breakpoints specific to each bird group. Our findings reveal notable variations in suitable habitat distribution among different bird groups in urban environments. Corridor layouts varied according to habitat preferences and migratory dispersal patterns. Despite these differences, urban built-up areas persist as central hubs for the distribution of suitable habitats for 75% of bird species, with peripheral mountain-plain transition areas constituting 63% of crucial dispersal corridors. This emphasizes the critical role of urban built-up areas in maintaining biodiversity and ecological connectivity. Prioritizing connectivity between central urban areas and distant natural spaces is imperative. Our approach innovatively classifies and constructs networks to identify strategic areas with diverse species-specific attributes, providing valuable spatial information for land planning and guiding solutions to enhance target species. While the primary focus is on bird conservation in Beijing, our framework is broadly applicable to global biodiversity management and green planning under urbanization challenges. Overall, this study offers innovative insights for urban planning development and serves as decision support for prioritizing urban actions.

GEOSPATIAL MONITORING OF THE ROAD NETWORK OF THE DNIPROPETROV REGION

The development of the road transport network is considered to be one of the crucial factors of the sustainable development of the country and regions. The presence of an extensive and topologically efficient road network and their appropriate technical condition ensure not only transport accessibility of settlements and road safety and stability, but also the speed and volume of transportation. The geographical location of Dnipropetrovsk oblast determines the important role of the region's road transport network in the formation of both external and intra-regional socio-economic relations. The oblast's road transport network consists of a few tens of thousands of kilometres of roads of various types of surfaces, and it has a complex internal structure, specific organization, and functional orientation. Therefore, geospatial monitoring of roads in Dnipropetrovsk oblast is an effective instrument for solving a number of regional transportation problems. On the basis of crowdsourced geospatial data from Open Street Map using QGIS, the study of spatial and territorial features of networks (road length, level of spatial complexity, structure, provision, stability, density, etc.) of different types of roads both for the oblast as a whole and over its administrative districts was conducted. The calculation of the total length of the region's roads using geospatial analysis showed a figure of 70823 km (all types of pavement), of which 3005 km are roads of national importance (4% of the total length), 33219 km are roads of local importance (47%) and 34599 km are roads in settlements (49%). It has been established that the structure of the state-owned road network in the oblast varies from a centralized type in the western (with a central hub in the city of Kryvyi Rih), northern (with a central hub in the village of Mahdalynivka) and north-eastern (with a central hub in the city of Pavlohrad) parts to a distributed type in other regions. It should be noted that the centralized structure of the western part of the region is formed by national and regional roads, the northern part by territorial roads, and the north-eastern part by international and territorial roads. This plays an important role in assessing the efficiency and sustainability of the network. The length of state roads of the territorial type in the region significantly dominates the length of international and national roads, which, given the European integration orientation of Ukraine's economy, indicates shortcomings in the state of the region's road transport network. At the same time, almost all international roads pass through the oblast's cities and towns, which does not meet the requirements for this type of road. Therefore, given the favourable geographical location of the oblast, the formation of a new network of highways through its territory will ensure intensive socio-economic development of both the region and Ukraine as a whole. The average density of the national highway network is only 0.0049 km/km². This is several times less than the rate used in developed countries for citywide highways. The hot spots on the map are connected with the intersections of roads of different levels and are mostly located outside the territories of settlements. This allows us to conclude that the road network framework is a compromise between the historical location of settlements, natural and geographical features of the territory (terrain, hydrology, geological structure, etc.) and construction cost constraints. The length of local roads is several times longer than the length of national roads. As a result, their average density for the region is 1.04 km/km², with the highest concentration in the central parts of the region and the lowest in the east and south of the region. The analysis of the region's roads by administrative units (raions) confirmed their geospatial diversity. The longest roads are observed in the most economically developed districts – Dnipro and Kryvyi Rih raions, and the shortest – in Pavlohrad and Nikopol raions. The same tendency is typical for local roads and roads in the settlements of the raions. However, the longest roads of national importance are in Synelnykove, Dnipro and Kamianske raions. All types of roads in the raions of the eastern and north-eastern parts of the oblast (Novomoskovsk, Pavlohrad, and Synelnykove) are characterized by the highest figures for total density, demonstrating the best transport provision of roads in Dnipropetrovsk oblast in contrast to the western districts. The main reason for this is the low population size in the east of the oblast. Keywords: geospatial monitoring, road network, network structure, transport availability, road density, Dnipropetrovsk region.