Areas Of High Density Research Articles

Charting mobility patterns in the scientific knowledge landscape

From small steps to great leaps, metaphors of spatial mobility abound to describe discovery processes. Here, we ground these ideas in formal terms by systematically studying mobility patterns in the scientific knowledge landscape. We use low-dimensional embedding techniques to create a knowledge space made up of 1.5 million articles from the fields of physics, computer science, and mathematics. By analyzing the publication histories of individual researchers, we discover patterns of scientific mobility that closely resemble physical mobility. In aggregate, the trajectories form mobility flows that can be described by a gravity model, with jumps more likely to occur in areas of high density and less likely to occur over longer distances. We identify two types of researchers from their individual mobility patterns: interdisciplinary explorers who pioneer new fields, and exploiters who are more likely to stay within their specific areas of expertise. Our results suggest that spatial mobility analysis is a valuable tool for understanding the evolution of science.

Zoning strategies for ecological restoration in the karst region of Guangdong province, China: a perspective from the “social-ecological system”

Ecological restoration holds great significance in addressing environmental degradation and rock desertification in karst areas. Zoning strategy is a fundamental task in understanding the interrelationship between human-environment to foster sustainable development. We explore “social-ecological” system and conduct a case study on the karst region in Guangdong Province, China. An evaluation framework consists of “development pressure”, “sensitivity status”, and “resilience potential” was established. The results show that: regions with high pressure of development are predominantly located in high-density urban areas. The generally distribution of the comprehensive status index exhibits significant spatial heterogeneity. Regions with low sensitivity are found on the eastern and western sides of the study area. The comprehensive resilience values are largely influenced by per capita energy-saving and environmental protection expenditures. The restoration zones mainly concentrated in the contiguous regions of the northwestern and southern parts, covering more than half of the total area. The conservation zones are more numerous and primarily situated in the northern and eastern parts. By integrating socio-economic and ecological factors, this study proposes ecological restoration strategies for specific zones. It helps for improve development issues arising from complex interactions between human-environment, facilitating the implementation of restoration practices.

Planning location of parcel lockers using group Analytic Hierarchy Process in Spherical Fuzzy environment

Parcel lockers have emerged as an effective solution to address inefficiencies in last-mile delivery. However, the selection of an appropriate location plays a crucial role in ensuring optimal service and enhanced logistic performance. To address this challenge, this work aims to define the best location for parcel lockers in the capital of Ireland, Dublin by conducting a novel decision-making model. The Spherical Fuzzy Analytic Hierarchy Process (SF-AHP) has been adopted to deal with the uncertainty in the decision maker preferences, while the Euclidean Distance-Based Aggregation Method (EDBAM) has been conducted to aggregate the decision makers preferences. The proposed integrated model is an applicable approach to elude AHP deterministic disadvantages, moreover, it is the first application of SF-AHP and EDBAM to select parcel lockers’ location. The findings, including the identification of the top three optimal locations, namely “Post office,” “On commercial area,” and “High population density area,” along with their respective weight scores, provide valuable insights for policymakers making strategic decisions regarding parcel locker placements in Dublin city.

The challenge of noise pollution in high-density urban areas: Relationship between 2D/3D urban morphology and noise perception

Urban morphology is closely intertwined with people's perception of noise, understanding their relationship is crucial for resident health. Previous studies have primarily focused on actual environmental noise, neglecting variations in how people perceive noise in different urban environments. More study is needed to elucidate how noise perception varies across different types of noise and urban areas. This study, based on noise complaint data, quantifies the perceived noise environment in New York City. It establishes a framework for urban morphology measurement from both 2D and 3D perspectives and employs regression models to explore the correlation between urban morphology and the perception of distinct noise types, as well as regional disparities in noise perception. Findings indicate that:(1) Three-dimensional urban morphology indices, such as tree shape, Google view images (GVI) building index, provide a better explanation of noise perception than 2D indices. (2) The impact of urban morphology on the noise perception exhibits significant regional variations. In densely populated Manhattan, diverse building morphology can better enhance the quality of the perceived acoustic environment. However, this conclusion does not hold true in other regions. (3) Urban morphology also has distinct effects on different types of noise complaints. For instance, residential complaints are most strongly correlated with building height compared with other complaint types. Last, by considering the collaborative effects of various variables, specific recommendations are proposed for local areas with similar impact profiles. This study can serve as a reference for the construction of noise-friendly high-density cities and the promotion of sustainable urban health.

Large-scale genotypic identification reveals density-dependent natal dispersal patterns in an elusive bird of prey

BackgroundNatal dispersal, the distance between site of birth and site of first breeding, has a fundamental role in population dynamics and species’ responses to environmental changes. Population density is considered a key driver of natal dispersal. However, few studies have been able to examine densities at both the natal and the settlement site, which is critical for understanding the role of density in dispersal. Additionally, the role of density on natal dispersal remains poorly understood in long-lived and slowly reproducing species, due to their prolonged dispersal periods and often elusive nature. We studied the natal dispersal of the white-tailed eagle (Haliaeetus albicilla) in response to local breeder densities. We investigated the effects of the number of active territories around the natal site on (a) natal dispersal distance and (b) the difference between natal and settlement site breeder density. We were interested in whether eagles showed tendencies of conspecific attraction (positive density-dependence) or intraspecific competition (negative density-dependence) and how this related to settlement site breeder density.MethodsWe used a combination of long-term visual and genotypic identification to match individuals from their breeding site to their natal nest. We identified natal dispersal events for 355 individuals hatched between 1984 and 2015 in the Baltic Sea coast and Arctic areas of Finland. Of those, 251 were identified by their genotype.ResultsIndividuals born in high-density areas dispersed shorter distances than those born in low-density areas, but settled at lower density breeding sites in comparison to their natal site. Eagles born in low natal area densities dispersed farther but settled in higher density breeding sites compared to their natal site.ConclusionsWe show that eagles might be attracted by conspecifics (positive density-dependence) to identify high-quality habitats or find mates, but do not settle in the most densely populated areas. This indicates that natal dispersal is affected by an interplay of conspecific attraction and intraspecific competition, which has implications for population dynamics of white-tailed eagles, but also other top predators. Furthermore, our study demonstrates the value of long-term collection of both nestling and (non-invasive) adult DNA samples, and thereafter using genotype matching to identify individuals in long-lived and elusive species.

Deep Learning-Based Integrated Circuit Surface Defect Detection: Addressing Information Density Imbalance for Industrial Application

In this study, we aimed to address the primary challenges encountered in industrial integrated circuit (IC) surface defect detection, particularly focusing on the imbalance in information density arising from difficulties in data sample collection. To this end, we have developed a new hybrid architecture model for IC surface defect detection (SDDM), based on ResNet and Vision Transformer (ViT). The core innovation of SDDM lies in the integration of the concepts of image information density and dataset information density, effectively identifying and processing areas of high information density through multi-channel image segmentation techniques. The convolution operations performed within each patch of the model help to precisely capture positional information, thereby meticulously differentiating the complex details on the surface defect detection of ICs. We optimized the model to make it more suitable for industrial applications, significantly reducing computational and operational costs. The experimental results confirmed that the improved SDDM model achieved an accuracy rate of 98.6% on datasets with uneven information density, effectively enhancing the productivity of IC packaging and testing companies, particularly in handling datasets with imbalanced information density.

Rapid urban expansion and potential disaster risk on the Qinghai-Tibetan Plateau in the 21st century

ContextCities are still expanding in many parts of the world in the 21st century, especially in developing regions, where socioeconomic transition has triggered urbanization. The Qinghai-Tibetan Plateau, characterized by its high elevation, developing economy, and fragile environment, has undergone rapid urbanization in the past twenty years, potentially heightening the region’s risk of geological and hydrometeorological disasters.ObjectivesThis article examines the process of urbanization on the Qinghai-Tibetan Plateau in order to better understand the relationship between urban expansion and population change and to explore whether geological and hydrometeorological disasters threaten urban expansion.MethodsWe created a high-resolution urban built-up boundary dataset from 2000 to 2020 based on remote sensing and GIS. By examining the spatio-temporal pattern of urban expansion and its population dynamics from 2000 to 2020 in 15 cities across the Qinghai-Tibetan Plateau, we quantified the urban expansion characteristics and explored the rising geological and hydrometeorological disaster risks urban areas face.ResultsThe Qinghai-Tibetan Plateau has experienced rapid and uneven urbanization in the past 20 years. The total expansion rate was over 252% – 1.48 and 2.81 times higher than that of China and the world, respectively. Urban expansion exceeded population growth in most cities throughout the whole period. The urban built-up areas and population of the Qinghai-Tibetan Plateau tended to concentrate in the Yellow River-Huangshui River Valley of Qinghai Province and the Yarlung Zangbo River and its two tributaries of Tibet. High-density urban built-up areas and population distribution were exposed to geological and hydrometeorological disasters. The urban boundary dataset produced in this study has better accuracy than the other five existing datasets, for the given area and time range.ConclusionsThis study will not only provide a scientific reference for urban development research and future urban planning on the Qinghai-Tibetan Plateau at the regional scale, but will also contribute to research on the urbanization process of the plateau and mountainous regions on a global scale, raising awareness of geological and hydrometeorological disaster risk prevention in these areas worldwide

Capitella (Annelida: Capitellidae) species in the Gulf of Mexico: Delimitation, phylogeography and phylogeny

AbstractCapitella spp. are found in marine and estuarine benthos world‐wide. They are often treated as environmental sentinels because they occur in high densities in areas of anthropogenic disturbance and organic pollution. However, there are many cryptic species around the world, often grouped into the Capitella capitata complex. Historically, these have been differentiated using allozymes and developmental studies. Recently, single‐gene sequencing, especially cytochrome c oxidase subunit I, and phylogenetic methods have been used to characterise populations around the world. We present molecular support and provide descriptions for five new Capitella spp. from the Gulf of Mexico: Capitella gomexa sp. n., Capitella mandingensis sp. n., Capitella tampe sp. n., Capitella maculosa sp. n. and Capitella loucindae sp. n. Two were recently differentiated on the basis of larval development and morphology. Additionally, we present an updated look at global Capitella phylogeny. While no apparent patterns of phylogeography were recovered, we did find support for a single origin of thoracic acicular spines.

Remotely characterizing photosynthetic biocrust in snowpack-fed microhabitats of Taylor Valley, Antarctica

Microbial communities are the primary drivers of carbon cycling in the McMurdo Dry Valleys of Antarctica. Dense microbial mats, consisting mainly of photosynthetic cyanobacteria, occupy aquatic areas associated with streams and lakes. Other microbial communities also occur at lower densities as patchy surface biological soil crusts (hereafter, biocrusts) across the terrestrial landscape. Multispectral satellite data have been used to model microbial mat abundance in high-density areas like stream and lake margins, but no previous studies have investigated the lower detection limits of biocrusts. Here, we describe remote sensing and field-based survey and sampling approaches to study the detectability and distribution of biocrusts in the McMurdo Dry Valleys. Using a combination of multi- and hyperspectral tools and spectral linear unmixing, we modeled the abundances of biocrust in eastern Taylor Valley. Our spectral approaches can detect low masses of biocrust material in laboratory microcosms down to biocrust concentrations of 1% by mass. These techniques also distinguish the spectra of biocrust from both surface rock and mineral signatures from orbit. We found that biocrusts are present throughout the soils of eastern Taylor Valley and are associated with diverse underlying soil communities. The densest biocrust communities identified in this study had total organic carbon 5x greater than the content of typical arid soils. The most productive biocrusts were located downslope of melting snowpacks in unique soil ecosystems that are distinct from the surrounding arid landscape. There are similarities between the snowpack and stream sediment communities (high diversity of soil invertebrates) as well as their ecosystem properties (e.g., persistence of liquid water, high transfer of available nutrients, lower salinity from flushing) compared to the typical arid terrestrial ecosystem of the dry valleys. Our approach extends the capability of orbital remote sensing of photosynthetic communities out of the aquatic margins and into the drier soils which comprise most of this landscape. This interdisciplinary work is critical for measuring and monitoring terrestrial carbon stocks and predicting future ecosystem dynamics in this currently water-limited but increasingly dynamic Antarctic landscape, which is particularly climate-sensitive and difficult to access.

Restorative Effects of Pocket Parks on Mental Fatigue among Young Adults: A Comparative Experimental Study of Three Park Types

Urban parks have been proven to effectively reduce mental fatigue among city residents; however, there has been less focus on the mental health benefits offered by pocket parks in densely populated areas from a field experiment perspective. Additionally, there is insufficient evidence providing information on the environmental characteristics that support recovery from mental fatigue. This study was based on 80 young adults aged 19–25 years. Three types of pocket parks were selected: street corners, interblock spaces, and intrablock spaces. Through a field experiment with questionnaire collection, physiological (BP, HR, and LF/HF) and psychological indicators (FS-14 and VAS) were used to explore the relationship between various pocket park features and respondents’ mental fatigue recovery. This study investigated the restorative effects of 10 environmental features by collecting questionnaires. The results suggested that different types of pocket parks have the recovery effect of pocket parks. Four environmental factors, namely, vegetation colour (β = −0.472, p = 0.002), vegetation coverage (β = 0.298, p = 0.046), resting facility comfort (β = −0.336, p = 0.028), and plant species (β = −0.437, p = 0.003), were more predictive of mental fatigue recoverability. However, factors such as neighbourhood hygiene and spatial privacy did not show significant predictive effects. Our findings provide robust evidence for urban park planning and design. In the future landscape design of high-density urban areas, greater emphasis can be placed on the construction of pocket parks. The rational selection and configuration of environmental factors that contribute to recovery effects in pocket parks will contribute to meeting the psychological health service needs of high-density urban populations.

Influence of the food environment on obesity risk in a large cohort of US veterans by community type.

The aim of this study was to examine relationships between the food environment and obesity by community type. Using electronic health record data from the US Veterans Administration Diabetes Risk (VADR) cohort, we examined associations between the percentage of supermarkets and fast-food restaurants with obesity prevalence from 2008 to 2018. We constructed multivariable logistic regression models with random effects and interaction terms for year and food environment variables. We stratified models by community type. Mean age at baseline was 59.8 (SD = 16.1) years; 93.3% identified as men; and 2,102,542 (41.8%) were classified as having obesity. The association between the percentage of fast-food restaurants and obesity was positive in high-density urban areas (odds ratio [OR] = 1.033; 95% CI: 1.028-1.037), with no interaction by time (p = 0.83). The interaction with year was significant in other community types (p < 0.001), with increasing odds of obesity in each follow-up year. The associations between the percentage of supermarkets and obesity were null in high-density and low-density urban areas and positive in suburban (OR = 1.033; 95% CI: 1.027-1.039) and rural (OR = 1.007; 95% CI: 1.002-1.012) areas, with no interactions by time. Many healthy eating policies have been passed in urban areas; our results suggest such policies might also mitigate obesity risk in nonurban areas.

Comparison of the osteogenic effects of demineralized dentin matrix and acellular dentin matrix.

This study aims to compare the osteogenic effects of implanting demineralized dentin matrix and acellular dentin matrix in bone defect areas. Demineralized dentin matrix and acellular dentin matrix were prepared. Twenty-four male SPF-grade SD rats were randomly divided into four groups: demineralized group (group A), acelluar group (group B), Bio-Oss bone powder group (group C), and blank control group (group D), with six rats in each group. All rats were subjected to general anesthesia to prepare bilateral femoral bone defects. Rats in groups A, B, and C were implanted with demineralized dentin matrix, acellular dentin matrix, and Bio-Oss bone powder at the bone defect area, respectively, while rats in group D were not implanted with any material. At 4 and 8 weeks after surgery, three rats were randomly executed in each group. The healing of the bone defect area was analyzed through gross observation. The concentrations of osteogenic indicators bone morphogenetic protein-2 (BMP-2) and alkaline phosphatase (ALP) were detected by serology. The distribution of high-density gray area (representing bone healing) in the bone defect area was observed by X-ray examination, and the formation of new bone was observed by histomorphology. The rate of new bone formation was calculated. At 4 and 8 weeks, the bone formation ability of group A was more active than that of the other groups; the concentrations of BMP-2 and ALP in group A were higher than those in the other groups, and the differences were statistically significant (P<0.05). At 8 weeks, the imaging observation showed that the high-density gray area in the bone defect of group A was evenly distributed. The histomorphological observation showed the regular arrangement of bone matrix in group A. The rate of new bone formation in group A was 28.51%±0.55% at 4 weeks and 32.57%±2.28% at 8 weeks, both of which were significantly higher than those in the other groups (P<0.05). Demineralized dentin matrix has better osteogenic potential than acellular dentin matrix.

Analysis of Households’ Water Access and Consumption in Differential Urban Neighbourhoods of Osogbo, Nigeria

The study focused on scrutinizing the sources and consumption patterns of domestic water supply in Osogbo, with an emphasis on households' socio-economic characteristics. Data were collected from three deliberately chosen residential neighborhoods representing low, medium, and high-density areas, with a cumulative population of 134,159 and an estimated 26,829 households. Employing a multistage sampling technique, 25% of streets in each neighborhood were randomly selected, and systematic sampling was utilized to distribute 268 structured questionnaires (1% of households) to gather information. Descriptive analyses, such as means and percentages, were employed to scrutinize socio-economic characteristics and water consumption patterns. The study also utilized inferential statistics, specifically Multiple Analysis of Variance (MANOVA), to assess the impact of residential densities and water sources on water consumption volume. Results highlighted hand-dug wells (46%), public taps (22.4%), and boreholes (15.7%) as thepredominant water sources. MANOVA revealed a statistically significant influence of residential densities and water sources on water consumption volume (p=0.049). In low-density areas, households consumed an average of 960 liters per day, compared to 735 and 517.5 liters in medium- and high-density areas, respectively. Across Osogbo, the average household consumed 664.7 liters daily. Correlation analysis indicated a positive and statistically significant relationship between resident population and water consumption (p&lt;0.05). The study concluded by emphasizing the pivotal roles of government, communities, NGOs, and individuals in addressing water provision challenges in the area.

Spatial analysis of solid waste collection sites in Abakaliki metropolis

Waste management is becoming more difficult as a result of the growing population and increased waste generation. Waste collection is a crucial step in the waste management process. This study mapped out the locations of the current waste collection sites in Abakaliki metropolis, analyzed their spatial distribution using the Average Nearest Neighbor (ANN) tool in GIS software, and looked into the implications of these sites. The results showed 373 waste collection sites within the metropolis, of which 77.5% of them were unofficial. In addition, the analysis demonstrated that the distribution of the waste collection sites within the metropolis increases with a residential density waste/area ratio of 15.41, 1.63, and 0.76 for high, medium and low residential density areas respectively. The average nearest neighbor result also revealed that the distributions of the waste collection sites within the metropolis are clustered in three (3) out of the Six (6) classified land uses namely, high residential density areas, medium residential density areas and the commercial areas whereas the administrative and public areas showed dispersed distribution. The study concluded that waste collection sites within Abakaliki Metropolis were not selected based on empirical studies.

Clinically relevant molecular hallmarks of PFA ependymomas display intratumoral heterogeneity and correlate with tumor morphology

Posterior fossa type A (PF-EPN-A, PFA) ependymoma are aggressive tumors that mainly affect children and have a poor prognosis. Histopathology shows significant intratumoral heterogeneity, ranging from loose tissue to often sharply demarcated, extremely cell-dense tumor areas. To determine molecular differences in morphologically different areas and to understand their clinical significance, we analyzed 113 PF-EPN-A samples, including 40 corresponding relapse samples. Cell-dense areas ranged from 0 to 100% of the tumor area and displayed a higher proportion of proliferating tumor cells (p < 0.01). Clinically, cell density was associated with poor progression-free and overall survival (pPFS = 0.0026, pOS < 0.01). Molecularly, tumor areas with low and high cell density showed diverging DNA methylation profiles regarding their similarity to distinct previously discovered PF-EPN-A subtypes in 9/21 cases. Prognostically relevant chromosomal changes at 1q and 6q showed spatial heterogeneity within single tumors and were significantly enriched in cell-dense tumor areas as shown by single-cell RNA (scRNA)-sequencing as well as copy number profiling and fluorescence in situ hybridization (FISH) analyses of different tumor areas. Finally, spatial transcriptomics revealed cell-dense areas of different tumors to be more similar than various different areas of the same tumor. High-density areas distinctly overexpressed genes encoding histone proteins, WNT5A, TGFB1, or IGF2. Relapsing tumors displayed a higher proportion of cell-dense areas (p = 0.036), a change in PF-EPN-A methylation subtypes (13/32 patients), and novel chromosome 1q gains and 6q losses (12/32 cases) compared to corresponding primary tumors. Our data suggest that PF-EPN-A ependymomas habor a previously unrecognized intratumoral heterogeneity with clinical implications, which has to be accounted for when selecting diagnostic material, inter alia, by histological evaluation of the proportion of cell-dense areas.

Did the association between alcohol outlet density and crime change during COVID shelter-in-place orders?

We investigated whether greater concentrations of on- and off-sale alcohol outlets were associated with crime and whether this association was moderated by COVID-19 shelter-in-place orders (SIP) that restricted on-premises consumption of alcohol. Crimes (2019-2020) and addresses of licenced alcohol outlets in a medium-sized California city were geocoded within census block groups (N = 61). On- and off-sale alcohol outlet density was calculated as licenced outlets/2.59 km2 (1 square mile). Multilevel negative binomial regression analyses were conducted to examine associations between alcohol outlet density and crime, and possible moderating effects of SIP, controlling for block group demographic characteristics and density of other retail businesses. On-sale outlet density was positively associated with total crimes and Part 2 crimes, while off-sale outlet density was inversely associated with total crime and Part 2 crimes. Overall, SIP was not significantly associated with crime, but moderated the associations of on-sale density with total crime and Part 1 crimes such that reductions in crime during SIP were observed in higher density areas. The association of off-sale outlets with crime was not moderated by SIP policies. On-sale outlet density, but not off-sale density, appears to be associated with increased crime. The results further indicate that restrictions in hours and service imposed by SIP policies reduced crime in high on-sale outlet density areas. These findings reinforce the importance of regulating alcohol outlet density and hours of service, especially for on-sale outlets, as a crime reduction strategy.

Roles of Urban Green Spaces for Children in High-Density Metropolitan Areas during Pandemics: A Systematic Literature Review

For children living in one of the 30 megacities around the world, green spaces may be far away or tokenistic, with growing accounts of youth exhibiting a variety of nature deficit disorders. Amidst increasing pressure for more high-density metropolitan areas (HDMAs), international advocacy agencies are calling for policy makers and service providers to ensure good quality urban green spaces (UGSs) for all children. Furthermore, these green spaces need to be purposefully designed to cater to children’s needs, which continue to evolve amidst extreme weather such as heat waves. Recently, pandemics have placed additional constraints on how far children can travel and their time spent outdoors, making the quality of this experience for children even more important. This systematic literature review explored the roles of HDMA-UGSs for children during pandemics. From 551 studies retrieved and curated using the PRISMA methodology, 40 papers were subsequently thematically analysed. Four roles were synthesised for HDMA-UGSs in supporting children’s experiences during pandemics, which also benefit children during ‘normal’ day-to-day life’: (1) sustaining growth and development, (2) bridging social stratifications, (3) encouraging self-agency, and (4) facilitating independent mobility. Thirteen principles were distilled to support decision making in enabling these outcomes in new-build and refurbishment projects. The results are of immediate use for decision makers who are responsible for HDMA-UGS planning, procurement, installation, and maintenance. The UGS role descriptions enable targeted design interventions for supporting children’s health and well-being, including during times of constrained outdoor time.

Study of the Correlation between the Urban Wind–Heat Environment and Urban Development Elements in High-Density Urban Areas: A Case Study of Central Shanghai

To prevent damage to human life and health caused by high temperatures and extreme weather and to promote sustainable urban development, it is necessary to optimize the layout of urban development elements to improve the urban wind–heat environment. Taking the high-density urban area of Shanghai as an example, this study used wavelet analysis to investigate the cyclic changes of the average annual temperature of Shanghai from 1950 to 2022 and the average annual wind speed of Shanghai from 2000 to 2020. The correlation between the urban heat environment and the urban development elements was analyzed using geographically weighted regression. The correlation was then examined using BP neural network, and finally, the impacts of different urban spatial patterns on the wind environment were analyzed using CFD numerical simulation. The results show that the average annual temperature of Shanghai city has an overall upward trend, with significant cycles of 44 and 32 years that are shortening over time. The average annual wind speed has a downward trend, with a significant main cycle of 22 years. Greening and water coverage, as well as the floor area ratio, have a significant reducing effect on surface temperature, whereas building density is positively correlated with surface temperature. Building density has a significant reducing effect on wind speed, whereas the effect of floor area ratio is not significant. The effect of building density on wind speed is significantly weakened, whereas the effect of the floor area ratio is not significant. This study provides valuable references for Shanghai and other high-density cities to optimize urban spatial patterns in order to improve the safety and comfort of the urban wind–heat environments. This study is of significant importance and value in promoting sustainable urban development, protecting the health of urban residents, and advancing spatial justice and equal well-being.

The spatial distribution and environmental effects on hotspots and coldspots of micronekton in the southwestern Indian Ocean

Micronekton communities show large-scale spatiotemporal patterns in pelagic acoustic scattering layers. They are one of the most conspicuous and ecologically-important components of the vast mesopelagic zone of the world's oceans. They play an important role in fishery resources and marine ecology research. In this study, acoustic data from the southwestern Indian Ocean were used to perform a hotspot analysis exploring the differences in micronekton distribution at 16 different spatial scales. Moreover, a generalized additive model (GAM) was used to analyze the effects of environmental variables. The distribution of micronekton was found to be highly correlated with latitude at different spatial scales, with high-density areas (hotspots) distributed between 32°S and 42°S and low-density areas (coldspots) distributed between 43°S and 54°S. With increasing spatial scale, the centers of both high- and low-density micronekton areas tended to move southward. GAM analysis at 20′ × 20′ spatial scale revealed that the micronekton distribution was influenced by the interaction of multiple environmental variables, with photosynthetically active radiation and dissolved oxygen being the two key variables with the highest influence on hotspot and coldspot distributions. The present study provides indepth knowledge on which environmental variables influences the distribution of micronekton under hotspots and coldspots periods in the southwestern Indian Ocean.

Optimizing the construction of ecological networks in Beijing using a morphological spatial pattern analysis—minimal cumulative resistance model

Introduction: With the increasing fragmentation of landscapes caused by rapid urbanisation, constructing ecological networks strengthen the connectivity between fragmented habitat patches. As the capital of China, Beijing has a rapid development, resulting in a serious landscape fragmentation, and needing an urgent demand for this study to improve the ecological network system.Methods: In this study, we choose the elevation, slope, Normalized Difference Vegetation Index and land use data of Beijing in 2020 as the data use. Morphological spatial pattern analysis (MSPA) was used to identify ecological source areas for Beijing, Minimal cumulative resistance (MCR) and gravity models were used to construct ecological network, and stepping stones to improve it.Results: The core area of Beijing had the highest proportion (96.17%) of all landscape types, forest accounting for 82.01% thereof. Ten core areas were identified as ecological source areas. Forty-five ecological corridors (8 major and 37 ordinary) were constructed. The ecological corridors are mainly concentrated in the middle and eastern regions where ecological mobility is limited. Constructing stepping stones would help uphold the region’s ecological service functions and ecosystem balance. Twenty-nine stepping stones and 32 ecological obstacles were used to create the optimised ecological network, consisting of 171.Discussion: The results provide an optimised ecological model for Beijing and a reference constructing ecological spatial networks for the sustainable development of ecological environments in high-density urban areas.