Temporal Factors Research Articles

Factors associated with drowning in Portugal, 2019-2023

Abstract Worldwide, mortality from drowning amounted to 236.000 individuals in 2019, corresponding to 8% of the total global mortality, making drowning the third leading cause of death from unintentional injuries and a universal public health problem. Portugal has a coastal zone of 950 km long, with 658 bathing waters and, in 2023, 157 people died due to drowning. This work aims to determine the factors associated with drownings that occurred in Portugal, between 2019 and 2023. This epidemiological descriptive-analytical study used the National Maritime Authority database, regarding the users of the portuguese coastal zone who suffered maritime incidents between 2019 and 2023. SPSS was used for statistical analysis and the results of the Poisson regression models are presented as adjusted prevalence ratios (APR) with 95% confidence intervals, according to individual (sex, age group and nationality), temporal (period of the week and day) and environmental (maritime department and beach surveillance status) variables. The total sample was 406 drownings and 15 860 other maritime incidents. Overall, the frequency of drownings in Portugal was higher in men (APR=1.393, 95%CI=1.130-1.717, p=.002), in the >55y age group (APR=1.780, 95%CI=1.005-3.152, p=.048), in foreigners (APR= 1.293, 95%CI=1.037-1.612, p=.022), on weekends (APR=1.299, 95%CI=1.063-1.586, p=.010), in the afternoon (APR=1.584, 95%CI=1.127-2.226, p=.008) and on unsupervised beaches (APR=2.436, 95%CI=1.958-3.029, p<.001) in comparison with users who suffered other maritime incidents. Individual, temporal and environmental factors are associated with a higher frequency of drownings in Portugal. Despite the limitation of the study that only includes users suffering maritime incidents and not all users of the portuguese coastal zone, our results allow a preliminary characterization of the drowning profile in Portugal and can contribute to the design of preventive strategies and policies to address this public health problem. Key messages • This study shows that there are individual, temporal and environmental factors strongly associated with a higher frequency of drownings in Portugal. • Portugal has a large coastal zone and the characterization of a drowning profile is the first step for the development of prevention strategies in order to oppose drowning morbidity and mortality.

Metabolomic Fingerprints: Seasonal and Farm-Specific Differences in Heterotrigona itama Bee Bread

Stingless bees’ products such as honey and bee bread are beneficial to human health. However, the metabolite composition within the products may differ according to spatial and temporal factors. This study aims to investigate the impact of spatial and temporal factors on the significant metabolite composition present in Heterotrigona itama bee bread collected from different seasons and types of bee farms. Thus, tandem mass spectrometry (LCMS/MS) based metabolomics analysis was used to achieve the said goal, focusing on H. itama bee bread samples, followed by multivariate analysis using the MetaboAnalyst platform. Our findings revealed significant metabolites that set bee bread samples apart. In terms of temporal factors, the analysis highlights specific metabolites exclusive to the wet season, such as flavones and flavonoids. However, in contrast, during the wet season, there are no significant metabolites in herbal farm samples. The results also underscore the significance of phenolic compounds in wet season samples and as vital metabolites distinguishing the groups. This study highlights a total of 24 annotated significant metabolites identified in different bee bread samples, as well as their capacity to differentiate between seasons and bee farms. Notably, these results suggest a wide variety of potential plant families as a source of bee bread. These findings shed light on the impact of seasons and diverse plant families contributing to bee bread composition, which may impact the growing meliponiculture industry greatly.

Increasing trends in hepatitis E hospitalisations in Spain, 1997 to 2019.

BackgroundHepatitis E, a viral hepatitis caused mainly by the ingestion of raw or undercooked food, is not a notifiable disease in Spain.AimTo analyse the temporal trends, epidemiological characteristics and factors associated with severe disease from hepatitis E hospitalisations in Spain from 1997 to 2019.MethodsHospitalisation records were obtained from the Spanish National Hospital Discharge Database. Temporal trends and seasonality were analysed by Poisson regression in years 1997-2015 and 2016-19, given changes in hospital discharge databases. Multivariate logistic regression was used to identify factors associated with severe disease.ResultsHepatitis E hospitalisation incidence increased from 0.22 cases per 1,000,000 inhabitants in 1997 to a maximum of 2.95 in 2018. Seasonality was observed during 2016-19 period, with more cases in the second and third quarters of the year. The incidence was higher in men vs women, and in the population aged over 40 years. Factors independently associated with death were age ≥ 50 years (adjusted odds ratio (aOR): 2.43), chronic liver disease (aOR: 4.29), HIV infection (aOR: 3.00) and hepatitis B/C (aOR: 2.11).ConclusionsHepatitis E hospitalisations have increased in Spain in recent years, being more severe in cases with older age, chronic hepatic diseases and HIV infection. A greater incidence in men over 40 years and a possible seasonality were observed. Further studies are needed to assess the seasonality, geographical distribution and impact of the disease to guide public health actions for prevention and control.

Skin Bacterial and Fungal Microbiome Responses to Diet Supplementation and Rewilding in the Critically Endangered Southern Corroboree Frog.

The composition and dynamics of the skin bacterial and fungal microbiome is thought to influence host-pathogen defence. This microbial community is shaped by host captivity, diet, and microbial interactions between bacterial and fungal components. However, there remains little understanding of how specific micronutrients influence bacterial and fungal microbiome composition and their inter-domain interactions during rewilding of captive-bred animals. This study experimentally investigated the effect of dietary beta-carotene supplementation and subsequent field release on bacterial and fungal microbiome composition and dynamics using the Southern Corroboree frog (Pseudophryne corroboree) as a model system. We found large-scale diversification of bacterial communities post-release and similar diversification of fungal communities. The rewilded fungal mycobiome was more transient and demonstrated stronger temporal and micro-spatial fluctuations than the bacterial microbiome. Accounting for temporal and spatial factors, we found strong residual associations between bacterial members, yet limited evidence for inter-domain associations, suggesting that co-occurrence patterns between bacterial and fungal communities are largely a result of shared responses to the environment rather than direct interactions. Lastly, we found supplementation of dietary beta-carotene in captivity had no impact on post-release microbiome diversity, yet was associated with approximately 15% of common bacterial and fungal genera. Our research demonstrates that environmental factors play a dominant role over dietary beta-carotene supplementation in shaping microbiome diversity post-release, and suggest inter-domain interactions may also only exert a minor influence. Further research on the function and ecology of skin bacterial and fungal microbiomes will be crucial for developing strategies to support survival of endangered amphibian species.

Relationship between urban traffic crashes and temporal/meteorological conditions: understanding and predicting the effects

Urban traffic accidents pose significant challenges to public safety and transportation management. Previous studies have revealed that temporal and meteorological factors are the key contributors to accident rate. Besides the inconsistent observations or lack of exploration in some aspects such as snowfall, fog, wind and daily temperatures, it has been shown that these factors are essentially entangled. Furthermore, existing methodologies of analysis or prediction have been limited to relative risk or traditional models. Hence, this study is centered on understanding the detailed correlations between temporal and meteorological factors and accident rate of two types of crashes – moving vehicle and fixed-object crashes using the traffic accident data from Dalian. Further, by incorporating a diverse set of the features, a prediction model leveraging the random forest algorithm is proposed and proved effective in anticipating accident occurrences on the district level. The feature importance analysis has shown that time period and factors such as holiday, temperature and season are most important factors. The rate is higher on working days and in spring, and collisions of both types peak at 6–7 am. When the highest daily temperature is 27 °C and the lowest is 20 °C or -8 °C, the incidence is relatively higher. On the basis, the recommendations are aimed at optimizing transportation systems, mitigating accident risks, and enhancing public safety in urban environments.

Drone Insights: Unveiling Beach Usage through AI-Powered People Counting

Ocean beaches are a major recreational attraction in many coastal cities, requiring accurate visitor counts for infrastructure planning and value estimation. We developed a novel method to assess beach usage on the Gold Coast, Australia, using 507 drone surveys across 24 beaches. The surveys covered 30 km of coastline, accounting for different seasons, times of day, and environmental conditions. Two AI models were employed: one for counting people on land and in water (91–95% accuracy), and another for identifying usage types (85–92% accuracy). Using drone data, we estimated annual beach usage at 34 million people in 2022/23, with 55% on land and 45% in water—approximately double the most recent estimate from lifeguard counts, which are spatially limited and prone to human error. When applying similar restrictions as lifeguard surveys, drone data estimated 15 million visits, aligning closely with lifeguard counts (within 9%). Temporal (time of day, day of the week, season) and spatial (beach location) factors were the strongest predictors of beach usage, with additional patterns explained by weather variables. Our method, combining drones with AI, enhances the coverage, accuracy, and granularity of beach monitoring, offering a scalable, cost-effective solution for long-term usage assessment.

Space and spatially structured environmental variables account for variation in blackfly and mayfly communities in sub-tropical South African rivers

Using aquatic invertebrate assemblages for bioassessment of streams and rivers is a fast and cost-effective approach to studying the impact of environmental stressors in aquatic ecosystems. The use of aquatic invertebrates is premised on their predictable responses to environmental stressors. Assemblage structure is not, however, only influenced by environment, but also neutral processes and temporal variation. This study quantified the relative roles of the environment (niche processes), space (neutral processes) and temporal factors in structuring mayfly and blackfly assemblages at family and species levels. Asymmetric eigenvector maps in conjunction with canonical redundancy analysis and variation partitioning were used to explore the relative roles of these three factors in structuring macroinvertebrate assemblages. At a species level, flow and water temperature were more important in explaining assemblage structure than at the family level. At the family level, space was more important than temporal and environmental factors. Unexplained variation at species and family level was more than 50%. This suggests (i) caution in using family-level rapid assessments to infer the role of the environment in structuring aquatic macroinvertebrate assemblages, as neutral processes are also dominant; and (ii) that the importance of stochastic processes, such as dispersal, should not be underestimated in rapid assessments.

Using physicochemical properties to predict the impact of natural dissolved organic carbon on transepithelial potential in the freshwater rainbow trout (Oncorhynchus mykiss) at neutral and acidic pH.

Dissolved organic carbon (DOC) is a complex mixture of molecules that varies in composition based on origin as well as spatial and temporal factors. DOC is an important water quality parameter as it regulates many biological processes in freshwater systems, including the physiological function of the gills in fish. These effects are often beneficial, especially at low pH where DOCs mitigate ion loss and protect active ion uptake. DOCs of different compositions and quality have varied ionoregulatory effects. The molecular variability of DOCs can be characterized using optical and chemical indices, but how these indices relate to the physiological effects exerted by DOCs is not well understood. We tested the effects of five naturally sourced DOCs, at both pH 7 and pH 4, on transepithelial potential (TEP) (a diffusion potential between the blood plasma and the external water) in rainbow trout. The five chosen DOCs have been well characterized and span large differences in physicochemical characteristics. Each of the DOCs significantly influenced TEP, although in a unique manner or magnitude which was likely due to their physicochemical characteristics. These TEP responses were also a function of pH. With the goal of determining which physicochemical indices are predictive of changes in TEP, we evaluated correlations between various indices and TEP at pH 7 and pH 4. The indices included: specific absorbance coefficient at 340nm, molecular weight index, fluorescence index, octanol-water partition coefficient, molecular charge, proton binding index, % humic acid-like, % fulvic acid-like, and % protein-like components by parallel factor analysis on fluorescence data (PARAFAC). Our results demonstrate the novel finding that there are three particularly important indices that are predictors of changes in TEP across pHs in rainbow trout: specific absorbance coefficient at 340nm, octanol-water partition coefficient; and proton binding index.

The impact of the built environment on human mobility patterns during Covid-19: A study of New York City's Open Streets Program

This study uses the Open Streets Program in New York City as a natural experiment to test the effects of change in street use on foot traffic changes during COVID-19. In a two-stage-least-squares (2SLS) design, the Open Streets Program is used as an instrumental variable to isolate the exogenous effect of expanded streets for pedestrians on foot traffic patterns. We then estimate a difference-in-differences model that compares the change in foot traffic to public points-of-interests (POI) in neighborhoods that are part of the Open Streets Program with those that are not “before and after” the start of the city-wide program, in addition to other controls such as street types and weather characteristics to help reduce the error variance of the regression. We find that the Open Streets Program helped increase pedestrian activity at a neighborhood level, even when controlling for street types and other confounding temporal factors such as precipitation and temperature.

Daily Activity Rhythms of Animals in the Southwest Mountains, China: Influences of Interspecific Relationships and Seasons

Temporal and spatial factors regulate the interactions between apex predators, mesocarnivores, and herbivores. Prey adjust their activity patterns and spatial utilization based on predator activities; in turn, predators also adapt to the activities of their prey. To elucidate the factors influencing the daily activity rhythms of animals, 115 camera traps were established from September 2019 to June 2023 to assess the influences of interspecific relationships and seasons on the daily activity rhythms of animals in the southwest mountains of China. The species captured by the cameras included six Carnivora (such as Panthera pardus and Lynx lynx), six Artiodactyla (such as Moschus spp. and Rusa unicolor), one Primate (Macaca mulatta), and two Galliformes (Crossoptilon crossoptilon, Ithaginis cruentus). The results demonstrated that the 15 species exhibited different activity rhythms and peak activities to reduce intense resource competition. There were differences in the species’ activity rhythms in different seasons, with competition among different species being more intense in the cold season than in the warm season. In predation relationships, the overlap coefficient in the cold season exceeded that of the warm season, possibly due to the abundant resources in summer and food scarcity in winter. In competitive relationships, 15 pairs of species exhibited significantly higher overlap coefficients in the cold season compared to the warm season, possibly due to increased demands for energy during the cold period or seasonal changes in predatory behavior. By analyzing the daily and seasonal activity patterns of dominant species in the study area, temporal niche overlaps were established to compare the competition levels between species. These findings indicate that the activity rhythms of the animals in this area not only result from evolutionary adaptation but are also influenced by season, food resources, and interspecific relationships (predation and competition). Thus, efforts should be made to reduce human interference, protect food resources in the winter, and monitor animals’ interspecific relationships to protect animal diversity and maintain the stability of the ecosystem in this biodiversity hotspot in China.

Test of the relation between temporal and spatial [formula omitted] by Knopoff et al.

The quality factor is a dimensionless measure of the energy loss per cycle of wave modes in an attenuation medium. Accurate measurement is important in various fields, from seismological studies to detect zones of partial melting to the geophysics of reservoirs to study rock properties such as porosity, fluid properties and saturation and permeability. In seismology, the quality factors measured for normal (standing) modes and propagating waves differ, as well those of equivalent experiments based on resonant rods and ultrasonic pulses performed in the laboratory. These measurements result in temporal and spatial quality factors respectively. A relationship between these two different quality factors and between the corresponding attenuation factors was proposed by Knopoff et al. sixty years ago. The conversion factor is basically the ratio between the phase velocity and the group velocity, while for the attenuation factor is the group velocity. We test these relations, which hold for low-loss solids, for body waves, using a Kelvin-Voigt rheology and a constant Q model, which provide explicit expressions of the temporal and spatial quality factors and velocities involved in these relations. The proposed theory provides the basis for a complete characterization of temporal and spatial quality factors and velocity dispersion based on arbitrary stress–strain relationships.

Nationwide distribution and factors related to indoor fine particulate matter concentrations in subway stations in Korea: Results of first-year measurement

This study assessed the seasonal distribution and factors associated with PM2.5 in nationwide subway stations in Korea. A total of 229,644 data points collected over one year were used to determine one-day PM2.5 concentrations from 642 subway stations. The geometric mean of indoor PM2.5 concentrations was 26.6 µg/m3. PM2.5 concentrations were higher in the Seoul metropolitan area (SMA) compared to non-Seoul metropolitan areas (NSMA), with the highest level occurring in winter, followed by spring, fall, and summer, similar to the trend observed for outdoor PM2.5 concentrations. In SMA, PM2.5 concentrations were significantly associated with the operation year, number of air cleaners on platforms, and number of passengers. These findings may help in the development of national strategies for managing indoor PM2.5 concentrations in subway stations, taking into account spatial and temporal factors.

Physical effort precrastination determines preference in an isometric task.

How the brain decides when to invest effort is a central question in neuroscience. When asked to walk a mile to a destination, would you choose a path with a hill at the beginning or the end? The traditional view of effort suggests we should be indifferent-all joules are equal so long as it does not interfere with accomplishing the goal. Yet, when total joules are equal across movement decisions, the brain's sensitivity to the temporal profile of effort investment remains poorly understood. Here, we sought to parse the interaction of time and physical effort by comparing subjective preferences in an isometric arm-pushing task that varied the duration and timing of high and low effort. Subjects were presented with a series of two-alternative forced choices, where they chose the force profile they would rather complete. Subjects preferred earlier physical effort (i.e., to precrastinate) but were idiosyncratic about preference for task timing. A model of subjective utility that includes physical effort costs, task costs, and independent temporal sensitivity factors described subject preferences best. Interestingly, deliberation time and response vigor covary with the same subjective utility model for preference, suggesting a utility that underlies both decision making and motor control. These results suggest physical effort costs are temporally sensitive, with earlier investment of effort preferred to later investment, and that the representation of effort is based on not only the total energy required but also when it is required to invest that energy.NEW & NOTEWORTHY We use a novel paradigm that differentiates physical effort costs, task costs, and time, where subjects choose between isometric arm-pushing tasks. Subjects prefer high physical effort earlier than later. They also decide faster and respond more vigorously the greater their preference. We find a generalizable subjective utility model that includes independent time-sensitivity of physical effort and task costs. Together, we demonstrate that subjective effort includes not only the total effort invested but also its timing.

Temporal trend and attributable risk factors of Alzheimer's disease and other dementias burden in China: Findings from the Global Burden of Disease Study 2021

AbstractINTRODUCTIONWe examined the burden of Alzheimer's disease and other dementias (ADOD) and attributable factors at the national and provincial levels in China.METHODSUsing the Global Burden of Diseases Study 2021, we estimated incidence, prevalence, mortality rate, disability‐adjusted life years (DALYs), and the ratio of years lived with disability (YLD) to DALYs for ADOD in China. Estimated annual percentage changes (EAPCs) were used to quantify the temporal trends from 1990 to 2021.RESULTSIn 2021, China experienced the highest ADOD burden among Group of 20 member nations. The EAPCs for age‐standardized rates for incidence, age‐standardized rates for prevalence, and age‐standardized mortality rate were 0.41 (uncertainty intervals [UIs] 0.34–0.49); 0.44 (UI: 0.36–0.52); and –0.19 (UI: ‐0.23 to ‐0.15), respectively. Between 1990 and 2021, the number of people with ADOD increased by 322.18% and DALYs associated with ADOD increased by 272.71%; most of these increases were explained by population aging.DISCUSSIONConsidering the aging Chinese population, targeted strategies to prevent dementia are urgently needed.Highlights China experienced the highest dementia burden among Group of 20 member nations. High body mass index, high fasting plasma glucose, and smoking were major risk factors for Alzheimer's disease and other dementias (ADOD) burden. Since 1990, the incidence and prevalence of ADOD increased substantially in China. The mortality rate related to ADOD decreased consistently. Considering the aging Chinese population, targeted strategies are urgently needed.

The influence of fiscal transparency on expenditure by regional and provincial governments in Vietnam

The intricate relationship between budget transparency and government expenditure has been confirmed, with a particular focus on how these dynamics are influenced by spatial and temporal factors. This study deals with the spatio-temporal effects of transparent communal budgets on local government spending, specifically across the 63 provinces in Vietnam. By analyzing data over time, the study uncovers critical insights into how the disclosure of budget information influences government spending patterns, both in the short term and the long term. The findings reveal a nuanced relationship, where both the direct and indirect effects of budget transparency on expenditure tend to be negative, suggesting that increased transparency may lead to a reduction in government spending. This trend is observed from both a short-term perspective, where immediate changes in budget disclosure affect spending, and a long-term perspective, where the effects of sustained transparency become more evident. The study highlights significant regional disparities in the impact of budget transparency on government expenditure. It finds that the influence of budget disclosure is less pronounced in northern Vietnam compared to the southern regions. The results advocate for policies that support targeted resource allocation at the provincial or regional levels. Such tailored approaches are essential for achieving more effective and equitable government budget management, ensuring that transparency initiatives are adapted to the specific needs and conditions of different regions within Vietnam. Overall, this research contributes to the broader understanding of how transparency in budgetary processes can influence government spending. By highlighting the spatial and temporal dimensions of this relationship, the study provides valuable insights for policymakers seeking to enhance fiscal accountability and optimize public resource allocation in Vietnam.

Surveillance of tick-borne pathogens in domestic dogs from Chad, Africa

BackgroundTick-borne pathogens are understudied among domestic animals in sub-Saharan Africa but represent significant threats to the health of domestic animals and humans. Specifically, additional data are needed on tick-borne pathogens in Chad, Africa. Surveillance was conducted among domestic dogs in Chad for selected tick-borne pathogens to measure (1) the prevalence of antibodies against Anaplasma spp., Borrelia burgdorferi, and Ehrlichia spp.; (2) the prevalence of infections caused by Hepatozoon spp., Ehrlichia canis, Anaplasma platys, and Babesia spp.; and (3) associations of pathogens with demographic, spatial, and temporal factors. Blood samples were collected from domestic dogs at three time points (May 2019, November 2019, June 2020) across 23 villages in southern Chad.ResultsOf the 428 dogs tested with the IDEXX SNAP 4Dx test in May 2019, 86% (n = 370, 95% CI = 83–90%) were positive for antibodies to Ehrlichia spp., 21% (n = 88, 95% CI = 17–25%) were positive for antibodies to Anaplasma spp., and 0.7% (n = 3, 95% CI = 0.1–2%) were positive for antibodies to Borrelia burgdorferi. Four different pathogens were detected via PCR. Hepatozoon spp. were most commonly detected (67.2–93.4%, depending on the time point of sampling), followed by E. canis (7.0-27.8%), A. platys (10.1–22.0%), and Babesia vogeli (0.4–1.9%). Dogs were coinfected with up to three pathogens at a single time point, and coinfections were most common in May 2019 compared to November 2019 and May 2020.ConclusionsOverall, this study provides new data about the epidemiology of tick-borne pathogens in domestic dogs in Chad, with potential implications for dog and human health.

Exploring the Relationship Between COVID-19 Transmission and Population Mobility over Time

This study explores the dynamic relationship between COVID-19 transmission and transportation mobility, with an emphasis on understanding the time-varying bidirectional interplay across the different phases of the pandemic. To gain insight into this relationship, we analyzed county-level data on transmission and mobility patterns from the United States over a 74-week period using a comprehensive list of factors including: temporal factors, socio-demographics, health indicators, health care infrastructure attributes, and spatial factors. For our analysis, we proposed a simultaneous econometric model system that explicitly accounts for the bidirectional relationship between COVID-19 transmission and mobility patterns while also accounting for the influence of common unobserved factors on the two variables. The model results strongly support our hypothesis that COVID-19 transmission and mobility patterns are interconnected. Further, our findings show distinct phases of the bidirectional relationship influenced by behavior changes, vaccine availability, and the emergence of new variants. Additionally, we conducted a validation exercise on a hold-out sample to assess the robustness of our model. The results confirm the superiority of the simultaneous model system with enhanced interpretability and prediction capability. By analyzing data from several weeks for the COVID-19 pandemic, our study provides valuable insights into the evolving dynamics and potential strategies for future pandemics.

Driving the Evolution of Land Use Patterns: The Impact of Urban Agglomeration Construction Land in the Yangtze River Delta, China

The rapid increase in population and economic activities has greatly influenced land use and spatial development. In urban agglomerations where socioeconomic activities are densely concentrated, the clash between ecological protection and economic growth is becoming more evident. Therefore, a thorough quantitative assessment of spatial changes driven by land use dynamics, alongside an examination of temporal and spatial driving factors, is crucial in offering scientific backing for the long-term and sustainable growth of urban agglomerations. This paper focuses on the major urban agglomerations in China’s Yangtze River Delta region, examining the spatiotemporal evolution of land use and landscape patterns from 2000 to 2020. By employing the standard deviation ellipse technique, coupled with multiple linear regression and the geographical detector model, we conduct a quantitative assessment of the directional trends in urban construction land expansion as well as the diverse impacts of temporal and spatial factors on this expansion across various periods and regions. The findings indicate that over the past 20 years, construction land in the Yangtze River Delta Urban Agglomeration expanded in concentrated patches, showing significant scale effects with relatively intact farmland and forest land being increasingly encroached upon. Landscape-type transitions predominantly occurred in cities around Taihu Lake and Hangzhou Bay, with the most significant transition being farmland converted to construction land, resulting in a greater number of patches and more pronounced land fragmentation. Throughout the 20 years, the standard deviation ellipse of construction land in the Yangtze River Delta Urban Agglomeration expanded and shifted, with the predominant expansion trending from the northwest toward the southeast, and the EN orientation being the most intense expansion area, covering 1641.24 km2. The influence of temporal and spatial driving factors on the expansion of urban construction land differed across various periods and regions. This study thoroughly examines the driving factors that affect the evolution of urban construction land in the region, offering valuable scientific evidence and references for future planning and development of the Yangtze River Delta Urban Agglomeration, aiding in the formulation of more precise and efficient urban management and land use strategies.

Back to the past: long-term persistence of bull kelp forests in the Strait of Georgia, Salish Sea, Canada

The Salish Sea, a dynamic system of straits, fjords, and channels in southwestern British Columbia, is home to ecologically and culturally important bull kelp (Nereocystis luetkeana) forests. Yet the long-term fluctuations in the area and the persistence of this pivotal coastal marine habitat are unknown. Using very high-resolution satellite imagery to map kelp forests over two decades, we present the spatial changes in kelp forest area within the Salish Sea, before (2002 to 2013) and after (2014 to 2022) the ‘Blob,’ an anomalously warm period in the Northeast Pacific. This analysis was spatially constrained by local environmental conditions. Based on nearshore sea surface temperatures (SSTs) from four decades (1984–2022), we found two periods of distinct increases in SST, one starting in 2000 and another in 2014. Further, the highest SST anomalies occurred on warmer coastlines in the enclosed inlets and the Strait of Georgia, while smaller anomalies were found on colder coastlines near the Strait of Juan de Fuca and the Discovery Passage. The total area of bull kelp forests from 2014 to 2022 has decreased compared to 2002 to 2013, particularly in the northern sector of the Salish Sea. Using the satellite-derived kelp data, we also present an analysis of kelp persistence compared with historical distribution of kelp forests depicted on British Admiralty Nautical Charts from 1858 to 1956. This analysis shows that warm, sheltered areas experienced a considerable decrease in persistence of kelp beds when compared to satellite-derived distribution of modern kelp, confirming a century-scale loss. In particular, the presence of kelp forests in the Strait of Georgia and on the warmest coasts has decreased considerably over the century, likely due to warming temperatures. While the coldest coasts to the south have maintained their centennial persistence, the northern Salish Sea requires further research to understand its current dynamics. This research contributes to a wider understanding of temporal and spatial factors for kelp from the regional perspective of the Salish Sea.

Temporal and oceanographic factors differentially affect two size classes of white shark at a Southern California aggregation site

Ontogenetic habitat shifts are a common feature of many marine species, including sharks, which face conservation threats when their distributions overlap with human resource extraction and habitat modification. White sharks Carcharodon carcharias, for example, exhibit a distinctly coastal phase as juveniles, with a limited distribution compared to the basin-scale range of adults. Using an unoccupied aerial vehicle (UAV), we studied a coastal aggregation site within a Southern California Bight nursery area to determine how fine-scale temporal and oceanographic factors affect white sharks at different developmental stages. White shark density, as measured via UAV, was highly variable across time of day and day of year, with modest variation across years. Typically, more sharks were observed in the late afternoon hours. Sharks, especially those <3 m total length, were observed more often during periods of colder seafloor temperatures, potentially reflecting avoidance of these colder, deeper waters by more cold-intolerant smaller white sharks. Alternate models incorporating sea surface temperature showed a very small but significant association between surface temperatures and <3 m total length white sharks for the months we surveyed, but no such association for larger sharks. There were no or only modest effects of visibility, swell height, chl a levels, sea state, and tidal height on UAV-observed shark density. Understanding how temporal patterns and oceanographic predictors of density change over time as well as how shark ontogeny interacts with these factors can help us to better understand how this species uses coastal habitats and predict when they may be more likely to share marine space with humans.