High Hot Spots Research Articles

Maternal and perinatal mortality: Geospatial analysis of inequality in pregnancy and perinatal mortality in Ethiopia.

While there is ample evidence of the overall reduction in perinatal and pregnancy-related mortality in Ethiopia, it remains uncertain if geographic disparities have diminished. This study aimed to investigate perinatal and pregnancy-related mortality spatial distributions, trends over time, and factors associated with the distribution in Ethiopia. We used data from Ethiopian Demographic and Health Surveys conducted in Ethiopia in 2000, 2005, 2011, and 2016. In each survey, around 15,500 women aged 15-49 were interviewed from about 550 neighborhoods randomly sampled from across the country. Perinatal and pregnancy-related mortality were used as outcome variables. We carried out Optimized Hotspot Analysis using the Getis-Ord Gi* statistic in ArcGIS Pro to identify the time trend of geographical clusters with high (hot spot) and low (cold spot) perinatal and pregnancy-related mortality. In addition, we conducted a Geographically Weighted Poisson Regression in R to examine the factors associated with the spatial distribution of perinatal and pregnancy-related mortality. Perinatal and pregnancy-related mortality exhibited a clustering pattern indicating the presence of geographic inequality, with a decreasing pattern from 2000 to 2016. We detected hotspot areas in developed administrative regions of Amhara, Oromia, and Southern Nations, indicating inequality within large regions. Inequality in perinatal mortality was associated with rural residence, younger age of women, and high birth rate, whereas pregnancy-related mortality was associated with low autonomy, younger age, and anemia. We found that anemia (p-value = 0.01) has a geographically varying relationship with perinatal mortality, while education (p-value = 0.03) and wealth (p-value = 0.01) with pregnancy-related mortality. While there has been a reduction during the study period, geographical disparities in perinatal and pregnancy-related mortality still persist. Therefore, targeting intervention programs in areas where spatial inequalities still persist is essential for effectively utilizing scarce resources.

Sustained Fishing Threatens Globally Protected Species: Insights from Digital Catch and Genomic Data

Small-scale fisheries capture a wide marine biodiversity including highly vulnerable and endangered species. Despite global conservation efforts, at regional scale, strategies to conserve threatened species are often constrained by poor biological information and a paucity of fisheries data to understand the level of threat posed to their populations. In Myanmar, devil and manta rays (mobulids) are caught for meat consumption and export of gill plates. The impact of this exploitation is not fully understood as mobulid rays, especially in this region, have been poorly studied, catch levels are under-reported and the fishery is unregulated. An accurate knowledge of the species composition and catch levels is an important first step to inform potential management and protection strategies for these species. This study is the first to combine digital catch recording alongside genomic tools to analyze mobulid rays caught in the Tanintharyi Region of south Myanmar. Our catch data analyses indicate a sustained catch and decrease in total landings of mobulids from 2016 to 2018 in Tanintharyi. We identified five species of mobulid rays, including the first record of M. tarapacana for Myanmar. Our analyses of population genomics provided evidence of structured populations of M. thurstoni and partial admixture in M. mobular. Our findings are highly valuable 1) contributing to fill the knowledge gap for these threaten species in the region, and 2) as the first documentation of sustained fishing pressure these rays are exposed to, and the species under potential fishing threat in the Tanintharyi Region, a high priority biodiversity hotspot.

A new method for temperature field characterization of microsystems based on transient thermal simulation

Microsystems face challenges such as high heat flux density and localized hot spots in the temperature field, significantly impacting their thermal reliability. Accurately and comprehensively characterizing the temperature field is a challenging problem in current research. We present a general high-order finite difference (GHOFD) algorithm for the high-accuracy numerical solution of the two-dimensional transient heat conduction equations (THCEs). The 10th-order GHOFD algorithm is accurate up to 10−7 °C. Secondly, we present a viable approach for characterizing microsystems' steady-state and transient heat conduction mechanisms. We introduce two new characterization parameters: the gradient modulus and the heat flux direction factor (HFDF). The gradient modulus can more clearly characterize the magnitude of the gradient vector and quantitatively analyze the spatial position of the temperature field change in the microsystem. The HFDF can dynamically display the heat conduction process in the temperature field. Finally, using temperature field simulation and microsystem characterization, we have validated the effectiveness of the proposed method and new parameters.

Stability and reliability of regional cumulative impact mapping: A Canadian Pacific case study

Cumulative impact mapping is a commonly applied spatial representation of the impacts of human activities on the ocean. This spatial model has been applied at varying scales around the world, in part due to its ability to visually communicate complicated information in a simple way. The application of the model to decision-making processes requires an understanding of the reliability and stability of its outputs. This paper represents both an updated regional application in Pacific Canada and an evaluation of the tool over two iterations, 2015 and 2023. The regional application utilised higher model resolution and new and improved data inputs including 38 habitats and 46 activities across five sectors. High impact hotspots were found around major population centres and ports, as well as in fishing and shipping areas along the continental shelf. Commercial fishing, shipping, and climate change (sea surface temperature change) remained the major drivers of cumulative impacts in the region, and cumulative impacts per unit area continued to be highest in kelp and seagrass. Results suggest evidence of decreased impacts where improved protection for sponge reefs were implemented but show an overall increase in cumulative impacts for the region. Results showed consistency and reliability in the location of cumulative impact hotspots. Refinements in data quality and resolution of spatial data inputs contributed towards increasing the spatial precision of hot spot areas identified. Confidence in the cumulative impact mapping outputs and applications for marine spatial planning, marine protected area designation and management, research, and decision support are discussed.

Investigating illicit drug hotspots and daily variations using sewer-network wastewater analysis

Previous wastewater-based epidemiology (WBE) research on illicit drug use has predominantly focused on wastewater treatment plant (WWTP) influents, but information on sewer-network wastewater is very limited. This study represents a pioneering small-scale WBE investigation based on the analysis of sewer-network wastewater samples from different sewer manholes in suburban (Tamsui region) and urban areas (Zhongshan and Wanhua regions) and a comparison of the results with those obtained from corresponding WWTP influents. Among sixteen illicit drugs, methamphetamine exhibited the highest concentration in sewer-network wastewater across both areas. Suburban–urban variations were observed, with more types of illicit drugs detected in the suburban area. Back-calculation indicated that methamphetamine and ketamine were the most-consumed illicit drugs in both sewer-network wastewaters and WWTP influents. Similar types of illicit drugs were detected in the sewer-network wastewaters and WWTP influents, indicating the representativeness of WWTP influents in assessing regional illicit drug abuse. Nevertheless, the sewer-network wastewater results offered additional information making it possible to pinpoint potential hotspots of illicit drug and identify peak usage periods throughout the day, in contrast to the WWTP influent results. In the non-suspected suburban area of Tamsui, high potential hotspots of methamphetamine (sampling points 3 and 6) and ketamine (sampling points 1 and 8) were identified. Although the Zhongshan and Wanhua regions were chosen as suspected hotspots of illicit drug abuse, more severe illicit drug use was observed in Wanhua. Moreover, a trend toward higher illicit drug use from early morning to morning was observed. Despite sampling challenges and higher costs, small-scale WBE via sewer-network wastewater analysis provides superior identification of drug abuse hotspots and peak usage periods. Therefore, this study provides valuable insights for law enforcement and can help prevent and combat illicit drug abuse by targeting potential hotspots and understanding daily illicit drug use dynamics.

Spatial Analysis of Prediabetes and Associated Risk Factor Prevalence Among Late Adolescents in San Luis Potosí, México.

Introduction The prevalence of prediabetes is increasing worldwide. However, the determinants that contribute to its onset in young individuals remain poorly understood. An essential aspect of directing control and preventive initiatives is comprehending the geographical distribution of these disorders and pinpointing regions with a high prevalence. Objective The objective of this study was to determine the spatial distribution of prediabetes and associated risk factor prevalence among late adolescents in the metropolitan area of San Luis Potosí (MASLP), México, during the years 2008, 2009, and 2010. Methods This was a cross-sectional study that included 15,672 participants between the ages of 18 and 21 years. We made a cartographic overlay of the body mass index (BMI), systolic blood pressure (BP), diastolic BP, and impaired fasting glucose (IFG) using a 2010 marginalization index. Results The prevalence of prediabetes was 5.5%, whereas the prevalence of overweight and obesity remained stable for three years. However, in 2010, the prevalence of both diastolic BP and prediabetes increased.Spatial analysis revealed that the urban basic geostatistical area (Area Geo-Estadística Básica (AGEB)), with 11-20 participants with prediabetes, was mainly concentrated in the areas of medium and low marginalization throughout all years. Conclusion We found a yearly increase in prediabetes prevalence and increased diastolic BP. Prediabetes varies across the region. MASLP has statistically detected significant high hot spots in prediabetes. The findings of this study are valuable for directing resource distribution and highlighting intervention programs that target modifiable prediabetes predictors. To improve health coverage, it is necessary to consider different local realities.

New Methods and Challenges for IPM in Archives, Modern and Historic Libraries

ABSTRACT In this article the most important aspects of IPM, new challenges like climate change, new pests and updated methods of detection are presented. The grey silverfish has already resulted in many problems in archives and libraries across Europe. To set priorities and evaluate a large storage building with many rooms, we present a pest index for detecting high infestation rates and hotspots in the building. For the biscuit beetle we present two new detection methods: The use of a scent detecting (or sniffing) dog trained to detect the larvae of the beetle and the Insect Activity Detection System (IADS), a new technology that uses the acoustical emissions of the larvae feeding on the material. The last aspect of this paper is climate change: in the future higher temperatures, extreme weather events and introduced species will be new challenges for libraries and archives.

Abstract A057: Superfund sites and cancer risk: Cluster analysis in Puerto Rican municipalities between 2010 and 2020

Abstract Introduction: Living within proximity to hazardous waste (superfund) sites can pose an increased risk of exposure to chemicals of concern, including cancerogenic substances. Per- square mile, Puerto Rico has a high density of contaminated sites, including the designation of 19 superfund sites by the Environmental Protection Agency across the archipelago. Understanding how living within proximity to superfund sites can help recognize communities that are at greater health risks, such as increased cancer risks. Objectives: Identify clusters and outliers for all types of cancer, to assess ecological risk, by the presence of superfund sites across Puerto Rico. Methods: All types of cancer were recorded and provided by the Puerto Rico Central Cancer Registry for the period of 2010-2020. This data was summarized by municipalities (n=78). Cancer cases in each county were aggregated and divided by population in 2020 to show prevalence of cases. Using geographical information systems (ArcGIS), a Local Moran’s I was run to identify potential municipalities that have clusters; location with similar high (hot spots) or low values (cold spots) and outliers; locations with dissimilar values from their surrounding neighbors. A layer representing municipalities with superfund sites was also applied to the map to see if there was a relationship between living in a superfund site and cancer risk. This study was approved by UPRCCC IRB Protocol #2023-11-124. Results: Between 2010 and 2020, a total of 114,560 diagnosis occurred for all types of cancer in PR, from which 48.06% accounted for females and 51.93% for males, with breast and prostate as the primary cancer sites, respectively. Our analyses showed one hotspot and three cold spots with statistically significant differences from their neighboring municipalities. One hotspot was in Canovanas (p=0.03) which has a superfund site related to pharmaceutical chemicals. The three coldspots were in Cataño (p=0.04), Trujillo Alto (p=0.04), and Guánica (p=0.03). Additionally, four high and low outliers were identified. Across the municipalities, in the lower outliers Vega Alta (p=0.04), Corozal (p=0.002) are the only ones with current Superfund sites. Cabo Rojo (p=0.002) and San German (p=0.006) are included in the list of higher outliers, which are places with superfund sites. However, Hormigueros (p=0.03), and Arroyo (p=0.03), are also in this category. Conclusion: The results identify the key cancer clusters and outliers across municipalities in comparison to neighboring municipalities on the island. Results show municipalities with and without Superfund sites as part of the higher outliers list, which additional research could help establish other contributing factors. Further analysis is needed to consider what factors affect the clusters such as age range, type of cancer, and presence of other environmental contaminants in the area. Acknowledgements: This research was supported by award 1R25CA240120-01 (Cancer Prevention & Control Research Training Program) from the National Cancer Institute. Citation Format: Sailing JT Tang, Nancy R. Cardona, Ana P. Ortiz. Superfund sites and cancer risk: Cluster analysis in Puerto Rican municipalities between 2010 and 2020 [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A057.

The Additive to Mass Manufacturing Process of Mixed Potential Electrochemical Sensors

Additive manufacturing allows for quick turn around and low cost of production of small numbers of parts. These attributes lend the technology to prototype development, where design changes are many and production numbers are low [1]. Once design parameters have been nailed down, additive manufacturing’s low throughput and poor reproducibility limit application to high volume production.Here, we discuss the implementation of direct-write extrusion of ceramic pastes and metal inks for prototype manufacturing of mixed potential electrochemical sensors and the transition to tape casting and screen printing for high volume production. Throughout the prototyping phase, direct write extrusion enabled quick and easy production of low numbers of parts, enabling various changes in sensor design and material to improve sensor performance. Sensor design evolved from a disk shape (Fig. 1 a) to a stick with integrated heater (Fig. 1 b, c). Direct write extrusion of substrate enabled quick testing of various stabilized zirconia ceramics to improve the sensitivity of the device [2]. Limitations of additive manufacturing became apparent when attempting to integrate the heater into the device, the inconsistent linewidths led to areas of high resistance and hot spots (Fig. 1 c). Tape-casting and screen printing of the devices was adopted for three reasons, first, to improve line fidelity, which is vitally important when printing small electrodes as well as heater traces (Fig. 1 d), second, to further decrease conductivity of substrate by laminating multiple layers of different ceramic materials, and finally to increase manufacturing throughput (Fig. 1 d, e).This work was supported by US Department of Energy Award DE-FE0031864References[1] T. D. Ngo, A. Kashani, G. Imbalzano, K. T. Q. Nguyen, and D. Hui, “Additive manufacturing (3D printing): A review of materials, methods, applications and challenges,” Compos. Part B Eng., vol. 143, pp. 172–196, Jun. 2018, doi: 10.1016/j.compositesb.2018.02.012.[2] S. Halley, K. Ramaiyan, F. Garzon, and L. Tsui, “Massive enhancement in sensitivity of mixed potential sensors towards methane and natural gas through magnesia stabilized zirconia low ionic conductivity substrate,” Sens. Actuators B Chem., vol. 392, p. 134031, Oct. 2023, doi: 10.1016/j.snb.2023.134031. Figure 1

Recent Advances in Regulating Ceramic Monolithic Catalyst Structure for Preferential Oxidation of CO in H2.

Preferential oxidation of CO (CO-PROX) has tremendous significance in purifying hydrogen for fuel cells to avoid catalyst poisoning by CO molecules. Traditional powder catalysts face numerous challenges, including high pressure drop, aggregation tendency, hotspot formation, poor mass and heat transfer efficiency, and inadequate thermal stability. Accordingly, ceramic monolithic catalysts, known as their excellent thermal stability, high surface area, and superior mass and heat transfer characteristics, are gaining increasing research attention. This review examines recent studies on ceramic monolithic catalysts in CO-PROX, placing emphasis on the regulation of active sites (e.g., precious metals like Pt and Au, and non-precious metals like CuO and CeO2), monolith structures, and coating strategies. In addition, the structure-catalytic performance relationships, as well as the potential and limitations of different ceramic monolithic catalysts in practical application, are discussed. Finally, the challenges of monolithic catalysts and future research prospects in CO-PROX reactions are highlighted.

A novel three-dimensional porous Ag/TiO2 hybrid aerogels with high dense hot spot as effective SERS substrate for ultrasensitive detection

This research focuses on preparing a series of new TiO2/Ag hybrid aerogels with varying TiO2 contents, and demonstrates their application as ultrasensitive SERS substrates. The synthesized TiO2/Ag hybrid aerogels exhibited excellent SERS behavior when detecting 4-Mercaptobenzoic acid (4-MBA), and the calculated SERS enhancement factor (EF) was 6.34 × 106. 3D structured aerogels can create more hot spots and adsorption sites, and multiple interband chemical transfer (CT) pathways emerged and enhanced CT efficiency because of the large number of surface oxygen vacancies of meso-TiO2 NPs. Therefore, the synergy of electromagnetic field enhancement and chemical enhancement leads to SERS enhancement. In addition, the composite SERS substrate has high sensitivity, and the detection limit of adsorbed 4-MBA probe molecules reaches 10-11 M. Furthermore, the TiO2/Ag hybrid aerogels demonstrate good reproducibility with minimal standard deviation in terms of SERS signals. In addition, even after standing for 6 months, there is almost no attenuation in the SERS signal intensity, which highlights the excellent stability of this substrate. Therefore, these highly sensitive TiO2/Ag hybrid aerogels SERS substrates have important practical value in environmental monitoring, medical inspection and food supervision.

Mapping malaria transmission foci in Northeast Thailand from 2011 to 2021: approaching elimination in a hypoendemic area

BackgroundThailand is approaching local elimination of malaria in the eastern provinces. It has successfully reduced the number of cases over the past decade, but there are persistent transmission hot spots in and around forests. This study aimed to use data from the malaria surveillance system to describe the spatiotemporal trends of malaria in Northeast Thailand and fine-scale patterns in locally transmitted cases between 2011 and 2021.MethodsCase data was stratified based on likely location of infection and parasite species. Annual Parasite Index per 1000 population (API) was calculated for different categories. Time series decomposition was performed to identify trends and seasonal patterns. Statistically significant clusters of high (hot spots) and low (cold spots) API were identified using the Getis-Ord Gi* statistic. The stability of those hot spots and the absolute change in the proportion of API density from baseline were compared by case type.ResultsThe total number of confirmed cases experienced a non-linear decline by 96.6%, from 1061 in 2011 to 36 in 2021. There has been a decline in both Plasmodium vivax and Plasmodium falciparum case numbers, with only four confirmed P. falciparum cases over the last two years—a 98.89% drop from 180 in 2011. API was generally higher in Si Sa Ket province, which had peaks every 2–3 years. There was a large outbreak in Ubon Ratchathani in 2014–2016 which had a high proportion of P. falciparum reported. The proportion of cases classified increased over the study period, and the proportion of cases classed as indigenous to the village of residence increased from 0.2% to 33.3%. There were stable hot spots of indigenous and imported cases in the south of Si Sa Ket and southeast of Ubon Ratchathani. Plasmodium vivax hot spots were observed into recent years, while those of P. falciparum decreased to zero in Ubon in 2020 and emerged in the eastern part in 2021, the same year that P. falciparum hot spots in Si Sa Ket reached zero.ConclusionsThere has been a large, non-linear decline in the number of malaria cases reported and an increasing proportion of cases are classed as indigenous to the patient’s village of residence. Stable hot spots of ongoing transmission in the forested border areas were identified, with transmission likely persisting because of remote location and high-risk forest-going behaviours. Future efforts should include cross-border collaboration and continued targeting of high-risk behaviours to reduce the risk of imported cases seeding local transmission.

The Complete Chloroplast Genome Sequence of the Medicinal Moss Rhodobryum giganteum (Bryaceae, Bryophyta): Comparative Genomics and Phylogenetic Analyses.

Rhodobryum giganteum (Bryaceae, Bryophyta), a rare medicinal bryophyte, is valued for its cardiovascular therapeutic properties in traditional Chinese medicine. This study presents the first complete chloroplast genome sequence of R. giganteum, including its assembly and annotation. The circular chloroplast genome of R. giganteum is 124,315 bp in length, displaying a typical quadripartite structure with 128 genes: 83 protein-coding genes, 37 tRNAs, and 8 rRNAs. Analyses of codon usage bias, repetitive sequences, and simple sequence repeats (SSRs) revealed an A/U-ending codon preference, 96 repetitive sequences, and 385 SSRs in the R. giganteum chloroplast genome. Nucleotide diversity analysis identified 10 high mutational hotspots. Ka/Ks ratio analysis suggested potential positive selection in rpl20, rps18, petG, and psbM genes. Phylogenetic analysis of whole chloroplast genomes from 38 moss species positioned R. giganteum within Bryales, closely related to Rhodobryum laxelimbatum. This study augments the chloroplast genomic data for Bryales and provides a foundation for molecular marker development and genetic diversity analyses in medicinal bryophytes.

Reviving health mediation during the COVID-19 crisis and beyond: an implementation study in deprived neighbourhoods of Marseille, France.

In 2020, during France's COVID-19 response, healthcare professionals from a hospital and an association initiated health mediation interventions in Marseille's vulnerable neighbourhoods, funded by the regional health authorities. This mixed method research evaluates the CORHESAN program that lasted until June 2022. We examined CORHESAN documents and reports, conducted interviews, and analysed activity data, comparing it to the COVID-19 hotspots identified on a weekly basis at the neighbourhood level, using generalised linear mixed models (GLMMs). CORHESAN was implemented by a team of up to nine health mediators, six private nurses hired on an ad hoc basis, supervised by a general coordinator and two part-time medical and nursing coordinators. Multiple partnerships were established with shelters, associations, social-housing landlords and local institutions. The team accompanied 6,253 people affected by COVID-19 or contact in the practical implementation of their isolation and contact tracing. Of the 5,180 nasopharyngeal samples for RT-PCR and 1,875 for antigenic testing: 12% were taken at home and 27% in partner facilities in the targeted neighbourhoods; 32% were taken from symptomatic patients and 30% in the context of contact tracing; and 40% were positive. Multiple awareness sessions on prevention methods and distributions of personal protection kits and self-diagnostic tests were conducted in the streets, in shelters, in associations or at home. A total of 5,929 doses of COVID-19 vaccine were administered in a walk-in vaccination centre, at temporary street vaccination posts, during operations at partner facilities, or during home-visits to patients with limited autonomy. GLMMs showed that the intervention significantly targeted its testing interventions in neighbourhoods with socioeconomic disadvantage and/or past under-testing (adjusted odds ratio (aOR), 2.75 [1.50-5.00]) and those with high hotspot level (aOR for level-3 versus level-0, 1.83 [1.24-2.71]). The pandemic emphasised the potential of health mediation interventions to address health disparities. Building on this, a new program began in July 2022, aiming at enhancing cancer screening and vaccinations in deprived areas of Marseille. Evaluations are ongoing to assess its activities and impact, and provide evidence to future implementation initiatives.

Fabrication of versatile Fe3O4/GO/Au composite nanomaterial as SERS-active substrate for detection of pesticide residue.

Highly active Fe3O4/GO/Au composite nanomaterial was fabricated as a substrate of surface-enhanced Raman spectroscopy (SERS) and applied for pesticide residue detection. The three-layer multifunctional Fe3O4/GO/Au nanoparticles (NPs) were designed by facile method, with high hotspots, and were characterized by various techniques, including ultraviolet spectrophotometry (UV), X-ray diffraction (XRD), infrared absorption spectrometer (IR), and transmission electron microscopy (TEM). The performance of Fe3O4/GO/Au was evaluated by Raman spectroscopy with R6G as a probe molecule to verify its enhancement effect. It exhibited a strong Raman signal with 10-6M of R6G. Furthermore, the presence of Fe3O4/GO/Au nanohybrid enabled the SERS-based method to detect mancozeb and showed an excellent linear relationship in the range of 0.25-25 ppm, with a low limit of detection (0.077 ppm), satisfactory EF, stability, and repeatability. In addition, the mechanism of SERS enhancement with electromagnetic mechanism (EM) and chemical mechanism (CM) was discussed in detail. Therefore, the proposed SERS approach holds promise as an auxiliary technique for screening contaminated agricultural products, environmental sample, and food in the future.

Ecosystem structure and function of the North Water Polynya

The North Water Polynya is one of the most productive Arctic regions on Earth, sustaining the world's northernmost Inuit communities for millennia. The polynya is a large and persistent region of open water surrounded by sea ice and exhibits high primary productivity, is a biodiversity hotspot, and is a key habitat and migration corridor for Arctic species. Many aspects of the ecosystem structure and the role of resident species in the North Water Polynya remain uncertain. To shed light on these, we developed the first representation of the North Water Polynya food web using the Ecopath modelling framework. Modelled trophic flows indicated that pelagic and benthic communities were primarily connected by Age 1+ Arctic cod ( Boreogadus saida), walrus ( Odobenus rosmarus), and ringed seal ( Pusa hispida). Large copepods, Age 1+ Arctic cod, and bivalves were key prey species. Overall productivity in the North Water Polynya was higher compared to Western Baffin Bay and Western Greenland, corroborating expectations of relatively high productivity within the polynya. This model provides a baseline description of the North Water Polynya ecosystem structure and function prior to future climate-driven food web changes and the emergence of large-scale commercial fisheries.

Distinguishing the contributions of different smelting emissions to the spatial risk footprints of toxic elements in soil using PMF, Bayesian isotope mixing models, and distance-based regression

Toxic element pollution of soils emanating from smelting operations is an escalating global concern due to its severe impact on ecosystems and human health. In this study, soil samples were collected and analyzed to quantify the risk contributions and delineate the spatial risk footprints from smelting emissions for 8 toxic elements. A comprehensive health risk contribution and delineation framework was utilized, consisting of Positive matrix factorization (PMF), spatial interpolation, an advanced Bayesian isotope mixing model via Mixing Stable Isotope Analysis in R (MixSIAR), and distance-based regression. The results showed that the mean concentrations of As, Cd, Cu, Hg, Pb, and Zn exceeded the background levels, indicating substantial contamination. Three sources were identified using the PMF model and confirmed by spatial interpolation and MixSIAR, with contributions ranked as follows: industrial wastewater discharge and slag runoff from the smelter site (48.9 %) > natural geogenic inputs from soil parent materials (26.7 %) > atmospheric deposition of dust particles from smelting operations (24.5 %). Among the identified sources, smelter runoff posed the most significant risk, accounting for 97.9 % of the non-carcinogenic risk (NCR) and 59.9 % of the carcinogenic risk (CR). Runoff also drove NCR and CR exceedances at 7.8 % and 4.7 % of sites near the smelter, respectively. However, atmospheric deposition from smelting emissions affected soils across a larger 0.8 km radius. Although it posed lower risks, contributing just 1.1 % to NCR and 22.6 % to CR due to the limited elevation of toxic elements, deposition reached more distant soils. Spatial interpolation and distance-based regression delineated high NCR and CR exposure hotspots within 1.4 km for runoff and 0.8 km for deposition, with exponentially diminishing risks at further distances. These findings highlight the need for pathway-specific interventions that prioritize localized wastewater containment and drainage controls near the smelter while implementing broader regional air pollution mitigation measures.

Effect of fluid properties on intensification of heat transfer process in oil-water droplet flow in a T-shaped microchannel

Droplet-based microfluidics refers to the production and utilization of micrometer-sized droplets. This technology has found widespread applications in drug delivery, biotechnology, disease prevention, chemical analysis, cell research, and functional material synthesis. Cooling of high heat flux electronic systems and hot spots is another application of the droplet flow which is focused by the current work. In this paper, formation and hydrothermal performance of oil droplets in water flow in a T-junction microchannel is studied by a 3D numerical simulation. Effects of different parameters such as surface tension, wettability and heat flux on the droplet size, heat transfer rate and pressure drop are investigated. It is observed that the shear between the discrete and continuous phases results in recirculating zones in both phases which contribute to improved mixing and heat transfer rates. Liquid film thickness adjacent to the heated surface and the droplet velocity are two other factors that positively affect the heat transfer. Decreasing the surface tension is shown to enhance the heat transfer rate. Moreover, an optimum value is found for the contact angle as 135° at which a 23 % heat transfer enhancement is achieved. Results also indicate that droplet size decreases with increase of contact angle while it slightly increases with increase of the surface tension and negligibly varies with the applied heat flux.

Assessment and prediction of human-elephant conflict hotspots in the human-dominated area of Rajaji-Corbett landscape, Uttarakhand, India

Understanding the dynamics that drive human-wildlife conflict and identifying potential mitigation solutions requires understanding the spatial patterns of conflict. The juxtaposition of ecological preservation and economic growth has led to increased conflicts between humans and Asian elephants Elephas maximus in the Rajaji-Corbett landscape of Uttarakhand, India, where the conversion of elephant habitat to agricultural land have increased over the last several decades. We investigated the predictors influencing household-level human-elephant conflicts (HECs) using binomial Generalized Linear Models (GLMs) collected from semi-structured questionnaire-based surveys of 266 households in the human-wildlife interface next to protected areas. Further, we modelled the landscape predictors that influence the spatial distribution of HECs by collecting occurrence data of HECs in 25 km2 grid units (N = 1473 grids) using Maxent software. We discovered that HECs are directly influenced by the diversity of major and minor crops planted and the proximity to agricultural land (conflicts decreased with increasing distance from the agricultural land). We also observed that the probability of HECs decreased with increasing elevation, increase in road networks, and with increasing slope in the study area; while HECs increased with increase in human population. We discovered that nearly one-fifth of areas sampled (3606.87 km2) in the Rajaji-Corbett landscape were at high risk of HEC, especially flat, agrarian areas where most people reside. Farmers in the susceptible risk areas identified by our study could lessen the likelihood of crop damage and HEC incidents by cultivating highly profitable alternative crops that are less attractive to elephants. Additionally, implementing mobile-based Early Warning System in high HEC hotspot areas could mitigate crop raiding and potentially reduce the occurrence of HECs. The findings of our study can assist policymakers and park management in designing landscape-scale human-wildlife conflict mitigation strategies tailored to identified conflict hotspots.

Abstract P104: Geospatially Varying Relationships of Green and Blue Spaces With Biomarkers of Stress and Cardiometabolic Risk in Racially and Ethnically Diverse Children

Introduction: Neighborhood green (e.g., parks) and blue (e.g., lakes) spaces have been associated with reduced stress and cardiometabolic risk (CMR), but research is limited in socially vulnerable urban communities affected by structural racism and redlining. This study explored the spatial correlation between green and blue spaces and cortisol levels, BMI percentile, waist circumference (WC), pulse, and systolic (SBP) and diastolic blood (DBP) pressure in a sample of racially/ethnically diverse children. Methods: We used cross-sectional data from the Family Matters cohort study, consisting of 1307 racially/ethnically diverse families with children (age 7±1.5 yrs). Participant addresses were matched to the US 2010 Census tract attributes. We used 246 sample locations across 149 census tracts in the 7-county Twin Cities, MN, metro area. Green and blue spaces were retrieved from the Twin Cities Metropolitan Council. Hair cortisol (chronic stress biomarker), BMI, WC, pulse, SBP and DBP were objectively measured in a subsample of 246 children. We used Decision Tree and Geographically Weighted Regression (GWR) to examine the spatially varying associations of CDC’s Social Vulnerability Index (SVI) and green and blue spaces (independent variables) with biomarkers of stress and CMR (dependent variables). SVI reflects four themes: socioeconomic status, household composition and disability, racial and ethnic minority status and language, and housing type and transportation. Results: Northwest Minneapolis was identified as a hotspot for elevated cortisol, BMI, and WC, while east St. Paul was a hotspot for elevated BMI and WC. Decision trees indicated that green and blue spaces explain variation in accumulated cortisol after tract socioeconomic status and racial and ethnic minority status. GWR revealed nonuniform relationships with the highest explanatory power in high social vulnerability hotspots. GWR’s R 2 for cortisol (0.07), BMI (0.14), and WC (0.14) were driven by hotspots where local R 2 was 2-5 times stronger than areas not identified as hotspots indicating robust geographical variations in the northern areas (areas of high social vulnerability) and distance from green and blue spaces. Patterns were inconsistent for pulse, SBP, and DBP. Conclusions: The spatially varying relationships of green and blue spaces with biomarkers of stress and CMR in children were heterogeneous, possibly indicating different mechanisms across biomarkers and geographical areas. Higher cortisol levels, BMI percentile, and WC in northern Twin Cities areas may reflect the legacy of structural racism and redlining, which have resulted in inequitable use of green and blue spaces for minoritized communities. Future interventions co-developed with local communities to improve green and blue spaces’ access and use, as well as to reduce disparities in stress and CMR, are needed to advance health equity.