Niche Approach Research Articles

Gender Lens Investing: A Scoping Review from Theoretical Foundations to Public Equity Applications

This scoping review explores the dynamic field of Gender Lens Investing (GLI), examining its evolution from a niche approach to its current status as a widely recognized investment strategy with the potential to contribute to sustainable development and yield social, financial, and economic benefits. This study provides a comprehensive overview of the theoretical foundations of GLI and its practical applications across public equity markets. By conducting research across four major databases, we performed a thematic analysis that identified four principal themes: Benefits and Impacts, GLI Strategies, GLI Instruments and Innovations, and Challenges and Barriers to Implementation. Key findings reveal an increased implementation of GLI in various forms and a gradual increase in publications, reflecting growing interest within academia and industry. Despite these advancements, critical gaps remain in understanding the financial and social impacts of GLI strategies and instruments. While GLI has been broadly defined and implemented, further empirical research is necessary to evaluate the effectiveness of GLI in public equities and its long-term impacts. The limitations of this review include a focus on English-language publications, which might limit the comprehensiveness of the analysis.

The cumulative niche approach: A framework to assess the performance of ecological niche model projections.

Ecological Niche Models (ENMs) are often used to project species distributions within alien ranges and in future climatic scenarios. However, ENMs depend on species-environment equilibrium, which may be absent for actively expanding species. We present a novel framework to estimate whether species have reached environmental equilibrium in their native and alien ranges. The method is based on the estimation of niche breadth with the accumulation of species occurrences. An asymptote will indicate exhaustive knowledge of the realised niches. We demonstrate the CNA framework for 26 species of mammals, amphibians, and birds. Possible outcomes of the framework include: (1) There is enough data to quantify the native and alien realised niches, allowing us to calculate niche expansion between the native and alien ranges, also indicating that ENMs can be reliably projected to new environmental conditions. (2) The data in the native range is not adequate but an asymptote is reached in the alien realised niche, indicating low confidence in our ability to evaluate niche expansion in the alien range but high confidence in model projections to new environmental conditions within the alien range. (3) There is enough data to quantify the native realised niche, but not enough knowledge about the alien realised niche, hindering the reliability of projections beyond sampled conditions. (4) Both the native and alien ranges do not reach an asymptote, and thus few robust conclusions about the species' niche or future projections can be made. Our framework can be used to detect species' environmental equilibrium in both the native and alien ranges, to quantify changes in the realised niche during the invasion processes, and to estimate the likely accuracy of model projections to new environmental conditions.

Population genetics and ecological niche modelling provide insights into management strategies of the herbivorous pest Phytomyza horticola (Diptera: Agromyzidae)

AbstractAimResearch on population genetic patterns and potential distribution dynamics can provide insights into the development of pest management strategies. Herein, we integrated population genetic analyses with the climatic niche approach to investigate spatial population genetic variations and potential geographical distribution (PGD) of the herbivorous pest Phytomyza horticola. We also analysed its population response patterns to both late Pleistocene climatic events and future climate change.LocationChina.MethodsWe analysed the patterns of genetic diversity distribution in 29 populations from 19 regions across China using three mitochondrial (COI, COII and Cytb) genes as markers. We estimated demographic histories using neutrality tests, mismatch distributions and Bayesian skyline plots. Changes in PGD were assessed using an ecological niche model.ResultsHigh genetic diversity was found in most populations, and the northern population exhibited higher haplotype diversity. The population genetic structure included the Tibet lineage and a large lineage comprising the remaining populations. Demographic analyses indicated that rapid population expansion occurred during the cold Last Glacial Maximum. In addition, our projections suggested that P. horticola currently has a vast PGD in China, for which the human influence index was the strongest variable. Large areas of cold northern regions were highly suitable for its survival. Under future global warming, highly suitable habitats will shift towards the higher latitudes.Main conclusionsP. horticola is widely distributed across varied environments, which may be attributed to its high degree of genetic variation. Human activities likely facilitated the current PGD and the frequent gene flow that homogenized differentiation among most populations. In addition, P. horticola exhibits strong adaptability to cold climates and environments from the past to the future. Considering future climatic changes, prevention and control should focus on high‐latitude regions, and vigilance regarding human‐mediated pest dispersals and outbreaks should be maintained.

Modeling potential risk areas of Orthohantavirus transmission in Northwestern Argentina using an ecological niche approach

BackgroundHantavirus Pulmonary Syndrome (HPS) is a rodent-borne zoonosis in the Americas, with up to 50% mortality rates. In Argentina, the Northwestern endemic area presents half of the annually notified HPS cases in the country, transmitted by at least three rodent species recognized as reservoirs of Orthohantavirus. The potential distribution of reservoir species based on ecological niche models (ENM) can be a useful tool to establish risk areas for zoonotic diseases. Our main aim was to generate an Orthohantavirus risk transmission map based on ENM of the reservoir species in northwest Argentina (NWA), to compare this map with the distribution of HPS cases; and to explore the possible effect of climatic and environmental variables on the spatial variation of the infection risk.MethodsUsing the reservoir geographic occurrence data, climatic/environmental variables, and the maximum entropy method, we created models of potential geographic distribution for each reservoir in NWA. We explored the overlap of the HPS cases with the reservoir-based risk map and a deforestation map. Then, we calculated the human population at risk using a census radius layer and a comparison of the environmental variables’ latitudinal variation with the distribution of HPS risk.ResultsWe obtained a single best model for each reservoir. The temperature, rainfall, and vegetation cover contributed the most to the models. In total, 945 HPS cases were recorded, of which 97,85% were in the highest risk areas. We estimated that 18% of the NWA population was at risk and 78% of the cases occurred less than 10 km from deforestation. The highest niche overlap was between Calomys fecundus and Oligoryzomys chacoensis.ConclusionsThis study identifies potential risk areas for HPS transmission based on climatic and environmental factors that determine the distribution of the reservoirs and Orthohantavirus transmission in NWA. This can be used by public health authorities as a tool to generate preventive and control measures for HPS in NWA.

Assessing the international co-opetition dynamics of rare earth resources between China, USA, Japan and the EU: An ecological niche approach

As one of the basic raw materials for the development of strategic emerging industries, rare earth resources (RERs) are regarded as strategic critical minerals by many countries such as China, the USA, Japan and the EU. In recent years, rare earth resources have become the focus of world great power competition. However, a dynamic evolutionary trend of the co-opetition relationships between the global major economies competing for rare earth resources is still unknown in the existing literature. To this end, in this study we constructed a dynamic index system for assessing the rare earth (RE) resource co-opetition relationships between the world major countries in five dimensions, i.e., endowment of resources, scale of economy, infrastructure, trade market and technological innovation, and revealed the dynamic evolutionary trends of the co-opetition relationships between China, USA, Japan and the EU by adopting the ecological niche models using a panel dataset from 2008 to 2021. The results indicate that: (1) China, the USA, Japan and the EU have significant differences in the overall competitive advantages of rare earth resources, China's competitive advantage is obvious, followed by USA and Japan, while the EU is the weakest; (2) Among the four major economies, the competition for rare earth resources between the USA, Japan and the EU has always been fierce. The degrees of competition between China and the other three major economies are different. The most fierce competition with China is the USA, followed by Japan, and China's competition with the two countries is increasing. The competition between China and the EU is the weakest; (3) The most advantageous dimensions in the ecological niche of rare earth resources in these four countries vary greatly. Finally, we proposed corresponding policy recommendations based on these conclusions.

Potential Threat of an Invasive Fish Species for Two Native Newts Inhabiting Wetlands of Europe Vulnerable to Climate Change

In the modern world, when the problems of the environment are most acutely associated with climate change, amphibians are considered to be the most vulnerable group of anamniotes as an indicator of the state of wetlands. Along with a decrease of numbers among amphibians in Europe, nowadays newts especially suffer from the impact of invasive species, in particular predators such as the Chinese sleeper, Perccottus glenii. This predatory fish species has recently spread to areas of primary relevance for newt reproduction. This fish consumes eggs, larvae, and even adult newt individuals. Using an ecological niche approach and climate based species distribution models (SDM), we applied the coefficient of determination (R2) for comparing the level of similarity of the built SDM for the newts Triturus cristatus and Lissotriton vulgaris, and the Chinese sleeper. We show that by 2050, the level of climatic niche similarity for these native and invasive species will increase from 12% to 22% throughout Europe, and from 44% to 66% in Eastern Europe. This study highlights the expansion of the Chinese sleeper as a real threat to European biodiversity of wetlands in the near future, especially in their most northeastern distribution range.

Data completion and verification in social research projects based on the third methodological path

Purpose: The main goal of the paper is to provide an overview of possible applications of the integration of methodological approaches in research projects that aim to complete and verify data. Design/methodology/approach: The paper is methodological. Critical literature analysis was used. The range of possibilities of methodological integration was based on the achievements of Creswell & Plano Clark and Harrison & Reilly. The authors' own research experience allowed outlining the ways of data integration, both in parallel procedures of data collection, where quantitative research in the positivist trend and qualitative research in the interpretative trend were conducted separately and in sequential research, where quantitative research was first carried out, then the results were interpreted and designed, and qualitative research was carried out. The embedded approach was also illustrated, where quantitative data constituted a valuable extension and confirmation of conclusions obtained in qualitative research. Findings: Methodological analysis shows that the third path allows the accumulation of broader and deeper knowledge in research projects than using a single methodological approach. Considering various ways of integrating research approaches, the authors show that the best results in completing and verifying data are achieved using a sequential approach. Practical implications: The article is a methodological guide to the application of an integrated approach in research practice in social sciences, particularly in consumer behavior. Originality/value: The third methodological path is beyond the dominant research trend in social sciences, and in the field of consumer behavior, it is a niche approach. The possible use of this approach is the original contribution of the authors. Keywords: data completion; data verification; third methodological path; mixed methods. Category of the paper: General review.

Invader abundance and contraction of niche breadth during replacement of a native gammarid amphipod.

The introduction of non‐native species to new locations is a growing global phenomenon with major negative effects on native species and biodiversity. Such introductions potentially bring competitors into contact leading to partial or total species replacements. This creates an opportunity to study novel species interactions as they occur, with the potential to address the strength of inter‐ and intraspecific interactions, most notably competition. Such potential has often not been realized, however, due to the difficulties inherent in detecting rapid and spatially expansive species interactions under natural field conditions. The invasive amphipod crustacean Gammarus pulex has replaced a native species, Gammarus duebeni celticus, in river and lake systems across Europe. This replacement process is at least partially driven by differential parasitism, cannibalism, and intraguild predation, but the role of interspecific competition has yet to be resolved. Here, we examine how abundance of an invasive species may affect spatial niche breadth of a native congeneric species. We base our analyses of niche breadth on ordination and factor analysis of biological community and physical parameters, respectively, constituting a summative, multidimensional approach to niche breadth along environmental gradients. Results derived from biological and environmental niche criteria were consistent, although interspecific effects were stronger using the biological niche approach. We show that the niche breadth of the native species is constrained as abundance of the invader increases, but the converse effect does not occur. We conclude that the interaction between invasive G. pulex and native G. d. celticus under natural conditions is consistent with strong interspecific competition whereby a native, weaker competitor is replaced by a superior invasive competitor. This study indicates a strong role of interspecific competition, alongside other known interactions such as differential intraguild predation, in rapid and expansive species replacements following biological invasions.

First ecological assessment of the endangered Lichtenfelder’s Tiger Gecko (Goniurosaurus lichtenfelderi) from northern Vietnam: micro-habitat and macro-climatic niche comparisons between island and mainland populations

Abstract The Lichtenfelder’s Tiger Gecko, Goniurosaurus lichtenfelderi is currently known only from northern Vietnam and southern China. Because of its restricted distribution, the species is potentially threatened by extinction due to anthropogenic impacts. Recently, the species has been listed in the IUCN Red List of Threatened Species as “Vulnerable” and included in CITES Appendix II and the Vietnam Governmental Decree – Group IIB. However, conservation activities to safeguard wild populations of G. lichtenfelderi have not yet been implemented due to a lack of detailed information about the population status and its ecological requirements. In this study, the micro-habitat use of G. lichtenfelderi was assessed. As a result of our field surveys, we found this species in evergreen forest areas with a high percentage of vegetation coverage and in close proximity to medium or small stream sections with rocky shelters on granitic formations. Canopy coverage, three micro-climatic variables (air, substrate temperature and humidity), weather condition and substrate type were the most important characteristics explaining the variation in the micro-habitat use of G. lichtenfelderi. Coupled with a macro-ecological (climate niche) approach, the complex niches of G. lichtenfelderi were defined by comparing them between two geographically distant populations in island and mainland sites. We found high similarities in macro-climatic and micro-habitat niches between the island and mainland populations of G. lichtenfelderi. Based on the ecological information, we recommend conservation actions to protect the core refugia of G. lichtenfelderi and reduce negative influences of anthropogenic impacts on wild populations in the future.

Becoming a process drama practitioner: An exploratory study of higher education language teachers in Japan

Research in language learning indicates that process drama (PD), an educational approach where students and teachers work in and out of role to explore themes and issues, can be well suited to the Japanese higher education (HE) context. Despite the benefits highlighted in the literature, PD remains a niche approach to language teaching and learning, with a limited number of practitioners in Japan. This study seeks to uncover language teachers’ experiences of becoming Process Drama Practitioners (PDPs) and using and sharing PD as an English language teaching approach in Japanese HE. Data were collected via in-depth interviews with six experienced PDPs. The findings indicate that prior positive experiences with drama was an encouraging factor of the adoption and self-directed initial use of PD in their teaching practices. Positive student outcomes and feedback were primary motivators for continued use of PD. Experiences of sharing PD led to a perceived need to distinguish PD from theatre-based approaches and establish connections to familiar approaches to language teaching.

Applying niche and gratification theory approach to examine the users' indulgence towards over-the-top platforms and conventional TV

Recently, the advent of over-the-top (OTT) platforms had disrupted users’ viewing behaviour through technological advancement and personal adaptations impacting conventional TV viewing. Therefore, this study investigates the users’ indulgence level towards the OTT platforms and Conventional TV. It will also discuss how the socio-demographics of the users correlate with the seven components of the niche and gratification approach. 329 valid responses were administered utilising an online survey instrument using convenience and snowball sampling methods. Results of Multiple Hierarchical Regression reveal that all the Components of conventional TV have no significant correlation with the users’ socio-demographics. For OTT platforms, users’ family income shows a substantial correlation with the relaxation and convenience component. Except for the convenience component, the scores of niche breadth for all components of Conventional TV were found to be higher than those of OTT platforms. The competitive superiority of Conventional TV was found to be higher than OTT platforms in all the gratification components except the convenience component. Results show that the financial benefit and relaxation are the strongest niches for Conventional TV, while the convenience component exposed the strongest niche for OTT platforms. Though previous studies have focused on studying the user’s perceptions of the OTT platform’s picture quality and content specifications, this will be the first attempt to measure the indulgence of users towards OTT platforms and Conventional TV.

Important social and technical factors shaping the prospects for thermal energy storage

Thermal energy storage is likely to be integral to a sustainable, secure and affordable energy system facing ever greater challenges in matching supply and demand. Techno-economic studies have explored the potential for thermal storage deployment, but transitions in the energy system are also influenced by the activities and decisions of an array of actors. We gathered new empirical evidence from a desk-based survey on thermal energy storage in the UK and through a sociotechnical analysis explored the status and role of thermal storage in the energy transition. We find the technology remains a relatively niche approach in the UK subject to complex national and local policy and governance arrangements and the impacts of a stable fossil-based heating regime benefitting from significant lock-in effects. Whilst we acknowledge the limitations of a focus on single technology-systems to deliver the transformative energy system change required, we find thermal storage delivering both local and national benefits to support system balancing and mitigate seasonal peaks in demand, whilst having the potential to deliver other benefits. Promising innovations in business models are helping to enable thermal storage deployment, and these are also applicable to low carbon heat provision more widely.

Complementary Contribution of Wild Bumblebees and Managed Honeybee to the Pollination Niche of an Introduced Blueberry Crop.

Simple SummaryBlueberry is a crop that is increasing globally, both in terms of yield and extent, mostly thanks to the recent introduction of North American blueberry in the temperate areas of Europe, Asia, and South America. As blueberry depends largely on insects for pollination, farmers in these expansion areas face the challenge of adapting this crop to unexpected pollinator species, whose traits and features may not entirely fit the pollination needs of the introduced crop. Here we study the abundance, the behaviour, and the response to environmental conditions of different managed and wild native pollinators of blueberry in northern Spain. Our findings suggest the dominant role of native wild bumblebees and managed honeybee as suppliers of pollination service. Honeybee and bumblebees differed in both when and where they occurred, in how they responded to environmental conditions, and in how they behaved as an effective pollinator. The role of bumblebees and honeybee as blueberry pollinators thus seems complementary and additive. These results encourage the preservation of populations of native wild bees in order to ensure the effective management of introduced blueberry crops.The entomophilous pollination niche (abundance, phenotypic traits, foraging behaviours and environmental tolerances of insect pollinators) helps to understand and better manage crop pollination. We apply this niche approach to assess how an entomophilous crop (blueberry, Vaccinium ashei) can be expanded into new territories (i.e., northern Spain) far from their original area of domestication (North America). Insect visits to blueberry flowers were monitored in a plantation on 12 different days, at 8 different times during day and covering various weather conditions. Abundance, visitation rate, pollen gathering behaviour, and frequency of inter-plant and inter-row movements were recorded. The pollinator assemblage was basically composed of one managed honeybee species (50.8% of visits) and three native bumblebee species (48.3%). There was a marked pattern of seasonal segregation throughout bloom, with bumblebees dominating the early bloom and honeybee the late bloom. Pollinators also segregated along gradients of daily temperature and relative humidity. Finally, the two pollinator types differed in foraging behaviour, with bumblebees having a visitation rate double that of honeybee, collecting pollen more frequently and changing plant and row more frequently. The spatio-temporal and functional complementarity between honeybee and bumblebees suggested here encourages the consideration of an integrated crop pollination strategy for blueberries, based on the concurrence of both wild and managed bees.

Multidimensional trophic niche revealed by complementary approaches: Gut content, digestive enzymes, fatty acids and stable isotopes in Collembola.

Trophic niche differentiation may explain coexistence and shape functional roles of species. In complex natural food webs, however, trophic niche parameters depicted by single and isolated methods may simplify the multidimensional nature of consumer trophic niches, which includes feeding processes such as food choice, ingestion, digestion, assimilation and retention.Here we explore the correlation and complementarity of trophic niche parameters tackled by four complementary methodological approaches, that is, visual gut content, digestive enzyme, fatty acid and stable isotope analyses—each assessing one or few feeding processes, and demonstrate the power of method combination.Focusing on soil ecosystems, where many omnivore species with cryptic feeding habits coexist, we chose Collembola as an example. We compiled 15 key trophic niche parameters for 125 species from 40 studies. We assessed correlations among trophic niche parameters and described variation of these parameters in different Collembola species, families and across life‐forms, which represent microhabitat specialisation.Correlation between trophic niche parameters was weak in 45 out of 64 pairwise comparisons, pointing at complementarity of the four methods. Jointly, the results indicated that fungal‐ and plant‐feeding Collembola assimilate storage, rather than structural polysaccharides, and suggested bacterial feeding as a potential alternative feeding strategy. Gut content and fatty acid analyses suggested alignment between ingestion and assimilation/retention processes in fungal‐ and plant‐feeding Collembola. From the 15 trophic niche parameters, six were related to Collembola family identity, suggesting that not all trophic niche dimensions are phylogenetically structured. Only three parameters were related to the life‐forms, suggesting that species use various feeding strategies when living in the same microenvironments.Consumers can meet their nutritional needs by varying their food choices, ingestion and digestion strategies, with the connection among different feeding processes being dependent on the consumed resource and consumer adaptations. Multiple methods reveal different dimensions, together drawing a comprehensive picture of the trophic niche. Future studies applying the multidimensional trophic niche approach will allow us to trace trophic complexity and reveal niche partitioning of omnivorous species and their functional roles, especially in cryptic environments such as soils, caves, deep ocean or benthic ecosystems.

87Sr/86Sr in Archeological and Paleobiological Research: A Perspective

The stable isotope ratio 87Sr/86Sr has been shown to have extraordinary potential for documenting the movement and life-histories of humans and other animals, both in history and prehistory. Thirty years of expanding applications has taken the method from a niche (if not fringe) approach to a normal part of archeological and paleobiological enquiry; indeed a “Golden Age.” The technique is inherently interdisciplinary, because in addition to those archeologists and paleobiologists wishing to apply it, most applications require informed input from ecologists, geochemists, and calcified tissue biologists. This perspective explores how such interdisciplinarity is both a strength and an impediment to further advancement.

The niche of shrimp stocks (Xiphopenaeus kroyeri Heller, 1862) from southeastern Brazil: a stable isotope approach

The penaeid shrimp Xiphopenaeus kroyeri is the second most important species of crustacean in Brazilian fisheries. Stable isotopes of carbon and nitrogen are chemical proxies to provide quantitative information about the consumer isotopic niche, which is associated with its feeding ecology and ecological niche in the environment. This study evaluated the niche dimensions of X. kroyeri from different stocks through stable isotopes determinations. Shrimps were sampled in four fishing areas from southeastern Brazil (Vitória and Anchieta, in Espírito Santo State, and Atafona and Farol de São Tomé, in Rio de Janeiro State). The stable isotopes of carbon and nitrogen were determined in the abdominal muscle. Quantitative metrics of the isotopic niche estimated the trophic diversity and trophic redundancy among stocks. Shrimp stocks from Espírito Santo State had highest trophic diversity, indicating greater variety of food sources and wider utilization of the available food sources. The shrimps from Rio de Janeiro State had highest trophic redundancy, revealing a more homogeneous dietary pattern. The isotopic niche approach allowed the discrimination of X. kroyeri stocks distributed in southeastern Brazil, and the results will be helpful to assist fisheries management.

Update on exhaled breath condensate analyses in occupational disease.

The present work represents an update of the review published in this journal by Corradi et al., regarding the use of exhaled breath condensate (EBC) to investigate occupational lung diseases. The relevant literature was searched in the Medline database, assessed through PubMed using key terms such as 'breath AND condensate AND occupational'. Eleven pertinent publications were retrieved between January 2018 and October 2019. One article only was related to occupational allergy, and the conclusion is that EBC hydrogen peroxide is not an useful marker in laboratory animal allergy. The biomarkers of exposure most often assessed with EBC are metals. However, it is controversial whether this approach has any advantage over the conventional environmental monitoring. The biomarkers of effect studied by the majority of investigations were those related to oxidative stress. They appear consistently elevated upon occupational exposures to various agents, including welding fumes, crystalline silica, nanomaterials and chemicals. Although EBC represent a suitable tool to sample airway lining fluid in a noninvasive manner, it remains a niche approach to the investigation of occupational diseases. The confounding influence of EBC dilution should be better addressed in the expression of the results.

C$^\text{2}$TIG: Dynamic C$^\text{2}$MOS Design Based on Three-Independent-Gate Field-Effect Transistors

Dynamic logic has become a niche approach in circuit design, mainly due to the reliability limitations that have been aggravated with process down-scaling. To that extent, the performance and area benefits of dynamic design approaches, such as the integration of the Clocked CMOS (C $^{2}$ MOS) approach, are left on the table. In this article, we propose employing the Three-Independent-Gate Field-Effect Transistor (TIGFET) technology for the implementation of the C $^\text{2}$ MOS approach, which we call the Clocked Complementary TIG (C $^\text{2}$ TIG) approach. Electrical simulations at 22nm demonstrate the enhanced robustness of the C $^\text{2}$ TIG approach, while providing gains in power, performance, and area. Finally, new design opportunities for synchronous systems are demonstrated with the C $^\text{2}$ TIG approach.

Spatial Risk Distribution of Dengue Based on the Ecological Niche Model of Aedes aegypti (Diptera: Culicidae) in the Central Mexican Highlands.

Dengue is the most important viral disease transmitted by mosquitoes, predominantly Aedes (Stegomyia) aegypti (L.) (Diptera:Culicidae). Forty percent of the world's population is at risk of contracting the disease, and a large area of Mexico presents suitable environmental conditions for the life cycle of Ae. aegypti. In particular, the Central Mexican Highlands have a high population density, increasing the risk of transmission and propagation of dengue. In the present study, the potential distribution of Ae. aegypti was modeled under an ecological niche approach using the maximum entropy technique with the aim of determining the spatial risk distribution of dengue. The final model of five variables (minimum temperature of the coldest month |Bio6|, precipitation of the wettest month |Bio13|, precipitation seasonality |Bio15|, the normalized difference vegetation index (NDVI), and relative humidity) contributed to more than 90% of the model's performance. The results of the potential distribution model were then compared with the number of dengue cases per locality during the 2009-2015 period considering four suitability of presence categories. Category 4 corresponded with the highest suitability of presence (0.747 to 1) and the greatest risk of dengue (odds ratio [OR] = 103.27; P < 0.001). In conclusion, the present ecological niche model represents an important tool for the monitoring of dengue and the identification of high-risk areas.

Mapping Environmental Suitability of Scrub Typhus in Nepal Using MaxEnt and Random Forest Models.

Being a globally emerging mite-borne zoonotic disease, scrub typhus is a serious public health concern in Nepal. Mapping environmental suitability and quantifying the human population under risk of the disease is important for prevention and control efforts. In this study, we model and map the environmental suitability of scrub typhus using the ecological niche approach, machine learning modeling techniques, and report locations of scrub typhus along with several climatic, topographic, Normalized Difference Vegetation Index (NDVI), and proximity explanatory variables and estimated population under the risk of disease at a national level. Both MaxEnt and RF technique results reveal robust predictive power with test The area under curve (AUC) and true skill statistics (TSS) of above 0.8 and 0.6, respectively. Spatial prediction reveals that environmentally suitable areas of scrub typhus are widely distributed across the country particularly in the low-land Tarai and less elevated river valleys. We found that areas close to agricultural land with gentle slopes have higher suitability of scrub typhus occurrence. Despite several speculations on the association between scrub typhus and proximity to earthquake epicenters, we did not find a significant role of proximity to earthquake epicenters in the distribution of scrub typhus in Nepal. About 43% of the population living in highly suitable areas for scrub typhus are at higher risk of infection, followed by 29% living in suitable areas of moderate-risk, and about 22% living in moderately suitable areas of lower risk. These findings could be useful in selecting priority areas for surveillance and control strategies effectively.