Population Research Articles

A general multi-scale description of metastable adaptive motion across fitness valleys

We consider a stochastic individual-based model of adaptive dynamics on a finite trait graph G=(V,E)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$G=(V,E)$$\\end{document}. The evolution is driven by a linear birth rate, a density dependent logistic death rate and the possibility of mutations along the directed edges in E. We study the limit of small mutation rates for a simultaneously diverging population size. Closing the gap between Bovier et al. (Ann Appl Probab 29(6):3541–358, 2019) and Coquille et al. (Electron J Probab 26:1–37, 2021) we give a precise description of transitions between evolutionary stable conditions (ESC), where multiple mutations are needed to cross a valley in the fitness landscape. The system shows a metastable behaviour on several divergent time scales, corresponding to the widths of these fitness valleys. We develop the framework of a meta graph that is constituted of ESCs and possible metastable transitions between them. This allows for a concise description of the multi-scale jump chain arising from concatenating several jumps. Finally, for each of the various time scales, we prove the convergence of the population process to a Markov jump process visiting only ESCs of sufficiently high stability.

Evaluating the risk perception due to land subsidence within onyeama mine, South East Nigeria

This paper conducts a systematic evaluation of risk perception due to land subsidence monitored within a major coalmine in Nigeria. There is a general assumption in most hazard research that risk perception should be a first determinant of whether adaptive action is taken or not. To gain a comprehensive insight using land subsidence, we propose a technique that integrates quantitative evaluation (vulnerability assessment) and subjective evaluation (perception analysis) of human responses towards this environmental hazard. Perception of risk, which is dependent on risk magnitude appraisal and risk acceptance, was amplified into the overall risk constellation. Vulnerability assessment was conducted based on the human development index (HDI) at fourteen locations investigated for the study, with particular focus on building networks as an index for loss estimation. We exploit data from Sentinel-1 Synthetic Aperture Radar (SAR) Satellites and Small-Baseline Subset Differential Interferometric Synthetic Aperture Radar (SBAS-DInSAR) technique to map Onyeama Coal Mine in South – East, Nigeria. From the HDI and according to the vulnerability assessment, the margin of error (E) is estimated as 0.06754, with samples proportion of ρˆ= 0.85. The 95 % confidence interval for proportion is in the range of 0.783 to 0.917. The results indicates that with an average of a finite population size of N = 1413 buildings at each study location, about 85 % of the samples (n=100) do not recognize that land subsidence is ongoing and constantly affecting their buildings. As a result of this ignorance and lack of awareness, constantly progressing subsidence becomes normalized in peoples’ perceptions, and their outlook toward danger is not integrated into day-to-day habits. Thus, risk perception is a lesser determinant of mitigation responses towards slowly progressing subsidence, and not actual exposure leading to action.

Comparison of thermal cameras and human observers to estimate population density of fallow deer (Dama dama) from aerial surveys in Tasmania, Australia

Context The population of introduced fallow deer (Dama dama) is thought to have increased exponentially across much of the island of Tasmania, Australia, since 2000. Historically, deer management decisions have relied on population trend data from vehicular spotlight surveys. Renewed focus on the contemporary management of the species requires development of more robust and precise population estimation methodology. Aims This study demonstrates two aerial survey methods – conventional counts by trained human observers, and thermal imaging footage recorded during the same flights – to inform future survey practices. Methods Conventional counts were carried out by three observers, two seated on the left side of the helicopter, and one on the right. A high-resolution thermal camera was fitted to the helicopter and was orientated to meet the assumptions of distance sampling methodologies. Both survey methods were used to generate deer population density estimates. Spatial distribution of deer was also analysed in relation to patches of remnant native vegetation across an agricultural landscape. Mark–recapture distance sampling was used to estimate density from human observer counts and provide a comparison to the distance sampling estimates derived from the thermal camera. Key results Human observer counts gave a density estimate of 2.7 deer per km2, while thermal camera counts provided an estimate of 2.8 deer per km2. Deer population density estimates calculated via both methods were similar, but variability of the thermal camera estimate (coefficient of variation (CV) of 36%) was unacceptably high. Human observer data was within acceptable bounds of variability (CV, 19%). The estimated population size in central and north-eastern Tasmania for 2019 approximated 53,000 deer. Deer were primarily congregated within 200 metres of the interface between canopy cover and open pasture. Conclusions The population density estimate provides a baseline for monitoring and managing the Tasmanian deer population. Human observer data was more precise than thermal camera data in this study, but thermal counts could be improved by reducing sources of variability. Implications Improvements for the collection of thermal imagery are recommended. Future control efforts may be more efficient if they preferentially target habitat edges at this time of year, paired with random or grid-based searches where population density is lower.

Do Sex Ratio Distorting Microbes Inhibit the Evolution of Pesticide Resistance? An Experimental Test.

We are still largely reliant on pesticides for the suppression of arthropod pests which threaten human health and food production, but the recent rise of evolved resistance among important pest species has reduced pesticide efficacy. Despite this, our understanding of strategies that effectively limit the evolution of resistance remains weak. Male-killing sex ratio distorting microbes (SRDMs), such as Wolbachia and Spiroplasma, are common among arthropod species. Previous theoretical work has suggested that they could limit adaptive potential in two ways: first, because by distorting sex ratios they reduce the effective population size, and second, because infected females produce no male offspring which restricts gene flow. Here we present the results of a novel experiment in which we test the extent by which these two mechanisms limit the adaptive response of arthropods to pesticide. Using a fully factorial design, we manipulated the adult sex ratio of laboratory populations of Drosophila melanogaster, both in the presence and absence of SRDMs, and exposed these populations to six generations of pesticide poisoning. This design allows the effects of SRDMs on sex ratio and their effects on gene flow to be estimated separately. After six generations, individuals from populations with even sex ratios displayed a higher resistance to pesticide relative to individuals from female-biased populations. By contrast, we found no effect of the presence of SRDMs in host populations on pesticide resistance independent of sex ratio. In addition, males were more susceptible to pesticide than females-this was true of flies from both naïve and previously exposed populations. These findings provide the first empirical proof of concept that sex ratio distortion arising from SRDMs can limit adaptation to pesticides, but cast doubt on the theoretical effect of male-killers limiting adaptation by disrupting gene flow.

ZIP Code and ZIP Code Tabulation Area Linkage: Implications for Bias in Epidemiologic Research.

To our knowledge, no agreed-upon best practices exist for joining U.S. Census ZIP Code Tabulation Areas (ZCTAs) and U.S. Postal Service ZIP Codes (ZIPs). One-to-one linkage using 5-digit ZCTA identifiers excludes ZIPs without direct matches. "Crosswalk" linkage may match a ZCTA to multiple ZIPs, avoiding losses. We compared non-crosswalk and crosswalk linkages nationally and for mortality and health insurance in California. To elucidate selection implications, generalized additive models related sociodemographics to whether ZCTAs contained non-matching ZIPs. Nationwide, 15% of ZCTAs had non-matching ZIPs, i.e., ZIPs dropped under non-crosswalk linkage. ZCTAs with non-matching ZIPs were positively associated with metropolitan core location, lower socioeconomics, and non-white population. In California, 34% of ZIPs in the mortality and 25% in the health insurance data had ZCTAs with non-matching ZIPs; however, these ZIPs constitute only 0.03% of total mortality and 0.44% of total insurance enrollees. Our study findings support the use of crosswalk linkages and ZCTAs as a unit of analysis. One-to-one linkage may cause bias by differentially excluding ZIPs with more disadvantaged populations, although affected population sizes appear small.

Zingiber baumii Chatan & Promprom: A New Species of Zingiberaceae From Thailand.

Zingiber baumii Chatan & Promprom, a new species from the Zingiberaceae family, is described from Sakon Nakhon Province in northeastern Thailand. This species was identified during field expeditions conducted between 2018 and 2024 in Phu Pha Yol National Park. The morphological characteristics of Z. baumii, such as red or pinkish-red leaf sheaths, leaf blades (1.5-) 2.0-3.0 cm wide, pink petioles, and bright yellow corolla with a red patch, distinguish it from closely related species such as Z. isanense Triboun & K. Larsen. Zingiber baumii grows in slightly shaded dry dipterocarp forests at elevations of 300-380 m. The preliminary conservation assessment indicates that this species should be classified as Endangered (EN) according to IUCN criteria due to its limited distribution and small population size. Detailed morphological comparisons with related species are provided, along with illustrations and habitat descriptions.

Hybridization and inbreeding affect the survival of a critically endangered coral.

Coral reefs face escalating pressures leading to unprecedented declines in the populations of reef-building corals.1,2 Conservation genomic studies are critical in understanding and formulating interventions to reverse such declines but thus far have only focused on a handful of broadcast-spawning species in shallow waters.3,4 The recent International Union for Conservation of Nature (IUCN) reclassification of six different brooding corals as "critically endangered"5 indicates that such species are equally threatened. However, we lack a thorough understanding of the factors underlying their decline. Here, we comprehensively examine the genetic impacts of a severe population decline in the brooding coral Helioseris cucullata, once a major contributor to Caribbean reefs but now critically endangered.6,7,8 Genome-wide sequencing of colonies across five locations revealed the presence of two distinct species, indicating that the remaining population sizes are even smaller than previously estimated. Using an exhaustive, spatially explicit sampling approach (across a total of ∼2.5 hectares), we observed extremely low genetic diversity and identified how localized dispersal, excessive inbreeding, and prevalent asexual reproduction may contribute to an extinction vortex. However, we also found evidence for recent hybridization and introgression, providing an avenue for the reintroduction of genetic diversity into both lineages. With many brooding species now under threat, these results highlight the critical need to assess the genetic processes associated with their declines so that these can be harnessed or mitigated to deliver effective conservation outcomes.

Genetic diversity and molecular evolution of the internal transcribed spacer regions (ITS1–5.8S-ITS2) of Babesia vogeli

Canine babesiosis, a severe haemoparasitic disease caused by Babesia species, has a significant global presence and can be fatal if left untreated. The current study was aimed to perform the population genetic characterization of B. vogeli on the basis of the internal transcribed spacer regions (ITS1–5.8S-ITS2). A maximum likelihood tree constructed with the Hasegawa-Kishino-Yano model grouped all sequences into a single major clade (BvG1), with the exception of a Taiwanese isolate (EF186914), which branched separately. This Taiwanese isolate represented a novel genotype (BvG2) identified in the present study. Nucleotide sequences (n = 62) exhibited 92.5–100 % nucleotide identity among themselves. However, the BvG1 and BvG2 genotypes shared a lower identity of 92.5–93.8 % between them. Notably, the newly generated Indian sequences (n = 21) demonstrated a high degree of homology, with 98.3–100 % identity. Alignment of the nucleotide sequences revealed 58 variations across the dataset. Additionally, 32 sites exhibited variation within the BvG1 genotype, while 56 sites differed between BvG1 and BvG2 genotypes. Within different B. vogeli populations, the nucleotide diversity (π) was low, but the haplotype diversity (Hd) was high. The haplotype diversity of the Indian population, BvG1 genotype and the combined dataset was ~0.8 suggesting a high haplotype diversity. The median-joining haplotype network displayed a total of 21 haplotypes, out of which six haplotypes consisted of more than one sequence (2–25 sequences). Haplotype distribution showed significant geographical structuring, with most haplotypes confined to a single country. Only two haplotypes (9.52 %; Hap_1 and Hap_4) were shared between countries, whereas 19 haplotypes (90.48 %) were country-specific. Hap_1, Hap_6, and Hap_4 were the most representative haplotypes, comprising 25, 10, and four sequences, respectively. India exhibited the highest number of haplotypes (h = 13) followed by China (h = 4), the United States of America (h = 3), Taiwan and Tunisia (h = 2), and Thailand (h = 1). Both location-wise and genotype-wise median joining haplotype networks clustered the haplotypes in two groups, representing two distinct genotypes (BvG1 and BvG2). The B. vogeli populations between Thailand and Tunisia exhibited the highest genetic differentiation (FST = 0.80) with a low gene flow (Nm = 0.125) between them. Results of AMOVA revealed a higher genetic variation within populations (69.43 %) as compared to the variation between them (30.57 %). Neutrality indices and the mismatch distributions of the Indian population and the overall dataset of B. vogeli indicated a constant population size to population expansion and population expansion, respectively, with the presence of two distinct genotypes. These data provide information about parasite population genetics and highlight the importance of starting a long-term molecular surveillance program. In conclusion, a high genetic diversity along with the presence of two distinct genotypes of B. vogeli were observed on the basis of internal transcribed spacer regions (ITS1–5.8S-ITS2).

The Effects of Egg- and Substrate-Associated Microbiota on the Larval Performance of the Housefly, Musca domestica.

Increasing human population size and income growth are causing an increasing demand for food and feed. Insects are a more sustainable alternative to conventional animal source proteins, as they can convert waste and by-products from the agricultural industry into biomass for commercial feed for livestock and, potentially, serve as a food source for human consumption. Moreover, insects together with their microorganisms have been shown to play a pivotal role in the development of insects and in the breakdown of complex growth substrates, and are, therefore, closely tied to insect production. This study aims to determine if the removal of egg- and substrate-associated microorganisms impacts larval performance (growth, final biomass, and the survival rate) of M. domestica Linnaeus. Four treatments are tested: disinfected eggs and non-autoclaved substrate, non-disinfected eggs and autoclaved substrate, disinfected eggs and autoclaved substrate, and a control without any removal of microbiota. The results show a significant decrease in the final biomass of larvae subjected to the treatments with only disinfected eggs, only autoclaved substrate, and both compared to the control, and a significant decrease in survival rate for non-disinfected eggs and autoclaved substrate and disinfected eggs and autoclaved substrate compared to the control group. Moreover, larval growth shows a significant difference across days within all treatments. Together, this suggests that the microorganisms of housefly eggs and the growth substrate play an important role in biomass, which is critical in commercial insect production. Together this suggest, that more studies are needed to examine these parameters with respect to more commercially relevant substrates.

Genetic diversity and population structure of superior shea trees (Vitellaria paradoxa subsp. paradoxa) using SNP markers for the establishment of a core collection in Côte d'Ivoire.

The shea tree is a well-known carbon sink in Africa that requires a sustainable conservation of its gene pool. However, the genetic structure of its population is not well studied, especially in Côte d'Ivoire. In this study, 333 superior shea tree genotypes conserved in situ in Côte d'Ivoire were collected and genotyped with the aim of investigating its genetic diversity and population structure to facilitate suitable conservation and support future breeding efforts to adapt to climate change effects. A total of 7,559 filtered high-quality single nucleotide polymorphisms (SNPs) were identified using the genotyping by sequencing technology. The gene diversity (HE) ranged between 0.1 to 0.5 with an average of 0.26, while the polymorphism information content (PIC) value ranged between 0.1 to 0.5 with an average of 0.24, indicating a moderate genetic diversity among the studied genotypes. The population structure model classified the 333 genotypes into three genetic groups (GP1, GP2, and GP3). GP1 contained shea trees that mainly originated from the Poro, Tchologo, and Hambol districts, while GP2 and GP3 contained shea trees collected from the Bagoué district. Analysis of molecular variance (AMOVA) identified 55% variance within populations and 45% variance within individuals, indicating a very low genetic differentiation (or very high gene exchange) between these three groups (FST = 0.004, gene flow Nm = 59.02). Morphologically, GP1 displayed spreading tree growth habit, oval nut shape, higher mean nut weight (10.62g), wide leaf (limb width = 4.63cm), and small trunk size (trunk circumference = 133.4cm). Meanwhile, GP2 and GP3 showed similar morphological characteristics: erect and spreading tree growth habit, ovoid nut shape, lower mean nut weight (GP2: 8.89g; GP3: 8.36g), thin leaf (limb width = 4.45cm), and large trunk size ( GP2: 160.5cm, GP3: 149.1cm). A core set of 100 superior shea trees, representing 30% of the original population size and including individuals from all four study districts, was proposed using the "maximum length sub-tree function" in DARwin v. 6.0.21. These findings provide new knowledge of the genetic diversity and population structure of Ivorian shea tree genetic resources for the design of effective collection and conservation strategies for the efficient use of inbreeding.

Immediate Genetic Augmentation and Enhanced Habitat Connectivity Are Required to Secure the Future of an Iconic Endangered Freshwater Fish Population.

Genetic diversity is rapidly lost from small, isolated populations by genetic drift. Measuring the level of genetic drift using effective population size (N e) is highly useful for management. Single-cohort genetic N e estimators approximate the number of breeders in one season (N b): a value < 100 signals likely inbreeding depression. Per-generation N e < 1000 estimated from multiple cohort signals reduced adaptive potential. Natural populations rarely meet assumptions of N e-estimation, so interpreting estimates is challenging. Macquarie perch is an endangered Australian freshwater fish threatened by severely reduced range, habitat loss, and fragmentation. To counteract low N e, augmented gene flow is being implemented in several populations. In the Murrumbidgee River, unknown effects of water management on among-site connectivity impede the design of effective interventions. Using DArT SNPs for 328 Murrumbidgee individuals sampled across several sites and years with different flow conditions, we assessed population structure, site isolation, heterozygosity, inbreeding, and N e. We tested for inbreeding depression, assessed genetic diversity and dispersal, and evaluated whether individuals translocated from Cataract Reservoir to the Murrumbidgee River bred, and interbred with local fish. We found strong genetic structure, indicating complete or partial isolation of river fragments. This structure violates assumptions of N e estimation, resulting in strongly downwardly biased N b estimates unless assessed per-site, highlighting the necessity to account for population structure while estimating N e. Inbreeding depression was not detected, but with low N b at each site, inbreeding and inbreeding depression are likely. These results flagged the necessity to address within-river population connectivity through flow management and genetic mixing through translocations among sites and from other populations. Three detected genetically diverse offspring of a translocated Cataract fish and a local parent indicated that genetic mixing is in progress. Including admixed individuals in estimates yielded lower N e but higher heterozygosity, suggesting heterozygosity is a preferable indicator of genetic augmentation.

Characterising the Genomic Landscape of Differentiation Between Annual and Perennial Rye.

Annuality and perenniality represent two different life-history strategies in plants, and an analysis of genomic differentiation between closely related species of different life histories bears the potential to identify the underlying targets of selection. Additionally, understanding the interactions between patterns of recombination and signatures of natural selection is a central aim in evolutionary biology, because patterns of recombination shape the evolution of genomes by affecting the efficacy of selection. Here, our aim was to characterise the landscape of genomic differentiation between weedy annual rye (Secale cereale L.) and wild perennial rye (Secale strictum C. Presl), and explore the extent to which signatures of selection are influenced by recombination rate variation. We used population-level sequence data of annual and perennial rye to analyse population structure and their demographic history. Based on our analyses, annual and perennial rye diverged approximately 26,500 years ago (ya) from an ancestral population size of ~85,000 individuals. We analysed patterns of genetic diversity and genetic differentiation, and found highly differentiated regions located in low-recombination regions, indicative of linked selection. Although all highly differentiated regions, as revealed by F ST-outlier scans, were located in low-recombining regions, not all chromosomes showed this tendency. We therefore performed a gene ontology enrichment analysis, which showed that highly differentiated regions comprise genes involved in photosynthesis. This enrichment was confirmed when F ST outlier scans were performed separately in low- and intermediate-recombining regions, but not in high-recombining regions, suggesting that local recombination rate variation in rye affects outlier scans. Cultivated rye is an annual crop, but the introduction of perenniality may be advantageous in regions with poor soil quality or under low-input farming. Although the resolution of our analysis is limited to a broad-scale, knowledge about the evolutionary divergence between annual and perennial rye might support breeding efforts towards perennial rye cultivation.

Reconciling Top‐Down and Bottom‐Up Estimates of Ecosystem Respiration in a Mature Eucalypt Forest

AbstractEcosystem respiration (Reco) arises from interacting autotrophic and heterotrophic processes constrained by distinct drivers. Here, we evaluated up‐scaling of observed components of Reco in a mature eucalypt forest in southeast Australia and assessed whether a land surface model adequately represented all the fluxes and their seasonal temperature responses. We measured respiration from soil (Rsoil), heterotrophic soil microbes (Rh), roots (Rroot), and stems (Rstem) in 2018–2019. Reco and its components were simulated using the CABLE–POP (Community Atmosphere‐Biosphere Land Exchange–Population Orders Physiology) land surface model, constrained by eddy covariance and chamber measurements and enabled with a newly implemented Dual Arrhenius and Michaelis‐Menten (DAMM) module for soil organic matter decomposition. Eddy‐covariance based Reco (Reco.eddy, 1,439 g C m−2 y−1) was slightly higher than the sum of the respiration components (Reco.sum, 1,295 g C m−2 y−1) and simulated Reco (1,297 g C m−2 y−1). The largest mean contribution to Reco was from Rsoil (64%) across seasons. The measured contributions of Rh (49%), Rroot (15%), and Rstem (22%) to Reco.sum were very close to model outputs of 46%, 11%, and 22%, respectively. The modeled Rh was highly correlated with measured Rh (R2 = 0.66, RMSE = 0.61), empirically validating the DAMM module. The apparent temperature sensitivities (Q10) of Reco were 2.22 for Reco.sum, 2.15 for Reco.eddy, and 1.57 for CABLE‐POP. This research demonstrated that bottom‐up respiration component measurements can be successfully scaled to eddy covariance‐based Reco and help to better constrain the magnitude of individual respiration components as well as their temperature sensitivities in land surface models.

Evaluating the Impact of Chinese FDI in the Energy Sector on Green GDP Growth: A Spatial Econometric Analysis of MENA Countries

This study analyzes the impact of Chinese foreign direct investment (FDI) in the energy sector on the green GDP (GGDP) growth of seven Middle East and North Africa (MENA) countries based on data from 2009 to 2019. Using panel regression analysis, the study focuses on the effects of FDI, economic development level, population size, energy consumption structure, environmental regulation intensity, government fiscal expenditure, and the KOF Economic Globalization Index on GGDP growth. By comparing fixed-effects and random-effects models and applying the Hausman test to select the most appropriate model, the research indicates that the random-effects model is the most suitable. The results show that FDI, economic development level, and population size have significant positive effects on GGDP, while shifts in energy consumption structure also promote sustainable economic growth. In contrast, environmental regulation intensity and the globalization index have no significant impact on GGDP, suggesting that GGDP growth in MENA countries relies more on internal economic policies and the efficiency of resource allocation.

Resequencing reveals population structure and genetic diversity in Tibetan sheep

BackgroundThe Tibetan sheep is one of the three major primitive sheep breeds in China, representing a unique and high-quality genetic resource in the Qinghai-Tibet Plateau and neighboring high-altitude regions, exhibiting exceptional adaptability to high-altitude climatic environments. However, research on the genetic relationships among different populations of Tibetan sheep at the whole-genome level remains insufficient. This study aims to explore the population structure and historical dynamics among 11 Tibetan sheep populations, accurately assess the genetic diversity within the populations, and providing a theoretical basis for the development of targeted genetic breeding strategies for Tibetan sheep.ResultsIn this study, a total of 10,884,454 high-quality SNPs were obtained. All Tibetan sheep populations exhibited varying degrees of linkage disequilibrium, with similar decay rates; among them, the WT population showed the fastest decay, while the TS population exhibited the slowest decay rate. Analyses using Tajima’s D and π indicated that the genetic diversity levels of the Tibetan sheep populations are generally low. Fst results revealed that most populations exhibited moderate to low levels of genetic differentiation. The effective population size among Tibetan sheep populations showed an increasing trend over time. The evolutionary relationships among Tibetan sheep populations reflect the correlation between their geographical locations and genomic genetic distances, while also indirectly confirming the impact of historical activities such as early human migration, admixture, fusion, and expansion on the population sizes and distributions of Tibetan sheep.ConclusionsThe results indicate that the genetic diversity levels and genetic differentiation among Tibetan sheep populations are relatively low. In this study, we identified the genetic characteristics of Tibetan sheep populations, which exhibit low levels of diversity, genetic differentiation, and a strong population structure. A deeper genomic exploration of the population structure and diversity status of Tibetan sheep populations will provide theoretical support for subsequent genetic breeding and diversity conservation efforts.

Geopolitical Aspects of Demographic Processes: Development of Scientific Ideas of L. L. Rybakovsky

Demographic processes play a key role in the formation of the geopolitical picture of the world. Population size, its age structure, growth rates and migration flows have a significant impact on the economic power of states, their military potential and their ability to project power in the international arena. This article examines contemporary and historical views on the significance of demographic factors in the geopolitical competition of countries and the measurement of a state's national power. The study covers both contemporary and historical aspects of the issue. The paper provides a systematic review of the evolution of scientific views on the significance of demographic factors in the geopolitical context. Particular attention is paid to modern methodological approaches to measuring the national power of a state considering demographic indicators. The article offers a critical analysis of existing models for assessing geopolitical influence based on demographic factors and considers their applicability in the context of global demographic transformations. The study also addresses topical issues of the impact of demographic trends on the geopolitical strategies of states in the 21st century, including the problems of population aging, migration processes and demographic imbalances between developed and developing countries. Special attention is paid to the analysis of geopolitical aspects of demographic processes in the works of the outstanding Russian demographer L.L.Rybakovsky. The paper considers the key concepts of the scientist, including demographic security, the geopolitical significance of migration processes, the relationship between demography and spatial development of Russia, as well as the role of demographic policy as an instrument of geopolitical influence.

Willingness to Pay for Solid Waste Collection in Bo District, Southern Sierra Leone: An Analysis of Influencing Factors

This study assesses the willingness to pay for solid waste management services in Bo District, Southern Sierra Leone. The research aims to identify the key factors influencing this willingness. Five semi-urban communities were selected based on their population size, and 60 household heads from randomly selected households were interviewed using a semi-structured questionnaire. Using logistic regression analysis, we found that factors such as income, education, occupation, and satisfaction with the current waste management system had varying degrees of significance in influencing willingness to pay. However, variables such as mode of waste collection and age were found to have a significant effect. This study suggests that policymakers in Bo District should consider these factors when implementing fee-based waste collection services.

Assessing the Effects of Chinese Foreign Direct Investment on Green GDP Development in North and South American Regions

This study aims to investigate the impact of foreign direct investment (FDI) on the growth of green GDP (GGDP) in North America and South America. The research is based on a comprehensive dataset covering the period from 2009 to 2019, drawn from multiple countries. By employing a two-way fixed-effects model, the study analyzes the effects of key factors, including FDI, trade openness, economic development level, urbanization level, population size, and industrial structure on GGDP growth.The findings indicate that, in North America, both FDI and the level of economic development exert a significant positive influence on GGDP growth, whereas trade openness demonstrates a negative impact, suggesting that increased trade activities may exacerbate environmental pressures. In South America, while the level of economic development shows a significant positive correlation with GGDP, the effect of FDI is not statistically significant. The study recommends that policymakers focus on enhancing the effectiveness of foreign investment and implement stricter environmental protection policies to ensure that trade activities do not adversely affect the environment. Furthermore, there is an urgent need to adjust the current industrial structure to promote a transition toward more sustainable development models. Ultimately, this research emphasizes the importance of ensuring environmental sustainability while fostering foreign investment and economic growth to achieve long-term growth in green GDP.

Telemedicine and outcome in patient care: Review

Telemedicine is a term given to the use of electronic and telecommunication methods in patient’s healthcare. Presently it is being used for diagnostic, treatment and research purposes. Since the recent pandemic telemedicine has become more transformative and has enhanced patient’s access to different medical settings across the globe, this review will evaluate the role of telemedicine in improving patient outcomes. The management of chronic diseases in areas of the world where specialty medical services are not easily accessible has been evaluated along with the patient's involvement and use of modern and state-of-the-art technologies. The overall findings indicate that telemedicine has improved the patient's ability to actively participate in their health management, with more compliance toward the management of the medical problem and fewer OPD visits. On the other hand, it encourages fewer doctor and paramedical staff requirements for a particular population size and the limited role of physical examination of the patient.

Ocean conditions influence the quality of recruiting benthic marine invertebrate larvae—Insights from fatty acids

AbstractMany marine benthic invertebrates have a pelagic life stage, during which larvae need to accumulate enough reserves to complete metamorphosis to a settled benthic juvenile. Currently, very little is known about how ocean conditions affect quality of the larvae. We studied this for three settlement seasons (2017–2019) by collecting returning Dungeness crab (Metacarcinus magister) megalopae at the Oregon coast and analyzing them for fatty acid biomarkers. We found that the larvae are omnivorous and have versatile diets. The daily larval abundance was positively correlated with larval quality. Despite the relatively high day‐to‐day variation, we found pronounced seasonal and inter‐annual differences in the body condition (size and total fatty acid content) and biomarker composition of megalopae. Especially, the early season recruits of 2017 had lower content of lipids and polyunsaturated fatty acids known to be beneficial to crustaceans. This is likely related to lingering effects of the eastern Pacific marine heat wave (2014–2016) on pelagic communities. The larvae were rich in docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) with lower levels in benthic juveniles, indicating an ontogenetic diet shift and likely lower availability of DHA and EPA in the benthic environment. The pulsed megalopa recruitment may provide substantial carbon and lipid inputs to the nearshore ecosystem as a form of pelagic subsidy. Our results reveal that ocean conditions may have an effect on the quality of returning larvae, which likely influence their recruitment performance and early juvenile success, and thus potentially also the population size and commercial catch 4 yr later.