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Stochastic population models with mild catastrophes have gained much attention in recent years due to their wide application in a variety of areas including computer-communications systems. This article considers a population model in which both the arrival process of individuals and catastrophes occur as per the Markovian arrival process (MAP) and are independent of each other. The killing mechanism takes place according to the binomial distribution. The steady-state analysis of the model is carried out using the vector generating function approach and the population size distributions at an arbitrary, post-catastrophe, and pre-arrival epochs are presented in terms of the roots of the characteristic equation. Several performance measures of the system are studied in detail, and the impact of critical parameters is duly investigated. [ABSTRACT FROM AUTHOR]

Aims: Advanced chronic liver disease and advanced chronic liver disease‐related ascites have a high mortality. The pharmacological treatment of ascites and fluid overload has changed little over time. Empagliflozin, a sodium‐glucose cotransporter type 2 inhibitor is an untested potential novel treatment in cirrhosis, as it has survival benefits in heart failure, which has similar pathophysiological fluid overload mechanisms. Before investigating empagliflozin's potential benefit in cirrhosis, its safety must be addressed. Methods: Ten participants (five each with compensated or decompensated advanced chronic liver disease, based on Child–Pugh class) received empagliflozin 10 mg orally daily for 4 weeks with 2 weeks follow‐up. Empagliflozin safety, pharmacokinetics and pharmacodynamics were investigated. Results: In total, eight patients (80%) reported an adverse event, and three patients (30%) experienced a serious adverse event, one of which was attributed to empagliflozin. Overall, the frequency of adverse events was similar to previous phase 3 trials of gliflozins. Higher plasma empagliflozin concentrations did not significantly increase the risk of adverse events. Conclusions: Four‐week treatment with empagliflozin was safe and well tolerated in patients with advanced chronic liver disease. These preliminary data support assessment of long‐term treatment on disease‐related and mortality outcomes in patients with cirrhosis through randomized control trials. [ABSTRACT FROM AUTHOR]

Due to their dependence on environmental temperatures, ectothermic animals are likely to be particularly sensitive to global climate change. Accurate prediction of ectotherm population responses to climate change requires a mechanistic understanding of effects of increased temperatures on survival and reproduction. Yet, despite organismal development through distinct life stages that may differ in sensitivity to temperature, most studies measure effects on a single life stage. Using a combination of greenhouse and field experiments, including a large restoration experiment, we measured the effects of temperature increases on all annual life stages in a multivoltine butterfly. We then used the vital rate – temperature relationships to develop a population model parameterized with (1) increased temperatures relative to observed field temperatures and (2) downscaled global climate model data. Our goal was to model population dynamics under future climate change in order to understand what temperature variables have the strongest effects on vital rates, which life stages is population growth most sensitive to under increased temperatures, and how projected warming will affect future growth rates. We found that maximum temperature over each life stage time period was the most important temperature variable explaining changes in vital rates with temperature. Population growth rates dropped below one (shrank) at temperature increases of 1.5 °C. Our population model projected that annual growth rates will go from growing to shrinking during the 2060s at latest under the RCP 8.5 scenario. Our findings demonstrate the need for conservation strategies for ectotherms that target specific vulnerable life stages and consider differing effects of climate variables. [ABSTRACT FROM AUTHOR]

Bycatch is one of the leading threats facing aquatic organisms, worldwide. Pesticide bycatch can occur when nontarget species are incidentally killed during chemical application targeting noxious species. The common mudpuppy (Necturus maculosus) is a river‐dwelling salamander that is susceptible to bycatch from 3‐trifluoromethyl‐4‐nitrophenol (TFM) applications. However, the long‐term consequences of TFM bycatch on mudpuppy populations are not well understood. We used population viability analysis to reveal potential impacts of TFM application on a mudpuppy population in Ohio's Grand River under plausible bycatch scenarios. We found that the population was more sensitive to increased juvenile mortality and rapid declines occurred when both adults and juveniles were impacted at high bycatch rates (≥5% of the population) or more frequent TFM intervals (≥5 years). Our results suggest that continued use of TFM could pose a risk to mudpuppy population persistence if bycatch occurs at moderate to high levels and affects both juveniles and adults. Future TFM use and management decisions should be directed with these potential nontarget impacts in mind. [ABSTRACT FROM AUTHOR]

Recovery of endangered species is challenging and lengthy, especially when it involves reintroduction and dynamic environmental conditions. Because managers often need to decide between many management strategies with uncertain outcomes, periodically assessing progress toward recovery using population viability analysis (PVA) can help guide decision‐making. We developed a PVA for the critically endangered Puerto Rican parrot (Amazona vittata) to evaluate current status and potential future management strategies to reach goals set in the Recovery Plan. Having grown from their nadir of 13 birds in 1976 to 686 in 2021, the recovery effort has made great progress. Using 15 years of data, we built an individual‐based PVA that included interactions between two captive and three wild populations connected via annual releases. If management continues as planned, the wild populations have no to moderate risks of extinction (0–32%) over the next 100 years. However, wild populations remain dependent on releases to sustain growth, and recovery targets for stable population growth and connectivity have not yet been reached. Our analysis suggests that hurricanes are an impediment to reaching recovery targets and impact some wild populations more than others based on geography. Projections with climate‐change‐induced higher hurricane impact resulted in wild populations being less likely to stabilize. We identified demographic rates and associated management strategies that could positively impact wild populations: increasing reproduction (e.g., via increasing artificial nests, improving nest success) and decreasing first‐year mortality (e.g., via targeted predator control). Based on our current understanding of Puerto Rican parrot demographics, species recovery will continue to be management‐dependent unless demographic rates can be altered. As more data are gathered, especially for data‐sparse populations and in the face of environmental change, future iterations of this model can re‐evaluate progress, update management strategies, and provide support for deciding if and when to delist this iconic species. [ABSTRACT FROM AUTHOR]

Since the first autochthonous transmission of West Nile Virus was detected in Germany (WNV) in 2018, it has become endemic in several parts of the country and is continuing to spread due to the attainment of a suitable environment for vector occurrence and pathogen transmission. Increasing temperature associated with a changing climate has been identified as a potential driver of mosquito-borne disease in temperate regions. This scenario justifies the need for the development of a spatially and temporarily explicit model that describes the dynamics of WNV transmission in Germany. In this study, we developed a process-based mechanistic epidemic model driven by environmental and epidemiological data. Functional traits of mosquitoes and birds of interest were used to parameterize our compartmental model appropriately. Air temperature, precipitation, and relative humidity were the key climatic forcings used to replicate the fundamental niche responsible for supporting mosquito population and infection transmission risks in the study area. An inverse calibration method was used to optimize our parameter selection. Our model was able to generate spatially and temporally explicit basic reproductive number (R0) maps showing dynamics of the WNV occurrences across Germany, which was strongly associated with the deviation from daily means of climatic forcings, signaling the impact of a changing climate in vector-borne disease dynamics. Epidemiological data for human infections sourced from Robert Koch Institute and animal cases collected from the Animal Diseases Information System (TSIS) of the Friedrich-Loeffler-Institute were used to validate model-simulated transmission rates. From our results, it was evident that West Nile Virus is likely to spread towards the western parts of Germany with the rapid attainment of environmental suitability for vector mosquitoes and amplifying host birds, especially short-distance migratory birds. Locations with high risk of WNV outbreak (Baden-Württemberg, Bavaria, Berlin, Brandenburg, Hamburg, North Rhine-Westphalia, Rhineland-Palatinate, Saarland, Saxony-Anhalt and Saxony) were shown on R0 maps. This study presents a path for developing an early warning system for vector-borne diseases driven by climate change. [ABSTRACT FROM AUTHOR]

This paper studies the steady states to a diffusive Lotka–Volterra cooperative model with population flux by attractive transition. The first result gives many bifurcation points on the branch of the positive constant solution under the weak cooperative condition. The second result shows every steady state approaches a solution of the scalar field equation as the coefficients of the flux tend to infinity. Indeed, the numerical simulation using pde2path exhibits the global bifurcation branch of the cooperative model with large population flux is near that of the scalar field equation. [ABSTRACT FROM AUTHOR]

Population models can be a useful tool for ecological risk assessment to increase ecological realism. In the present study, population models were used to extrapolate toxicity test results of four metals (Ag, Cu, Ni, Zn) to the population level. In total, three primary producers, five invertebrate species, and five fish species were covered. The ecological modeling–based laboratory to population effect extrapolation factor (ECOPEX factor), defined as the ratio of the predicted 10% effect concentration (EC10) at the population level and the observed EC10 for the laboratory toxicity test, ranged from 0.7 to 78.6, with a median of 2.8 (n = 27). Population modeling indicated clearly higher effect concentrations in most of the cases (ECOPEX factor >2 in 14 out of 27 cases), but in some cases the opposite was observed (in three out of 27 cases). We identified five main contributors to the variability in ECOPEX factors: (1) uncertainty about the toxicity model, (2) uncertainty about the toxicity mechanism of the metal, (3) uncertainty caused by test design, (4) impact of environmental factors, and (5) impact of population endpoint chosen. Part of the uncertainty results from a lack of proper calibration data. Nonetheless, extrapolation with population models typically reduced the variability in EC10 values between tests. To explore the applicability of population models in a regulatory context, we included population extrapolations in a species sensitivity distribution for Cu, which increased the hazardous concentration for 5% of species by a factor 1.5 to 2. Furthermore, we applied a fish population model in a hypothetical Water Framework Directive case using monitored Zn concentrations. This article includes recommendations for further use of population models in (metal) risk assessment. Environ Toxicol Chem 2024;43:2308–2328. © 2024 SETAC [ABSTRACT FROM AUTHOR]

Ecosystems worldwide are increasingly being invaded by multiple species, and the rate of biological invasion is accelerating, leading to more interactions among invasive species. One such interaction that has received little attention is the phenomenon of 'serial replacement' or 'over-invasion', where an established invasive species is supplanted by a second invasive species. Understanding this interaction is important as controlling the second species could inadvertently lead to an increase in the abundance of the first species. We used a hierarchical state-space model to analyse changes in annual abundances (commercial catch-per-unit-effort) of three invasive fish species, tench (Tinca tinca), common carp (Cyprinus carpio) and redfin perch (Perca fluviatilis), in the Murray-Darling River system (MDRS), Australia between 1954–2002. Tench were present at low abundances until the mid-1970 s, before declining to the point of no commercial catch post-1989. This rapid decline coincided with a significant increase in carp abundance, suggesting that carp may have driven the tench decline through habitat modification (particularly the destruction of aquatic plants), consistent with findings from European studies that show the disappearance of tench from ponds with intensive carp farming. Redfin perch populations, were inferred to be much less impacted by the invading carp population. While carp were present in the MDRS for the duration of the study, the rapid increase in carp abundance in the early 1970 s coincided with the introduction of a specific genetic lineage—the "Boolarra strain". Our analysis provides compelling evidence of serial replacement of long-established tench by invading common carp triggered by the introduction of a novel carp strain. [ABSTRACT FROM AUTHOR]

Abstract Since the first autochthonous transmission of West Nile Virus was detected in Germany (WNV) in 2018, it has become endemic in several parts of the country and is continuing to spread due to the attainment of a suitable environment for vector occurrence and pathogen transmission. Increasing temperature associated with a changing climate has been identified as a potential driver of mosquito-borne disease in temperate regions. This scenario justifies the need for the development of a spatially and temporarily explicit model that describes the dynamics of WNV transmission in Germany. In this study, we developed a process-based mechanistic epidemic model driven by environmental and epidemiological data. Functional traits of mosquitoes and birds of interest were used to parameterize our compartmental model appropriately. Air temperature, precipitation, and relative humidity were the key climatic forcings used to replicate the fundamental niche responsible for supporting mosquito population and infection transmission risks in the study area. An inverse calibration method was used to optimize our parameter selection. Our model was able to generate spatially and temporally explicit basic reproductive number (R0) maps showing dynamics of the WNV occurrences across Germany, which was strongly associated with the deviation from daily means of climatic forcings, signaling the impact of a changing climate in vector-borne disease dynamics. Epidemiological data for human infections sourced from Robert Koch Institute and animal cases collected from the Animal Diseases Information System (TSIS) of the Friedrich-Loeffler-Institute were used to validate model-simulated transmission rates. From our results, it was evident that West Nile Virus is likely to spread towards the western parts of Germany with the rapid attainment of environmental suitability for vector mosquitoes and amplifying host birds, especially short-distance migratory birds. Locations with high risk of WNV outbreak (Baden-Württemberg, Bavaria, Berlin, Brandenburg, Hamburg, North Rhine-Westphalia, Rhineland-Palatinate, Saarland, Saxony-Anhalt and Saxony) were shown on R0 maps. This study presents a path for developing an early warning system for vector-borne diseases driven by climate change.

The individual-based model describes the dynamics of genetic diversity of a population scattered on a spatial continuum in the case of a finite number of individuals. During extinction events in a certain area, a portion of the population dies, after which new individuals with the genotype of the parent are born during recolonization event. In this paper we examine the model, as well as its modification, and derive properties related to population parameters. The study demonstrates that the lifespan of individuals follows an exponential distribution, allele probabilities remain constant over time, and the average heterozygosity, constrained by the number of individuals during extinction and recolonization, equals a similar quantity in the Moran model. The joint distribution of alleles is generalized for populations continuously scattered in space. Joint allele distribution and heterozygosity are computed through simulations.

There is limited information available on wolverine (Gulo gulo) population density and trends in the boreal forest of North America. We estimated wolverine density using spatial capture‐recapture methods across 2 boreal forest study areas in Red Lake, Ontario (26,568 km2) and Rainbow Lake, Alberta (19,084 km2), Canada. We also used radio‐telemetry data to estimate annual survival of adult and sub‐adult wolverines and evaluated population trends with a stage‐based matrix model. We used an array of run poles and live traps to detect wolverines. In Red Lake over 3 winter field seasons (2019–2022), we detected 56 individual wolverines (17 females, 32 males, and 7 unknown sex), and in Rainbow Lake over 2 field seasons (2014–2016), we detected 48 individuals (19 females, 18 males, and 11 of unknown sex). Average densities in Red Lake and Rainbow Lake were 3.64 and 6.74 wolverines/1,000 km2, respectively. Adults and sub‐adults occurred at equal abundance. Spring snow cover, roads, and industrial developments were not associated with spatial patterns of wolverine density. Most deaths occurred near roads; wolverines were killed in fur traps set along roads, by wolves using roads to travel, and by vehicles. The largest source of death was from incidental (n = 6 in Red Lake) or licensed fur trapping (n = 8 in Rainbow Lake) and we report 8 injuries from fur trapping sets. Red Lake survival estimates for adults (0.87) and sub‐adults (0.86) contributed to a stable population trend. Rainbow Lake survival estimates for adults (0.66) and sub‐adults (0.50) contributed to a declining population trend based on a relatively low sample of radio‐days. Red Lake and Rainbow Lake combined survival estimates for adults (0.77) and sub‐adults (0.73) also contributed to a declining population trend. Our survival and population modeling suggests that human‐caused mortality is a significant risk to these populations. Our results can be applied to wolverine status assessments and used as benchmarks for future monitoring. Wolverine population stability or growth might be achieved by reducing incidental trapping deaths or injury and hindering human access to wolverine habitats through decommissioning or limiting development of industrial roads or other anthropogenic linear features. [ABSTRACT FROM AUTHOR]

Background and objectives: Despite being clinically utilized for the treatment of infections, the limited therapeutic range of polymyxin B (PMB), along with considerable interpatient variability in its pharmacokinetics and frequent occurrence of acute kidney injury, has significantly hindered its widespread utilization. Recent research on the population pharmacokinetics of PMB has provided valuable insights. This study aims to review relevant literature to establish a theoretical foundation for individualized clinical management. Methods: Follow PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, Pop-PK studies of PMB were searched in PubMed and EMBASE database systems from the inception of the database until March 2023. Result: To date, a total of 22 population-based studies have been conducted, encompassing 756 subjects across six different countries. The recruited population in these studies consisted of critically infected individuals with multidrug-resistant bacteria, patients with varying renal functions, those with cystic fibrosis, kidney or lung transplant recipients, patients undergoing extracorporeal membrane oxygenation (ECMO) or continuous renal replacement therapy (CRRT), as well as individuals with obesity or pediatric populations. Among these studies, seven employed a one-compartmental model, with the range of typical clearance (CL) and volume (Vc) being 1.18–2.5L /h and 12.09–47.2 L, respectively. Fifteen studies employed a two-compartmental model, with the ranges of the clearance (CL) and volume of the central compartment (Vc), the volume of the peripheral compartment (Vp), and the intercompartment clearance (Q) were 1.27–8.65 L/h, 5.47–38.6 L, 4.52–174.69 L, and 1.34–24.3 L/h, respectively. Primary covariates identified in these studies included creatinine clearance and body weight, while other covariates considered were CRRT, albumin, age, and SOFA scores. Internal evaluation was conducted in 19 studies, with only one study being externally validated using an independent external dataset. Conclusion: We conclude that small sample sizes, lack of multicentre collaboration, and patient homogeneity are the primary reasons for the discrepancies in the results of the current studies. In addition, most of the studies limited in the internal evaluation, which confined the implementation of model-informed precision dosing strategies. [ABSTRACT FROM AUTHOR]

In the first range-wide population viability model for the northwestern and southwestern pond turtles (Actinemys marmorata and Actinemys pallida, respectively), a stage-based population projection matrix was assembled with 3 life stages: hatchling, juvenile, and adult. Vital rates were defined using biologically appropriate statistical distributions, with additional parametric uncertainty included for the adult survival parameter. A triple-loop stochastic simulation model was built around a population viability analysis to project pond turtle populations into the future. Initial abundance was calculated using available historical presence data and remotely sensed landscape condition metrics. A negative binomial regression was used to predict the relationship between abundance, habitat area, and human modification. Populations of pond turtles are dominated by adult individuals, so we applied a nonstable stage distribution to initial abundance values. Initial abundances of analysis units were variable across the species' ranges, but all populations declined precipitously in the population projections. By the end of the century, the mean range-wide probability of extinction was 44.3% for the northwestern species and 57.8% for the southwestern species. Consistent with other long-lived chelonian species, population growth rate was most sensitive to adult survival, indicating that where possible, conservation efforts focusing on increasing or maintaining adult survival would benefit the species. Elasticity analysis indicated a bet-hedging life history strategy where long-term reproductive output is maximized through longevity, small clutches, and frequent reproductive bouts in the face of highly variable juvenile survival. The population dynamics presented here indicate that efforts to bolster adult survival would be most beneficial in terms of long-term population viability, which can inform targeted research and management. The feasibility of such efforts is an important consideration in conservation management for these long-lived species. [ABSTRACT FROM AUTHOR]

PollinERA aims to reverse pollinator population declines and reduce the harmful impacts of pesticides. It addresses the call through four objectives: SO1 filling ecotoxicological data gaps to enable realistic prediction of the source and routes of exposure and impact of pesticides on pollinators and their sensitivity to individual pesticides and mixtures. SO2 developing and testing a co-monitoring scheme for pesticides and pollinators across European cropping systems and landscapes, developing risk indicators and mixture exposure information. SO3 developing models for predicting pesticide toxicological effects on pollinators for chemicals and organisms, environmental fate, toxicokinetic/ toxicodynamic, and population models. SO4 developing a population-level systems-based approach to risk and policy assessment considering multiple stressors and long-term spatiotemporal dynamics at the landscape scale and generating an open database for pollinator/pesticide data and tools. This will be achieved through developing knowledge and protocols for a broad range of toxicological testing, feeding to in silico models (QSARS, toxicokinetic/toxicodynamic, and population). Using a strong stakeholder co-development approach, these models will be combined in a One System framework taking a systems view on risk assessment and policy evaluation, including an international monitoring program. The One System framework is based on EFSA's system ERA view, expanding on the tools used for bees to include butterflies, moths and hoverflies. The consortium partners are experts in the field needed for this development and are well-placed to facilitate the uptake of tools by European bodies to guarantee the project's future impact. Expected impacts target Destination impacts of better understanding and addressing drivers of biodiversity decline, interconnected biodiversity research using digital technologies, and understanding the biodiversity and health nexus at the ecosystem level. [ABSTRACT FROM AUTHOR]

Coastal and estuarine habitats are essential for both growth and survival at juvenile stages for a large proportion of marine fish but are exposed to a variety of threats. However, the quantitative impacts of anthropic‐mediated nursery degradation on exploited population dynamics and productivity are rarely addressed. We developed a comprehensive steepness‐based parameterization of the stock–recruitment relationship that directly depends upon juvenile habitat quality and surface area and used a generic age‐ and stage‐structured model to simulate exploited population dynamics under nursery degradation/restoration scenarios. Population responses to juvenile habitat modification were estimated for three species with contrasting life histories. Modifying the surface area of nursery habitat has a predictable direct scaling effect on population size and affects biomass and fishing yield, with identical responses observed for various life histories. Modification of habitat quality affects both the population size and the shape of the productivity curve, leading to more complex responses of biomass and fishing yields that depend upon combinations of life history traits. Populations with low steepness and hence lower resiliency to fishing are the most sensitive to the degradation of habitat quality. Our study emphasizes the critical impact of juvenile habitat modification on population dynamics and productivity and the need to integrate habitat consideration into the management of exploited marine species. Our modelling framework is generalizable and can be extended to handle many diverse life histories and case studies to quantify the consequences of coastal habitat degradation/restoration for the dynamics of exploited marine fish populations. [ABSTRACT FROM AUTHOR]

In the present paper, we further study the asymptotical behavior of the following higher order nonlinear difference equation \begin{equation*} x(n+1)= ax(n)+ bf( x(n)) + cf(x(n-k)), \qquad n=0, 1, \dots \end{equation*} where $a, b $ and $c$ are constants with $00$ for $x>0$, and $k$ is a positive integer, which has been recently studied in: On global attractivity of a higher order difference equation and its applications [Electron. J. Qual. Theory Diff. Equ. 2022, No. 2, 1–14]. We obtain some new sufficient conditions for the global attractivity of positive solutions of the equation, and show the applications of these results to some population models.

Bangladesh has a higher population density than most other nations in the world. This project aims to evaluate the effects of experimental family planning and maternal and child health. Bangladesh saw changes in the use of contraceptives, the continuation of contraception, fertility, and infant and child mortality between 2012 and 2022. The project's current goal is to guarantee improved family health. To satisfy the changing needs and priorities of families and to provide better health for all, this paper has proposed several novel initiatives, such as enhanced health and family planning services, and enhancing maternal and child health. The goal of this project is to improve the health of women and children through family planning using an age-structured population model. It also covers the graphical presentation of the data using programs like Matlab, Mathematica, Excel, and others.

A model combines demographic data provided by the United States Census Bureau for 2021 with survey data on sexual activity from the Centers for Disease Control and Prevention to estimate the structure by age and sex of the sexually active population in the United States. It also provides the proportions of newly sexually active people by age and sex. The model is based on percentages of sexually active people by age and sex, and on an ordinary differential equation formalizing a "learning process" for the years 2009 to 2019. The data produced fit well with the empirical data for each age and sex. [ABSTRACT FROM AUTHOR]

Species population estimates are a fundamental component of conservation planning, but there are deficiencies in reliable data for many seabirds. The Pink-footed Shearwater Ardenna creatopus is a seabird that breeds on three islands worldwide, with the largest population on Isla Mocha, Chile. We aimed to update the breeding population estimate of Pink-footed Shearwaters on Isla Mocha, comparing results from design- and model-based estimation methods. We counted shearwater burrows in 220 randomly generated five-meter-radius plots across pre-defined strata on Isla Mocha. We estimated total number of burrows using area-based extrapolation (design-based method), and separately using a model predicting burrow density based on habitat (model-based method). We multiplied burrow abundance estimates by burrow occupancy for final population estimates. The stratum-area-weighted burrow density estimate for the 15.8 km² study area was 0.0106 burrows·m-2 (standard error [SE] = 0.0030). The average island-wide proportion of occupied burrows was 0.758 (standard deviation [SD] = 0.121). The design-based method estimated 168 209 burrows (95% confidence interval [CI] = 74 715-261 704, coefficient of variation [CV] = 0.28), and 127 503 breeding pairs (95% CI = 87 610-167 395). The model-based method estimated 233 436 burrows (95% CI = 151 237-332 179, CV = 0.19) and 181 859 breeding pairs (95% CI = 95 773-267 945, CV = 0.24). These population estimates are greater than previous estimates for Isla Mocha, whose means ranged from 19 440-42 095 breeding pairs. Because our study design differed from those used to generate previous estimates, our estimate should be considered a stand-alone result rather than an increase in the breeding population. Because of the low fit of the model-based result, the design-based result may be a more reliable estimate to use for species management efforts. Based on our estimate, approximately 90% of the Pink-footed Shearwater world population breeds on Isla Mocha, and with its restriction to only three breeding localities world-wide, the species remains vulnerable. The full manuscript in Spanish can be found in Appendix 1, available on the website. [ABSTRACT FROM AUTHOR]

The paper addresses a computational method to simulate more accurate models for population growth with immigration, focusing on integral equations (IEs) featuring a delay parameter in the time variable. The proposed method utilizes Legendre wavelets within the Galerkin scheme as a orthonormal basis. Legendre wavelets are known for their localized functions, offering suitable precision and stability in simulating time-delay biological models. This approach employs the composite Gauss-Legendre (CGL) quadrature rule to compute integrals appeared in the scheme. An error bound analysis demonstrates a convergence rate of order 2 − M k. Additionally, various numerical examples are presented to show the efficiency, accuracy and validate the theoretical error estimate of the novel technique. [ABSTRACT FROM AUTHOR]

An implicit Euler finite-volume scheme for a nonlocal cross-diffusion system on the one-dimensional torus, arising in population dynamics, is proposed and analyzed. The kernels are assumed to be in detailed balance and satisfy a weak cross-diffusion condition. The latter condition allows for negative off-diagonal coefficients and for kernels defined by an indicator function. The scheme preserves the nonnegativity of the densities, conservation of mass, and production of the Boltzmann and Rao entropies. The key idea is to "translate" the entropy calculations for the continuous equations to the finite-volume scheme, in particular to design discretizations of the mobilities, which guarantee a discrete chain rule even in the presence of nonlocal terms. Based on this idea, the existence of finite-volume solutions and the convergence of the scheme are proven. As a by-product, we deduce the existence of weak solutions to the continuous cross-diffusion system. Finally, we present some numerical experiments illustrating the behavior of the solutions to the nonlocal and associated local models. [ABSTRACT FROM AUTHOR]

Predators mediate the strength of trophic cascades indirectly by decreasing the number of prey consuming a basal resource and by altering prey responses that dictate prey foraging. The strength of these indirect effects further depends on abiotic factors. For example, attributes of the environment, such as turbulent flows in aquatic habitats that disrupt spatial information available from chemical cues, can impose "sensory stresses" that impair the ability of predators or prey to detect each other. The multi-faceted impacts of sensory stress on both the predators and prey create challenges in predicting the overall effect on the trophic cascade. Here, we explore how sensory stress affects the strength of trophic cascades using a tri-trophic dynamical model that incorporates the sensory environment and anti-predatory responses. We explore two crucial parameters that govern outcomes of the model. First, we allow predation rates to either strengthen or weaken depending on whether prey or predators are more sensitive to sensory stress, respectively. Second, we explore scenarios where anti-predatory responses can either drive a strong or weak reduction in prey foraging. We find that sensory stress usually weakens trophic cascades except in scenarios where predators are relatively unaffected by sensory stress and the loss of anti-predatory responses does not affect prey foraging. The model finally suggests that "hydra effects" can manifest, whereby an increase in prey population occurs despite an increase in per capita predation. This last feature emerges due to the interaction between logistic growth of the basal resource and anti-predatory responses reducing the over-consumption of the basal resource. [ABSTRACT FROM AUTHOR]

Green space resources, in the context of urbanisation, cannot meet the actual needs of residents well, and the study of the balance of green space resource allocation based on the relationship between supply and demand is an urgent problem to be solved. This study quantitatively evaluates the green space supply level from four dimensions by constructing a framework for assessment in the community life circle. It also evaluates the matching of green space supply and demand, resource distribution fairness, and distribution equilibrium under group differentiation through the supply–demand coupling matrix, the Gini coefficient, and the Kruskal–Wallis H non-parametric rank-sum test, respectively. This study shows that: (1) A significant spatial imbalance exists in green space resource allocation in community life circles in different dimensions. (2) The comprehensive green space supply level in the community life circle matched the total demand of residents to a low degree. (3) There was significant inequality in green space resource allocation within the community life circle (the Gini coefficient of each evaluation perspective was >0.4). Based on the study results, we were able to identify community life circles with spatial mismatches, different supply and demand, and other green space resource allocation problems, which is of great significance to urban green space research and planning practice under the 'green justice' framework. [ABSTRACT FROM AUTHOR]

Population models provide a logical knowledge base before conducting laborious and expensive field experiments. Historically, two types of population models have been developed: highly realistic simulations and simple analytical models. Highly realistic simulations comprise a complicated systems model, whereas simple analytical models comprise various analytical models that focus only on the fundamental structure of the target pest population. Although both approaches have contributed to pest management science, each has limitations, poor predictability, and lacks substantial connections to reality. Assimilation by state-space modeling, in which observation and process models are jointly incorporated, is a good compromise between a simple model and reality in nature. In the big data era, artificial intelligence (AI), specifically aimed at high predictability, has recently become popular. If vital physical and biological records are automatically censored in the field with high precision, AI will produce the most plausible predictions, providing the best practical solution given our current knowledge. AI can be a powerful tool in the contemporary world; however, deductive modeling approaches are still important when considering the behavior of AIs and may also provide important insights to detect deficient information in the data. [ABSTRACT FROM AUTHOR]

The objective was to apply a population model to describe the time course and variability of serum creatinine (sCr) in (near)term neonates with moderate to severe encephalopathy during and after therapeutic hypothermia (TH). The data consisted of sCr observations up to 10 days of postnatal age in neonates who underwent TH during the first 3 days after birth. Available covariates were birth weight (BWT), gestational age (GA), survival, and acute kidney injury (AKI). A previously published population model of sCr kinetics in neonates served as the base model. This model predicted not only sCr but also the glomerular filtration rate normalized by its value at birth (GFR/GFR0). The model was used to compare the TH neonates with a reference full term non-asphyxiated population of neonates. The estimates of the model parameters had good precision and showed high between subject variability. AKI influenced most of the estimated parameters denoting a strong impact on sCr kinetics and GFR. BWT and GA were not significant covariates. TH transiently increased sCr in TH neonates over the first days compared to the reference group. Asphyxia impacted not only GFR, but also the sCr synthesis rate. We also observed that AKI neonates exhibit a delayed onset of postnatal GFR increase and have a higher sCr synthesis rate compared to no-AKI patients. Our findings show that the use of sCr as marker of renal function in asphyxiated neonates treated with TH to guide dose selection for renally cleared drugs is challenging, while we captured the postnatal sCr patterns in this specific population. [ABSTRACT FROM AUTHOR]

Purpose – In this paper, the author presents a hybrid method along with its error analysis to solve (1+2)-dimensional non-linear time-space fractional partial differential equations (FPDEs). Design/methodology/approach – The proposed method is a combination of Sumudu transform and a semi-analytc technique Daftardar-Gejji and Jafari method (DGJM). Findings – The author solves various non-trivial examples using the proposed method. Moreover, the author obtained the solutions either in exact form or in a series that converges to a closed-form solution. The proposed method is a very good tool to solve this type of equations. Originality/value – The present work is original. To the best of the author's knowledge, this work is not done by anyone in the literature.

This paper is concerned with a population model with prey refuge and a Holling type Ⅲ functional response in the presence of self-diffusion and cross-diffusion, and its Turing pattern formation problem of Hopf bifurcating periodic solutions was studied. First, we discussed the stability of periodic solutions for the ordinary differential equation model, and derived the first derivative formula of periodic functions for the perturbed model. Second, applying the Floquet theory, we gave the conditions of Turing patterns occurring at Hopf bifurcating periodic solutions. Additionally, we determined the range of cross-diffusion coefficients for the diffusive population model to form Turing patterns at the stable periodic solutions. Finally, our research was summarized and the relevant conclusions were simulated numerically.

Avoiding the undesirable impacts of invasive species requires robustly evaluating the effects of alternative management scenarios. Such evaluations depend on reliable spatio‐temporal projections of changes in the distribution and abundance of the invasive species under different scenarios. However, commonly used modelling approaches are constrained for this purpose because they do not incorporate demographic processes and are seldom validated.We develop a spatially and temporally explicit grid‐based population model for invasive fallow deer Dama dama in Tasmania, Australia, validated against observed distribution and abundance 'targets' using a pattern‐oriented approach. We use this validated model to project the future invasion patterns of deer, including encroachment into areas of high conservation value, under eight harvest and habitat suitability scenarios.Projected population sizes of deer differ greatly depending on harvest and habitat suitability scenarios. Without harvest, the population grows sixfold, from about 80,000 deer in 2019 to over 500,000 by 2100. In contrast, the population stabilises at 32,000–41,000 deer with 25% annual harvest. Abundance in the environmentally sensitive Tasmanian Wilderness World Heritage Area (TWWHA), a region of high conservation value, increases in all scenarios. We identify likely areas in the expanding range of deer where targeted removal should be most effective at minimising deer numbers in the TWWHA.Synthesis and applications: Using a pattern‐oriented model validated with spatio‐temporal data, we show how the future distribution and abundance of invasive fallow deer in Tasmania can be substantially reduced by targeted increases in harvest and prioritising areas for removal around high conservation value regions. Our approach can be used to project likely effects of management interventions on future distributions and abundances for a range of invasive taxa. [ABSTRACT FROM AUTHOR]

Reintroductions are one means of managing species distributions, but the feasibility of such efforts is uncertain. Here we consider reintroduction for threatened bull trout (Salvelinus confluentus) that currently occupy a small fraction of historically occupied habitats in the upper Klamath River basin owing to climate warming and human modifications of ecosystems. We engaged stakeholders across multiple organizations to co-produce a decision support model that estimated the potential of reintroduction to establish new populations and persistence of donor populations. Stakeholders identified recipient and donor populations, strategy (e.g., artificial propagation, translocation), number of individuals, and life stage of bull trout. The most optimal decision for reintroduction was artificial propagation of 10,000 fry into Annie Creek. This strategy may have negative consequences on donor populations, with the exception of Sun Creek, which was resilient to simulated removal of bull trout. Donor populations and recipient streams identified as most feasible were generally consistent across all of these scenarios. During model development, however, an unexpected and intense wildfire affected half of the streams considered and may have dramatically impacted donor populations. With models in hand from the initial feasibility assessment, we adapted them to further evaluate the potential of supplementation following this massive disturbance. Overall, results of this study indicate the value of developing co-produced tools that can be rapidly adapted to evaluate the consequences of whole-system transformations in near-real-time assessments. [ABSTRACT FROM AUTHOR]

With their large diversity of species, solitary bees are important pollinators of crops and native plant communities in agricultural landscapes. Stressors such as changing landscapes, climate and pesticide exposures may affect populations differently, dependent on each species' ecological traits.We developed a population model for solitary bees, SolBeePop, which can be applied to simulate a variety of species by using species‐specific traits, including the nesting strategies. Species' phenological traits are mechanistically combined with input time series capturing temporal and spatial variability in landscape compositions.Calibration and validation of the model with empirical study data demonstrate that the model can capture realistic dynamics in bee populations. In simulations conducted representing four species, Osmia bicornis, Megachile rotundata, Nomia melanderi and Eucera pruinosa, identical conditions and assumed nesting resource limitations resulted in different population‐level outcomes, indicating the importance of interactions between external factors and species‐specific traits including phenological, survival and reproductive traits.Synthesis and applications. The publicly available model is intended as a tool for the assessment of population‐level outcomes of stressors, for instance, the limitation of floral resources in agricultural landscapes, limitation of nesting habitat and the exposure to pesticides. Realistic landscape scenarios can be tested and available data for one species can be used to estimate outcomes in other solitary bee species, informing conservation plans and risk assessment approaches to support managed and natural populations in the field. [ABSTRACT FROM AUTHOR]

An ecohydraulic model system was developed to evaluate the effects of the Da‐Wei dam construction and possible fish restoration strategies. The ecohydraulic model system consists of a hydrodynamic model, a hydromorphology model, a habitat model, and the logistic and matrix population models. The effects of dam construction and fish stocking strategy on fish habitat and population status were studied in the Jiao‐Mu River, providing the modeled ecological status of Schizothorax prenanti and Schizothorax plagiostomus heckel populations within the river segment. The two fish species richness, fish age structures, and fish density distributions were predicted. Based on the fish number prediction, the optimal number of fish to stock was evaluated with the population models, and an optimal fish stocking proposition was worked out. The results indicated that the two fish species habitat quality and fish richness would decrease due to the hydropower dam construction, and the fish stocking strategy could make up the fish species ecological status. The findings could facilitate the quantity and quality assessment of a dam development plan and increase the success rate of fish restoration. [ABSTRACT FROM AUTHOR]

BACKGROUND: The tomato russet mite, Aculops lycopersici, is a major pest in tomato crops, causing damage through leaf and stem browning, defoliation and russeting of fruit. Biological control of this mite on tomato plants is difficult. While several phytoseiid mites feed on the pest, they cannot survive, move, or reproduce on tomato plants due to the presence of glandular trichomes. Pronematus ubiquitus has recently been identified as a biocontrol agent of A. lycopersici in tomato crops, but the predator–prey interaction between these two species is not well studied. In this paper, we present a validated logistic regression predator–prey model based on a 3‐year study supplemented with additional datasets. Besides the predator and the prey, this model takes into account an extra generalist predator, Macrolophus pygmaeus, and various climate parameters. RESULTS: The population trend of A. lycopersici is best explained by the presence of the predator P. ubiquitus, the relative humidity and the fact that the crop was lit or unlit using artificial light. P. ubiquitus has proved to be an efficient biocontrol agent of A. lycopersici. For P. ubiquitus the presence of M. pygmaeus, the vapour pressure deficit, the number of light hours and radiation explained the population trend best. For both the predator and the prey density‐dependent interactions were identified. Model outcomes are discussed in detail. CONCLUSION: Our study provides insights into the potential use of P. ubiquitus as a biocontrol agent for A. lycopersici in tomato crops in combination with M. pygmaeus. However, we highlight the importance of considering the presence of other predators and environmental conditions when developing integrated pest management strategies. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The seabird meta-population viability model (mPVA) uses a generalized approach to project abundance and quasi-extinction risk for 102 seabird species under various conservation scenarios. The mPVA is a stage-structured projection matrix that tracks abundance of multiple populations linked by dispersal, accounting for breeding island characteristics and spatial distribution. Data are derived from published studies, grey literature, and expert review (with over 500 contributions). Invasive species impacts were generalized to stage-specific vital rates by fitting a Bayesian state-space model to trend data from Islands where invasive removals had occurred, while accounting for characteristics of seabird biology, breeding islands and invasive species. Survival rates were estimated using a competing hazards formulation to account for impacts of multiple threats, while also allowing for environmental and demographic stochasticity, density dependence and parameter uncertainty.•The mPVA provides resource managers with a tool to quantitatively assess potential benefits of alternative management actions, for multiple species•The mPVA compares projected abundance and quasi-extinction risk under current conditions (no intervention) and various conservation scenarios, including removal of invasive species from specified breeding islands, translocation or reintroduction of individuals to an island of specified location and size, and at-sea mortality amelioration via reduction in annual at-sea deaths.

Shifted Legendre polynomials (SLPs) with the Riemann–Liouville fractional integral operator have been used to create a novel fractional integration tool. This tool will be called the fractional shifted Legendre integration matrix (FSL B-matrix). Two algorithms depending on this matrix are designed to solve two different types of integral equations. The first algorithm is to solve fractional Volterra integro-differential equations (VIDEs) with a non-singular kernel. The second algorithm is for Abel's integral equations. In addition, error analysis for the spectral expansion has been proven to ensure the expansion's convergence. Finally, several examples have been illustrated, including an application for the population model. [ABSTRACT FROM AUTHOR]

Temperature-dependent development of Helicoverpa armigera (Hüber) fed with an artificial diet was studied at different temperatures. The instar pathway (IPW) defined as the number of instars prior to pupation significantly affected larval development time, with higher IPW leading to longer larval development time. The IPW was determined at the fifth instar to proceed to 6–7 IPW, when the development time of fifth instar was largely shortened. Accordingly, the development time after the fourth instar was combined (i.e. the fifth–seventh instar) as a single stage to simplify the various IPW and applied to develop phenology models. In linear models, the lower threshold temperature (LT) and thermal constant (degree-days, DD) for each stage were estimated. DD based on the common LT of 10.7 °C were 43, 287, and 191 DD for eggs, larvae, and pupae, respectively. DD model (253.6 DD with LT 10.3 °C for larvae and 181.5 DD with 11.6 °C for pupae) showed good performance in predicting the 50% occurrences of pupae and adults. In nonlinear models, stage transition (ST) models were constructed using the development rate and distribution models to simulate the proportion of individuals shifted from one stage to the next stage. The ST model showed good performance, indicating an average discrepancy of 1.74 days at 25%, 50%, 75%, and 90% adult emergence. Our models developed here will be useful to predict the phenology of H. armigera in the field and to construct a deterministic population model in the future. [ABSTRACT FROM AUTHOR]

Feral horse (Equus caballus) population management is a challenging problem around the world because populations often exhibit density‐independent growth, can exert negative ecological effects on ecosystems, and require great cost to be managed. However, strong value‐based connections between people and horses cause contention around management decisions. To help make informed decisions, natural resource managers might benefit from more detailed understanding of how horse management alternatives, including combinations of removals and fertility control methods, could achieve objectives of sustainable, multiple‐use ecosystems while minimizing overall horse handling and fiscal costs. Here, we describe a modeling tool that simulates horse management alternatives and estimates trade‐offs in predicted metrics related to population size, animal handling, and direct costs of management. The model considers six management actions for populations (removals for adoption or long‐term holding; fertility control treatment with three vaccines, intrauterine devices, and mare sterilization), used alone or in combination. We simulated 19 alternative management scenarios at 2‐, 3‐, and 4‐year management return intervals and identified efficiency frontiers among alternatives for trade‐offs between predicted population size and six management metrics. Our analysis identified multiple alternatives that could maintain populations within target population size ranges, but some alternatives (e.g., removal and mare sterilization, removal and GonaCon treatment) performed better at minimizing overall animal handling requirements and management costs. Cost savings increased under alternatives with more effective, longer lasting fertility control techniques over longer management intervals compared with alternatives with less‐effective, shorter lasting fertility control techniques. We built a user‐friendly website application, PopEquus, that decision makers and interested individuals can use to simulate management alternatives and evaluate trade‐offs among management and cost metrics. Our results and website application provide quantitative trade‐off tools for horse population management decisions and can help support value‐based management decisions for wild or feral horse populations and ecosystems at local and regional scales around the world. [ABSTRACT FROM AUTHOR]

The rate and extent of drug dissolution and absorption from a solid oral dosage form depend largely on the fluid volume along the gastrointestinal tract. Hence, a model built upon the gastric fluid volume profiles can help to predict drug dissolution and subsequent absorption. To capture the great inter- and intra-individual variability (IAV) of the gastric fluid volume in fasted human, a stochastic differential equation (SDE)-based mixed effects model was developed and compared with the ordinary differential equation (ODE)-based model. Twelve fasted healthy adult subjects were enrolled and had their gastric fluid volume measured before and after consumption of 240 mL of water at pre-determined intervals for up to 2 hours post ingestion. The SDE- and ODE-based mixed effects models were implemented and compared using extended Kalman filter algorithm via NONMEM. The SDE approach greatly improved the goodness of fit compared with the ODE counterpart. The proportional and additive measurement error of the final SDE model decreased from 14.4 to 4.10% and from 17.6 to 4.74 mL, respectively. The SDE-based mixed effects model successfully characterized the gastric volume profiles in the fasted healthy subjects, and provided a robust approximation of the physiological parameters in the very dynamic system. The remarkable IAV could be further separated into system dynamics terms and measurement error terms in the SDE model instead of only empirically attributing IAV to measurement errors in the traditional ODE method. The system dynamics were best captured by the random fluctuations of gastric emptying coefficient Kge. [ABSTRACT FROM AUTHOR]

Biological and financial models are examples of dynamical systems where both stochastic and historical behavior are important to be considered. The fractional Brownian motion (fBM) is commonly used, sometimes with fractional-order derivatives, to model the combined stochastic and fractional effects. Recently, spectral techniques are used to analyze models with fBM using, e.g., iterated Itô fractional integrals such as the fractional Wiener-Hermite (FWHE). In the current work, FWHE is generalized and adapted to be consistent with the Malliavin calculus approach. The conditions for existence and uniqueness are outlined in addition to the proof of convergence. The solution algorithm is described in detail. Using FWHE, the stochastic fractional model is replaced by a deterministic fractional-order system that can be handled using well-known mathematical tools to evaluate the solution statistics. Analytical solutions can be obtained for many important models such as the fractional stochastic Black–Scholes model. The convergence is studied and compared with the exact solution and high convergence is noticed compared with other techniques. A general numerical algorithm is described to analyze the resultant deterministic system in the case of no feasible analytical solutions. The algorithm is applied to study and simulate the population model with nonlinear losses for different values of the Hurst parameter. The results show the efficiency of FWHE in analyzing practical linear and nonlinear models. [ABSTRACT FROM AUTHOR]

In the present paper, we study the asymptotic behavior of the following higher order nonlinear difference equation with unimodal terms \[x(n+1)= ax(n)+ bx(n)g(x(n)) + cx(n-k)g(x(n-k)), \quad n=0, 1, \ldots,\] where \(a\), \(b\) and \(c\) are constants with \(0\lt a\lt 1\), \(0\leq b\lt 1\), \(0\leq c \lt 1\) and \(a+b+c=1\), \(g\in C[[0, \infty), [0, \infty)]\) is decreasing, and \(k\) is a positive integer. We obtain some new sufficient conditions for the global attractivity of positive solutions of the equation. Applications to some population models are also given.

Abstract Feral horse (Equus caballus) population management is a challenging problem around the world because populations often exhibit density‐independent growth, can exert negative ecological effects on ecosystems, and require great cost to be managed. However, strong value‐based connections between people and horses cause contention around management decisions. To help make informed decisions, natural resource managers might benefit from more detailed understanding of how horse management alternatives, including combinations of removals and fertility control methods, could achieve objectives of sustainable, multiple‐use ecosystems while minimizing overall horse handling and fiscal costs. Here, we describe a modeling tool that simulates horse management alternatives and estimates trade‐offs in predicted metrics related to population size, animal handling, and direct costs of management. The model considers six management actions for populations (removals for adoption or long‐term holding; fertility control treatment with three vaccines, intrauterine devices, and mare sterilization), used alone or in combination. We simulated 19 alternative management scenarios at 2‐, 3‐, and 4‐year management return intervals and identified efficiency frontiers among alternatives for trade‐offs between predicted population size and six management metrics. Our analysis identified multiple alternatives that could maintain populations within target population size ranges, but some alternatives (e.g., removal and mare sterilization, removal and GonaCon treatment) performed better at minimizing overall animal handling requirements and management costs. Cost savings increased under alternatives with more effective, longer lasting fertility control techniques over longer management intervals compared with alternatives with less‐effective, shorter lasting fertility control techniques. We built a user‐friendly website application, PopEquus, that decision makers and interested individuals can use to simulate management alternatives and evaluate trade‐offs among management and cost metrics. Our results and website application provide quantitative trade‐off tools for horse population management decisions and can help support value‐based management decisions for wild or feral horse populations and ecosystems at local and regional scales around the world.

We investigate two stochastic models of a growing population with discrete and non-overlapping generations, subject to selection and mutation. In our models each individual carries a fitness which determines its mean offspring number. Many of these offspring inherit their parent's fitness, but some are mutants and obtain a fitness randomly sampled, as in Kingman's house-of-cards model, from a distribution in the domain of attraction of the Fréchet distribution. We give a rigorous proof for the precise rate of superexponential growth of these stochastic processes and support the argument by a heuristic and numerical study of the mechanism underlying this growth. This study yields in particular that the empirical fitness distribution of one model in the long time limit displays periodic behaviour. [ABSTRACT FROM AUTHOR]

The European population of Eurasian Curlew Numenius arquata arquata, a near‐threatened wader subspecies, has undergone pronounced population declines over the past 30 years. To assess the demography and viability of its global population, we surveyed studies quantifying demographic rates (productivity and survival) and complemented this review with new estimates of survival probability at the flyway scale. Then, using a demographic model, we estimated population growth rates while accounting for the range of variation of demographic parameters, and compared these estimates (expected based on demographic rates) with those observed based on population censuses. Both observed and expected average growth rates were negative but the observed rates were higher than estimates from demographic models (λ = 0.98–0.99 compared with 0.85–0.95). This discrepancy implies that there is geographical variation in the demography of different populations that is not fully covered by current demographic data, namely unstudied regions with higher productivity. According to our calculations, at the flyway scale, productivity is currently c. 0.57 fledglings per pair per year, higher than the average reported productivity of 0.29, but lower than the 0.68 needed to achieve a stable global population size (λ = 1). Adult survival, estimated at 0.90, was the most sensitive parameter determining population growth rates, but the low productivity levels over the last few decades seems to be the most probable cause of population declines. The negative population growth rates require immediate conservation actions to preserve adult survival and increase the extremely low productivity in western and northern European populations to values above 0.68 fledglings per pair per year. We hope our synthesis on the demographic status of Curlew in Europe will encourage the collection of more demographic data and allow concrete management goals at the flyway scale to be established in order to recover the global population of this iconic species. [ABSTRACT FROM AUTHOR]

A common explanation for women's underrepresentation in many economic contexts is that women exit talent pipelines at higher rates than men. Recent empirical findings reveal that, in male-dominated selection contexts, women are less likely than men to reapply after being rejected for an opportunity. We examine the conditions under which this gender difference contributes to women's underrepresentation in talent pipelines over time. We formally model and analyze the population dynamics of a generic selection context, which we then ground using three distinct empirical settings. We show that gender differences in reapplication are an important mechanism of gender segregation in some selection contexts but negligible in others. The extent to which gender differences in reapplication contribute to women's underrepresentation is driven in part by the rejection rate. Higher rejection rates increase the stock of rejected applicants, which in turn enables gender differences in reapplication to disproportionally reduce women's representation. The results demonstrate that interactions between individuals' choices on the supply side and screeners' behavior on the demand side may have consequences for gender inequality, even if we were able to fully eliminate demand-side biases. We discuss the theoretical and policy implications of our research for understanding women's underrepresentation in talent pipelines. We also interrogate the effectiveness of common interventions focused on encouraging women to apply for opportunities in male-dominated domains. Supplemental Material: The online appendix is available at https://doi.org/10.1287/orsc.2022.1635. [ABSTRACT FROM AUTHOR]

Sagebrush (Artemisia spp.) ecosystems provide critical habitat for the Greater sage‐grouse (Centrocercus urophasianus), a species of conservation concern. Thus, future loss of sagebrush habitat because of land use change and global climate change is of concern. Here, we use a dynamic additive spatiotemporal model to estimate the effects of climate on sagebrush cover dynamics at 32 sage‐grouse management (core) areas in Wyoming. We use the fitted models to quantify the sensitivity of each management area to precipitation and temperature, and to make probabilistic projections of sagebrush cover from present to 2100 under three climate change scenarios. Global circulation models predict an increase in temperature and no change in precipitation for Wyoming. Sensitivity to climate varied among management areas, but the most common response (70% of management areas) was a positive effect of temperature on sagebrush performance. The combination of positive sensitivity to temperature and the predicted increase in temperature under all climate change scenarios resulted in projections of increased sagebrush cover for most management areas. We characterized management areas as "optimal" or "suboptimal" based on the percentage of grid cells in each management area with sagebrush cover exceeding a nesting habitat target value. Only 18% of management areas are projected to switch from being currently optimal to suboptimal in the future. Thirty‐five percent of management areas are projected to switch from being suboptimal to optimal. The most common outcome (47%) was for currently suboptimal management areas to remain suboptimal, even though average cover tended to increase in those areas. The direct effects of climate change appear to favor sagebrush performance in the future for most sage‐grouse core areas in Wyoming. Our approach is broadly applicable to quantitative climate change assessments where remotely sensed estimates of habitat‐defining vegetation are available. [ABSTRACT FROM AUTHOR]

This paper presents an extensive study of traveling wave solutions for a population model where the growth function incorporates the Allee effect. We are able to find closed form solutions for solitary waves that are kinks and pulses (bell type). Additionally, for every solution that we find, we show the corresponding phase portrait. Interestingly, we discover that, under certain conditions, standing waves of the bell and kink types exist too. [ABSTRACT FROM AUTHOR]

In this paper, we study the stability of a nonlinear population system with a weighted total size of scale structure and migration in a polluted environment, where fertility and mortality depend on the density in different ways. We first prove the existence and uniqueness of the equilibrium point via a contraction mapping and give the expression for the equilibrium point. Some conditions for asymptotic stability and instability are presented by means of a characteristic equation. When the effect of density restriction on mortality is not considered, the threshold value of equilibrium stability can be obtained as Λ=0. When Λ0, the equilibrium is unstable. In addition, the upwind difference method is used to discrete the model, and two examples are given to show the evolution of species.