An epidemiological model based on probabilistic cellular automaton is proposed to investigate the dynamics of two co-circulating infections. In the model, one of these two diseases compromises the immune response to future infections; however, there is vaccine against this immunosuppressive disease. The goal is to evaluate the impact of the vaccination coverage on the prevalence and on the cumulative

Although the quantification and evaluation of ecosystem services has been discussed on the Loess Plateau of China, few studies have specifically focused on quantifying the ecosystem services of trade-off and finding win-win areas. Based on previous studies about the evaluation of ecosystem services, we proposed a comprehensive spatial analysis method based on the InVEST and CASA models to analyse the

The paper is devoted to a compartmental epidemiological model of infection progression in a heterogeneous population which consists of two groups with high disease transmission (HT) and low disease transmission (LT) potentials. Final size and duration of epidemic, the total and current maximal number of infected individuals are estimated depending on the structure of the population. It is shown that

We present a continuous time predator-prey model and predator’s growth subjected to component Allee effect. The model also includes density dependent mortality of predator. We investigate our model both analytically and numerically, and highlighted the effect of density independent mortality and Allee effect. In our system, we find that a fixed point representing the extinction of predator is always

In the absence of valid medicine or vaccine for treating the pandemic Coronavirus (COVID-19) infection, other control strategies like; quarantine, social distancing, self- isolation, sanitation and use of personal protective equipment are effective tool used to prevent and curtail the spread of the disease. In this paper, we present a mathematical model to study the dynamics of COVID-19. We then formulate

Vaccines do save lives; however, no vaccine provides complete immunity for all vaccinated individuals. Thus, some individuals remain susceptible to the contagious disease against which they were vaccinated. By relying on the supposed acquired immunity, these individuals can reduce the self-imposed prevention measures and, as a consequence, they can involuntarily promote the spread of the infection

Marine ecosystems are open, complex, adaptive, and hierarchical systems highly integrated through the exchange of matter and energy flows. This flows exchange allows marine ecosystems to operate at different scales acting as dissipative structures, building natural capital stocks capable of generating several ecosystem services vital for human well-being. Humans derive a wide range of goods and services

In this paper, a mathematical model for the interacting dynamics of phytoplankton-zooplankton is proposed. The phytoplankton have the ability to take refuge and release toxins to avoid over predation by zooplankton. The zooplankton are provided some additional food to persist in the system. The phytoplankton are assumed to be affected directly by external toxic substances whereas zooplankton are affected

A model for the Colorado potato beetle (CPB), potato plant and mycorrhiza mutual interactions is presented, accounting for the symbiotic and predator-prey features of this system. The study is performed to determine if arbuscular mycorrhizal fungi (AMF) increase potato tolerance to CPB. To this end, data collected by biological experiments are used. The system exhibits several possible equilibria that

Dissimilarity indices differ in the relative weight given to rare species. Heavy-weighting of rare species may be justified in terms of sampling. An index may erroneously estimate high dissimilarity between two identical communities if they are composed of many rare species and the sampling effort is insufficient to observe most of them in both samples. Heavy-weighting of rare species is thought to

Rapid qualitative field methods can be used to evaluate ecological integrity (EI) at a landscape level. This study evaluates the EI of 63 landscape types (LCTs) in Cyprus derived from Landscape Character Mapping. Following a stratified sampling, LCTs were evaluated using 209 Land Description Units (LDUs) i.e., homogeneous map entities, sharing a similar pattern of natural and cultural elements. In

Association between species may strengthen the fitness of the species involved It is not rare that avian species associate on the breeding and feeding grounds. However, a species associated with a potential egg predator is less common. In this study, a synchronized breeding of Indian House Crow (Corvus splendens) and breeding Indian Pond Herons (Ardeola grayii) in urban conditions is reported. Both

Intermittent population trajectories are likely to emerge in almost any population that faces a predator yet has a refuge from that predator. Using the well-known model of Pomeau and Manneville for intermittent populations, a collection of a group of inherently unstable subpopulations can survive through the balance of extinction and migration rates, which is a metapopulation. This formulation also

Organisms susceptible to disease, from humans to crops, inevitably have spatial geometry that influence disease dynamics. Understanding how spatial structure emerges through time in ecological systems and how that structure influences disease dynamics is of practical importance for natural and human management systems. Here we use the perennial crop, coffee, Coffea arabica, along with its pathogen

The use of ecological models to assess the effects of pesticides on the structure and function of aquatic ecosystems is of growing interest. Of utmost concern is assessment of pesticides that have the potential to biodegrade into metabolites that are as toxic as the parent pesticide. In this work, a mathematical model to predict and evaluate the effect of two pesticides on the population of aquatic

The prevalence of sexual reproduction in most animal species despite its considerable costs such as useless males, energy spent on mating, the cost of meiosis and genome dilution remains a puzzle in evolutionary theory. One prominent single factor attempt to solve this persistent puzzle is the claim that sexual reproduction is instrumental in eliminating deleterious alleles from the species genome

Ferula ovina (Boiss.) is a valuable but vulnerable monocarpic perennial forb species from Apiaceae plant family whose habitat has been degraded over the years; hence identifying the factors controlling its distribution is important to assist range managers for the reclamation activities. The specific objective of this study was to investigate the quantitative relationships between soil properties,

Cultural hereditary transmission is indeed very important for the recognition of human personalities and countries are seeking to integrate them into their school curriculum. A deterministic mathematical model for human behavior transmission is extracted and built into the present study. The fundamental characteristics of the model are well established and the reproduction number is evaluated. The

In this paper, we study a mathematical bio-economic model of a fishery with varying price. The three dimensional model describes the time evolution of the resource, the fishing effort and the price. The model is original because it considers a nonlinear harvesting function assumed to depend upon stock size and fishing effort with a saturation effect with respect to the resource as well as a price equation

The relationship between biodiversity and ecosystem functioning, and the mechanisms underpinning the food web stability, have been intensively investigated in ecological research. The ubiquities of generalists in natural food webs and its important role in dictating these ecosystem properties have been generally recognized. However, how competition between multiple top predators shape these ecosystem

In the era of big data analysis, it is of interest to develop diagnostic tools for preliminary scanning of large spatial databases. One problem is identification of locations where certain characteristics exceed a given norm, e.g. timber volume or mean tree diameter exceeding a user-defined threshold. Some of the challenges are, large size of the database, randomness, complex shape of the spatial mean

Abstract Micro-grid systems (MGS) are increasingly investigated for green and energy efficient buildings in order to reduce energy consumption while maintaining occupants’ comfort. It includes renewable energy sources for power production, storage devices for storing power excess, and control strategies for orchestrating all components and improving the system's efficiency. In fact, MGS can be seen

Abstract Communities of nodes are one of the most important meso structures in a network. In static networks they are essentially characterized by the nodes they hold, how modular they are and how they connect to other communities. Once identified, they do not change. In networks that evolve over time, communities can shed and acquire new nodes. This generates new constructs and raises the question

Abstract In order to reduce carbon emissions and improve environmental governance, the paper discusses the interactive forms of environmental regulation based on the two-regime spatial Durbin model. The effects of environmental regulation and interactive behavior of environmental regulation on carbon dioxide (CO2) emissions are explored by using the spatial lag of X (SLX) model. It is found that there

Abstract Fish growth in river ecosystems is influenced by a multitude of environmental drivers, including the heterogeneity of these drivers. Globally, river ecosystems are subject to anthropogenic stressors that can simplify riverine landscapes, homogenize riverine communities, and favor nonnative fishes. Yet, how anthropogenically driven simplification of riverine landscapes affects fish life-history

Abstract In this paper, a stochastic diseased predator system with modified LG-Holling type II functional response is studied. By It o ^ ’s formula, stochastic comparison principle and other mathematical analysis skills, the existence and uniqueness of global positive solution of the system are obtained. Furthermore, the extinction or persistence in the mean of each specie in the system is discussed

Abstract Bighorn sheep (Ovis canadensis) management involves ecological and socioeconomic aspects, creating a social-ecological system (SES). Social-ecological thresholds can be identified in the system to assess its specific resilience in response to climate stressors. Thus, the aim of this study is to build a dynamic model to assess whether this system is resilient to a particular stressor (water

Abstract Interplay between predator and prey is a complex process in ecosystems due to its nature. The population dynamics can be affected by many extrinsic and intrinsic factors. In this paper, we make an attempt to uncover the effects from environmental disturbances when populations are subject to habitat complexity and aggregation effect. We firstly propose a stochastic predator-prey model with

Abstract A prey-predator model incorporating prey refuge with variable carrying capacity and Holling type-II functional response is proposed and analyzed. The model includes a case of increasing carrying capacity as well as a decreasing carrying capacity case. Sufficient conditions are derived to ensure the existence and local stability of the equilibrium points of the proposed model. Moreover, the

Most countries around the world are battling to limit the spread of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). As the world strives to get an effective medication to control the disease, appropriate control measures for now remains one of the effective measures to reduce the spread of the disease. In this study, a fractional optimal control model is formulated in Atangana-Baleanu-Caputo

We study an integral-differential equation that models a pure birth-jump process, where birth and dispersal cannot be decoupled. A case has been made that these processes are more suitable for phenomena such as plant dynamics, fire propagation, and cancer cell dynamics. We contrast the dynamics of this equation with those of the classical reaction-diffusion equation, where the reaction term models

ABSTRACT The ULEX model, in its present state, involves the study of the biomass and the population of the shrub Ulex parviflorus Pourret, but while being a dynamic model, it is static in the sense that it does not imply the appearance of new specimens of this plant. As a complement to the ULEX model in its two dynamic and spatial aspects, and with the idea of extending the model, the authors have

Abstract This work demonstrates an interdisciplinary modeling process between economists and computer scientists to formulate an Agent-Based Model of Land Use and Cover Change (ABM/LUCC). The MR POTATOHEAD (Model Representing Potential Objects That Appear in The Ontology of Human - Environmental Actions & Decisions) generic modeling methodology for ABM/LUCC process building is used to construct the

We propose a compartmental mathematical model for the spread of the COVID-19 disease, showing its usefulness with respect to the pandemic in Portugal, from the first recorded case in the country till the end of the three states of emergency. New results include the compartmental model, described by a system of seven ordinary differential equations; proof of positivity and boundedness of solutions;

Abstract As well-known, the interplay between human beings and their environment is complex and non-linear, with changes to initial conditions and local behaviors often being associated with the emergence of dramatically different global (macroscopic) changes. This paper discusses the problem of inducing significant behavioral changes in ecologically biocomplex systems. The role of social translucence

Abstract The triangle conceptual model is a construct that is foundational across several fields of the natural sciences including the study of diseases, invasive species, and fire. The invasion triangle incorporates the complex ecological and evolutionary interactions between the qualities of the abiotic environment, the invader, and the biotic interactions that describes or predicts the impacts of

Abstract Urbanism development makes cities more congested and then more polluted. Hence, the primary factor that influences the urban environment directly is traffic flow. Therefore, this complex system requires efficient control methods to reduce its impact at urban zones, in particular for traffic light within intersections. In this paper, a dynamic control strategy of traffic signal at urban intersections

Abstract Synergy is known to be vital for the group collaboration among non-kin individuals. In order to evaluate the condition of synergy that initiates group living, we build a model of food intake based on three types of functional response. We show that type III functional response is prerequisite for synergy to allow group living. The optimal number of gathering individuals can be also evaluated

Currently, SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is a major worldwide public-health problem. Here, its propagation is modeled by using a probabilistic cellular automaton (PCA). In this model, sick individuals can either remain asymptomatic during the infection or become symptomatic. In order to derive an analytical expression for the basic reproduction number R 0 , a mean-field

Abstract Marine fisheries are a critically important source of food, nutrition, and employment for millions of people. As the global population increases, new and expanding pressures are created on fish resources. Marine Protected Areas (MPAs) have been widely promoted as valuable tools for rebuilding or maintaining fish stocks around the world. The success of MPAs, however, widely depends on their

Abstract No matter Socio-economic system or Eco-environment system, both closely bonded up with environment pollution. With the continuous degrading of the natural environment, to understand the coordination development between Socio-economic and Eco-environment systems is of great importance towards environment improvement. In order to know the coupling coordination state of each province in China

Abstract At present, the frequent occurrence of haze in China has attracted extensive attention around the world. However, there are few researches based on simultaneous equation model to evaluate the relationship among clean energy consumption, haze pollution and economic growth. Whether the relationship among clean energy consumption, haze pollution and economic growth can be clarified correctly

Abstract Within a community, body mass variation among frugivore species is associated with: a) animal's ecological, physiological and functional traits; b) community-level biogeographic/climatic variables; c) anthropogenic factors, and methodological approaches. Furthermore, frugivore-plant relationships are highly context dependent; thus, variation in species attributes at the community level might

Abstract Seasonality is an important feature of essentially all natural systems but the consequences of seasonality have been vastly underappreciated. Early work emphasized the role of seasonality in driving cyclic population dynamics, but the consequences of seasonality for ecological processes are far broader. Yet, seasonality is often not explicitly included in either empirical or theoretical studies

Abstract Dispersal is a key mechanism shaping observed ecological and evolutionary processes. Owing to its inherent costs, dispersal incur trade-offs with many life-history traits. Here we propose and investigate a metapopulation model that follows an extinction-colonization dynamics. The problem is investigated within an evolutionary perspective in which individuals are constrained by a trade-off

Abstract Global warming is a major threat to the natural environment worldwide with potential adverse impact on plankton community. This will ultimately lead to a change in the dynamics of aquatic food webs. In this study we used seasonally forced multi-species version of the classic Rosenzweig–MacArthur predator–prey model to understand the role and stochastic influence of increasing temperature on

Abstract Chemical Organization Theory (COT) has been successfully applied to analyze complex reaction networks where species interact and new species can emerge. The COT has been well studied, but is yet to analyze high dimensional systems dynamics over time equivalent to ordinary differential equations. Moreover, spatial effects, such as diffusion and boundary conditions have also not been considered

Abstract We model bioeconomic interrelations between a commercial fishery and an aquaculture industry by using a dynamical systems theory approach. The biomass follows a logistic growth where the pollution emerging from aquaculture is accounted for by means of a retardation term. We investigate the existence and stability of the equilibrium states of this model as a function of the growth-retardation

Abstract We consider a tritrophic system with one basal and one top species and a large number of primary consumers, and derive upper and lower bounds for the total biomass of the middle trophic level. These estimates do not depend on dynamical regime, holding for fixed point, periodic, or chaotic dynamics. We have two kinds of estimates, depending on whether the predator abundance is zero. All these

Abstract Climate change is uncertain and has uncertain effects on the suitabilities of species habitats. Conservation strategies have to take this uncertainty into account. Two concepts for addressing uncertainty are, to make strategies adaptive and robust. Using a stylized ecological-economic model in which a decision maker can allocate a conservation budget between two time periods and two regions

Abstract The study of change in land use has been recently included in territorial planning in order to inform spatial planners and policy makers of the possible future developments and therefore optimize their management decisions. Several models have been proposed to simulate land use change. These models are used to understand and analyze the previous change in order to explore the future evolutions

Abstract An applied ecological approach was used to assess the anthropogenic disturbances on the aquatic systems of the Sorocaba river and its wetlands in the Sorocaba-SP municipality (Southeastern Brazil). Two samplings of water, sediment, macroinvertebrates, and macrophytes were performed in 2017, during the rainy season (February) and dry season (June). Traditional limnological methods were applied

Abstract Peary caribou (Rangifer tarandus pearyi) is listed as Endangered under Canada's Species at Risk Act. Studying rare and endangered species can be particularly challenging due to the constraints posed by incomplete datasets owing to poor weather conditions, lack of technology, organizational deficiencies, and high survey costs in remote areas. A defensible way to remedy data gaps and thus improve

Abstract We propose an innovative mathematical model for studying the dynamics of a complex network of forest ecosystems, in which two forest patches interact which each other through water exchanges. Our model reproduces a recently analyzed principle of constant precipitation quantity over densely forested areas. We perform a stability and bifurcation analysis and show that the distance separating