Dispersive Model Research Articles

Real-time application and modelling of the NOx-sorption reaction on a particulate calcium carbonate surface-flow filter exposed to combustion exhaust.

Of major interest, especially in city environments, and increasingly inside vehicles or industrial plants, is the drive to reduce human exposure to nitrogen oxides (NOx). This trend has drawn increasing attention to filtration, which has developed remarkably owing to the capabilities of recently developed mathematical models and novel filter concepts. This paper reports on the study of the kinetic modelling of adsorption of nitrogen dioxide (NO2), collected from the tailpipe of a diesel engine, reacting to calcium nitrate salt (Ca(NO3)2) on a surface flow filter consisting of a coating of fine ground limestone or marble (CaCO3) in combination with micro-nanofibrillated cellulose (MNFC) acting as binder and humectant applied onto a multiply recycled newsprint substrate. The coating and substrate are both porous, but on different pore size scales, with the coating having significantly lower permeability. To maximise gas-coating contact, therefore, the coating deposition is pixelated, achieved by pin coating. An axially dispersed gaseous plug flow model (dispersion model) was used to simulate the transport within the coating pore network structure, following earlier flow modelling studies, and a kinetic reaction model was used to examine NO2 to NO3- conversion in correlation with experimental results. Modelling results indicate a 60.38% conversion of exposed NO2 gas to Ca(NO3)2 under the specific conditions applied, with an absolute relative error between the predicted and experimentally estimated value being 0.81%. The model additionally enabled a prediction of effects of changing parameters over a limited perturbation range, thus assisting in predicting filter element consumption, with attention given to the active component CaCO3 surface as a function of particle size in relation to the gas contact exchange, promoting the reaction over time. It is intended that the Ca(NO3)2 formed from the reaction can go on to be used as a value-added fertiliser, thus contributing to circular economy.

Optical solitons for the dispersive concatenation model with power law of self-phase modulation: undetermined coefficients

AbstractThis paper recovers 1-soliton solutions to the dispersive concatenation model that comes with power law of self-phase modulation. The method of undetermined coefficients has made this retrieval possible. The parameter constraints are listed for the existence of the solitons. While a full spectrum of solitons is enumerated and exhibited, it is proved that dark 1-solitons exist only for Kerr law of nonlinear refractive index change.

Effect of Sn nanoparticles on the optical properties of PEDOT:PSS thin films

Introduction: In this study, we focus on enhancing the optical properties of PEDOT:PSS thin films by incorporating pure Sn nanoparticles (NPs) synthesized using the ultrasonic ablation technique. The objective is to investigate the impact of Sn concentration on the optical characteristics of the films, with a specific emphasis on applications in organic solar cells.Methods: We systematically varied the concentrations of Sn in PEDOT:PSS thin films and characterized their optical properties. The index of refraction (n) and extinction coefficient (k) were precisely determined by analyzing the transmission and reflection spectra of the films. Additionally, Sellmeier’s dispersal model was employed to elucidate the obtained results of n, and dispersive factors were calculated and interpreted.Results: The incorporation of Sn nanoparticles led to improvements in the energy bandgap (Eg) values of PEDOT:PSS films. Notably, as the concentration of Sn increased, the n values decreased, indicating enhanced suitability for organic solar cell applications. The study also unveiled a decrease in the dielectric constant of PEDOT:PSS/Sn films with increasing Sn content, resulting in improved transmittance velocity and enhanced efficacy of microelectronic devices. This, in turn, promotes the development of large-frequency and large-velocity stretchy circuit boards.Discussion: The comprehensive assessment of optical and dielectric parameters, including complex dielectric constant, complex optical conductance, and nonlinear optical constants, provides valuable insights into the potential applications of PEDOT:PSS/Sn films. The larger nonlinear optical constants observed in the present films suggest their suitability for diverse applications such as all-optical switching, limiting, phase modulation, and frequency conversion. Overall, our findings highlight the promising potential of Sn-incorporated PEDOT:PSS thin films in advancing the field of optoelectronics and microelectronics.

Efficacy of Wolbachia-based mosquito control: Predictions of a spatially discrete mathematical model.

Wolbachia is an endosymbiont bacterium present in many insect species. When Wolbachia-carrying male Aedes aegypti mosquitoes mate with non-carrier females, their embryos are not viable due to cytoplasmic incompatibility. This phenomenon has been exploited successfully for the purpose of controlling mosquito populations and the spread of mosquito-borne illnesses: Wolbachia carriers are bred and released into the environment. Because Wolbachia is not harmful to humans, this method of mosquito control is regarded as a safer alternative to pesticide spraying. In this article, we introduce a mathematical framework for exploring (i) whether a one-time release of Wolbachia carriers can elicit a sustained presence of carriers near the release site, and (ii) the extent to which spatial propagation of carriers may allow them to establish fixation in other territories. While some prior studies have formulated mosquito dispersal models using advection-reaction-diffusion PDEs, the predictive power of such models requires careful ecological mapping: advection and diffusion coefficients exhibit significant spatial dependence due to heterogeneity of resources and topography. Here, we adopt a courser-grained view, regarding the environment as a network of discrete, diffusively-coupled "habitats"-distinct zones of high mosquito density such as stagnant ponds. We extend two previously published single-habitat mosquito models to multiple habitats, and calculate rates of migration between pairs of habitats using dispersal kernels. Our primary results are quantitative estimates regarding how the success of carrier fixation in one or more habitats is determined by: the number of carriers released, sizes of habitats, distances between habitats, and the rate of migration between habitats. Besides yielding sensible and potentially useful predictions regarding the success of Wolbachia-based control, our framework applies to other approaches (e.g., gene drives) and contexts beyond the realm of insect pest control.

Rare, long-distance dispersal underpins genetic connectivity in the pink sea fan, Eunicella verrucosa.

Characterizing patterns of genetic connectivity in marine species is of critical importance given the anthropogenic pressures placed on the marine environment. For sessile species, population connectivity can be shaped by many processes, such as pelagic larval duration, oceanographic boundaries and currents. This study combines restriction-site associated DNA sequencing (RADseq) and passive particle dispersal modelling to delineate patterns of population connectivity in the pink sea fan, Eunicella verrucosa, a temperate octocoral. Individuals were sampled from 20 sites covering most of the species' northeast Atlantic range, and a site in the northwest Mediterranean Sea to inform on connectivity across the Atlantic-Mediterranean transition. Using 7510 neutral SNPs, a geographic cline of genetic clusters was detected, partitioning into Ireland, Britain, France, Spain (Atlantic), and Portugal and Spain (Mediterranean). Evidence of significant inbreeding was detected at all sites, a finding not detected in a previous study of this species based on microsatellite loci. Genetic connectivity was characterized by an isolation by distance pattern (IBD) (r 2 = 0.78, p < 0.001), which persisted across the Mediterranean-Atlantic boundary. In contrast, exploration of ancestral population assignment using the program ADMIXTURE indicated genetic partitioning across the Bay of Biscay, which we suggest represents a natural break in the species' range, possibly linked to a lack of suitable habitat. As the pelagic larval duration (PLD) is unknown, passive particle dispersal simulations were run for 14 and 21 days. For both modelled PLDs, inter-annual variations in particle trajectories suggested that in a long-lived, sessile species, range-wide IBD is driven by rare, longer dispersal events that act to maintain gene flow. These results suggest that oceanographic patterns may facilitate range-wide stepping-stone genetic connectivity in E. verrucosa and highlight that both oceanography and natural breaks in a species' range should be considered in the designation of ecologically coherent MPA networks.

Approximation of nonlocal dispersal problem with inhomogeneous kernel

In this paper, we study the Neumann problem for a class of nonlocal dispersal models with inhomogeneous kernel function. We investigate the existence, uniqueness, and limit of solutions when the inhomogeneous diffusion kernel is rescaled. Our result exhibits that the inhomogeneous nonlocal dispersal equation is analogous to local problem without convection in the limit case.

PROMETHEUS: Probability in the Mediterranean of Tephra dispersal for various grain sizes. A tool for the evaluation of the completeness of the volcanic record in medial-distal archives

PROMETHEUS is a statistical tool that allows creating maps showing the probability of finding tephra deposits of different grain sizes, originating from eruptions of a specific volcanic source, at any location around the vent. It couples wind profiles at different heights in the Mediterranean area with terminal velocity of volcanic particles. The input parameters include the height of the eruption column (which characterizes the intensity of the eruption), wind statistics (directions and intensities), and tephra deposits of a selected grain size. In particular, we used the parameterizations provided by Costa et al. (2016) and performed simulations using the HAZMAP tephra dispersal model to determine the maximum reachable distances that tephra can cover under weak, medium, and strong wind conditions (e.g. 7, 30, and 70 m/s velocities at the tropopause) and with column heights of 10, 20, and 30 km, depositing of at least the loading corresponding to 0.1 mm (corresponding to cryptotephra). Three alternative configurations of the model are validated analyzing first the eruptive source of Somma Vesuvius, with the related explosive eruptions from 22 ka Pomici di Base to the 1944 eruption. A further validation is made by comparing the probabilistic maps with the tephrostratigraphy of known marine and terrestrial cores using standard test of proportions (binomial distributions) and the binary logistic regression model, statistically quantifying the effectiveness of the model against the tephrostratigraphy recorded within this time frame. Based on this validation, a preferred configuration of PROMETHEUS is selected. PROMETHEUS probability maps will guide the selection of sampling sites for specific tephra deposits and could also support the study of the completeness of overall eruption catalogs over time.

Spread management priorities to limit emerald ash borer (Agrilus planipennis) impacts on United States street trees

AbstractThe invasive emerald ash borer (Agrilus planipennis) causes damage to street trees which is estimated to reach US$ 900 million over the next 30 years. Although millions of dollars are spent annually to control this species, spatiotemporal management plans are often based on rules of thumb that ignore future pest dispersal. Here, we reveal an optimal management strategy to protect urban trees in North America from A. planipennis. To achieve this, we embedded a pest dispersal model within a mixed integer programming framework. We discovered that optimized strategies consistently outperformed those based on rules of thumb, potentially resulting in the protection of an additional nearly 1 million street trees and savings of $ 629 million. Critically, the best management strategies always relied on quarantines and biological control (constituting 98–99% and 1–2% of the project budget, respectively), in contrast with current practices, where federal spending has been diverted to biological control. Our findings serve to inform future pest control efforts and can help protect many more trees from this invasive species.

Tephra segregation profiles based on disdrometer observations and tephra dispersal modeling: Vulcanian eruptions of Sakurajima volcano, Japan

The profile of tephra concentration along a volcanic plume (i.e., the tephra segregation profile) is an important source parameter for the simulation of tephra transport and deposition and thus for the tephra sedimentation load. The most commonly-used approach is to treat an eruption as a single event (i.e., with a time-averaged mass eruption rate; MER). In this case, it is common to use pre-determined profiles that feature most of the tephra segregate at the top of the plume. However, case studies based on observations have revealed that large concentration maxima also appear at the lower part of the plume. To investigate this discrepancy, the impact of plume height on the temporal variations in the MER is examined. To this end, we use the tephra transport and dispersion model Tephra4D with MER estimates obtained from geophysical monitoring and maximum plume height observations to calculate the spatial distribution of the tephra deposit load for 39 eruptive events that consisted of explosions and quasi-steady particle emission from the Sakurajima volcano, Japan. A comparison of the model results with observations from a disdrometer network revealed that for both kinds of activity, maxima in tephra segregation can occur at heights below the reported plume height. The tephra segregation profiles of Vulcanian eruptions at Sakurajima volcano are consistent with most of the modeling studies giving profiles that feature most of the tephra segregating at the top of the plume if the temporal variation of the MER is taken into consideration to properly represent the total series of eruptive events in a sequence. This highlights that even though the activity at Sakurajima volcano is commonly characterized simply as Vulcanian eruptions, in addition to the primary plume developed due to the initial instantaneous release caused by the explosion, the subsequent continuous plume that can accompany the eruption plays an important role in particle emission. Calculations could not reproduce the simultaneous deposition of particles with a wide range of settling velocities in observations, suggesting the importance of volcanic ash fingers caused by gravitational instability in tephra transport simulations.Graphical

Bidirectional biotic interchange between Taiwan Island and Mainland China via land bridges—A case study of Obeidia Walker (Geometridae, Lepidoptera)

AbstractBiotic exchanges between Taiwan and Mainland China have shaped the biodiversity and ecosystems of both regions. Exchanges from Mainland China to Taiwan have received more attention, mainly studied in terrestrial vertebrates, while the reverse direction and invertebrates have largely been overlooked. Here, we explore the dispersal events between these two regions based on the moths of three species groups of Obeidia, including Taiwan taxa and its relatives from mainland. We conducted mixed methods and analysis, including reconstructing a phylogenetic tree, estimating associated divergence times and inferring ancestral areas and source regions, to explore the phylogeographical structure and genetic pattern of three groups based on eight genes. Our results revealed a structure of three clades and every clade included at least one Taiwanese taxa and its closest relatives of mainland of China, and also served Taiwan as an important source region of two mainland taxa. Our study revealed various origin pattern and dispersal models on the basis of three species groups of Obeidia. Bi‐directional biotic exchange via a land bridge were found: four Taiwanese taxa originated from mainland, and two of them migrated back to mainland. Both eastern Himalayas and south China are important origin areas for Taiwan biota, and the dominant source region may need multiple insect cases to confirm. Our study also provided evidences for disjunct distribution from the perspective of insecta molecular phylogeny.

Larval dispersal and climate models provide insights into present and future distribution of a tropical sardine

ABSTRACT Climate change impacts the distribution of marine organisms and threatens fisheries. Marine protected areas (MPAs) may buffer the detrimental effects of environmental change by acting as biodiversity spillover to neighboring areas. Yet, it is uncertain whether MPAs on islands favor passive dispersal of species through oceanic currents, and how fish abundance and distribution will be impacted by ongoing global warming. Using the Brazilian-endemic scaled-sardines (Harengula sp.) as model, we implemented a Lagrangian particle-tracking model to estimate dispersal in the Brazilian coast and four MPAs in islands. Then, we projected an ecological niche model (ENM) of Harengula sp. to three climatic scenarios in 2100. Dispersal models suggested that three MPAs in islands export eggs and larvae acting as source of biomass to the coast. ENMs indicated a decrease in environmental suitability for Harengula sp. at the Equatorial Brazilian coast and a southward shift that increases as the climatic scenario is aggravated. Ocean warming may lead to a decrease in suitability for Harengula sp. in the northernmost part of its current distribution concomitant with an increase in offshore zones in the south of its current distribution. Ecosystem disturbance with environmental suitability shifts can aggravate the isolation of populations in islands.

Subtropical coastal microbiome variations due to massive river runoff after a cyclonic event

BackgroundCoastal ecosystem variability at tropical latitudes is dependent on climatic conditions. During the wet, rainy season, extreme climatic events such as cyclones, precipitation, and winds can be intense over a short period and may have a significant impact on the entire land‒sea continuum. This study focused on the effect of river runoff across the southwest coral lagoon ecosystem of Grand Terre Island of New Caledonia (South Pacific) after a cyclonic event, which is considered a pulse disturbance at our study site. The variability of coastal microbiomes, studied by the metabarcoding of V4 18S (protists) and V4–V5 16S (bacteria) rDNA genes, after the cyclone passage was associated with key environmental parameters describing the runoff impact (salinity, organic matter proxies, terrestrial rock origin metals) and compared to community structures observed during the dry season.ResultsMicrobiome biodiversity patterns of the dry season were destructured because of the runoff impact, and land-origin taxa were observed in the coastal areas. After the rainy event, different daily community dynamics were observed locally, with specific microbial taxa explaining these variabilities. Plume dispersal modeling revealed the extent of low salinity areas up to the coral reef area (16 km offshore), but a rapid (< 6 days) recovery to typical steady conditions of the lagoon's hydrology was observed. Conversely, during the same time, some biological components (microbial communities, Chl a) and biogeochemical components (particulate nickel, terrigenous organic matter) of the ecosystem did not recover to values observed during the dry season conditions.ConclusionThe ecosystem resilience of subtropical ecosystems must be evaluated from a multidisciplinary, holistic perspective and over the long term. This allows evaluating the risk associated with a potential continued and long-term disequilibrium of the ecosystem, triggered by the change in the frequency and intensity of extreme climatic events in the era of planetary climatic changes.

Making Your Own Luck: Weak Vertical Swimming Improves Dispersal Success for Coastal Marine Larvae

Dispersive early life stages are common in nature. Although many dispersing organisms (“propagules”) are passively moved by outside forces, some improve their chances of successful dispersal through weak movements that exploit the structure of the environment to great effect. The larvae of many coastal marine invertebrates, for instance, swim vertically through the water column to exploit depth-varying currents, food abundance, and predation risk. Several swimming behaviors and their effects on dispersal between habitats are characterized in the literature, yet it remains unclear when and why these behaviors are advantageous. We addressed this gap using a mathematical model of larval dispersal that scored how well behaviors allowed larvae to simultaneously locate habitats, avoid predators, and gather energy. We computed optimal larval behaviors through dynamic programming, and compared those optima against passive floating and three well documented behaviors from the literature. Optimal behaviors often (but not always) resembled the documented ones. However, our model predicted that the behaviors from the literature performed robustly well, if not optimally, across many conditions. Our results shed light on why some larval behaviors are widespread geographically and across species, and underscore the importance of carefully considering the weak movements of otherwise passive propagules when studying dispersal.

Assessing regional connectivity patterns of bivalvia in fragmented archipelagos: Insights from biophysical modeling in French Polynesia

Larval dispersal and connectivity are key processes that drive marine metapopulation dynamics, and therefore should be well characterized when designing effective management strategies. While temperature and food availability can structure marine species connectivity patterns, their contribution has not been thoroughly investigated in highly fragmented archipelagos. We used biophysical modeling of larval dispersal to explore the connectivity patterns of species with complex life-cycles across French Polynesia (FP), a territory formed by more than a hundred small, geographically isolated islands covering an area as large as Europe. We first simulated ten years of larval dispersal to investigate the spatial and temporal (seasonal and interannual) variability in larval dispersal pathways for different hypothetical species exhibiting a range of Larval Precompetency Period (LPP) values. Then, using the black-lip pearl oyster (Pinctada margaritifera) as a model species, we accounted for variability in the LPP induced by temperature and food availability, as derived from a Dynamic Energy Budget (DEB) model. The model showed that food availability and mesoscale turbulence (eddies) in the Marquesas jointly constrained larval dispersal, reducing its potential connectivity with other archipelagos in FP. The DEB simulations also revealed seasonal and interannual variability in connectivity driven by environmental conditions. However, accounting for food and temperature effects on larval development, barely changed the connectivity pattern at regional scale due to the remoteness of this archipelago. Our study thus provides appropriate management units definition at regional scale for the species across FP.

Larval Dispersal Modelling of the Blue Swimming Crab Portunus pelagicus (Linnaeus, 1758) from the Crab Banks along the Coast of Trang Province, Southern Thailand

In Thailand, the populations of a commercially important crab Portunus pelagicus (Linnaeus, 1758) have been decreasing due to overfishing, raising concerns about the conservation efforts of this crab species. The Crab Bank Project has recently been established to restore crab populations by releasing crab larvae from each crab bank station. However, the fate of crab larvae after the release is poorly understood. Here, we assessed the dispersal and settlement patterns of the larvae P. pelagicus released from crab banks along the coast of Trang Province, Southern Thailand. The Lagrangian particle tracking model was employed to simulate the larval dispersal and settlement patterns after release from the crab banks during the inter-monsoon, southwest monsoon, and northeast monsoon. Our simulation revealed that virtual larvae were predominantly retained within inshore areas after the release for 14 days, regulated by tidal-driven currents, wind-induced currents, and local coastal topography. Monsoon periods affected the larval dispersal, with some larvae being transported into estuaries due to the SW monsoonal effects. After the 14-day release period, our modelled simulations suggested that the crab larvae arrived at numerous seagrass meadows along the coast, indicating potential settlement and growth. This result highlights the connectivity of sources and sinks for crab larvae after release from crab banks. Moreover, significant implications for conservation efforts and the fishery management of P. pelagicus were also discussed based on our modelled simulations.

A gap analysis on modelling of sea lice infection pressure from salmonid farms. II. Identifying and ranking knowledge gaps: output of an international workshop

Sea lice are a major health hazard for farmed Atlantic salmon in Europe, and their impact is felt globally. Given the breadth of ongoing research in sea lice dispersal and population modelling, and focus on research-led adaptive management, we brought experts together to discuss research knowledge gaps. Gaps for salmon lice infection pressure from fish farms were identified and scored by experts in sea lice-aquaculture-environment interactions, at an international workshop in 2021. The contributors included experts based in Scotland, Norway, Ireland, Iceland, Canada, the Faroe Islands, England and Australia, employed by governments, industry, universities and non-government organisations. The workshop focused on knowledge gaps underpinning 5 key stages in salmon lice infection pressure from fish farms: larval production; larval transport and survival; exposure and infestation of new hosts; development and survival of the attached stages; and impact on host populations. A total of 47 research gaps were identified; 5 broad themes emerged with 13 priority research gaps highlighted as important across multiple sectors. The highest-ranking gap called for higher quality and frequency of on-farm lice count data, along with better sharing of information across sectors. We highlight the need for synergistic international collaboration to maximise transferable knowledge. Round table discussions through collaborative workshops provide an important forum for experts to discuss and agree research priorities.

Araucaria bidwillii genomics suggest Indigenous Peoples broadened translocation practices in response to settler colonialism

Abstract Retracing past anthropogenic dispersal of culturally important taxa offers insights to the biogeographic history of species, as well as the history of the people who interacted with them. Bunya Pine (Araucaria bidwillii Hook.) is a culturally and spiritually significant conifer tree for several Indigenous groups in eastern Australia. Sharing the edible nuts and attending Bunya gatherings is an important way for these groups to maintain their cultural connections and it has been hypothesized that prior to European colonization, Indigenous Peoples facilitated the dispersal of Bunya Pine as part of these ancient traditions. We used ethnohistorical information on the use of Bunya Pine by Indigenous Peoples to interpret genomic patterns within and between disjunct distributions of Bunya Pine. We found signatures of long‐term isolation within the Australian Wet Tropics (AWT) and extensive gene flow within southeast Queensland (SEQ) that does not fit models of faunal or passive dispersal. Within SEQ, we found greater population structure amongst sites known to pre‐date European colonization, than when colonial‐era planted sites were included in our analyses, suggesting that pre‐colonial translocation was sporadic or localized rather than systematic and widespread. Increased Indigenous translocations in conjunction with plantings by European settlers appears to have erased the natural pre‐colonial population structure of SEQ Bunya Pine. Our stairway plot models suggest sharp population decline of SEQ Bunya Pine in the early and late Pleistocene, though we did not find evidence that anthropogenic dispersal facilitated effective population size growth of the species in the Holocene. We concluded that pre‐colonial translocation of SEQ Bunya Pine was likely restricted by kinship‐based custodial rights, and that when Indigenous Peoples were displaced by European settlers, translocation was intensified to maintain cultural connectivity. This study is an example of how Indigenous Australian groups adapt plant management strategies to meet socio‐cultural needs and demonstrates the potential for plant genomics to supplement Indigenous Biocultural Knowledge that has been impacted by colonial dispossession. Read the free Plain Language Summary for this article on the Journal blog.

Spatial propagation of a nonlocal dispersal cooperation model under a shifting habitat: Acceleration or not?

In this paper, we study the spreading properties of a nonlocal dispersal reducible cooperation model under a shifting habitat. By considering the corresponding upper and lower control systems, we find that the left and right expansion fronts of the solutions with exponentially unbounded kernels propagate with finite speed and infinite speed, respectively. This is quite different from the case of exponentially bounded kernels (Wang and Li, 2020), in which the expansion fronts of the solutions always spread to the left and right with finite speeds. That is to say, we have found a new phenomenon that linear extension and accelerating propagation appear at the same time for such a system.

Integral Management Zones: A novel strategy for marine bivalve production in the Gulf of California, Mexico

Abstract The development of area‐based tools that combine fishing, aquaculture and repopulation practices is increasingly necessary and important to conserve ecosystems, promote sustainable use of marine resources and contribute to the well‐being of the people that rely on them. In the Gulf of California, Mexico, two small‐scale fishers' cooperatives were granted a Permit for Exploratory Aquaculture of bivalve species, and their members decided to set three zones within those concessions: (i) a zone for natural seed collection and repopulation, (ii) a no‐take zone and (iii) an area where fishing was allowed. This management arrangement, named by them as the Integral Management Zone (Zona de Manejo Integral), was conceived as an innovative alternative to the current policy tools available in the Mexican General Law for Sustainable Fisheries and Aquaculture. The natural collection of bivalve larvae in the artificial collectors was sufficient to allow the development of the repopulation project. Based on hydrodynamic models of larval dispersal, self‐recruitment was low, and the collection of seed depended on distant sources. The broader scale (regional) connectivity source–sink patterns should be considered in the design stages of the Integral Management Zones. The implementation of the Integral Management Zones can complement other conservation and fisheries management tools available in Mexican environmental and fisheries laws. The approach envisioned to implement this tool is participative, with a meaningful role of local fishers in the decisions concerning the use of these zones, with a supportive engagement of governmental and other stakeholders (e.g., academia and civil society organizations).

Traveling waves for a nonlocal dispersal SIRS epidemic model with age structure

&lt;abstract&gt;&lt;p&gt;This paper focuses on a SIRS infectious model of nonlocal dispersal adopted with age structure. We primarily investigate the existence and nonexistence of traveling wave solutions connecting the disease-free equilibrium state and the endemic equilibrium state. To be more precise, we obtain the existence of traveling wave solutions by constructing suitable upper and lower solutions and then applying Schauder's fixed point theorem when $ R_0 &amp;gt; 1 $ and $ c &amp;gt; c^* $. In addition, we prove the nonexistence of traveling wave solutions by applying the Laplace transform for $ R_0 &amp;gt; 1 $ and $ 0 &amp;lt; c &amp;lt; c^* $.&lt;/p&gt;&lt;/abstract&gt;