Search

In this Communication, we demonstrate that a deep artificial neural network based on a transformer architecture with self-attention layers can predict the long-time population dynamics of a quantum system coupled to a dissipative environment provided that the short-time population dynamics of the system is known. The transformer neural network model developed in this work predicts the long-time dynamics of spin-boson model efficiently and very accurately across different regimes, from weak system–bath coupling to strong coupling non-Markovian regimes. Our model is more accurate than classical forecasting models, such as recurrent neural networks, and is comparable to the state-of-the-art models for simulating the dynamics of quantum dissipative systems based on kernel ridge regression. [ABSTRACT FROM AUTHOR]

We derive an analytic expression of the non-equilibrium Fermi's golden rule (NE-FGR) expression for a Holstein–Tavis–Cumming Hamiltonian, a universal model for many molecules collectively coupled to the optical cavity. These NE-FGR expressions capture the full-time-dependent behavior of the rate constant for transitions from polariton states to dark states. The rate is shown to be reduced to the well-known frequency domain-based equilibrium Fermi's golden rule (E-FGR) expression in the equilibrium and collective limit and is shown to retain the same scaling with the number of sites in non-equilibrium and non-collective cases. We use these NE-FGR to perform population dynamics with a time-non-local and time-local quantum master equation and obtain accurate population dynamics from the initially occupied upper or lower polariton states. Furthermore, NE-FGR significantly improves the accuracy of the population dynamics when starting from the lower polariton compared to the E-FGR theory, highlighting the importance of the non-Markovian behavior and the short-time transient behavior in the transition rate constant. [ABSTRACT FROM AUTHOR]

We investigate the plasmon-mediated nonlinear dynamics and the optics of a laser emission of random nanoemitters (NEs) embedded in a two-dimensional (2D) lattice of conducting nanorings (NRs) enhanced by plasmon–polariton (PP) excitations. The interaction of quantum NEs with the PP field in the NRs perturbs the dynamics of the electronic populations in NEs, leading to a significant dependence of laser generation (dynamics) on the plasma frequency ωp of PP. This results in a strong coupling of NE field emission with the PP field and sharp variations of the average current in the NR lattice. The phase transition in the system was found when the macroscopic structures of PP fields are excited simultaneously in different regions of the system if ωp (control parameter) reaches critical value ωc. We have established the analytical dependence of the PP current I = I(ωp/ωc) on the plasma frequency, which is in excellent agreement with the results of numerical simulations. This effect may allow the design of new types of PP active devices with the use of conducting NRs in modern nanoelectronics. [ABSTRACT FROM AUTHOR]

In this paper, we introduce the Floquet mean-field dynamics and Floquet surface hopping approaches to study the nonadiabatic dynamics in periodically driven solid systems. We demonstrate that these two approaches can be formulated in both real and reciprocal spaces. Using the two approaches, we are able to simulate the interaction between electronic carriers and phonons under periodic drivings, such as strong light–matter interactions. Employing the Holstein and Peierls models, we show that strong light–matter interactions can effectively modulate the dynamics of electronic population and mobility. Notably, our study demonstrates the feasibility and effectiveness of modeling low-momentum carriers' interactions with phonons using a truncated reciprocal space basis, an approach impractical in real space frameworks. Moreover, we reveal that even with a significant truncation, carrier populations derived from surface hopping maintain greater accuracy compared to those obtained via mean-field dynamics. These results underscore the potential of our proposed methods in advancing the understanding of carrier–phonon interactions in various periodically driven materials. [ABSTRACT FROM AUTHOR]

Understanding the dynamics of excited-state vibrational energy relaxation in photosynthetic pigments is crucial for elucidating the mechanisms underlying energy transfer processes in light-harvesting complexes. Utilizing advanced femtosecond broadband transient fluorescence (TF) spectroscopy, we explored the excited-state vibrational dynamics of Chlorophyll-a (Chl-a) both in solution and within the light-harvesting complex II (LHCII). We discovered a vibrational cooling (VC) process occurring over ∼6 ps in Chl-a in ethanol solution following Soret band excitation, marked by a notable ultrafast TF blueshift and spectral narrowing. This VC process, crucial for regulating the vibronic lifetimes, was further elucidated through the direct observation of the population dynamics of higher vibrational states within the Qy electronic state. Notably, Chl-a within LHCII demonstrated significantly faster VC dynamics, unfolding within a few hundred femtoseconds and aligning with the ultrafast energy transfer processes observed within the complex. Our findings shed light on the complex interaction between electronic and vibrational states in photosynthetic pigments, underscoring the pivotal role of vibrational dynamics in enabling efficient energy transfer within light-harvesting complexes. [ABSTRACT FROM AUTHOR]

The dynamics of the sub-Ohmic spin-boson model under polarized initial conditions at finite temperatures is investigated by employing both analytical tools and the numerically accurate hierarchical equations of motion-tensor train method. By analyzing the features of nonequilibrium dynamics, we discovered a bifurcation phenomenon, which separates two regimes of the dynamics. It is found that before the bifurcation time, increasing temperature slows down the population dynamics, while the opposite effect occurs after the bifurcation time. The dynamics is highly sensitive to both initial preparation of the bath and thermal effects. [ABSTRACT FROM AUTHOR]

As an emerging technology in liquid inactivation, one of the main challenges of pulsed electric fields (PEFs) inactivation lies in quantitatively describing and predicting its lethality to microorganisms. However, due to its cross-scaled complexity and the consequent numerous regulatory factors, there is currently still no unified framework to understand the PEF dose–response relationship and the population dynamics theoretically. In this study, a simple yet powerful model from multiscale coarse-graining method is proposed to simulate the bacterial inactivation in suspensions during PEF processing. The complex dose–response effects at the macroscale are successfully reconstructed from simple evolution rules and several coarse-graining parameters, while considering the damage and death of a single bacterium at the microscale. Our model uncovers the seemingly chaotic and even controversial dose–response relationship of PEF in literatures and systematically explores the regulatory effect of experimental parameters in a unified framework. One of the interesting findings is that PEF with shorter pulsed width enhances lethality and reduces the minimal inhibitory time at a constant energy output per pulse, owing to the phase transitions in three bacterial population dynamics (Bistability mode, Avalanche mode, and Hybrid mode). Our study provides a new insight for numerically modeling PEF lethality in liquid inactivation and could serve as a guide for dosage management in practical applications. [ABSTRACT FROM AUTHOR]

Predicting the effects of warming temperatures on the abundance and distribution of organisms under future climate scenarios often requires extrapolating species-environment correlations to climatic conditions not currently experienced by a species, which can result in unrealistic predictions. For poikilotherms, incorporating species' thermal physiology to inform extrapolations under novel thermal conditions can result in more realistic predictions. Furthermore, models that incorporate species and spatial dependencies may improve predictions by capturing correlations present in ecological data that are not accounted for by predictor variables. Here, we present a joint species, spatially dependent physiologically guided abundance (jsPGA) model for predicting multispecies responses to climate warming. The jsPGA model uses a basis function approach to capture both species and spatial dependencies. We apply the jsPGA model to predict the response of eight fish species to projected climate warming in thousands of lakes in Minnesota, USA. By the end of the century, the cold-adapted species was predicted to have high probabilities of extirpation across its current range-with 10% of lakes currently inhabited by this species having an extirpation probability >0.90. The remaining species had varying levels of predicted changes in abundance, reflecting differences in their thermal physiology. Though the model did not identify many strong species dependencies, the variation in estimated spatial dependence across species suggested that accounting for both dependencies was important for predicting the abundance of these fishes. The jsPGA model provides a new tool for predicting changes in the abundance, distribution, and extirpation probability of poikilotherms under novel thermal conditions.

Decisions to disperse from a habitat stand out among organismal behaviours as pivotal drivers of ecosystem dynamics across scales. Encounters with other species are an important component of adaptive decision-making in dispersal, resulting in widespread behaviours like tracking resources or avoiding consumers in space. Despite this, metacommunity models often treat dispersal as a function of intraspecific density alone. We show, focusing initially on three-species network motifs, that interspecific dispersal rules generally drive a transition in metacommunities from homogeneous steady states to self-organized heterogeneous spatial patterns. However, when ecologically realistic constraints reflecting adaptive behaviours are imposed-prey tracking and predator avoidance-a pronounced homogenizing effect emerges where spatial pattern formation is suppressed. We demonstrate this effect for each motif by computing master stability functions that separate the contributions of local and spatial interactions to pattern formation. We extend this result to species-rich food webs using a random matrix approach, where we find that eventually, webs become large enough to override the homogenizing effect of adaptive dispersal behaviours, leading once again to predominately pattern-forming dynamics. Our results emphasize the critical role of interspecific dispersal rules in shaping spatial patterns across landscapes, highlighting the need to incorporate adaptive behavioural constraints in efforts to link local species interactions and metacommunity structure. This article is part of the theme issue Diversity-dependence of dispersal: interspecific interactions determine spatial dynamics.

By employing the numerically accurate multiple Davydov Ansatz (mDA) formalism in combination with the thermo-field dynamics (TFD) representation of quantum mechanics, we systematically explore the influence of three parameters—temperature, photonic-mode detuning, and qubit–phonon coupling—on population dynamics and absorption spectra of the Holstein–Tavis–Cummings (HTC) model. It is found that elevated qubit–phonon couplings and/or temperatures have a similar impact on all dynamic observables: they suppress the amplitudes of Rabi oscillations in photonic populations as well as broaden the peaks and decrease their intensities in the absorption spectra. Our results unequivocally demonstrate that the HTC dynamics is very sensitive to the concerted variation of the three aforementioned parameters, and this finding can be used for fine-tuning polaritonic transport. The developed mDA-TFD methodology can be efficiently applied for modeling, predicting, optimizing, and comprehensively understanding dynamic and spectroscopic responses of actual molecular systems in microcavities. [ABSTRACT FROM AUTHOR]

Scaffolded molecular networks are important building blocks in biological pigment–protein complexes, and DNA nanotechnology allows analogous systems to be designed and synthesized. System–environment interactions in these systems are responsible for important processes, such as the dissipation of heat and quantum information. This study investigates the role of nanoscale molecular parameters in tuning these vibronic system–environment dynamics. Here, genetic algorithm methods are used to obtain nanoscale parameters for a DNA-scaffolded chromophore network based on comparisons between its calculated and measured optical spectra. These parameters include the positions, orientations, and energy level characteristics within the network. This information is then used to compute the dynamics, including the vibronic population dynamics and system–environment heat currents, using the hierarchical equations of motion. The dissipation of quantum information is identified by the system's transient change in entropy, which is proportional to the heat currents according to the second law of thermodynamics. These results indicate that the dissipation of quantum information is highly dependent on the particular nanoscale characteristics of the molecular network, which is a necessary first step before gleaning the systematic optimization rules. Subsequently, the I-concurrence dynamics are calculated to understand the evolution of the vibronic system's quantum entanglement, which are found to be long-lived compared to these system–bath dissipation processes. [ABSTRACT FROM AUTHOR]

Ecological and evolutionary theories have proposed that species traits should be important in mediating species responses to contemporary climate change; yet, empirical evidence has so far provided mixed evidence for the role of behavioral, life history, or ecological characteristics in facilitating or hindering species range shifts. As such, the utility of trait-based approaches to predict species redistribution under climate change has been called into question. We develop the perspective, supported by evidence, that trait variation, if used carefully can have high potential utility, but that past analyses have in many cases failed to identify an explanatory value for traits by not fully embracing the complexity of species range shifts. First, we discuss the relevant theory linking species traits to range shift processes at the leading (expansion) and trailing (contraction) edges of species distributions and highlight the need to clarify the mechanistic basis of trait-based approaches. Second, we provide a brief overview of range shift-trait studies and identify new opportunities for trait integration that consider range-specific processes and intraspecific variability. Third, we explore the circumstances under which environmental and biotic context dependencies are likely to affect our ability to identify the contribution of species traits to range shift processes. Finally, we propose that revealing the role of traits in shaping species redistribution may likely require accounting for methodological variation arising from the range shift estimation process as well as addressing existing functional, geographical, and phylogenetic biases. We provide a series of considerations for more effectively integrating traits as well as extrinsic and methodological factors into species redistribution research. Together, these analytical approaches promise stronger mechanistic and predictive understanding that can help society mitigate and adapt to the effects of climate change on biodiversity.

Stochastic chemical kinetics is a widely used formalism for studying stochasticity of chemical reactions inside single cells. Experimental studies of reaction networks are generally performed with cells that are part of a growing population, yet the population context is rarely taken into account when models are developed. Models that neglect the population context lose their validity whenever the studied system influences traits of cells that can be selected in the population, a property that naturally arises in the complex interplay between single-cell and population dynamics of cell fate decision systems. Here, we represent such systems as absorbing continuous-time Markov chains. We show that conditioning on non-absorption allows one to derive a modified master equation that tracks the time evolution of the expected population composition within a growing population. This allows us to derive consistent population dynamics models from a specification of the single-cell process. We use this approach to classify cell fate decision systems into two types that lead to different characteristic phases in emerging population dynamics. Subsequently, we deploy the gained insights to experimentally study a recurrent problem in biology: how to link plasmid copy number fluctuations and plasmid loss events inside single cells to growth of cell populations in dynamically changing environments. [ABSTRACT FROM AUTHOR]

Obtaining robust estimates of population abundance is a central challenge hindering the conservation and management of many threatened and exploited species. Close-kin mark-recapture (CKMR) is a genetics-based approach that has strong potential to improve the monitoring of data-limited species by enabling estimates of abundance, survival, and other parameters for populations that are challenging to assess. However, CKMR models have received limited sensitivity testing under realistic population dynamics and sampling scenarios, impeding the application of the method in population monitoring programs and stock assessments. Here, we use individual-based simulation to examine how unmodeled population dynamics and aging uncertainty affect the accuracy and precision of CKMR parameter estimates under different sampling strategies. We then present adapted models that correct the biases that arise from model misspecification. Our results demonstrate that a simple base-case CKMR model produces robust estimates of population abundance with stable populations that breed annually; however, if a population trend or non-annual breeding dynamics are present, or if year-specific estimates of abundance are desired, a more complex CKMR model must be constructed. In addition, we show that CKMR can generate reliable abundance estimates for adults from a variety of sampling strategies, including juvenile-focused sampling where adults are never directly observed (and aging error is minimal). Finally, we apply a CKMR model that has been adapted for population growth and intermittent breeding to two decades of genetic data from juvenile lemon sharks (Negaprion brevirostris) in Bimini, Bahamas, to demonstrate how application of CKMR to samples drawn solely from juveniles can contribute to monitoring efforts for highly mobile populations. Overall, this study expands our understanding of the biological factors and sampling decisions that cause bias in CKMR models, identifies key areas for future inquiry, and provides recommendations that can aid biologists in planning and implementing an effective CKMR study, particularly for long-lived data-limited species.

The coexistence of obligate mutualists is often precariously close to tipping points where small environmental changes can drive catastrophic shifts in species composition. For example, microbial ecosystems can collapse by the decline of a strain that provides an essential resource on which other strains cross-feed. Here, we show that tipping points, ecosystem collapse, bistability and hysteresis arise even with very weak (non-obligate) mutualism provided the population is spatially structured. Based on numeric solutions of a metacommunity model and mean-field analyses, we demonstrate that weak mutualism lowers the minimal dispersal rate necessary to avoid stochastic extinction, while species need to overcome a mean threshold density to survive in this low dispersal rate regime. Our results allow us to make numerous predictions for mutualistic metacommunities regarding tipping points, hysteresis effects, and recovery from external perturbations, and let us draw general conclusions for ecosystems even with random, not necessarily mutualistic, interactions and systems with density-dependent dispersal rather than direct mutualistic interactions.

This two-year research was conducted to study the relationship(s) between the soil properties and the species diversity of weed community in saffron (Crocus sativus) fields in production poles of Afghanistan, including the Karukh, Injil, and the Ghoryan Districts, during 2020–2021 and 2021–2022 cropping seasons. The saffron fields (one-, two-, and larger than two-hectare fields) were selected based on the saffron cultivated area in each district. Weed sampling from the fields was done using a 0.25-m2 quadrat depending on the field area, between 5 (one-hectare fields) and 13 times (larger than two-hectare fields), through a W-shaped pattern within fields. The functional diversity of weeds (life cycle and vegetative form) was determined, and diversity indices were used to calculate the abundance, density, and dominance of weed species in each district. Also, soil properties of fields were investigated from the depths of 0–25 and 25–50 cm. The results showed that six variables, including electrical conductivity, absorbable potassium, carbon/nitrogen ratio, pH, moisture, and organic carbon percentage, had the highest effect on weed diversity. In conclusion, changing these factors might be a sustainable method for weed management in saffron fields in a way that these conditions negatively affect weed growth and establishment. [ABSTRACT FROM AUTHOR]

The Hefang crucian carp (HFJ) derived from Carassius cuvieri (♀) × C. auratus red var. (♂) and the crucian carplike homodiploid fish (NCRC) derived from Cyprinus carpio (♀) × Megalobrama amblycephala (♂) are important germplasm resources of crucian carp. To investigate the population characteristics and reveal the current genetic situations of these hybrid varieties, we sequenced one nuclear molecular marker transferrin (Tf) among six Carassius populations, which included two hybrid varieties (HFJ and NCRC), one laboratory variety (red crucian carp, RCC) and three wild populations. A total of 166 distinct Tf alleles (A1~A166) were identified, with sequence lengths ranging from 1145 bp to 1244 bp. Unexpectedly, the nucleotide diversity of Tf alleles in cultured populations (HFJ, NCRC, and RCC) exceeded that of wild populations. The phylogenetic reconstruction analysis results showed that HFJ and C. cuvieri were closely related, but they could not be separated from C. auratus. Besides, while most Tf alleles of NCRC and other Carassius populations were intermixed in five clades, two Tf alleles, together with Cy. carpio, formed a distinct monophyletic clade. Moreover, network and genetic structure analyses failed to distinguish between wild and cultured populations. Although AMOVA analysis based on Tf alleles indicated genetic differentiation among all six populations, the majority of the genetic variation (92.00 %) was observed within populations. Furthermore, the population dynamics analysis suggested that these populations have maintained relative stability in recent history. Therefore, the elevated nucleotide diversity of Tf alleles in cultured populations, the ambiguous population structure, and the limited genetic divergence among the six Carassius populations highlighted the hybrid genetic characteristics of HFJ and NCRC. These findings, based on Tf alleles, differ from the results obtained using mitochondrial gene markers, providing an alternative perspective for germplasm evaluation of hybrid varieties and crucian carp breeding. [ABSTRACT FROM AUTHOR]

Density dependence is often assumed in population dynamics, but its importance in small, isolated populations has been questioned. We evaluated the relative influence of density dependence, environmental conditions, and sporadic events (disease outbreaks and specialist predators) on annual population growth rate, annual female reproduction, and annual survival of juveniles and adult females in three populations of mountain ungulates. We analyzed long-term (30–47 years) individual-based data on two bighorn sheep populations and one mountain goat population in Alberta, Canada. The effect of cougar predation episodes and pneumonia epizootics on annual population growth rate was twice as strong as that of population density. While pneumonia reduced adult female and juvenile survival and predation episodes decreased all demographic rates, high density lowered only juvenile survival. Long-term studies are pivotal for understanding the dynamics of large herbivore populations, but they are rarely duplicated. Our analysis of three mountain ungulate populations with similar life history and ecological characteristics provides evidence that infrequent sporadic events can have a greater relative influence on annual population growth than density-dependent factors in isolated populations. This result contrasts with studies of larger, well-connected populations, highlighting the importance of considering sporadic events in the management and conservation of isolated populations. [ABSTRACT FROM AUTHOR]

Motivated by population growth in a heterogeneous environment, this manuscript builds a reaction-diffusion model with spatially dependent parameters. In particular, a term for spatially uneven maturation durations is included in the model, which puts the current investigation among the very few studies on reaction-diffusion systems with spatially dependent delays. Rigorous analysis is performed, including the well-posedness of the model, the basic reproduction ratio formulation and long-term behavior of solutions. Under mild assumptions on model parameters, extinction of the species is predicted when the basic reproduction ratio is less than one. When the birth rate is an increasing function and the basic reproduction ratio is greater than one, uniqueness and global attractivity of a positive equilibrium can be established with the help of a novel functional phase space. Permanence of the species is shown when the birth function is in a unimodal form and the basic reproduction ratio is greater than one. The synthesized approach proposed here is applicable to broader contexts of studies on the impact of spatial heterogeneity on population dynamics, in particular, when the delayed feedbacks are involved and the response time is spatially varying. [ABSTRACT FROM AUTHOR]

Population status and dynamics of Greater Flamingos were studied at selected wetlands in Gurugram and Rewari districts of Haryana State during 63 monthly periodic visits between July, 2019 and June, 2021. The population estimation of Greater Flamingo was accounted using the point count method at various sites during the field survey. The population status of flamingos in the area, as well as their habitat preferences, is still poorly known. Hence, the purposes of the present study were to assess the population structure and dynamics of the Greater Flamingo in the study area. A maximum of 1350 individuals of flamingo were counted at the Najafgarh Jheel sites consisting of 13 flocks with flock sizes ranging 29 to 211 individuals per sighting. The overall mean flock size of Greater Flamingos was 79.34 ± 04.80 SE. The age composition of flamingo populations indicates the presence of both adult and sub-adult groups within the flock. Najafgarh Jheel experienced an increase in adult flamingos from 58.6 to 73.2% and a decrease in sub-adults from 41.3 to 26.7%, with total numbers decreasing from 7175 to 4968. There were more flamingos recorded in the first year of study (July, 2019 to March, 2020) as compared to the second year of study (July, 2020 to June, 2021). Overall, data from a two-year study demonstrate that the majority of the Greater Flamingo population is found in Najafgarh Jheel. However, increased fishing activity adversely affects the population of flamingos in Najafgarh Jheel. During the second year of study road construction activities are at their peak which are major disturbances, due to which a huge decline is observed in the flamingo's population at Basai Wetland. The continuous monitoring of population distribution of Greater Flamingos helps in planning and establishment of appropriate conservation measures for this species. [ABSTRACT FROM AUTHOR]

Lumbricid earthworms as ecosystem engineers are of a profound significance for the functioning of detrital food webs; hence, their responses to effects of soil environment need to be investigated for a better understanding of their activities. However, despite the ample knowledge on the effects of various soil parameters, studies on their combined effects on earthworm performance are rare. In the present study reproduction activity of an epigeic species, Dendrobaena octaedra, was experimentally assessed as affected by a combination of several parameters of soil environment (namely, temperature and moisture constant and fluctuating regimes, amount of leaf-litter food resource and presence of conspecifics), in the gradients of their intensity in the nature. Temperature regime most significantly explained the rates of offspring production in D. octaedra. The range of daily temperature fluctuations around the reproductive optimum (15°C) was the major factor determining the variation of earthworm fecundity and biomass loss, apparently promoting a reallocation of available resources between self-maintenance and reproduction effort. In contrast, changes in moisture from constantly moist litter to fluctuations between wet—relatively dry litter did not prove significant suggesting a considerable tolerance of D. octaedra reproduction activity to variations in moisture regime. Amount of litter—food and shelter of earthworms showed a subordinate significance. A second important factor was intraspecific competition strongly negatively affecting reproduction rates in D. octaedra. Possible consequences of these effects for carbon budget of earthworm individuals and dynamics of field populations are discussed. [ABSTRACT FROM AUTHOR]

The stock assessment model for the Antarctic krill fishery is a population model operating on daily timesteps, which permits modeling within‐year patterns of some population dynamics. We explored the effects of including within‐year patterns in natural and fishing mortality on catch limits of krill, by incorporating temporal presence of key predator species and contemporary temporal trends of the fishing fleet. We found that inclusion of within‐year variation in natural and fishing mortalities increased catch limits. Fishing mortality had a greater effect than natural mortality despite differences in top‐down predation on krill, and potentially increased catch limits by 24% compared to the baseline model. Additionally, the stock assessment model allowed a higher catch limit when fishing was during peak summer months than autumn. Number of days with active fishing was negatively related to precautionary catch limits. Future stock assessments should incorporate contemporary spatiotemporal fishing trends and consider implementing additional ecosystem components into the model. [ABSTRACT FROM AUTHOR]

Tree hollows support a specialised species‐rich fauna. We review the habitat requirements of saproxylic (= deadwood dependent) invertebrates which occupy tree hollows. We focus on studies quantifying relationships between species occurrence patterns and characteristics of tree hollows, hollow trees, and the surrounding landscape. We also explore the processes influencing species occurrence patterns by reviewing studies on the spatio‐temporal dynamics of populations, including their dispersal and genetic structure. Our literature search in the database Scopus identified 52 relevant publications, all of which were studies from Europe. The dominant taxonomic group studied was beetles. Invertebrates in hollow trees were often more likely to be recorded in trees with characteristics reflecting a large amount of resources or a stable and warm microclimate, such as a large diameter, large amounts of wood mould (= loose material accumulated in the hollows mainly consisting of decaying wood), a high level of sun exposure, and with entrance holes that are large and either at a low or high height, and in dry hollows, with entrances not directed upwards. A stable microclimate is probably a key factor why some species of saproxylic invertebrates are confined to tree hollows. Other factors that are different in comparison to downed dead wood is the fact that hollows at a given height from the ground provide shelter from ground‐living predators, that hollows persist for longer, and that the content of nutrients might be enhanced by the accumulation of dead leaves, insect frass, and remains from dead insects. Several studies have identified a positive relationship between species occupancy per tree and the amount of habitat in the surrounding landscape, with a variation in the spatial scale at which characteristics of the surrounding landscape had the strongest effect over spatial scales from 200 to 3000 m. We found empirical support for the extinction threshold hypothesis, which predicts that the frequency of species presence per tree is greater if a certain number of trees are aggregated into a few large clusters of hollow trees rather than distributed among many small clusters. Observed thresholds in species occurrence patterns can be explained by colonisation–extinction dynamics, with species occupancy per tree influenced by variation in rates of immigration. Consistent with this assumption, field studies suggest that dispersal rate and range can be low for invertebrates occupying tree hollows, although higher in a warmer climate. For one species in which population dynamics has been studied over 25 years (Osmoderma eremita), the observed population dynamics have characteristics of a "habitat‐tracking metapopulation", as local extinctions from trees occur possibly because those trees become unsuitable as well as due to stochastic processes in small populations. The persistence of invertebrate fauna confined to tree hollows may be improved by prolonging the standing life of existing hollow trees. It is also important to recruit new generations of hollow trees, preferably close to existing larger groups of hollow trees. Thus, the spatio‐temporal dynamics of hollow trees is crucial for the invertebrate fauna that rely upon them. [ABSTRACT FROM AUTHOR]

The life history of parasitoids is divided into a parasitic immature stage living in or on a host invertebrate and a free‐living adult stage. We still have little consensus on how larvae and adult parasitoids differ in their responses to environmental heat waves.We tested the performance of two cosmopolitan drosophila pupal parasitoids, Pachycrepoideus vindemiae (Hymenoptera: Pteromalidae) and Trichopria drosophilae (Hymenoptera: Diapriidae), when exposed to 35 and 40°C heat waves in the larval and adult stage, respectively. Additionally, we tested if heat hardening in the larval stage influenced the thermal tolerance of adult parasitoids.P. vindemiae had a higher tolerance to heat waves than T. drosophilae in both the larval and adult stages. We did not find significantly increased thermal tolerance of adult wasps that experienced heat hardening during the larval stage.A 35°C heat wave had no effect on P. vindemiae. Larval T. drosophilae that experienced a 35°C heat wave had longer development times, but individuals that survived showed no significant decrease in longevity and fecundity compared with those without warming experience. By contrast, adult T. drosophilae suffered less mortality from the 35°C heat wave, but individuals that survived had significantly reduced longevity and fecundity. A 40°C heat wave resulted in higher mortality in the larval stage than in the adult stage for both parasitoid species.Our study clearly revealed the contrasting responses to heat waves in the larval and adult stages of two parasitoids and highlighted the importance of ontogenetic differences in thermal tolerance in predicting parasitoid distributions and population dynamics. [ABSTRACT FROM AUTHOR]

Dynamic occupancy model estimates the probabilities of occupancy, detection, extinction and colonization of individuals throughout seasons and is, thus, a useful tool for identifying whether individuals select a site to improve population phenology and fitness.We used multi‐season dynamics occupancy models to assess how abiotic factors (monthly variation, percentage of forest and edge and temperature) and biotic factors (female abundance) affect the demographic dynamics of coprophagous beetles Deltochilum mexicanum and Dichotomius satanas that differ in their habitat preferences in a human‐modified landscape in a cloud forest in Mexico.For both species, we captured a total of 1069 individuals with a density of 48.2 individuals per trap in forest areas and 14.8 individuals per trap in non‐forest areas. The species differed in their spatiotemporal occupancy dynamics in the landscape. Specifically, we found that monthly variation, percentage of forest cover and percentage of edge affected the models for both species. Each species showed a specific set of explanatory covariates for the model parameters, indicating that phenological and demographic regulatory mechanisms act as drivers of the spatiotemporal occupancy in a year period.We highlight the importance of considering abiotic factors (landscape characteristics) as drivers of occupancy, especially in highly heterogeneous landscapes. Such understanding is relevant to establish the effects of the landscape on the distribution and occurrence of dung beetles by determining how forest and generalist species differ in colonization and extinction patterns with respect to their phenology. [ABSTRACT FROM AUTHOR]

Continuous-time predator–prey models admit limit cycle solutions that are vulnerable to the phenomenon of phase-sensitive tipping (P-tipping): The predator–prey system can tip to extinction following a rapid change in a key model parameter, even if the limit cycle remains a stable attractor. In this paper, we investigate the existence of P-tipping in an analogous discrete-time system: a host-parasitoid system, using the economically damaging forest tent caterpillar as our motivating example. We take the intrinsic growth rate of the consumer as our key parameter, allowing it to vary with environmental conditions in ways consistent with the predictions of global warming. We find that the discrete-time system does admit P-tipping, and that the discrete-time P-tipping phenomenon shares characteristics with the continuous-time one: Both require an Allee effect on the resource population, occur in small subsets of the phase plane, and exhibit stochastic resonance as a function of the autocorrelation in the environmental variability. In contrast, the discrete-time P-tipping phenomenon occurs when the environmental conditions switch from low to high productivity, can occur even if the magnitude of the switch is relatively small, and can occur from multiple disjoint regions in the phase plane. [ABSTRACT FROM AUTHOR]

Soy sauce is a popular fermented seasoning due to its distinct flavor and rich umami taste. Its traditional production involves two stages: solid-state fermentation and moromi (brine fermentation). During moromi, the dominant microbial population in the soy sauce mash changes, which is called microbial succession and is essential for the formation of soy sauce flavor compounds. Research has identified the sequence of succession, starting with Tetragenococcus halophilus, then Zygosaccharomyces rouxii, and lastly, Starmerella etchellsii. Factors such as the environment, microbial diversity, and interspecies relationships drive this process. Salt and ethanol tolerance influence microbial survival, while nutrients in the soy sauce mash support the cells in resisting external stress. Different microbial strains have varying abilities to survive and respond to external factors during fermentation, which impacts soy sauce quality. In this review, we would examine the factors behind the succession of common microbial populations in the soy sauce mash and explore how microbial succession affects soy sauce quality. The insights gained can help better manage the dynamic changes in microbes during fermentation, leading to improved production efficiency. [ABSTRACT FROM AUTHOR]

This study explores the Orthoptera community in the Nara Desert, Sindh, focusing on Oedipodinae species: Hilethera aeolopoides, Aiolopus thalassinus thalassinus, Acrotylus humbertianus, Acrotylus longipes longipes, Sphingonotus rubescens rubescens, Sphingonotus savignyi, Locusta migratoria, and Oedaleus senegalensis. We assessed their population dynamics, including diversity, density, and reproductive success, using field and laboratory methods. Our results show considerable species variation S. savignyi had the highest reproductive success (Net Reproduction Rate Ro = 9.0) and largest population (27 individuals), while A. longipes longipes had the lowest reproductive rate (0.5 births per pair) and highest mortality (0.3 deaths per pair), resulting in the smallest population (5 individuals). Density varied, with L. migratoria being the least dense, and A. longipes longipes and O. senegalensis being the densest. Dominance and evenness analyses showed S.rubescens rubescens and H. aeolopoides as more ecologically influential, while A.longipes longipes and L.migratoria had higher evenness. These findings highlight the impact of reproductive efficiency and density on species abundance and ecological roles, offering key insights for conservation and management in the Nara Desert to preserve biodiversity and ecological balance. [ABSTRACT FROM AUTHOR]

Leopards (Panthera pardus), as versatile carnivores, play a crucial role in ecosystem stability. However, their survival is threatened by habitat loss and poaching. Accurate population estimates are vital for effective conservation decisions, but precise data are often lacking. This study was conducted to assess the population dynamics and suitable habitats of leopards in two important urban landscapes of central India, namely, Indore and Jabalpur, Madhya Pradesh, from September 2021 to May 2022. The camera trap mark-recapture technique was employed to estimate leopard populations, and the maximum entropy (Maxent)-based habitat suitability model was used to assess suitable habitats for leopards in these urban areas. Substantial leopard populations were identified in both urban landscapes: 23.0 ± 4.8 in Indore and 17.6 ± 5.4 in Jabalpur, despite high human density, with forested areas within and around these cities serving as vital habitats. The habitat suitability analysis highlighted critical factors influencing leopard distribution, including temperature, precipitation, and the human footprint. This research underscores the importance of conservation measures to protect these habitats and preserve their ecological balance. The findings provide essential insights for wildlife conservation and urban planning, emphasizing the need to prioritize the protection of existing forest patches and the mitigation of human‒wildlife conflicts. This study contributes to understanding the intricate relationship between urban development and wildlife conservation in central India. [ABSTRACT FROM AUTHOR]

The productivity of Pacific Sockeye salmon (Oncorhynchus nerka) in the Columbia River has been declining over the past century. Yet, the Okanagan River Sockeye salmon population, which spawns in the Okanagan River, a Canadian tributary of the Columbia River, has seen a remarkable turnaround in abundance. Different hypotheses and lines of evidence covering multiple spatial scales have been proposed to explain this recovery; but they have never been comprehensively assessed. We adopted a weight-of-evidence approach to systematically assess the relative likelihood that each of these causal hypotheses contributed to the observed recovery. Our analysis disentangles the relative consequences of a set of environmental management actions that have been implemented to augment the Sockeye salmon freshwater productivity, while accounting for changes in freshwater and marine environmental conditions. Our list of potentially explanatory causal factors (anthropogenic and natural) included: (1) changes in escapement concurrent with improving local fish passage, (2) the implementation of fish-friendly flows in the Okanagan River, (3) initiating a hatchery restocking program, (4) potential improvements to Columbia dam operations to support higher relative survival of out-migrating juvenile fish, (5) possible shifts in survival-favorable conditions in the coastal marine environment for ocean-going life stages, and (6) broader changes to multi-stock harvest regimes in the Columbia River. Our assessment leveraged comparisons with the population dynamics of another Sockeye salmon stock in the Columbia River basin to differentiate between the impacts of management actions taken within the Okanagan watershed (our focus) from those occurring over the broader basin and marine scale. The results suggest that while shifts towards survival-favorable conditions in the coastal marine environment in 2007 played an important role in the upturn of the Okanagan population, alone it cannot explain the rate at which the Okanagan River Sockeye salmon recovered. Strong evidence supports the combined effect of increased escapement in conjunction with establishing and securing fish-friendly flows during spawning, incubation, and alevin emergence. Additionally, Sockeye salmon restocking improved the resilience of the stock against density-independent mortality events. These combined basin-level management actions played a pivotal role in magnifying the recovery trajectory afforded by improved marine survivorship. The spectacular response of the Okanagan River Sockeye salmon to the holistic perspectives and management interventions of Indigenous and other caretakers provides hope that other Pacific salmon stocks can be stabilized and recovered. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Lepidopteran pest control in agriculture has become heavily dependent on cultivars that express Bacillus thuringiensis (Bt) toxins as 'plant‐incorporated protectants'. However, populations of Spodoptera frugiperda (Smith) in Brazil appear resistant to the Bt traits currently available in commercial soybean cultivars. RESULTS: This study evaluated S. frugiperda life history when feeding on three different Bt soybean cultivars. Cultivars expressing Cry1Ac + Cry1F and Cry1A.105 + Cry2Ab2 + Cry1Ac Bt toxins caused 100% larval mortality in S. frugiperda. Both non‐Bt and Cry1Ac‐expressing soybean induced transgenerational effects that increased the survival of subsequent generations. A Cry1Ac soybean diet reduced the generation time (T) of S. frugiperda relative to non‐Bt soybean, resulting in shorter generation time and more rapid population growth. CONCLUSION: The implications of these results revealed how diet can alter aspects of insect life history and biology, and have important implications for sustainable management of S. frugiperda on soybean. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Population irruptions of the Pacific crown-of-thorns starfish (CoTS, Acanthaster cf. solaris) are a key source of coral loss on Australia's Great Barrier Reef (GBR). CoTS management currently involves their manual control (culling) to threshold densities below which net coral decline theoretically ceases based on analysis of a validated population dynamics model. Spatial variability in coral growth and community composition, and their predicted changes under continuing global warming, necessitate further consideration of current coral representation in CoTS models. Here, we consider the sensitivity of equilibrium coral-CoTS thresholds to coral growth rates and consider how the demographic composition of CoTS at a site may relate to culling thresholds. We found thresholds should be location-specific if the objective of CoTS control is coral recovery, but location-specific thresholds may not be needed if the objective is to limit coral cover loss based on coral growth and CoTS demography. The consequence of using a higher CPUE threshold than the analytical equilibrium coral-CoTS thresholds in terms of coral cover loss is suggested to be limited at coral cover < 40%, and varying control thresholds thereof may make little difference. Introducing a 0.06 CoTS.min−1 threshold for 40–60% coral cover may reduce coral loss at ~ 40% where it is likely greatest. With regional GBR coral cover averaging < 40%, this study validates the 0.04–0.08 CoTS.min−1 tiered threshold system for CoTS control and suggests methods developed from localised studies can be more broadly applicable and well-defined objectives (e.g. avoiding coral cover decline at a site) can help guide what thresholds are used and the sensitivity around these. [ABSTRACT FROM AUTHOR]

Fear associated with perceived predation risk can elicit behavioral and physiological changes in animals, including insects. Diamondback moth (DBM), Plutella xylostella, larvae are known to wriggle violently backwards and even fall off plants when attacked by predators and parasitoids. In the laboratory, the DBM larvae exposed to the specialist parasitoid Diadegma insulare were found to move to lower quality, older foliage, which negatively affected their development. In Hawaii, by far the dominant parasitoid species of DBM is the generalist Cotesia vestalis, with many sampling efforts often only yielding this species. Thus, in this study, we investigated the influence of C. vestalis on the behavior of DBM larvae. We focused on the distribution of DBM on cabbage plants, from the youngest to oldest leaves (leaf position 1–12, respectively), in the presence of C. vestalis in the lab and field. We found that in the lab, DBM larvae showed a clear preference for younger leaves (leaf positions 3–5). However, when C. vestalis was present, regardless of whether the parasitoids could touch the DBM, larvae were less likely to be on those preferred leaf positions. This change in larval distribution was also replicated when potted cabbage plants containing DBM larvae were placed in cabbage fields. Changes in herbivore feeding sites, whether mediated by natural enemies or other environmental factors, could have significant implications, not only for herbivore fitness, but also for economic damage to crops based on the value of plant parts affected. [ABSTRACT FROM AUTHOR]

Climate change can affect reef fish both directly (e.g., mortality, growth, fecundity) and indirectly (e.g., habitat degradation). The extent to which the effects of rising water temperature could drive changes in fish populations and if and how these effects may interact with potential management interventions remain unclear. The objective of this study was to test various hypothesized mechanisms by which sea surface temperature (SST) could affect reef fish population dynamics and explore these effects in combination with fishing effort restrictions and spatial closures. To do this, we modeled hypothesized relationships between SST and two governing parameters of the fish populations: intrinsic growth rate (r) and carrying capacity (K). We coupled these temperature-dependent fish population models with a fisheries harvest model and explored interactions between thermal effects, fishing effort level, and spatial closures. Under small closure scenarios, we found that the thermal effects models predicted substantially lower fish population biomass and harvest compared to the baseline (constant r and K) model. Under large closure scenarios, the thermal effects models more closely resembled the baseline. Generally, incorporating spatial closures mitigated some of the detrimental thermal effects on fish biomass and allowed for increased harvest under certain fishing effort levels. Whether intrinsic growth or carrying capacity most affected fish population levels also depended on the fishing effort and the spatial closure area. Overall, we described how fishing effort and spatial closures can influence the relative importance of key processes and the extent to which rising water temperatures affect fish populations and harvest. [ABSTRACT FROM AUTHOR]

We consider a drift-diffusion equation modelling the dynamics of a population of macrophage cells within the arterial wall in the presence of lipids. Lipids occupy a given and fixed region of the arterial wall. When macrophage cells pass through this region, they internalise lipids, causing them to grow and slow down. In this equation, the unknown function depends on the spatial variable and also on an additional structural variable: the quantity of lipid ingested. The diffusion coefficient depends on this additional variable and the drift acts on this variable through a power law coupled to a spatial localisation function. This leads to a problem whose mathematical novelty is the dependence of the diffusion coefficient on the past trajectory. We discuss global existence and blow-up of solutions to this model. [ABSTRACT FROM AUTHOR]

Measuring infaunal population dynamics relies on destructive sampling that disturbs sediments and removes animals from their habitat. Establishing effective, non-invasive sampling methods for monitoring infaunal populations can reduce the impact of scientific sampling and facilitate efficient population assessments. Using intertidal soft-shell clams (Mya arenaria L.) in eastern Canada, we explored whether population density and size structure could be estimated from visible siphon holes. Across four sites with varying sediment characteristics and infaunal species assemblages, we predicted the presence of M. arenaria with 78–100% accuracy by visually assessing siphon holes. Smaller holes (< 7.5 mm) were more likely to be misidentified. Siphon hole count was a strong predictor of actual clam count and biomass at most sites, except the site with wet muddy sediment and high densities of other infaunal species. Siphon hole length was positively related to clam shell length and wet weight at all sites; however, relationships typically had low R2 values (< 0.35). Ultimately, visual assessments of intertidal siphon holes can be effective for estimating M. arenaria densities and size structure in some habitats. Testing the application of this method to other habitats and species is warranted. [ABSTRACT FROM AUTHOR]

Urbanization and fragmentation of habitat are major drivers of population declines in wildlife in cities. This study evaluated fragmentation of aquatic systems in the context of urbanization, using the Eastern long-necked turtle Chelodina longicollis as a model as it is a generalist species, highly vagile and engages in regular overland migration. During two seasons (2020-22), we compared C. longicollis demography in stormwater ponds in two distinct urban drainages, one with greater habitat connectivity (lower road network and an unmodified creek) and one with lower habitat connectivity (higher road network and stormwater drains) in Canberra, south-eastern Australia. Most of the parameters related to habitat (pond age and size) and food requirements (phosphate and prey biomass) for C. longicollis were similar between the two drainages, in addition to proportion of females, overall size-frequency distributions and population size (corrected for variation in capture probability). However, there was a significant effect of the interaction between pond habitat connectivity and pond size with population sizes increasing more steeply in higher than in lower connectivity sites (F1, 4 = 14.3, p = 0.02). We also recaptured a marked turtle from a previous study in the drainage with more habitat connectivity, 14 years later and 15 km from its initial point of capture. This demonstrates the ability of the species to move within an urbanized context. Despite evidence of C. longicollis being resilient to urbanization, dispersal constraints seem to affect population dynamics and long term population viability in areas with low habitat connectivity. [ABSTRACT FROM AUTHOR]

Sympatric speciation is an important phenomenon in Evolution: a population being able to express two different phenotypes gives rise to a new species without a physical separation from the original population. In this paper, we describe a model that describes the sympatric speciation process using a population dynamics approach. Our aim is to point out some dynamical features that could be observed in a population where a sympatric speciation process is going on. Some interesting stochastic effects are discussed by means of numerical simulations. [ABSTRACT FROM AUTHOR]

ABSTRACT Quantifying connectivity between endangered or threatened marine populations is critical information for management and conservation, especially where abundance and productivity differ among such populations. Spatial patterns of such connectivity depend not only on extrinsic factors such as oceanography and bathymetry but also on intrinsic species‐specific factors such as life history, demography and the location of glacial refugia. Nevertheless, population structure is often inferred from related or ecologically similar species. For example, the population structure in most rockfish species (Sebastes spp.) in the Salish Sea and the US West Coast is currently inferred from genetic data of three species that are known to hybridise in Puget Sound. Here, we determined the population structure and connectivity in five Puget Sound Rockfish species (Black [Sebastes melanops], Yellowtail [S. flavidus], Redstripe [S. proriger], Greenstriped [S. elongatus], and Puget Sound Rockfish [S. emphaeus]) from over 12,000 restriction‐site associated DNA sequencing (RADseq) loci. We found species‐specific patterns of genetic differentiation, attributable to both extrinsic and intrinsic factors. Specifically, Black and Puget Sound rockfishes showed no genetic differentiation; Yellowtail and Greenstriped rockfishes were structured according to known geographic barriers; and Redstripe Rockfish revealed evidence for temporal genetic differentiation, suggesting irregular recruitment influences population structure. Only Yellowtail Rockfish followed the federal DPS boundaries generally assumed for rockfish, further emphasizing the importance of species‐specific management for the effective recovery and management of these rockfish populations and of marine species in general. [ABSTRACT FROM AUTHOR]

ABSTRACT Although efforts to estimate effective population size, census size and their ratio in wild populations are expanding, few empirical studies investigate interannual changes in these parameters. Hence, we do not know how repeatable or representative many estimates may be. Answering this question requires studies of long‐term population dynamics. Here we took advantage of a rich dataset of seven brook trout (Salvelinus fontinalis) populations, 5 consecutive years and 5400 individuals genotyped at 33 microsatellites to examine variation in estimates of effective and census size and in their ratio. We first estimated the annual effective number of breeders (N̂$$ \hat{N} $$b) using individuals aged 1+. We then adjusted these estimates using two life history traits, to obtain N̂badj2$$ {\hat{N}}_{b(adj2)} $$ and subsequently, N̂eadj2$$ {\hat{N}}_{e(adj2)} $$ following Waples et al. (2013). N̂eadj2$$ {\hat{N}}_{e(adj2)} $$ was estimated for the years 2014 to 2019. Census size was estimated by mark recapture using double‐pass electrofishing (N̂cMR$$ {\hat{N}}_{c(MR)} $$) (years 2014–2018) as well as by the Close Kin Mark Recapture approach (N̂cCKMR$$ {\hat{N}}_{c(CKMR)} $$) (years 2015–2017). Within populations, annual variation in N̂eadj2$$ {\hat{N}}_{e(adj2)} $$ (ratio of maximum to minimum N̂eadj2$$ {\hat{N}}_{e(adj2)} $$) ranged from 1.6‐fold to 58‐fold. Over all 7 populations, the median annual variation in N̂eadj2$$ {\hat{N}}_{e(adj2)} $$ was around 5‐fold. These results reflect important interannual changes in the variance in reproductive success and more generally in population dynamics. Within population N̂cMR$$ {\hat{N}}_{c(MR)} $$ varied between years by a (median) factor of 2.7 with a range from 2 to 4.3. Thus, estimated effective size varied nearly twice as much as did estimated census size. Our results therefore suggest that, at least in small populations like those examined in the present study, any single annual estimate of N̂eadj2$$ {\hat{N}}_{e(adj2)} $$ is unlikely to be representative of long‐term dynamics. At least 3–4 annual estimates may be required for an estimate of contemporary effective size to be truly representative. We then compared N̂cMR$$ {\hat{N}}_{c(MR)} $$ to N̂cCKMR$$ {\hat{N}}_{c(CKMR)} $$. For five of the seven populations, the estimates of population abundance based on mark recapture (N̂cMR$$ {\hat{N}}_{c(MR)} $$) were indistinguishable from those based on close kin mark recapture (N̂cCKMR$$ {\hat{N}}_{c(CKMR)} $$). The two populations with discordant N̂cMR$$ {\hat{N}}_{c(MR)} $$ and N̂cCKMR$$ {\hat{N}}_{c(CKMR)} $$ exhibited extremely low N̂eadj2/N̂cMR$$ {\hat{N}}_{e(adj2)}/{\hat{N}}_{c(MR)} $$ ratios and the largest annual variation in N̂eadj2$$ {\hat{\ N}}_{e(adj2)} $$ (58‐fold and 35.4‐fold respectively). These results suggest that sampling effort in these two streams may have been insufficient to properly capture the genetic diversity of the entire population and that individuals sampled were not representative of the population. Our study further validates CKMR as a method for estimating abundance in wild populations and it demonstrates how knowledge of the temporal variation in N̂e$$ {\hat{N}}_e $$ can be used to identify potential sources of discrepancies between N̂cMR$$ {\hat{N}}_{c(MR)} $$ and N̂cCKMR$$ {\hat{N}}_{c(CKMR)} $$. [ABSTRACT FROM AUTHOR]

This paper presents a compartmental model in ordinary differential equations of tuberculosis (TB) disease dynamics in a prison population, which is calibrated to reflect the unique conditions of the Democratic Republic of Congo. Data are sourced from various sources of statistics that are publicly available and also from other modeling publications. The model is utilized to determine the optimal roll‐out strategy for a combination of intervention strategies in TB control in a prison population. The two control functions both address treatment but are linked to different infection classes, making them distinct functions of time. Numerical simulations reveal that without well‐planned control measures, TB remains endemic. However, optimal control strategies can potentially eliminate the disease, provided the influx of TB‐infected prisoners is controlled. Implementing these strategies can significantly reduce the number of infectious TB cases while minimizing treatment costs. MSC2020 Classification: 92D30, 34K20 [ABSTRACT FROM AUTHOR]

Clinostomum species, a parasitic pathogen of freshwater fish, is widely distributed and infects various host species. Recently, the pathological effect due to Clinostomum metacercarial infection was described in aquaculture in Thailand; however, the global genetic diversity and population structure of this species have not been studied yet. Therefore, this study aimed to provide a detailed description of genetic diversity and population dynamics of the digenean Clinostomum isolated from Trichopodus pectoralis with globally recorded Clinostomum species. The species was characterized molecularly by analyzing 18S rDNA and inter‐transcribed spacer biomarker genes (ITS1 and ITS2). A BLAST search discovered that the 18S rDNA and ITS sequence had a 100% sequence similarity with Clinostomum piscidium isolated from India and Thailand. A comprehensive analysis revealed the presence of 12 distinct haplotypes among the Clinostomum populations. This study suggests that distinct patterns of genetic variation were identified by analyzing molecular variance, pairwise Fst, and employing structure analysis. It was observed that a gradient of genetic variation exists within continents, characterized by higher levels within different groups and lower levels of genetic differentiation. Additionally, a notable presence of mixed haplotypes was observed. The results of neutrality testing suggest that there has been a significant expansion in the populations of Clinostomum in India, America, and Kenya. The discoveries from this study will provide a valuable contribution to comprehending the genetics and evolution of Clinostomum species. Furthermore, key findings will be essential in developing efficient management approaches to prevent and control this parasite. [ABSTRACT FROM AUTHOR]

Dengue is the most prominent arboviral infection known to humans, especially in tropical regions of the world like Bangladesh. This is often a tricky outbreak to deal with, given its nature of seasonality, and due to the impact of climate change, variations in the length of its on‐season have been observed. This article models the dengue scenario in Bangladesh using a periodic, nonautonomous SIS vector–host model, proposes some development over the existing algorithm to determine the basic reproduction number, R0, for nonautonomous models, namely the "linear operator method," and hence patriots the behavior of R0 with respect to the length of the on‐season. Our experimentation shows that the infection transmission will be at its peak when the length of the on‐season is around 10 months. Based on the data of 2022, the current dynamic of the disease scenario in Bangladesh shows that the disease will not persist in the long run but occasional outbreaks may occur, given the right set of conditions. Finally, we conduct a sensitivity analysis of the model parameters, which shows that improving the recovery rate of the infected patient class and impeding the birth rate of the vector can effectively subdue the disease outbreak. [ABSTRACT FROM AUTHOR]

Background: The incidence of tick-borne diseases is increasing across the USA, with cases concentrated in the northeastern and midwestern regions of the country. Ixodes scapularis is one of the most important tick-borne disease vectors and has spread throughout the northeastern USA over the past four decades, with established populations in all states of the region. Methods: To better understand the rapid expansion of I. scapularis and the pathogens they transmit, we aggregated and analyzed I. scapularis abundance and pathogen prevalence data from across the northeastern USA, including the states of Connecticut, Maine, New Hampshire, New York and Vermont, from 1989 to 2021. Maine was the only state to collect data during the entire time period, with the other states collecting data during a subset of this time period starting in 2008 or later. We harmonized I. scapularis abundance by county and tick season, where the nymph season is defined as May to September and the adult season is October to December, and calculated I. scapularis pathogen infection prevalence as the percentage of ticks that tested positive for Anaplasma phagocytophilum, Babesia microti, Borrelia burgdorferi, and Borrelia miyamotoi. We then explored temporal trends in I. scapularis abundance and pathogen prevalence data using linear models. Results: The resulting dataset is one of the most spatially and temporally comprehensive records of tick abundance and pathogen prevalence in the USA. Using linear models, we found small or insignificant changes in the abundance of nymphs and adults over time; however, A. phagocytophilum, B. microti and B. burgdorferi prevalence in both nymphs and adults has increased over time. For the period 2017–2021, the statewide average prevalence of B. burgdorferi ranged from 19% to 25% in I. scapularis nymphs and from to 49% to 54% in I. scapularis adults. The statewide average prevalence of all other pathogens in I. scapularis for 2017–2021, including A. phagocytophilum (4–6% for nymphs, 4–9% for adults), B. microti (4–8% for nymphs, 2–13% for adults) and B. miyamotoi (1–2% for nymphs, 1–2% for adults), was considerably less. Conclusions: Our efforts revealed the complications of creating a comprehensive dataset of tick abundance and pathogen prevalence across time and space due to variations in tick collection and pathogen testing methods. Although tick abundance has not changed along the more southern latitudes in our study over this time period, and only gradually changed in the more northern latitudes of our study, human risk for exposure to tick-borne pathogens has increased due to increased pathogen prevalence in I. scapularis. This dataset can be used in future studies of I. scapularis and pathogen prevalence across the northeastern USA and to evaluate models of I. scapularis ecology and population dynamics. [ABSTRACT FROM AUTHOR]

Avian population sizes fluctuate and change over vast spatial scales, but the mechanistic underpinnings remain poorly understood. A key question is whether spatial and annual variation in avian population dynamics is driven primarily by variation in breeding season recruitment or by variation in overwinter survival. We present a method using large‐scale volunteer‐collected data from project eBird to develop species‐specific indices of net population change as proxies for survival and recruitment, based on twice‐annual, rangewide snapshots of relative abundance in spring and fall. We demonstrate the use of these indices by examining spatially explicit annual variation in survival and recruitment in two well‐surveyed nonmigratory North American species, Carolina wren Thryothorus ludovicianus and northern cardinal Cardinalis cardinalis. We show that, while interannual variation in both survival and recruitment is slight for northern cardinal, eBird abundance data reveal strong and geographically coherent signals of interannual variation in the overwinter survival of Carolina wren. As predicted, variation in wintertime survival dominates overall interannual population fluctuations of wrens and is correlated with winter temperature and snowfall in the northeastern United States, but not the southern United States. This study demonstrates the potential of participatory science (also known as citizen science) datasets like eBird for inferring variation in demographic rates and introduces a new complementary approach towards illuminating the macrodemography of North American birds at comprehensive continental extents. [ABSTRACT FROM AUTHOR]

AbstractAlthough there is a plethora of methods to estimate sensitivity indices associated with individual inputs, there is much less work on interaction effects of every order, especially when it comes to make inferences about the true underlying values of the indices. To fill this gap, a method that allows one to make such inferences simultaneously from a Monte Carlo sample is given. One advantage of this method is its simplicity: it leverages the fact that Shapley effects and Sobol indices are only linear transformations of total indices, so that standard asymptotic theory suffices to get confidence intervals and to carry out statistical tests. To perform the numerical computations efficiently, Möbius inversion formulas are used, and linked to the fast Möbius transform algorithm. The method is illustrated on two dynamical systems, both with an application in life sciences: a Boolean network modeling a cellular decision-making process involving 12 inputs, and a system of ordinary differential equations modeling some population dynamics involving 10 inputs. [ABSTRACT FROM AUTHOR]

Intrinsic and extrinsic factors, such as bioerosion at nesting sites, regulate population dynamics and are relevant for the long-term conservation of penguins. Colony trends (between 2004–2022) were studied in a Magellanic penguin colony on Martillo Island, Beagle Channel, Argentina and compared between zones with contrasting degrees of erosion (high, medium, low). Individuals from each zone were characterized for foraging ecology, stress, and reproductive performance during the 2017–2018 breeding season to better understand the colony dynamics. Changes in nest abundance varied in magnitude between nesting zones with different characteristics of occupation time, density and erosion. Declines in nest abundance in the densest, most eroded and longest occupied zone suggests that environmental degradation may be limiting the colony's carrying capacity. A higher percentage of late breeders (probably younger breeders) occupied the less eroded and more recently occupied zone. Foraging, breeding and stress barely differed between zones. New individuals recruiting into the breeding colony select less-eroded zones, either to reduce competition for nests or to avoid other effects of erosion and high-density areas. If this is the mechanism behind the shift in numbers throughout the island, we expect the island to be progressively occupied to the west. If competition or other density dependent factors are at play, a time will come when the vacant east side will begin to be recolonized by younger individuals. However, if erosion or other long-term effects spread throughout the island, recolonization may not occur and the colony may ultimately be abandoned as individuals search for new breeding grounds. Erosion at the breeding site may be a key factor in regional population trends of this burrow nesting species, by following an extinction / colonization of new sites process. [ABSTRACT FROM AUTHOR]

Populations of forest trees exhibit large temporal fluctuations, but little is known about the synchrony of these fluctuations across space, including their sign, magnitude, causes and characteristic scales. These have important implications for metapopulation persistence and theoretical community ecology. Using data from permanent forest plots spanning local, regional and global spatial scales, we measured spatial synchrony in tree population growth rates over sub-decadal and decadal timescales and explored the relationship of synchrony to geographical distance. Synchrony was high at local scales of less than 1 km, with estimated Pearson correlations of approximately 0.6–0.8 between species' population growth rates across pairs of quadrats. Synchrony decayed by approximately 17–44% with each order of magnitude increase in distance but was still detectably positive at distances of 100 km and beyond. Dispersal cannot explain observed large-scale synchrony because typical seed dispersal distances (<100 m) are far too short to couple the dynamics of distant forests on decadal timescales. We attribute the observed synchrony in forest dynamics primarily to the effect of spatially synchronous environmental drivers (the Moran effect), in particular climate, although pests, pathogens and anthropogenic drivers may play a role for some species. [ABSTRACT FROM AUTHOR]