A spatiotemporal model for the effects of toxicants on the competitive dynamics of aquatic species.

In this paper, we develop a reaction-diffusion model with negative toxicant-taxis that incorporates spatiotemporally inhomogeneous toxicant input to investigate the impact of toxicants on the competitive dynamics of two species in a polluted aquatic environment. Here the negative toxicant-taxis models the evasive movement of avoiding toxicants by species. We establish the global well-posedness of the model, analyze the existence and stability of spatially homogeneous steady states, and derive sufficient conditions for species extinction and coexistence.

Reducing catheter-related bloodstream infections using Lean Six Sigma methodology.

Background: Central venous catheters (CVC) are used for dialysis in end-stage renal disease patients, presenting a significant risk for Catheter-Related Bloodstream Infections (CRBSI). While Lean Six Sigma has been effective in reducing CRBSI, its efficacy outside intensive care units (ICU) remains less explored. This study aims to evaluate the effectiveness of Lean Six Sigma in mitigating CRBSI risks among non-ICU hemodialysis patients.

Autoimmune encephalitis followed by hemophagocytic lymph histiocytosis: a case report.

Objective: This study aims to report three cases of autoimmune encephalitis followed by hemophagocytic lymphohistiocytosis.

Methods: Data of relevant patients treated between 2019 and 2022 were retrospectively collected from the Department of Neurology at the Second Affiliated Hospital of Guangzhou Medical University.

Results: The age at onset of the three patients was 37, 63, and 36 years, respectively.

Dynamical analysis of a diffusive population-toxicant model with toxicant-taxis in polluted aquatic environments.

This paper deals with a diffusive population-toxicant model in polluted aquatic environments, with a toxicant-taxis term describing a toxicant-induced behavior change, that is, the population tends to move away from locations with high-level toxicants. The global existence of solutions is established by the techniques of the semigroup estimation and Moser iteration. Based on a detailed study on the properties of the principal eigenvalue for non-self-adjoint eigenvalue problems, we investigated the local and global stability of the toxin-only steady-state solution and the existence of positive steady state, which yields sufficient conditions that lead to population persistence or extinction.

A nonautonomous model for the interaction between a size-structured consumer and an unstructured resource.

In this paper, we propose and analyze a nonautonomous model that describes the dynamics of a size-structured consumer interacting with an unstructured resource. We prove the existence and uniqueness of the solution of the model using the monotone method based on a comparison principle. We derive conditions on the model parameters that result in persistence and extinction of the population via the upper-lower solution technique.

The correlation analysis between organizational justice, knowledge-hiding behaviour and Nurses' innovation ability: A cross-sectional study.

Aim: The aim of the study was to analyse the correlations among organizational justice, knowledge-hiding behaviour and nurses' innovation ability.

Design: A descriptive and cross-sectional design and the data were collected using questionnaires.

Methods: Demographic information, professional data, innovation capacity scales, knowledge-hiding scales and organizational justice scales were used in this study.

A Stage-Structured Continuous-/Discrete-Time Population Model: Persistence and Spatial Spread.

Population persistence and spatial propagation and their dependence on demography and dispersal are of great importance in spatial ecology. Many species with highly structured life cycles invade new habitats through the dispersal of organisms in their early life stages (e.g.

Forecast of the COVID-19 trend in India: A simple modelling approach.

By February 2021, the overall impact of the COVID-19 pandemic in India had been relatively mild in terms of total reported cases and deaths. Surprisingly, the second wave in early April becomes devastating and attracts worldwide attention. Multiple factors (e.

Polymers in Lithium-Sulfur Batteries.

Lithium-sulfur batteries (LSBs) hold great promise as one of the next-generation power supplies for portable electronics and electric vehicles due to their ultrahigh energy density, cost effectiveness, and environmental benignity. However, their practical application has been impeded owing to the electronic insulation of sulfur and its intermediates, serious shuttle effect, large volume variation, and uncontrollable formation of lithium dendrites. Over the past decades, many pioneering strategies have been developed to address these issues via improving electrodes, electrolytes, separators and binders.

Direct and indirect effects of toxins on competition dynamics of species in an aquatic environment.

When two competing species are simultaneously exposed in a polluted environment, one species may be more vulnerable to toxins than the other. To study the impact of environmental toxins on competition dynamics of two species, we develop a toxin-dependent competition model that incorporates both direct and indirect toxic effects on the species. The direct effects of toxins typically reduce population abundance by increasing mortality and reducing reproduction.

PPAR Regulates the Proliferation of Human Glioma Cells through miR-214 and E2F2.

Peroxisome proliferator-activated receptor (PPAR) is a member of the nuclear hormone receptor superfamily and functions as a transcription factor. Previous work showed that PPAR plays multiple roles in lipid metabolism in tissues such as cardiac and skeletal muscle, liver, and adipose tissue. Recent studies have discovered additional roles for PPAR in cell proliferation and metabolism, as well as tumor progression.

Bifurcations and global dynamics in a toxin-dependent aquatic population model.

The study of effects of environmental toxins on ecosystems is of great interest from both environmental and conservation points of view. In this paper, we present a global stability and bifurcation analysis of a toxin-dependent aquatic population model. Our analytical and numerical results show that both the environmental toxin level and the depuration capability of the population significantly affect the population persistence.

Simultaneous removal of cadmium, zinc and manganese using electrocoagulation: Influence of operating parameters and electrolyte nature.

In the present study, the influence of operating parameters and electrolyte nature on the simultaneous removal of toxic metals (cadmium, zinc and manganese) from synthetic smelting wastewater by batch electrocoagulation was investigated. This wastewater contained high concentrations of anion-cation electrolytes. Results indicated that the efficiency of heavy metals removal can be enhanced by increasing the solution pH and current density.

A toxin-mediated size-structured population model: Finite difference approximation and well-posedness.

The question of the effects of environmental toxins on ecological communities is of great interest from both environmental and conservational points of view. Mathematical models have been applied increasingly to predict the effects of toxins on a variety of ecological processes. Motivated by the fact that individuals with different sizes may have different sensitivities to toxins, we develop a toxin-mediated size-structured model which is given by a system of first order fully nonlinear partial differential equations (PDEs).

Temperature- and Turbidity-Dependent Competitive Interactions Between Invasive Freshwater Mussels.

We develop a staged-structured population model that describes the competitive dynamics of two functionally similar, congeneric invasive species: zebra mussels and quagga mussels. The model assumes that the population survival rates are functions of temperature and turbidity, and that the two species compete for food. The stability analysis of the model yields conditions on net reproductive rates and intrinsic growth rates that lead to competitive exclusion.

The impact of environmental toxins on predator-prey dynamics.

Predators and prey may be simultaneously exposed to environmental toxins, but one may be more susceptible than the other. To study the effects of environmental toxins on food web dynamics, we develop a toxin-dependent predator-prey model that combines both direct and indirect toxic effects on two trophic levels. The direct effects of toxins typically reduce organism abundance by increasing mortality or reducing fecundity.

A model for the impact of contaminants on fish population dynamics.

Mathematical models have been widely applied to perform chemical risk assessments on biological populations for a variety of ecotoxicological processes. In this paper, by introducing a dose-dependent mortality rate function, we formulate a toxin-dependent aquatic population model that integrates mortality as toxin effect in addition to considering the effects of toxin on growth and recruitment. The model describes the direct effect of toxin on population by treating the concentration of toxin in the environment as a parameter.

Fitting a structured juvenile-adult model for green tree frogs to population estimates from capture-mark-recapture field data.

We derive point and interval estimates for an urban population of green tree frogs (Hyla cinerea) from capture-mark-recapture field data obtained during the years 2006-2009. We present an infinite-dimensional least-squares approach which compares a mathematical population model to the statistical population estimates obtained from the field data. The model is composed of nonlinear first-order hyperbolic equations describing the dynamics of the amphibian population where individuals are divided into juveniles (tadpoles) and adults (frogs).

Stochastic juvenile--adult models with application to a green tree frog population.

We derive several stochastic models from a deterministic population model that describes the dynamics of age-structured juveniles coupled with size-structured adults. Numerical simulation results of the stochastic models are compared with the solution of the deterministic model. These models are then used to understand the effect of demographic stochasticity on the dynamics of an urban green tree frog (Hyla cinerea) population.