ABSTRACT
In this work, we formulate a random Wolbachia invasion model incorporating the effects of imperfect maternal transmission and incomplete cytoplasmic incompatibility (CI). Under constant environments, we obtain the following results: Firstly, the complete invasion equilibrium of Wolbachia does not exist, and thus the population replacement is not achievable in the case of imperfect maternal transmission; Secondly, imperfect maternal transmission or incomplete CI may obliterate bistability and backward bifurcation, which leads to the failure of Wolbachia invasion, no matter how many infected mosquitoes would be released; Thirdly, the threshold number of the infected mosquitoes to be released would increase with the decrease of the maternal transmission rate or the intensity of CI effect. In random environments, we investigate in detail the Wolbachia invasion dynamics of the random mosquito population model and establish the initial release threshold of infected mosquitoes for successful invasion of Wolbachia into the wild mosquito population. In particular, the existence and stability of invariant probability measures for the establishment and extinction of Wolbachia are determined.
Subject(s)
Mathematical Concepts , Models, Biological , Mosquito Vectors , Wolbachia , Wolbachia/physiology , Wolbachia/pathogenicity , Animals , Female , Mosquito Vectors/microbiology , Population Dynamics/statistics & numerical data , Cytoplasm/microbiology , Culicidae/microbiology , Male , Computer Simulation , Maternal InheritanceABSTRACT
Objective: This work aimed to develop a pressure ulcer prevention nursing and health education strategy by using mind map techniques, apply the strategy to critically ill inpatients, and evaluate its effect on preventing pressure ulcers in patients. Methods: A study population of 82 critically ill hospitalized patients received random assignments to the control group (routine nursing intervention, n = 41) and the observation group (mental map health education based on the control group, n = 20). Patients in each group were then compared for the incidence and knowledge of pressure ulcers before and after nursing intervention and health education. Results: The awareness rates of pressure ulcer knowledge in the control and observation groups were 78.85% and 94.21%, respectively. The awareness rates of prevention knowledge after intervention were 79.8% and 94.38%, respectively (P < .05). The proportion of patients with a high risk of pressure ulcers in the observation group was lower than that in the control group (P < .05). The proportion of patients with a mild risk of pressure ulcers in the observation group was higher than in the control group (P < .05). Stage I pressure ulcers in the control and observation groups were 12.3% and 3.65%, respectively (P < .05). The incidence of stage II and above pressure ulcers in the control group and the observation group were 25.8% and 20.1%, respectively (P < .05). Conclusions: The mind map health education model helped improve patients' cognition level of pressure ulcers and enhanced their awareness of active cooperation, significantly preventing pressure ulcers.
Subject(s)
Pressure Ulcer , Humans , Critical Illness , Inpatients , Pressure Ulcer/epidemiology , Pressure Ulcer/prevention & control , Research DesignABSTRACT
To model estimated deaths averted by COVID-19 vaccines, we used state-of-the-art mathematical modeling, likelihood-based inference, and reported COVID-19 death and vaccination data. We estimated that >1.5 million deaths were averted in 12 countries. Our model can help assess effectiveness of the vaccination program, which is crucial for curbing the COVID-19 pandemic.
Subject(s)
COVID-19 , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines , Humans , Immunization Programs , Likelihood Functions , Pandemics/prevention & control , SARS-CoV-2 , VaccinationABSTRACT
Ticks play a critical role as vectors in the transmission and spread of Lyme disease, an emerging infectious disease which can cause severe illness in humans or animals. To understand the transmission dynamics of Lyme disease and other tick-borne diseases, it is necessary to investigate the population dynamics of ticks. Here, we formulate a system of delay differential equations which models the stage structure of the tick population. Temperature can alter the length of time delays in each developmental stage, and so the time delays can vary geographically (and seasonally which we do not consider). We define the basic reproduction number [Formula: see text] of stage structured tick populations. The tick population is uniformly persistent if [Formula: see text] and dies out if [Formula: see text]. We present sufficient conditions under which the unique positive equilibrium point is globally asymptotically stable. In general, the positive equilibrium can be unstable and the system show oscillatory behavior. These oscillations are primarily due to negative feedback within the tick system, but can be enhanced by the time delays of the different developmental stages.
Subject(s)
Models, Biological , Ticks/growth & development , Animals , Arachnid Vectors/growth & development , Arachnid Vectors/microbiology , Arachnid Vectors/physiology , Basic Reproduction Number , Female , Humans , Lyme Disease/transmission , Male , Mathematical Concepts , Population Dynamics , Tick-Borne Diseases/transmission , Ticks/microbiology , Ticks/physiologyABSTRACT
The coronavirus disease 2019 (COVID-19) pandemic has caused a tremendous global impact both socially and economically. The mechanisms behind the disparity in the severity, vaccine coverage, and variant replacement patterns across European countries are unclear. In this work, we aim to reveal the possible reasons via data visualization and model fitting. We developed a model with a vaccination component to simulate the mortality waves in these countries. Deaths averted by the vaccination campaign were estimated. Finally, we discuss the potential reasons behind the differences in vaccine coverage across European countries. Contemporary transportation and global trade bring significant convenience to our daily life but also facilitate the spread of the novel virus COVID-19 to anywhere globally within a short time. The observations and results in this work highlight the importance of the global campaign to mitigate the COVID-19 pandemic and future pandemics under the One Health approach.
ABSTRACT
Purpose: To discuss the effect of the transtheoretical model (TTM) of behavior-based health information behavior combined with continuous nursing on cognitive function, motor function, living ability, and quality of life of cerebral stroke (CS) patients. Methods: 540 cases of CS patients hospitalized in our hospital from June 2020 to June 2021 were selected. All the subjects were divided into the control group (270 cases) and study group (270 cases) according to the random number table. The control group was given routine nursing intervention and the study group was given TTM-based health information behavior combined with continuous nursing. The patients were paid a return visit 6 months after discharge, and their cognitive function, motor function, living ability, and quality of life were observed before and after intervention. Results: After intervention, the Montreal cognitive assessment scale score, Fugl-Meyer assessment of motor function score, Barthel index score, and short health scale score of both groups were higher than before intervention, and the study group was higher than the control group (P < 0.05). Conclusion: TTM-based health information behavior combined with continuous nursing has a significant positive impact on cognitive function, motor function, living ability, and quality of life of CS patients.
ABSTRACT
BACKGROUND: It is very important to provide effective nursing programs to regulate the physical and mental state of patients and to improve treatment compliance after interventional surgery for coronary heart disease (CHD). AIM: To explore the effect of a nursing intervention based on Maslow's hierarchy of needs theory on patients with CHD undergoing percutaneous coronary intervention. METHODS: Ninety-four patients with CHD undergoing interventional surgery in our hospital from January 2020 to February 2021 were randomly divided into a research group (n = 47) and a control group (n = 47). The control group received routine nursing, and the research group received a nursing intervention based on Maslow's hierarchy of needs theory. The scores of self-efficacy, negative emotion [depression (SDS), anxiety (SAS)], intervention compliance (standardized medication, moderate exercise, healthy diet, and regular review), and nursing satisfaction were calculated before and after intervention for the two groups. RESULTS: Before intervention, there was no significant difference in the scores of disease general management self-efficacy, disease management self-efficacy, and total self-efficacy between the two groups (P = 0.795, 0.479, and 0.659, respectively). After intervention, these three scores in the research group were higher than those in the control group (P < 0.001). Before intervention, there was no significant difference in the scores of SAS and SDS between the two groups (P = 0.149 and 0.347, respectively). After intervention, the scores of SAS and SDS in the research group were lower than those in the control group (P < 0.001). The standardized drug use rate (97.87%), moderate exercise rate (97.87%), healthy diet rate (95.74%), and regular reexamination rate (97.87%) in the research group were higher than those in the control group (85.11%, 82.98%, 80.85%, and 87.23%, respectively) (P = 0.027, 0.014, 0.025, and 0.049, respectively). Nursing job satisfaction in the research group (93.62%) was higher than that in the control group (78.72%) (P = 0.036). CONCLUSION: A nursing program based on Maslow's hierarchy of needs theory can effectively alleviate negative emotion, enhance self-efficacy and intervention compliance, and ensure that the patients are highly satisfied with the nursing work.
ABSTRACT
PURPOSE: To explore the effect of nursing based on the hopeless self-esteem theory plus multi-dimensional intensive nursing on the self-esteem level and prognosis of elderly patients with acute cerebral infarction (ACI) complicated with depression. METHODS: Eighty patients with ACI complicated with depression who were treated in our hospital from September 2018 to September 2020 were selected and randomized into the observation group and the control group (n = 40 each). The observation group received the model of hopeless self-esteem theory combined with multi-dimensional intensive nursing, while the control group received conventional nursing. The clinical efficacy, depression degree, self-esteem level, living ability, quality of life, and attribution mode were compared. RESULTS: The overall effective rate was reported at a notably higher rate in the observation group (90.00%) compared to the control group (65.00%) (P < 0.05); After intervention, the observation group had a markedly lower Geriatric Depression Scale (GDS) score than the control group (P < 0.05); After intervention, the observation group showed appreciably higher Rosenberg Self Esteem Scale (RSES) score and Barthel index compared to the control group (P < 0.05); After intervention, the observation group had a remarkably higher level of the quality of life in all dimensions than the control group (P < 0.05); After intervention, there were more positive events in the observation group as compared to the control group (P < 0.05), whereas there were more negative events in the control group as compared to the observation group (P < 0.05). CONCLUSION: The hopeless self-esteem theory combined with multi-dimensional intensive nursing can apparently increase the self-esteem level of patients, establish a positive attribution mode, beef up their self-confidence, reduce the degree of depression, upgrade their postoperative living ability and quality of life, and improve prognosis and clinical efficacy.
ABSTRACT
Background: By February 2021, the overall impact of coronavirus disease 2019 (COVID-19) in South and Southeast Asia was relatively mild. Surprisingly, in early April 2021, the second wave significantly impacted the population and garnered widespread international attention. Methods: This study focused on the nine countries with the highest cumulative deaths from the disease as of August 17, 2021. We look at COVID-19 transmission dynamics in South and Southeast Asia using the reported death data, which fits a mathematical model with a time-varying transmission rate. Results: We estimated the transmission rate, infection fatality rate (IFR), infection attack rate (IAR), and the effects of vaccination in the nine countries in South and Southeast Asia. Our study suggested that the IAR is still low in most countries, and increased vaccination is required to prevent future waves. Conclusion: Implementing non-pharmacological interventions (NPIs) could have helped South and Southeast Asia keep COVID-19 under control in 2020, as demonstrated in our estimated low-transmission rate. We believe that the emergence of the new Delta variant, social unrest, and migrant workers could have triggered the second wave of COVID-19.
ABSTRACT
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.g., Delta variants with increased transmissibility) could have driven the rapid growth of the epidemic in India and led to a large number of deaths within a short period. We aim to reconstruct the transmission rate, estimate the infection fatality rate and forecast the epidemic size. We download the reported COVID-19 mortality data in India and formulate a simple mathematical model with a flexible transmission rate. We use iterated filtering to fit our model to deaths data. We forecast the infection attack rate in a month ahead. Our model simulation matched the reported deaths well and is reasonably close to the results of the serological study. We forecast that the infection attack rate (IAR) could have reached 43% by July 24, 2021, under the current trend. Our estimated infection fatality rate is about 0.07%. Under the current trend, the IAR will likely reach a level of 43% by July 24, 2021. Our estimated infection fatality rate appears unusually low, which could be due to a low case to infection ratio reported in previous study. Our approach is readily applicable in other countries and with other types of data (e.g., excess deaths).
Subject(s)
COVID-19 , Pandemics , Humans , India/epidemiology , SARS-CoV-2ABSTRACT
The raw case fatality rate (CFR, the reported number of COVID-19 deaths divided by the total number of cases) is an important indicator to quantify the severity or treatment efficacy. In many countries, the pandemic had experienced two waves to date. To our knowledge, no studies have compared the CFR between the two waves. In this work, we reported the CFR of 53 countries or regions with the highest COVID-19 death tolls. Of them, 43 had lower CFR estimates in the ongoing second wave than in the first wave. We discussed the possible reasons. Also, we compared the two-wave pattern of COVID-19 with those of influenza. Influenza activities in the pre-pandemic era provided an indicator for seasonality of climate in a country. The sharp drop in influenza activities in 2020 could an indicator of the effects of social distancing.
Subject(s)
COVID-19/epidemiology , Pandemics , SARS-CoV-2 , COVID-19/mortality , Global Health , Humans , Influenza, Human/epidemiology , Influenza, Human/mortalityABSTRACT
OBJECTIVE: To explore the application of a nursing crisis management system in the novel coronavirus pneumonia epidemic. METHODS: A retrospective nursing method was implemented. A total of 280 cases of patients were diagnosed with coronavirus pneumonia in the isolation ward of our hospital. The 280 cases of newly diagnosed pneumonia were divided into two groups: the nursing crisis management system group (n=150, the nursing crisis management was given) and the non-nursing crisis management system (n=130, routine nursing management was given). The psychological status (profile of mood states (POMS) score) of nursing staff before and after the implementation of the nursing crisis management, the psychological status of patients after the implementation of nursing crisis management (POMS score), emotion, cognition, behavior severity, patients' satisfaction with nursing, treatment compliance (Morisky Medication Compliance Scale (MMAS) score) of patients, the rate of cure of patients and the infection rate of nursing staff were compared. RESULTS: Compared with the non-nursing crisis management system group, the POMS scores of patients and nurses in the nursing crisis management system group decreased (all P<0.05). Compared with the non-nursing crisis management system group, the emotional, cognitive and behavioral scores of patients in the nursing crisis management system group were lower, while the MMAS score, satisfaction with nursing and cure rate were significantly increased (all P<0.05). The 142 nursing staff did not catch coronavirus. CONCLUSION: During the novel coronavirus pneumonia outbreak and the current normal epidemic prevention and control periods, our crisis management mode was introduced into nursing work. The construction of the nursing crisis management mode under the epidemic situation can improve the psychological state and improve the management efficiency of the patients and nurses. The patients' satisfaction is high and the treatment compliance is good.
ABSTRACT
Event-related potentials (ERP) is a good temporal resolution method to study the mechanism of visual field in brain. With the development of technique of high-density recording and brain imaging, the ERP is widely used in the location of the brain function. This article reviews the methods, results and primary conclusions in the field, and suggests several perspectives for the future research and application of ERP in the forensic science.
Subject(s)
Attention/physiology , Brain/physiology , Evoked Potentials/physiology , Space Perception/physiology , Visual Fields/physiology , Forensic Medicine , Humans , Photic Stimulation/methods , Visual PerceptionABSTRACT
To prevent the transmissions of mosquito-borne diseases (e.g., malaria, dengue fever), recent works have considered the problem of using the sterile insect technique to reduce or eradicate the wild mosquito population. It is important to consider how reproductive advantage of the wild mosquito population offsets the success of population replacement. In this work, we explore the interactive dynamics of the wild and sterile mosquitoes by incorporating the delay in terms of the growth stage of the wild mosquitoes. We analyze (both analytically and numerically) the role of time delay in two different ways of releasing sterile mosquitoes. Our results demonstrate that in the case of constant release rate, the delay does not affect the dynamics of the system and every solution of the system approaches to an equilibrium point; while in the case of the release rate proportional to the wild mosquito populations, the delay has a large effect on the dynamics of the system, namely, for some parameter ranges, when the delay is small, every solution of the system approaches to an equilibrium point; but as the delay increases, the solutions of the system exhibit oscillatory behavior via Hopf bifurcations. Numerical examples and bifurcation diagrams are also given to demonstrate rich dynamical features of the model in the latter release case.
Subject(s)
Culicidae , Mosquito Vectors , Pest Control, Biological/methods , Animals , Computer Simulation , Dengue/prevention & control , Dengue/transmission , Female , Humans , Malaria/prevention & control , Malaria/transmission , Male , Mathematical Concepts , Models, Biological , Pest Control, Biological/statistics & numerical data , Population Dynamics , West Nile Fever/prevention & control , West Nile Fever/transmissionABSTRACT
Calcium homeostasis is a fundamental cellular process in yeast. The regulation of the cytosolic calcium concentration is required for volume preservation and to regulate many vital calcium dependent processes such as mating and response to stress. The homeostatic mechanism is often studied by applying calcium pulses: sharply changing the calcium concentration in the yeast environment and observing the cellular response. To address these experimental investigations, several mathematical models have been proposed to describe this response. In this article we demonstrate that a previously studied model for this response predicts the presence of limit point instabilities and limit cycles in the dynamics of the calcium homeostasis system. We discuss the ways in which such dynamic characteristics can be observed with luminometric techniques. We contrast these predictions with experimentally observed responses and find that the experiments reveal a number of features that are consistent with modeling predictions. In particular, we find that equilibrium cytosolic concentrations have a sharp change in behavior as pulse size changes in the micromolar range. We show that such change is consistent with the presence of limit point instabilities. Additionally, we find that the response of synchronized yeast cells to millimolar range pulses is non-monotonic in its late stages. This response has characteristics similar to those associated with limit cycles.
Subject(s)
Calcium/metabolism , Cytosol/metabolism , Homeostasis/physiology , Models, Theoretical , Saccharomyces cerevisiae/metabolismABSTRACT
A model of ordinary differential equations is formulated for populations which are structured by many stages. The model is motivated by ticks which are vectors of infectious diseases, but is general enough to apply to many other species. Our analysis identifies a basic reproduction number that acts as a threshold between population extinction and persistence. We establish conditions for the existence and uniqueness of nonzero equilibria and show that their local stability cannot be expected in general. Boundedness of solutions remains an open problem though we give some sufficient conditions.
Subject(s)
Game Theory , Life Cycle Stages/physiology , Models, Biological , Predatory Behavior/physiology , Reproduction/physiology , Ticks/physiology , Animals , Computer Simulation , Extinction, Biological , Population GrowthABSTRACT
We formulate and analyze a delay differential equation model for the transmission of West Nile virus between vector mosquitoes and avian hosts that incorporates maturation delay for mosquitoes. The maturation time from eggs to adult mosquitoes is sensitive to weather conditions, in particular the temperature, and the model allows us to investigate the impact of this maturation time on transmission dynamics of the virus among mosquitoes and birds. Numerical results of the model show that a combination of the maturation time and the vertical transmission of the virus in mosquitoes has substantial influence on the abundance and number of infection peaks of the infectious mosquitoes.