Forward Index Research Articles

8398 Non-genomic Effects of Thyroid Hormones on the Breast Cancer Microenvironment

Abstract Disclosure: L. Drago: None. S. Shahrivari: None. N. Schwenk: None. P. Nelson: None. H. Hosseini: None. C. Spitzweg: None. Objective: Mesenchymal stem cells (MSCs) are central players in the genesis of the breast cancer tumor microenvironment and play a role in tumor initiation, progression, invasion, metastasis, angiogenesis as well as resistance to treatment. There is increasing evidence for an association between thyroid function and breast cancer risk. Thyroid hormone effects mediated through the αvβ3 integrin, a thyroid hormone receptor, are proposed as a pathophysiologic link to this observation. Methods: To evaluate the migratory behavior of MSCs in the presence or absence of thyroid hormone treatment in response to tumor-derived signals, a 3D migration assay was performed. MSCs pretreated with T3 (1nM) or T4 (1μM) with or without tetrac (100nM) (T4 analog, specific inhibitor of αvβ3 integrin-mediated thyroid hormone action) for 24 h were subjected to a gradient between serum-free medium and serum-free conditioned medium (CM) from five different breast cancer cell lines representative of different breast cancer subtypes including T47D as Luminal B, MCF7 as Luminal A, BT-474 and MDA-MB-453 as HER2, and MDA-MB-231 as Triple negative subtype. Results: MSCs subjected to a gradient between CM derived from each breast cancer cell line and serum-free medium showed directed chemotaxis towards tumor-CM with a significantly increased forward migration index (FMI) and center of mass (CoM). This migratory behavior was significantly enhanced upon treatment with T3 or T4. The cellular migration towards tumor-CM of MDA-MB-453, BT-474, and T47D was more effective upon MSC treatment with T3, but less so with T4. MSCs treated with T4 showed a better migratory performance towards the CM of MCF7 and MDA-MB-231. Except for T47D-CM, additional treatment with tetrac inhibited the enhanced effects of T3 and T4 on MSC migration demonstrating that this effect is mediated through αvβ3 integrin. Conclusion: Our preliminary in vitro data on the effects of thyroid hormones T3 and T4, and the thyroid hormone metabolite tetrac on MSC migration shows a distinct behaviour of MSCs in the presence of either T3 or T4 depending on the breast cancer cell subtype, suggesting a role of non-genomic, integrin αvβ3-mediated thyroid hormone action on MSC biology within the breast tumor microenvironment that warrants further investigation. Presentation: 6/3/2024

8398 Non-genomic Effects Of Thyroid Hormones On The Breast Cancer Microenvironment

Abstract Disclosure: L. Drago: None. S. Shahrivari: None. N. Schwenk: None. P. Nelson: None. H. Hosseini: None. C. Spitzweg: None. Objective: Mesenchymal stem cells (MSCs) are central players in the genesis of the breast cancer tumor microenvironment and play a role in tumor initiation, progression, invasion, metastasis, angiogenesis as well as resistance to treatment. There is increasing evidence for an association between thyroid function and breast cancer risk. Thyroid hormone effects mediated through the αvβ3 integrin, a thyroid hormone receptor, are proposed as a pathophysiologic link to this observation. Methods: To evaluate the migratory behavior of MSCs in the presence or absence of thyroid hormone treatment in response to tumor-derived signals, a 3D migration assay was performed. MSCs pretreated with T3 (1nM) or T4 (1μM) with or without tetrac (100nM) (T4 analog, specific inhibitor of αvβ3 integrin-mediated thyroid hormone action) for 24 h were subjected to a gradient between serum-free medium and serum-free conditioned medium (CM) from five different breast cancer cell lines representative of different breast cancer subtypes including T47D as Luminal B, MCF7 as Luminal A, BT-474 and MDA-MB-453 as HER2, and MDA-MB-231 as Triple negative subtype. Results: MSCs subjected to a gradient between CM derived from each breast cancer cell line and serum-free medium showed directed chemotaxis towards tumor-CM with a significantly increased forward migration index (FMI) and center of mass (CoM). This migratory behavior was significantly enhanced upon treatment with T3 or T4. The cellular migration towards tumor-CM of MDA-MB-453, BT-474, and T47D was more effective upon MSC treatment with T3, but less so with T4. MSCs treated with T4 showed a better migratory performance towards the CM of MCF7 and MDA-MB-231. Except for T47D-CM, additional treatment with tetrac inhibited the enhanced effects of T3 and T4 on MSC migration demonstrating that this effect is mediated through αvβ3 integrin. Conclusion: Our preliminary in vitro data on the effects of thyroid hormones T3 and T4, and the thyroid hormone metabolite tetrac on MSC migration shows a distinct behaviour of MSCs in the presence of either T3 or T4 depending on the breast cancer cell subtype, suggesting a role of non-genomic, integrin αvβ3-mediated thyroid hormone action on MSC biology within the breast tumor microenvironment that warrants further investigation. Presentation: 6/3/2024

A deterministic Analysis of an Age-Gender structured model for malaria transmission dynamics

Objectives: Children below five years and women especially pregnant women are at high risk of malaria infection and death due to their weak immunity and exposition to mosquitoes. Different studies have been undertaken considering only the age structured model and other factors but did not take into account the gender. The objective of this work is to develop and analyze the malaria transmission model including this structure, to contribute on the existing measures and mechanisms to eradicate malaria in Rwanda.Methods: The dynamic malaria transmission model considering age and gender structure was developed and analyzed. To study the dynamics of disease, the basic reproduction number was analytically computed and numerically estimated and the normalized forward sensitivity index was used to highlight its sensitive parameters.Results: The most positive sensitive parameters in the model are the force of infection and infection rate for vectors and Infection rate for female of 5 years and above. The most negative sensitive parameters are the per capita death rate for vectors and humans.Conclusion: To control the spread of malaria in Rwanda, the biting and infection rate should be decreased.Therefore, women must comply with government measures against malaria and educate children about it.

Designing a Multi-Level Caching Forward Index for Recommendation System Services

This paper introduces a forward index based on microservices, which effectively addresses the issue of forward read amplification in recommendation systems through a multi-layer caching mechanism. This allows the forward service to handle a large number of concurrent requests with limited resources while ensuring service stability and final value rate. The paper provides a detailed description of the forward index's data structure design, traffic penetration calculation, and overall service architecture design, dividing the system into three parts: SDK, proxy service, and storage, corresponding to data query, data processing, and data storage respectively. In the SDK design, three components are employed: Cache Slot, synchronous queue, and timer, supporting synchronous, asynchronous, and flexible request forms. The proxy service design handles heterogeneous data and online computation, supporting batch and asynchronous designs, and provides a dynamic data protocol to adapt to the characteristic needs of different microservices. The storage layer design considers performance, cost, and maintainability, utilizing a Cache & SSD model to cope with high-concurrency scenarios.

Utilizing fractional derivatives and sensitivity analysis in a random framework: a model-based approach to the investigation of random dynamics of malware spread

In this study, an ordinary-deterministic equation system modeling the spread dynamics of malware under mutation is analyzed with fractional derivatives and random variables. The original model is transformed into a system of fractional-random differential equations (FRDEs) using Caputo fractional derivatives. Normally distributed random variables are defined for the parameters of the original system that are related to the mutations and infections of the nodes in the network. The resulting system of FRDEs is simulated using the predictor-corrector method based fde12 algorithm and the forward fractional Euler method (ffEm) for various values of the model components such as the standard deviations, orders of derivation, and repetition numbers. Additionally, the sensitivity analysis of the original model is investigated in relation to the random nature of the components and the basic reproduction number (R0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$R_{0}$\\end{document}) to underline the correspondence of random dynamics and sensitivity indices. Both the normalized forward sensitivity indices (NFSI) and the standard deviation of R0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$R_{0}$\\end{document} with random components give matching results for analyzing the changes in the spread rate. Theoretical results are backed by the simulation outputs on the numerical characteristics of the fractional-random model for the expected number of infections and mutations, expected timing of the removal of mutations from the network, and measurement of the variability in the results such as the coefficients of variation. Comparison of the results from the original model and the fractional-random model shows that the fractional-random analysis provides a more generalized perspective while facilitating a versatile investigation with ease and can be used on different models as well.

Investigation of the causality between participation in global value chains and CO2 emissions between developed and developing countries

The production and consumption activities are cross-border and therefore, it is important to understand the role of Global Value Chains (GVCs) in fulfilling a country’s specific climate commitments. This study examines the causal relationship between selected GVC indices and CO2 emissions. We use the GVC position index, considered robust in comparison to the frequently used GVC participation index, for determining the impact on emissions. The forward and backward participation indices are considered in the analysis. The paper presents an analysis of 62 developing and developed economies from 1995 to –2018 using the Juodis A., Y. Karavias, and V. Sarafidis [2021. “A Homogeneous Approach to Testing for Granger non-Causality in Heterogeneous Panels.” Empirical Economics 60 (1): 93–112] approach, which is an improvement over the traditional approaches to analysing causality. The results show that the overall position in GVCs positively affects CO2 emissions for developing countries but a causal relationship does not exist for the developed countries. The developed countries attain a higher participation index but a lower position index. On the other hand, developing countries with fewer stringent environmental regulations may opt for an upstream position (more export-oriented) and by design specialize in more pollution-intensive industries. Noteworthy, production-based emissions in developed countries are reduced because of an increase in imports of emission-intensive products from developing countries.

Cost-effectiveness analysis of optimal control strategies on the transmission dynamics of HIV and Varicella-Zoster co-infection

HIV and Varicella-Zoster co-infection has been threatens the lives and livelihood of millions of individuals all over the world. In various nations of the world the co-infection disease is presently a major health problem. Although, various researchers carried out studies related with HIV and Zoster single infections, no one has carried out a study on the co-infection disease. Therefore, investigating the HIV and Varicella-Zoster co-infection transmission dynamics using mathematical modeling approach is relatively necessary. The main objective of this study is to investigate the cost-effective analysis of the proposed optimal control strategies on the transmission dynamics of HIV and Varicella-Zoster co-infection in the community using compartmental modeling approach. Qualitatively, we have computed the model equilibrium points and analyze their local stabilities using Routh-Hurwitz stability criteria, the effective reproduction numbers by using the next generator matrix operator method, we re-formulated the optimal control problem of the complete co-infection model by implementing five time dependent optimal control strategies, analyzed the optimal control problem by applying the Pontryagin's Maximum/Minimum principle. Sensitivity analysis and numerical simulations have been carried out using the forward sensitivity index formula and the fourth order Runge-Kutta numerical methods respectively and verified the analytic results. Finally, we have performed the cost effective analysis for the proposed controlling strategies and from the result we have observed that implementing strategy four (treatment of Varicella-Zoster infected individuals to increase their recovery rate and recovery period) is the most cost effective-strategy as compared with other alternatives.

A mathematical analysis of the effects of control strategies on the transmission dynamics of Chlamydiosis

Chlamydiosis remains a major public health concern in both developed and developing countries due to its effects on the human reproductive system. While limited modeling studies have been conducted on the transmission dynamics of the disease, none of them have examined the impacts of the combination of environmental hygiene and other control strategies. In this paper, we present a mathematical model to investigate the impacts of public health education, vaccination of susceptible individuals, treatment of symptomatic infected individuals, and environmental hygiene. The basic reproduction number is computed using the next-generation operator and is employed in the stability analysis of equilibrium points. We also perform a sensitivity analysis of the model using a normalized forward sensitivity index to identify the parameters significantly affecting the effective reproduction number. Findings from analytical solutions and numerical simulations demonstrate that, public health education, vaccination, treatment, and environmental hygiene significantly reduce chlamydiosis incidence and prevalence in the population. Consequently, the study recommends implementing these control measures, particularly in regions where the disease is endemic. Thus, findings from this study could be utilized to support decision-making in Chlamydiosis control strategies.

Mathematical model to assess the impact of contact rate and environment factor on transmission dynamics of rabies in humans and dogs

This paper presents a mathematical model to understand how rabies spreads among humans, free-range, and domestic dogs. By analyzing the model, we discovered that there are equilibrium points representing both disease-free and endemic states. We calculated the basic reproduction number, R0 using the next generation matrix method. When R0<1, the disease-free equilibrium is globally stable, whereas when R0≥1, the endemic equilibrium is globally stable. To identify the most influential parameters in disease transmission, we used the normalized forward sensitivity index. The simulations revealed that the contact rates between the infectious agent and humans, free-range dogs, and domestic dogs, have the most significant impact on rabies transmission. The study also examines how periodic changes in transmission rates affect the disease dynamics, emphasizing the importance of transmission frequency and amplitude on the patterns observed in rabies spread. To reduce disease sensitivity, one should prioritize effective disease control measures that focus on keeping both free-range and domestic dogs indoors. This is a crucial factor in preventing the spread of disease and should be implemented as a primary disease control measure.

Janus outdoor protective clothing with unidirectional moisture transfer, antibacterial, and mosquito repellent properties

Personal protective clothing with versatile and durable features is highly desirable for daily and specific environmental scenarios. Especially for outdoor workers or sports enthusiasts, prolonged outdoor exposure requires their clothing to be more functional to cope with a wide range of situations, such as heat stress in summer, odor generation after sweating, and mosquito bites. These not only reduce the wearing comfort of clothing, but also bring potential heat stroke, skin infections and diseases brought by mosquitoes. Currently, most outdoor protective clothes focus on a single function, such as waterproofing and UV protection and are not able to cope with the demand of multiple protections. In this paper, we developed permethrin-containing triblock cationic polymers (PTCPs) that can multi-functionalize outdoor clothing. Benefiting from their high affinity to polyester fibers, PTCP modified polyester yarns were obtained by an aqueous based finishing process. After that, a scalable machine-knitting fabrication technique is employed to fabricate Janus outdoor protective clothes (Janus-OPC). The as-prepared Janus-OPC exhibited excellent one-way moisture transfer properties (forward cumulative one-way transfer index (OWTI) of 924.23%, and backward OWTI of −690.52%), antimicrobial properties (97.73% and 99.72% against E. coli and S. aureus, respectively), and mosquito repellent properties (repelling rate of 76.19%). Moreover, the protective performance of the Janus-OPC was maintained after 50 times of equivalent home laundering cycles. This multifunctional protective clothing opens up a new direction for the next-generation outdoor wear.

Modeling the Transmission Dynamics of Tuberculosis in Humans

Tuberculosis (TB) is a major threat to human health particularly in most of developing countries. In this article, we formulate and analyze a deterministic model for the transmission dynamics of pulmonary and extra-pulmonary tuberculosis. The next generation method is employed to find the basic reproduction number R0 which helps to determine whether TB clears or persists in the human population. Global stability of model equilibria is done through Lyapunov functions whereas the normalized forward sensitivity index method is adopted to determine parameters that drive tuberculosis. Analysis shows that both TB free and endemic equilibria exist. The TB free equilibrium is globally asymptotically stable whenever the basic reproduction number R0 &lt; 1 whereas the endemic equilibrium is globally asymptotically stable whenever R0 &gt; 1. Sensitivity analysis shows that the TB infection rate, the fraction of individuals who progress to pulmonary tuberculosis and its induced death drive TB. Numerical results indicate that when there are no interventions, susceptible humans decline significantly with time until when they are attracted to the steady state whereas latently infected, pulmonary and extra-pulmonary TB individuals increase until when they settle at the equilibrium states supporting the analytical results for existence of the endemic equilibrium. In light of these findings, we recommend treating humans infected with pulmonary TB who are carriers of the disease.

Efficient Neural Ranking Using Forward Indexes and Lightweight Encoders

Dual-encoder-based dense retrieval models have become the standard in IR. They employ large Transformer-based language models, which are notoriously inefficient in terms of resources and latency. We propose Fast-Forward indexes—vector forward indexes which exploit the semantic matching capabilities of dual-encoder models for efficient and effective re-ranking. Our framework enables re-ranking at very high retrieval depths and combines the merits of both lexical and semantic matching via score interpolation. Furthermore, in order to mitigate the limitations of dual-encoders, we tackle two main challenges: Firstly, we improve computational efficiency by either pre-computing representations, avoiding unnecessary computations altogether, or reducing the complexity of encoders. This allows us to considerably improve ranking efficiency and latency. Secondly, we optimize the memory footprint and maintenance cost of indexes; we propose two complementary techniques to reduce the index size and show that, by dynamically dropping irrelevant document tokens, the index maintenance efficiency can be improved substantially. We perform an evaluation to show the effectiveness and efficiency of Fast-Forward indexes—our method has low latency and achieves competitive results without the need for hardware acceleration, such as GPUs.

High-Efficiency and Large-Angle Homo-Metagratings for the Near-Infrared Region

Compact photonic devices that integrate metasurfaces with light sources have been widely studied. However, experimental demonstrations of a higher efficiency of integration are still lacking. To enhance the efficiency of light sources integrated with metasurfaces, we employed a forward design optimization method and index matching between the light source and metasurface substrate to design metagratings. To optimize the overall diffraction efficiency, we manipulated the degrees of freedom in phase, the lattice constants, and the number of unit cells. The same material was utilized for the nanostructures and substrate (homo-metagrating) for index matching, while Si and GaAs materials were used for working at 1550 and 940 nm, respectively. The experimental homo-metagratings operating at 1550 nm and made of Si exhibited an overall average efficiency of 51.3% at diffraction angles of 60.3°. On the other hand, experimental homo-metagratings operating at 940 nm and made of GaAs exhibited an overall average efficiency of 52.4% at diffraction angles of 49.3°. This suggests that the future integration of metagratings with a polarization-specific laser can further enhance the overall diffraction efficiency.

Relationship between the strength of the ankle and toe muscles and functional stability in young, healthy adults.

This study investigates the relationship between ankle and toe strength and functional stability in young adults, with a sample comprising sixteen females and fourteen males. The research employed force platform data to determine the center of foot pressure (COP) and calculated the forward functional stability index (FFSI) through foot anthropometric measurements. Strength measurements of toe and ankle muscles, during maximal isometric flexion and extension, were conducted using force transducers. Notable positive correlations were found between toe flexor strength and FFSI (left flexor: r = 0.4, right flexor: r = 0.38, p < 0.05), not influenced by foot anthropometry. Contrarily, no significant correlation was observed between ankle muscle strength and FFSI, despite a positive correlation with the COP range. The moderate correlation coefficients suggest that while toe flexor strength is a contributing factor to functional stability, it does not solely determine functional stability. These findings highlight the critical role of muscle strength in maintaining functional stability, particularly during forward movements and emphasize the utility of FFSI alongside traditional COP measures in balance assessment. It is recommended to employ a multifaceted approach is required in balance training programs.

Mathematical modelling, analysis and numerical simulation of social media addiction and depression.

We formulate a mathematical model of social media addiction and depression (SMAD) in this study. Key aspects, such as social media addiction and depression disease-free equilibrium point (SMADDFEP), social media addiction and depression endemic equilibrium point (SMADEEP), and basic reproduction number (R0), have been analyzed qualitatively. The results indicate that if R0 < 1, the SMADDFEP is locally asymptotically stable. The global asymptotic stability of the SMADDFEP has been established using the Castillo-Chavez theorem. On the other hand, if R0 > 1, the unique endemic equilibrium point (SMADEEP) is locally asymptotically stable by Lyapunov theorem, and the model exhibits a forward bifurcation at R0 = 1 according to the Center Manifold theorem. To examine the model's sensitivity, we calculated the normalized forward sensitivity index and conducted a Partial Rank Correlation Coefficient (PRCC) analysis to describe the influence of parameters on the SMAD. The numerical results obtained using the Fourth-order Runge-Kutta (RK-4) scheme show that increasing the number of addicted individuals leads to an increase in the number of depressed individuals.

Mathematical Modeling of Coccidiosis Dynamics in Chickens with Some Control Strategies

Coccidiosis is an infectious disease caused by the Eimeria species. The species can infect a bird’s digestive system, severely slow down its growth, and is a serious economic burden for chickens. A mathematical model for the transmission dynamics of coccidiosis disease in chickens in the presence of control interventions has been formulated and analyzed to gain insights into the dynamics of the disease in the population. Three control interventions, namely vaccination, sanitation, and treatment, are implemented. The study intends to assess the effects of these control interventions in coccidiosis transmission dynamics. Using the theory of differential equations, the invariant set of the model was derived, and the model’s solution was found to be mathematically and biologically significant. Analytical methods are employed to establish equilibrium solutions and investigate the stability of the model system’s equilibria, while numerical simulations illustrate the analytical results. The effective reproduction number is obtained using the next-generation matrix method, and the local stability of the equilibria of the model is established. The disease-free equilibrium is proved to be locally stable when the effective reproduction number is less than unity. Also, the nature of the bifurcation and its implications for disease prevention are investigated through the application of the center manifold theory. On the other hand, sensitivity analysis is carried out to investigate the parameters that impact the transmission of coccidiosis disease using the normalized forward sensitivity index. The parameters that have a greater influence on the effective reproduction number should be targeted for control purposes to lessen the spread of disease. Furthermore, numerical simulation is performed to investigate the contribution of each control intervention.

Effects of mitral valve repair on valvular geometry and hemodynamics in dogs with myxomatous mitral valve disease.

To investigate the effects of mitral valve repair on the geometry of the mitral valve complex, hemodynamics, and cardiac function of dogs with myxomatous mitral valve disease (MMVD). Retrospective cohort study. Dogs (n = 77) with stage C MMVD undergoing mitral valve repair under cardiopulmonary bypass. Mitral valve geometry and cardiac function were assessed using echocardiography preoperatively, 1 week postoperatively and 3 months postoperatively. The coaptation length (0 [0-0] vs. 7 [6-8.5] mm, p < .001) and forward stroke volume index (1.5 ± 0.4 vs. 2.3 ± 0.6 mL/kg, p < .001) were higher at 3-months postoperatively than preoperatively, whereas the vertebral heart score (12.3 ± 1.2 vs. 10.8 ± 0.8 V, p < .001), left atrial-to-aortic ratio (2.2 ± 0.7 vs. 1.2 ± 0.3, p < .001), peak velocity of early diastolic transmitral flow (144 ± 34 vs. 91 ± 18 cm/s, p < .001), and regurgitant volume index (11.3 [8.2-14.0] vs. 1.6 [0.95-2.35] mL/kg, p < .001) were lower. Postoperatively, mitral valve geometry was completely changed within 1 week, whereas changes in vertebral heart score lasted for 3 months. Mitral valve repair changed valvular geometry and improved hemodynamics as assessed by follow-up echocardiography. This study acts as reference for surgeons and cardiologists considering or evaluating the effects of mitral valve repair in dogs and provides useful data for the enhancement of relevant surgical techniques and the selection of relevant pre- and postoperative observations.

Forward Looking Disclosure and Its Determinants: Empirical Evidence from the Listed Banks of Bangladesh

Forward looking information is an emerging issue in academic and corporate arena. Today’s dynamic and competitive business world, the disclosure of forward looking information gives competitive advantages. The main objective of the study is to empirically find out the extent of forward looking disclosure and it’s determinants in the banking sector of Bangladesh. To conduct the study total 120 firm years are considered as sample from 30 listed banks from DSE as sample during the period 2017 to 2021. The average mean value of forward looking information is 38% which indicates poor quality of forward looking information in the most regulated sectors of Bangladesh. The results using multivariate regression analysis shows that board independence, audit firm size and firm’s profitability have positive and significant relationship with forward looking disclosure index (FLDI). This study also finds that foreign ownership, board size and audit independence have significant negative relationship with FLDI. But this study didn’t find any significant association of forward looking information with firm size, female board members, sponsor /directors in the banking sector of Bangladesh. To the best of our knowledge, there is scarcity of research that has been examined the disclosure of forward looking information and it’s determinants in banking sector of Bangladesh as well as very limited work is done in other sectors. The study will contribute to the existing scarce literature and may influence the policymakers and regulators to incorporate regulations to increase the quality and extent of forward looking disclosure.

Stability and Bifurcation Analysis of Measles Model

A six compartmental deterministic mathematical model, governed by a system of ordinary differential equations for measles was formulated in other to study and analyze the transmission dynamics of measles in human population. The model was shown to be mathematically and epidemiologically meaningful. The basic reproduction number of the model was obtained and global stability of the disease-free equilibrium and endemic equilibrium were obtained and shown to be asymptotically stable, whenever the basic reproduction and unstable if otherwise. More so, if then the endemic equilibrium of the model equation is globally asymptotically stable The effect of some parameters of the model relatives to the basic reproduction number was calculated using the normalized forward sensitivity indices, and it was shown that increase in the parameters with negative indices will reduce the value of the basic Reproduction number, while increase in those with positive indices will increase the value of basic reproduction number. The bifurcation analysis was also carried out and the model was shown to exhibit backward bifurcation which indicates that is no longer sufficient for effective disease control. The numerical result shows that isolation of infective plays a major role in reducing the transmission of the disease in the population.

A fractional modeling approach for the transmission dynamics of measles with double-dose vaccination

Measles, a member of the Paramyxoviridae family and the Morbillivirus genus, is an infectious disease caused by the measles virus that is extremely contagious and can be prevented through vaccination. When a person with the measles coughs or sneezes, the virus is disseminated by respiratory droplets. Normally, the appearance of measles symptoms takes 10–14 d following viral exposure. Conjunctivitis, a high temperature, a cough, a runny nose, and a distinctive rash are some of the symptoms. Despite the measles vaccination being available, it is still widespread worldwide. To eradicate measles, the Reproduction Number (i.e. R 0 < 1 ) must remain less than unity. This study examines a SEIVR compartmental model in the caputo sense using a double dose of vaccine to simulate the measles outbreak. The reproduction number R 0 and model properties are both thoroughly examined. Both the local and global stabilities of the proposed model are determined for R 0 less and greater than 1. To achieve the model’s global stability, the Lyapunov function is used while the existence and uniqueness of the proposed model are demonstrated In addition to the calculated and fitted biological parameters, the forward sensitivity indices for R 0 are also obtained. Simulations of the proposed fractional order (FO) caputo model are performed in order to analyse their graphical representations and the significance of FO derivatives to illustrate how our theoretical findings have an impact. The graphical results show that the measles outbreak is reduced by increasing vaccine dosage rates.