Shilpa Samaddar - Academia.edu (original) (raw)

Papers by Shilpa Samaddar

Global behavior of a within-host viral dynamic model with non-cytolytic cure effect

In this paper, we propose a within-host viral dynamic model incorporating non-cytolytic cure proc... more In this paper, we propose a within-host viral dynamic model incorporating non-cytolytic cure process and the infection term with saturated mass action principle. It is been shown that the global behavior of the model counts on the biological threshold parameter, namely, basic reproduction number. We establish that the infection gets eradicated if the basic reproduction number is less than unity and persists in the host body if the basic reproduction number is greater than unity. A comparison study of three various viral infection models is performed through numerical analysis and the obtained results suggest that the inclusion of saturated mass action principle and cure rate has a significant impact in the viral infection dynamics. Further, an application of the proposed model to some in vivo data of HBV transgenic mice.

Impact of Refuge to the Heterogeneous Interaction of Species in Food Chain Model: A Holistic Approach

Iranian Journal of Science and Technology Transaction A-science, Jan 5, 2021

This paper deals with the dynamics of a prey dependent three species food chain model involving t... more This paper deals with the dynamics of a prey dependent three species food chain model involving the Holling type II response function elucidating the impact of refuge constants of prey and predator on the system. We present an exhaustive mathematical explanation of the suggested model to enhance the significance which has originated due to ecological phenomena. Biologically meaningful equilibrium points of the system are endowed along with the behaviors of the system around each equilibrium point. Specifically, boundedness, local and global stability, Hopf bifurcation analysis are performed. Besides, the geometrical significance is provided by all the diagrams supporting the analytical findings. Robustness of the dependence of the system dynamics to each parameter perturbations is presented numerically. Further, the effects of refuge parameters are demonstrated individually as well as simultaneously by two-dimensional and three-dimensional graphs to enhance the impacts more significantly. Moreover, chaotic behavior of the system dynamics is observed for some critical parameter values.

Iranian Journal of Science and Technology Transaction A-science, Jan 6, 2020

This paper deals with the dynamics of a prey-dependent two-species model, associating the Holling... more This paper deals with the dynamics of a prey-dependent two-species model, associating the Holling type II response function. We incorporate the prey refuge to the system with additional food supplement to self-competitive predator. We have found three ecologically significant equilibrium points as well as discussed their stability, instability conditions. The obtained results suggest that the coexisting equilibrium point can go through a Hopf bifurcation for some suitable value of prey refuge. Numerical simulations are performed to support all the analytical findings and to investigate the effects of additional food and self-interactions among predators for various densities of prey refuge. It can be observed that additional food supports coexisting behavior while intraspecific competition does not enhance coexistence so much but reducing the predator population, supports a stable solution. Although a very strong prey refuge forces the predators to extinct in both cases. Moreover, a comparison of four food web models has been performed to elaborate significantly the effects of prey refuge, additional food, and self-competition, respectively, on the system dynamics. The results yield that the model can fairly illustrate a realistic environmental ecology of two interacting populations and may be useful for species conservation.

Nonlinear Dynamics, Sep 13, 2019

In this paper, a mathematical model describing the viral infection dynamics with non-cytolytic ef... more In this paper, a mathematical model describing the viral infection dynamics with non-cytolytic effect of humoral immune response is presented and analyzed. The effect of non-cytolytic immune response on the process of viral infectivity has been basically described by the non-cytolytic cure of infected cells and inhibition of viral replication, i.e., the non-lytic immune response. The sufficient criteria for the local and global stability of the equilibria, namely diseasefree equilibrium, immune-free equilibrium and chronic equilibrium with humoral response, have been determined in terms of two threshold parameters, viz., the basic reproduction number, R 0 , and the humoral immune response reproduction number, R 1. The condition governing the occurrence of Hopf bifurcation around the chronic equilibrium with humoral response has been obtained using the rate of infection as a bifurcation parameter. The obtained results indicate that the infection gets eradicated for R 0 ≤ 1 and persists in the body for R 0 > 1. Numerical simulations are presented to support our analytical findings. The comparison of various viral dynamic models suggests that the incorporation of the non-cytolytic immune response increases the concentration of uninfected cells, but causes a depletion of humoral immune response. Further, the effect of non-cytolytic immune response on

Effect of Nonlinear Prey Refuge on Predator–Prey Dynamics

Springer proceedings in mathematics & statistics, 2023

Journal of Biological Systems, Jun 19, 2023

In the present article, a modified Leslie-Gower predator-prey model with double Allee effect, aff... more In the present article, a modified Leslie-Gower predator-prey model with double Allee effect, affecting the prey population, is proposed and analyzed. We have considered both strong and weak Allee effects separately. The equilibrium points of the system and their local stability have been studied. It is shown that the dynamics of the system are highly dependent upon the initial conditions. The local bifurcations (Hopf, saddle-node, Bogdanov-Takens) have been investigated by considering sufficient parameter(s) as the bifurcation parameter(s). The local existence of the limit cycle emerging through Hopf bifurcation and its stability is studied by means of the first Lyapunov coefficient. The numerical simulations have been done in support of the analytical findings. The result shows the emergence of homoclinic loop. The possible phase portraits and parametric diagrams have been depicted.

Effect of non-cytolytic cure and saturation response: An in silico study to instigate the viral spread inhibition

European Physical Journal Plus, May 1, 2020

Abstract The non-cytolytic cure of infected cells is an imperative mechanism that maintains the h... more Abstract The non-cytolytic cure of infected cells is an imperative mechanism that maintains the healthy state in the host body by reducing the level of infection. The primary purpose of humoral immune response, i.e., the B cell response, is to neutralize the extracellular virions present in the body. To explore the impact of infected cells and virus particle-mediated saturation response on the viral spread dynamics under the influence of these critical factors, we propose a viral infection model incorporating the coupling effect of non-cytolytic cure mechanism and saturation response in the presence of humoral immune responses. Through parameter variation experimentation, we obtain that under the exposure of a weak humoral response, the saturation response effectively reduces the level of virions, whereas it has a less significant effect on viral infection dynamics in the presence of a strong humoral response or non-cytolytic cure mechanism. We observe that the strength of humoral immune response depends on the number of activated B cells present in the body rather than the rate at which it neutralizes the viruses. Further, we demonstrate that the non-cytolytic cure mechanism plays a vital role in restoring the no infection phase in the host body in the presence of a high infection coefficient. Moreover, a case study of HCV-infected human hepatic Huh7.5.1 cell lines has been presented to describe the HCV infection dynamics in a real-life scenario using model prediction technique. Graphic Abstract

Modeling the cell-to-cell transmission dynamics of viral infection under the exposure of non-cytolytic cure

Journal of Applied Mathematics and Computing, Aug 18, 2020

To explore the effect of direct cell-to-cell transmission on viral infection dynamics under the e... more To explore the effect of direct cell-to-cell transmission on viral infection dynamics under the exposure of the non-cytolytic cure mechanism, a mathematical model integrating both the virus-to-cell and cell-to-cell transmissions with a non-cytolytic cure rate of infected cells in the presence of humoral immunity has been considered. Parameter variation experimentation suggests that a high cell-to-cell infection rate induces the chronic infection state in the host, whereas a high non-cytolytic cure rate positively contributes to the reduction of the viral load. We observe that a moderate cure rate under the exposure of a weak cell-to-cell transmission can effectively reduce the level of infection. Further, we examine the effect of cell-free transmission on the infection dynamics under the influence of cell-to-cell transmission. To substantiate our hypothesis, we present a case study of five HIV-1 infected patients to depict the primary HIV-1 infection dynamics in a real life scenario through model prediction.

Effect of fear on prey–predator dynamics: Exploring the role of prey refuge and additional food

Chaos, Jun 1, 2020

The effect of induced fear in the prey due to the presence of a predator can alone develop anti-p... more The effect of induced fear in the prey due to the presence of a predator can alone develop anti-predator resistance to such an extent that it might reduce the prey reproduction in a significant amount. As fear can perceptibly affect the densities of the terrestrial vertebrates, here we investigate the cost of fear on a Holling type II predator–prey model associated with prey refuge and additional food to the predator. We evidently provide conditions on the existence and stability of equilibria as well as the occurrence of the Hopf bifurcation. Besides, we study how the presence of fear re-calibrates the effects of prey refuge and additional food in terms of quality and quantity on the system dynamics. We observe that the effect of fear not only reduces the predator density but also considerably drives the system toward stability. All the results presented here are mainly analytical but to make it more comprehensive, we perform numerical simulation. Moreover, to show the vast applicability of our results, we compare it with a few other models according to the presence of fear, refuge, and additional food.

Ecological Aspects of Fear and Hunting Cooperation in Prey-Predator Dynamics: A Case Study Analysis

Routledge eBooks, Apr 4, 2023

Environment, Development and Sustainability, 2021

Drying of fish at the Sagar Island (21.7269° N, 88.1096° E) is generally carried out in open sun ... more Drying of fish at the Sagar Island (21.7269° N, 88.1096° E) is generally carried out in open sun on the seashore on plastic sheets or mat of palm leaves. This is not an environment-friendly and healthy practice. To alleviate the limitations of open sun drying, 600 kg (300 kg × 2) walk-in solar thermal dryer was installed at a fishing cooperative. The dryer consequently augmented the income of the fisher folk by enhancing throughput and refining the quality of dried fish. The design incorporated, (a) 80% UV cutoff film to take care of appearance of the dried fish; (b) facilitating proper air flow pattern for uniform both side drying; (c) completely dismantlable system to take care of incoming storms/cyclones in advance; (d) solar photovoltaic powered dehumidifiers to control the relative humidity at night and achieve a dried batch in less than 24 h. The fabricated solar thermal dryer had drying temperature in the range of 36.9-53.1 °C throughout the day. Due to the use of the dehumidifiers, an entire batch of fish could be dried from an initial 80% to final 10% moisture content (wet basis) in less than 24 h compared to 38 h in open sun drying. The solar thermal drying efficiency was 30.24% and specific energy consumption was found to be 2.35 kg/kWh. The embodied energy was 10,756 kWh and CO 2 emission was calculated to be 422 kg per year, which was lower than other fossil-driven drying systems.

JOURNAL OF MECHANICS OF CONTINUA AND MATHEMATICAL SCIENCES, 2022

Most of the functional responses which have been incorporated to formulate mathematical biology c... more Most of the functional responses which have been incorporated to formulate mathematical biology consider individual contact or predator cooperation. In this study, we have introduced a different functional response that describes the prey-predator system when predators form a line and cooperatively attack a group of predators. We have also described the effect of prey on this system. Additionally, we find all the equilibrium points and their local stability behaviour.

Impact of Refuge to the Heterogeneous Interaction of Species in Food Chain Model: A Holistic Approach

Iranian Journal of Science and Technology, Transactions A: Science, 2021

This paper deals with the dynamics of a prey dependent three species food chain model involving t... more This paper deals with the dynamics of a prey dependent three species food chain model involving the Holling type II response function elucidating the impact of refuge constants of prey and predator on the system. We present an exhaustive mathematical explanation of the suggested model to enhance the significance which has originated due to ecological phenomena. Biologically meaningful equilibrium points of the system are endowed along with the behaviors of the system around each equilibrium point. Specifically, boundedness, local and global stability, Hopf bifurcation analysis are performed. Besides, the geometrical significance is provided by all the diagrams supporting the analytical findings. Robustness of the dependence of the system dynamics to each parameter perturbations is presented numerically. Further, the effects of refuge parameters are demonstrated individually as well as simultaneously by two-dimensional and three-dimensional graphs to enhance the impacts more signific...

Global behavior of a within-host viral dynamic model with non-cytolytic cure effect

2019 IEEE Region 10 Symposium (TENSYMP), 2019

In this paper, we propose a within-host viral dynamic model incorporating non-cytolytic cure proc... more In this paper, we propose a within-host viral dynamic model incorporating non-cytolytic cure process and the infection term with saturated mass action principle. It is been shown that the global behavior of the model counts on the biological threshold parameter, namely, basic reproduction number. We establish that the infection gets eradicated if the basic reproduction number is less than unity and persists in the host body if the basic reproduction number is greater than unity. A comparison study of three various viral infection models is performed through numerical analysis and the obtained results suggest that the inclusion of saturated mass action principle and cure rate has a significant impact in the viral infection dynamics. Further, an application of the proposed model to some in vivo data of HBV transgenic mice.

Viral dynamic model with cellular immune response: A case study of HIV-1 infected humanized mice

In this paper, an attempt has been made to study the global dynamical behavior of a viral dynamic... more In this paper, an attempt has been made to study the global dynamical behavior of a viral dynamics model incorporating both the lytic and nonlytic immune responses. The global stability of the model is analyzed in terms of two threshold parameters, namely, basic reproduction number, R 0 and immune response reproduction number, R 1 . The obtained results signify that the infection dies out if R 0 ≤ 1 and persists if R 0 > 1 . We establish that the global dynamic behavior of the model has no concern with the efficacy of the nonlytic component. Numerical simulations are performed to support our theoretical findings and to investigate the effects of lytic and nonlytic components on the viral dynamics model. A comparison of two different viral infection models has been performed to illustrate the effect of viral replication inhibition through nonlytic effector mechanism on the infection dynamics. Moreover, a case study of HIV-1 infected humanized mice is presented and the result manif...

Effect of non-cytolytic cure and saturation response: An in silico study to instigate the viral spread inhibition

The European Physical Journal Plus

Abstract The non-cytolytic cure of infected cells is an imperative mechanism that maintains the h... more Abstract The non-cytolytic cure of infected cells is an imperative mechanism that maintains the healthy state in the host body by reducing the level of infection. The primary purpose of humoral immune response, i.e., the B cell response, is to neutralize the extracellular virions present in the body. To explore the impact of infected cells and virus particle-mediated saturation response on the viral spread dynamics under the influence of these critical factors, we propose a viral infection model incorporating the coupling effect of non-cytolytic cure mechanism and saturation response in the presence of humoral immune responses. Through parameter variation experimentation, we obtain that under the exposure of a weak humoral response, the saturation response effectively reduces the level of virions, whereas it has a less significant effect on viral infection dynamics in the presence of a strong humoral response or non-cytolytic cure mechanism. We observe that the strength of humoral immune response depends on the number of activated B cells present in the body rather than the rate at which it neutralizes the viruses. Further, we demonstrate that the non-cytolytic cure mechanism plays a vital role in restoring the no infection phase in the host body in the presence of a high infection coefficient. Moreover, a case study of HCV-infected human hepatic Huh7.5.1 cell lines has been presented to describe the HCV infection dynamics in a real-life scenario using model prediction technique. Graphic Abstract

Modeling the cell-to-cell transmission dynamics of viral infection under the exposure of non-cytolytic cure

Journal of Applied Mathematics and Computing

Effect of fear on prey–predator dynamics: Exploring the role of prey refuge and additional food

Chaos: An Interdisciplinary Journal of Nonlinear Science

Supplement of Additional Food: Dynamics of Self-Competitive Prey–Predator System Incorporating Prey Refuge

Iranian Journal of Science and Technology, Transactions A: Science

Modeling the effect of non-cytolytic immune response on viral infection dynamics in the presence of humoral immunity

Nonlinear Dynamics

In this paper, a mathematical model describing the viral infection dynamics with non-cytolytic ef... more In this paper, a mathematical model describing the viral infection dynamics with non-cytolytic effect of humoral immune response is presented and analyzed. The effect of non-cytolytic immune response on the process of viral infectivity has been basically described by the non-cytolytic cure of infected cells and inhibition of viral replication, i.e., the non-lytic immune response. The sufficient criteria for the local and global stability of the equilibria, namely disease-free equilibrium, immune-free equilibrium and chronic equilibrium with humoral response, have been determined in terms of two threshold parameters, viz., the basic reproduction number, \(R_0\), and the humoral immune response reproduction number, \(R_1\). The condition governing the occurrence of Hopf bifurcation around the chronic equilibrium with humoral response has been obtained using the rate of infection as a bifurcation parameter. The obtained results indicate that the infection gets eradicated for \(R_0 \le 1\) and persists in the body for \(R_0 > 1\). Numerical simulations are presented to support our analytical findings. The comparison of various viral dynamic models suggests that the incorporation of the non-cytolytic immune response increases the concentration of uninfected cells, but causes a depletion of humoral immune response. Further, the effect of non-cytolytic immune response on the dynamical behavior of the system has been demonstrated.

Global behavior of a within-host viral dynamic model with non-cytolytic cure effect

In this paper, we propose a within-host viral dynamic model incorporating non-cytolytic cure proc... more In this paper, we propose a within-host viral dynamic model incorporating non-cytolytic cure process and the infection term with saturated mass action principle. It is been shown that the global behavior of the model counts on the biological threshold parameter, namely, basic reproduction number. We establish that the infection gets eradicated if the basic reproduction number is less than unity and persists in the host body if the basic reproduction number is greater than unity. A comparison study of three various viral infection models is performed through numerical analysis and the obtained results suggest that the inclusion of saturated mass action principle and cure rate has a significant impact in the viral infection dynamics. Further, an application of the proposed model to some in vivo data of HBV transgenic mice.

Impact of Refuge to the Heterogeneous Interaction of Species in Food Chain Model: A Holistic Approach

Iranian Journal of Science and Technology Transaction A-science, Jan 5, 2021

This paper deals with the dynamics of a prey dependent three species food chain model involving t... more This paper deals with the dynamics of a prey dependent three species food chain model involving the Holling type II response function elucidating the impact of refuge constants of prey and predator on the system. We present an exhaustive mathematical explanation of the suggested model to enhance the significance which has originated due to ecological phenomena. Biologically meaningful equilibrium points of the system are endowed along with the behaviors of the system around each equilibrium point. Specifically, boundedness, local and global stability, Hopf bifurcation analysis are performed. Besides, the geometrical significance is provided by all the diagrams supporting the analytical findings. Robustness of the dependence of the system dynamics to each parameter perturbations is presented numerically. Further, the effects of refuge parameters are demonstrated individually as well as simultaneously by two-dimensional and three-dimensional graphs to enhance the impacts more significantly. Moreover, chaotic behavior of the system dynamics is observed for some critical parameter values.

Iranian Journal of Science and Technology Transaction A-science, Jan 6, 2020

This paper deals with the dynamics of a prey-dependent two-species model, associating the Holling... more This paper deals with the dynamics of a prey-dependent two-species model, associating the Holling type II response function. We incorporate the prey refuge to the system with additional food supplement to self-competitive predator. We have found three ecologically significant equilibrium points as well as discussed their stability, instability conditions. The obtained results suggest that the coexisting equilibrium point can go through a Hopf bifurcation for some suitable value of prey refuge. Numerical simulations are performed to support all the analytical findings and to investigate the effects of additional food and self-interactions among predators for various densities of prey refuge. It can be observed that additional food supports coexisting behavior while intraspecific competition does not enhance coexistence so much but reducing the predator population, supports a stable solution. Although a very strong prey refuge forces the predators to extinct in both cases. Moreover, a comparison of four food web models has been performed to elaborate significantly the effects of prey refuge, additional food, and self-competition, respectively, on the system dynamics. The results yield that the model can fairly illustrate a realistic environmental ecology of two interacting populations and may be useful for species conservation.

Nonlinear Dynamics, Sep 13, 2019

In this paper, a mathematical model describing the viral infection dynamics with non-cytolytic ef... more In this paper, a mathematical model describing the viral infection dynamics with non-cytolytic effect of humoral immune response is presented and analyzed. The effect of non-cytolytic immune response on the process of viral infectivity has been basically described by the non-cytolytic cure of infected cells and inhibition of viral replication, i.e., the non-lytic immune response. The sufficient criteria for the local and global stability of the equilibria, namely diseasefree equilibrium, immune-free equilibrium and chronic equilibrium with humoral response, have been determined in terms of two threshold parameters, viz., the basic reproduction number, R 0 , and the humoral immune response reproduction number, R 1. The condition governing the occurrence of Hopf bifurcation around the chronic equilibrium with humoral response has been obtained using the rate of infection as a bifurcation parameter. The obtained results indicate that the infection gets eradicated for R 0 ≤ 1 and persists in the body for R 0 > 1. Numerical simulations are presented to support our analytical findings. The comparison of various viral dynamic models suggests that the incorporation of the non-cytolytic immune response increases the concentration of uninfected cells, but causes a depletion of humoral immune response. Further, the effect of non-cytolytic immune response on

Effect of Nonlinear Prey Refuge on Predator–Prey Dynamics

Springer proceedings in mathematics & statistics, 2023

Journal of Biological Systems, Jun 19, 2023

In the present article, a modified Leslie-Gower predator-prey model with double Allee effect, aff... more In the present article, a modified Leslie-Gower predator-prey model with double Allee effect, affecting the prey population, is proposed and analyzed. We have considered both strong and weak Allee effects separately. The equilibrium points of the system and their local stability have been studied. It is shown that the dynamics of the system are highly dependent upon the initial conditions. The local bifurcations (Hopf, saddle-node, Bogdanov-Takens) have been investigated by considering sufficient parameter(s) as the bifurcation parameter(s). The local existence of the limit cycle emerging through Hopf bifurcation and its stability is studied by means of the first Lyapunov coefficient. The numerical simulations have been done in support of the analytical findings. The result shows the emergence of homoclinic loop. The possible phase portraits and parametric diagrams have been depicted.

Effect of non-cytolytic cure and saturation response: An in silico study to instigate the viral spread inhibition

European Physical Journal Plus, May 1, 2020

Abstract The non-cytolytic cure of infected cells is an imperative mechanism that maintains the h... more Abstract The non-cytolytic cure of infected cells is an imperative mechanism that maintains the healthy state in the host body by reducing the level of infection. The primary purpose of humoral immune response, i.e., the B cell response, is to neutralize the extracellular virions present in the body. To explore the impact of infected cells and virus particle-mediated saturation response on the viral spread dynamics under the influence of these critical factors, we propose a viral infection model incorporating the coupling effect of non-cytolytic cure mechanism and saturation response in the presence of humoral immune responses. Through parameter variation experimentation, we obtain that under the exposure of a weak humoral response, the saturation response effectively reduces the level of virions, whereas it has a less significant effect on viral infection dynamics in the presence of a strong humoral response or non-cytolytic cure mechanism. We observe that the strength of humoral immune response depends on the number of activated B cells present in the body rather than the rate at which it neutralizes the viruses. Further, we demonstrate that the non-cytolytic cure mechanism plays a vital role in restoring the no infection phase in the host body in the presence of a high infection coefficient. Moreover, a case study of HCV-infected human hepatic Huh7.5.1 cell lines has been presented to describe the HCV infection dynamics in a real-life scenario using model prediction technique. Graphic Abstract

Modeling the cell-to-cell transmission dynamics of viral infection under the exposure of non-cytolytic cure

Journal of Applied Mathematics and Computing, Aug 18, 2020

To explore the effect of direct cell-to-cell transmission on viral infection dynamics under the e... more To explore the effect of direct cell-to-cell transmission on viral infection dynamics under the exposure of the non-cytolytic cure mechanism, a mathematical model integrating both the virus-to-cell and cell-to-cell transmissions with a non-cytolytic cure rate of infected cells in the presence of humoral immunity has been considered. Parameter variation experimentation suggests that a high cell-to-cell infection rate induces the chronic infection state in the host, whereas a high non-cytolytic cure rate positively contributes to the reduction of the viral load. We observe that a moderate cure rate under the exposure of a weak cell-to-cell transmission can effectively reduce the level of infection. Further, we examine the effect of cell-free transmission on the infection dynamics under the influence of cell-to-cell transmission. To substantiate our hypothesis, we present a case study of five HIV-1 infected patients to depict the primary HIV-1 infection dynamics in a real life scenario through model prediction.

Effect of fear on prey–predator dynamics: Exploring the role of prey refuge and additional food

Chaos, Jun 1, 2020

The effect of induced fear in the prey due to the presence of a predator can alone develop anti-p... more The effect of induced fear in the prey due to the presence of a predator can alone develop anti-predator resistance to such an extent that it might reduce the prey reproduction in a significant amount. As fear can perceptibly affect the densities of the terrestrial vertebrates, here we investigate the cost of fear on a Holling type II predator–prey model associated with prey refuge and additional food to the predator. We evidently provide conditions on the existence and stability of equilibria as well as the occurrence of the Hopf bifurcation. Besides, we study how the presence of fear re-calibrates the effects of prey refuge and additional food in terms of quality and quantity on the system dynamics. We observe that the effect of fear not only reduces the predator density but also considerably drives the system toward stability. All the results presented here are mainly analytical but to make it more comprehensive, we perform numerical simulation. Moreover, to show the vast applicability of our results, we compare it with a few other models according to the presence of fear, refuge, and additional food.

Ecological Aspects of Fear and Hunting Cooperation in Prey-Predator Dynamics: A Case Study Analysis

Routledge eBooks, Apr 4, 2023

Environment, Development and Sustainability, 2021

Drying of fish at the Sagar Island (21.7269° N, 88.1096° E) is generally carried out in open sun ... more Drying of fish at the Sagar Island (21.7269° N, 88.1096° E) is generally carried out in open sun on the seashore on plastic sheets or mat of palm leaves. This is not an environment-friendly and healthy practice. To alleviate the limitations of open sun drying, 600 kg (300 kg × 2) walk-in solar thermal dryer was installed at a fishing cooperative. The dryer consequently augmented the income of the fisher folk by enhancing throughput and refining the quality of dried fish. The design incorporated, (a) 80% UV cutoff film to take care of appearance of the dried fish; (b) facilitating proper air flow pattern for uniform both side drying; (c) completely dismantlable system to take care of incoming storms/cyclones in advance; (d) solar photovoltaic powered dehumidifiers to control the relative humidity at night and achieve a dried batch in less than 24 h. The fabricated solar thermal dryer had drying temperature in the range of 36.9-53.1 °C throughout the day. Due to the use of the dehumidifiers, an entire batch of fish could be dried from an initial 80% to final 10% moisture content (wet basis) in less than 24 h compared to 38 h in open sun drying. The solar thermal drying efficiency was 30.24% and specific energy consumption was found to be 2.35 kg/kWh. The embodied energy was 10,756 kWh and CO 2 emission was calculated to be 422 kg per year, which was lower than other fossil-driven drying systems.

JOURNAL OF MECHANICS OF CONTINUA AND MATHEMATICAL SCIENCES, 2022

Most of the functional responses which have been incorporated to formulate mathematical biology c... more Most of the functional responses which have been incorporated to formulate mathematical biology consider individual contact or predator cooperation. In this study, we have introduced a different functional response that describes the prey-predator system when predators form a line and cooperatively attack a group of predators. We have also described the effect of prey on this system. Additionally, we find all the equilibrium points and their local stability behaviour.

Impact of Refuge to the Heterogeneous Interaction of Species in Food Chain Model: A Holistic Approach

Iranian Journal of Science and Technology, Transactions A: Science, 2021

This paper deals with the dynamics of a prey dependent three species food chain model involving t... more This paper deals with the dynamics of a prey dependent three species food chain model involving the Holling type II response function elucidating the impact of refuge constants of prey and predator on the system. We present an exhaustive mathematical explanation of the suggested model to enhance the significance which has originated due to ecological phenomena. Biologically meaningful equilibrium points of the system are endowed along with the behaviors of the system around each equilibrium point. Specifically, boundedness, local and global stability, Hopf bifurcation analysis are performed. Besides, the geometrical significance is provided by all the diagrams supporting the analytical findings. Robustness of the dependence of the system dynamics to each parameter perturbations is presented numerically. Further, the effects of refuge parameters are demonstrated individually as well as simultaneously by two-dimensional and three-dimensional graphs to enhance the impacts more signific...

Global behavior of a within-host viral dynamic model with non-cytolytic cure effect

2019 IEEE Region 10 Symposium (TENSYMP), 2019

In this paper, we propose a within-host viral dynamic model incorporating non-cytolytic cure proc... more In this paper, we propose a within-host viral dynamic model incorporating non-cytolytic cure process and the infection term with saturated mass action principle. It is been shown that the global behavior of the model counts on the biological threshold parameter, namely, basic reproduction number. We establish that the infection gets eradicated if the basic reproduction number is less than unity and persists in the host body if the basic reproduction number is greater than unity. A comparison study of three various viral infection models is performed through numerical analysis and the obtained results suggest that the inclusion of saturated mass action principle and cure rate has a significant impact in the viral infection dynamics. Further, an application of the proposed model to some in vivo data of HBV transgenic mice.

Viral dynamic model with cellular immune response: A case study of HIV-1 infected humanized mice

In this paper, an attempt has been made to study the global dynamical behavior of a viral dynamic... more In this paper, an attempt has been made to study the global dynamical behavior of a viral dynamics model incorporating both the lytic and nonlytic immune responses. The global stability of the model is analyzed in terms of two threshold parameters, namely, basic reproduction number, R 0 and immune response reproduction number, R 1 . The obtained results signify that the infection dies out if R 0 ≤ 1 and persists if R 0 > 1 . We establish that the global dynamic behavior of the model has no concern with the efficacy of the nonlytic component. Numerical simulations are performed to support our theoretical findings and to investigate the effects of lytic and nonlytic components on the viral dynamics model. A comparison of two different viral infection models has been performed to illustrate the effect of viral replication inhibition through nonlytic effector mechanism on the infection dynamics. Moreover, a case study of HIV-1 infected humanized mice is presented and the result manif...

Effect of non-cytolytic cure and saturation response: An in silico study to instigate the viral spread inhibition

The European Physical Journal Plus

Abstract The non-cytolytic cure of infected cells is an imperative mechanism that maintains the h... more Abstract The non-cytolytic cure of infected cells is an imperative mechanism that maintains the healthy state in the host body by reducing the level of infection. The primary purpose of humoral immune response, i.e., the B cell response, is to neutralize the extracellular virions present in the body. To explore the impact of infected cells and virus particle-mediated saturation response on the viral spread dynamics under the influence of these critical factors, we propose a viral infection model incorporating the coupling effect of non-cytolytic cure mechanism and saturation response in the presence of humoral immune responses. Through parameter variation experimentation, we obtain that under the exposure of a weak humoral response, the saturation response effectively reduces the level of virions, whereas it has a less significant effect on viral infection dynamics in the presence of a strong humoral response or non-cytolytic cure mechanism. We observe that the strength of humoral immune response depends on the number of activated B cells present in the body rather than the rate at which it neutralizes the viruses. Further, we demonstrate that the non-cytolytic cure mechanism plays a vital role in restoring the no infection phase in the host body in the presence of a high infection coefficient. Moreover, a case study of HCV-infected human hepatic Huh7.5.1 cell lines has been presented to describe the HCV infection dynamics in a real-life scenario using model prediction technique. Graphic Abstract

Modeling the cell-to-cell transmission dynamics of viral infection under the exposure of non-cytolytic cure

Journal of Applied Mathematics and Computing

Effect of fear on prey–predator dynamics: Exploring the role of prey refuge and additional food

Chaos: An Interdisciplinary Journal of Nonlinear Science

Supplement of Additional Food: Dynamics of Self-Competitive Prey–Predator System Incorporating Prey Refuge

Iranian Journal of Science and Technology, Transactions A: Science

Modeling the effect of non-cytolytic immune response on viral infection dynamics in the presence of humoral immunity

Nonlinear Dynamics

In this paper, a mathematical model describing the viral infection dynamics with non-cytolytic ef... more In this paper, a mathematical model describing the viral infection dynamics with non-cytolytic effect of humoral immune response is presented and analyzed. The effect of non-cytolytic immune response on the process of viral infectivity has been basically described by the non-cytolytic cure of infected cells and inhibition of viral replication, i.e., the non-lytic immune response. The sufficient criteria for the local and global stability of the equilibria, namely disease-free equilibrium, immune-free equilibrium and chronic equilibrium with humoral response, have been determined in terms of two threshold parameters, viz., the basic reproduction number, \(R_0\), and the humoral immune response reproduction number, \(R_1\). The condition governing the occurrence of Hopf bifurcation around the chronic equilibrium with humoral response has been obtained using the rate of infection as a bifurcation parameter. The obtained results indicate that the infection gets eradicated for \(R_0 \le 1\) and persists in the body for \(R_0 > 1\). Numerical simulations are presented to support our analytical findings. The comparison of various viral dynamic models suggests that the incorporation of the non-cytolytic immune response increases the concentration of uninfected cells, but causes a depletion of humoral immune response. Further, the effect of non-cytolytic immune response on the dynamical behavior of the system has been demonstrated.