Pub Date : 2017-09-27DOI: 10.1142/S1793048017500060
Minchuan Zhang, Peiming He, Jing Su, D. T. Singh, Hailei Su, Haibin Su
Ebola virus is a highly lethal filovirus, claimed thousands of people in its recent outbreak. Seven viral proteins constitute ebola viral structure, and four of them (nucleoprotein (NP), polymerase L, VP35 and VP30) participate majorly in viral replication and transcription. We have elucidated a conformation change of NP cleft by VP35 NP-binding protein domains through superimposing two experimental NP structure images and discussed the function of this conformation change in the replication and transcription with polymerase complex (L, VP35 and VP30). The important roles of VP30 in viral RNA synthesis have also been discussed. A “tapping” model has been proposed in this paper for a better understanding of the interplay among the four viral proteins (NP, polymerase L, VP35 and VP30). Moreover, we have pinpointed some key residue changes on NP (both NP N- and C-terminal) and L between Reston and Zaire by computational studies. Together, this paper provides a description of interactions among ebola viral proteins (NP, L, VP35, VP30 and VP40) in viral replication and transcription, and sheds light on the complex system of viral reproduction.
{"title":"Interplay Among Constitutes of Ebola Virus: Nucleoprotein, Polymerase L, Viral Proteins","authors":"Minchuan Zhang, Peiming He, Jing Su, D. T. Singh, Hailei Su, Haibin Su","doi":"10.1142/S1793048017500060","DOIUrl":"https://doi.org/10.1142/S1793048017500060","url":null,"abstract":"Ebola virus is a highly lethal filovirus, claimed thousands of people in its recent outbreak. Seven viral proteins constitute ebola viral structure, and four of them (nucleoprotein (NP), polymerase L, VP35 and VP30) participate majorly in viral replication and transcription. We have elucidated a conformation change of NP cleft by VP35 NP-binding protein domains through superimposing two experimental NP structure images and discussed the function of this conformation change in the replication and transcription with polymerase complex (L, VP35 and VP30). The important roles of VP30 in viral RNA synthesis have also been discussed. A “tapping” model has been proposed in this paper for a better understanding of the interplay among the four viral proteins (NP, polymerase L, VP35 and VP30). Moreover, we have pinpointed some key residue changes on NP (both NP N- and C-terminal) and L between Reston and Zaire by computational studies. Together, this paper provides a description of interactions among ebola viral proteins (NP, L, VP35, VP30 and VP40) in viral replication and transcription, and sheds light on the complex system of viral reproduction.","PeriodicalId":88835,"journal":{"name":"Biophysical reviews and letters","volume":"12 1","pages":"117-140"},"PeriodicalIF":0.0,"publicationDate":"2017-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1793048017500060","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47137589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-09-27DOI: 10.1142/S1793048017500072
Y. Babayan, S. Hakobyan, R. S. Ghazaryan, M. Shahinyan
Thermostability of DNA complexes with anti-tumorous compound — mitoxantrone — at 0.011M and 0.11 M NaCl ionic strengths of solution by spectrophotometric and microcalorimetric methods has been studied. It was shown that at small fillings when one molecule of mitoxantrone corresponds to 250 or more base pairs of DNA, the thermostability of complexes strongly depends on the solution’s ionic strength; moreover, at an ionic strength of 0.011 M NaCl the melting temperature dependence on mitoxantrone concentration passes through a minimum. In the mentioned region of mitoxantrone concentration the melting enthalpy of the complexes increases linearly with mitoxantrone concentration enhancement. The observed phenomenon, which is not observed for ethidium bromide complexes with DNA, is qualitatively explained by the increasing of coil-shaped state of DNA–mitoxantrone complex due to additional freedom of rotation of mitoxantrone side groups.
用分光光度法和微量热法研究了抗肿瘤化合物米托蒽醌与DNA配合物在0.011M和0.11 M NaCl离子强度下的热稳定性。结果表明，当一个米托蒽醌分子对应250个或更多的DNA碱基对时，配合物的热稳定性很大程度上取决于溶液的离子强度;此外，在离子强度为0.011 M NaCl时，熔化温度对米托蒽醌浓度的依赖性最小。在米托蒽醌浓度范围内，配合物的熔融焓随米托蒽醌浓度的增加而线性增加。溴化乙锭与DNA配合物所观察到的现象，定性地解释为由于米托蒽醌侧基的额外旋转自由，DNA -米托蒽醌配合物的盘绕状态增加。
{"title":"Thermostability of DNA Complexes with Mitoxantrone at Small Fillings","authors":"Y. Babayan, S. Hakobyan, R. S. Ghazaryan, M. Shahinyan","doi":"10.1142/S1793048017500072","DOIUrl":"https://doi.org/10.1142/S1793048017500072","url":null,"abstract":"Thermostability of DNA complexes with anti-tumorous compound — mitoxantrone — at 0.011M and 0.11 M NaCl ionic strengths of solution by spectrophotometric and microcalorimetric methods has been studied. It was shown that at small fillings when one molecule of mitoxantrone corresponds to 250 or more base pairs of DNA, the thermostability of complexes strongly depends on the solution’s ionic strength; moreover, at an ionic strength of 0.011 M NaCl the melting temperature dependence on mitoxantrone concentration passes through a minimum. In the mentioned region of mitoxantrone concentration the melting enthalpy of the complexes increases linearly with mitoxantrone concentration enhancement. The observed phenomenon, which is not observed for ethidium bromide complexes with DNA, is qualitatively explained by the increasing of coil-shaped state of DNA–mitoxantrone complex due to additional freedom of rotation of mitoxantrone side groups.","PeriodicalId":88835,"journal":{"name":"Biophysical reviews and letters","volume":"12 1","pages":"141-149"},"PeriodicalIF":0.0,"publicationDate":"2017-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1793048017500072","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45976327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-09-27DOI: 10.1142/S1793048017500084
L. Tavadyan, S. Minasyan, Gaspar Kocharyan, A. Antonyan, V. G. Sahakyan, M. Parsadanyan, P. O. Vardevanyan
The binding of both ethidium bromide (EtBr) and Hoechst 33258 (H33258) to calf thymus DNA differing by the mechanism at different ionic strengths of NaCl water solutions (2, 20 and 150mM) has been quantitatively studied by square wave voltammetry (SWV). It was revealed that EtBr binds to DNA by more than one mode: at the solution ionic strengths 2 and 150mM, two modes were revealed, at 20mM — three modes. Values of EtBr binding constant (K) to DNA and the number of nucleotides per one binding site (n) for respective binding modes were determined. For H33258 under the same conditions, two binding modes were found and for both these modes values of K and n were determined. Dependence of the binding types and parameters on the solution ionic strength by SWV method was revealed, which differs by the binding type of EtBr and H33258. The obtained data are in good accordance with the ones determined by spectroscopic (absorption and fluorescence) and differential pulse voltammetry (DPV) methods. The obtained data indicate the sensibility and high precision of SWV method which may be applied to studies on interaction of different ligands with DNA, which reveal some peculiarities of their binding to DNA that are hidden and are not found by other methods.
{"title":"Exploring the Interaction of Ethidium Bromide and HOECHST 33258 with DNA by Means of Electrochemical Approach","authors":"L. Tavadyan, S. Minasyan, Gaspar Kocharyan, A. Antonyan, V. G. Sahakyan, M. Parsadanyan, P. O. Vardevanyan","doi":"10.1142/S1793048017500084","DOIUrl":"https://doi.org/10.1142/S1793048017500084","url":null,"abstract":"The binding of both ethidium bromide (EtBr) and Hoechst 33258 (H33258) to calf thymus DNA differing by the mechanism at different ionic strengths of NaCl water solutions (2, 20 and 150mM) has been quantitatively studied by square wave voltammetry (SWV). It was revealed that EtBr binds to DNA by more than one mode: at the solution ionic strengths 2 and 150mM, two modes were revealed, at 20mM — three modes. Values of EtBr binding constant (K) to DNA and the number of nucleotides per one binding site (n) for respective binding modes were determined. For H33258 under the same conditions, two binding modes were found and for both these modes values of K and n were determined. Dependence of the binding types and parameters on the solution ionic strength by SWV method was revealed, which differs by the binding type of EtBr and H33258. The obtained data are in good accordance with the ones determined by spectroscopic (absorption and fluorescence) and differential pulse voltammetry (DPV) methods. The obtained data indicate the sensibility and high precision of SWV method which may be applied to studies on interaction of different ligands with DNA, which reveal some peculiarities of their binding to DNA that are hidden and are not found by other methods.","PeriodicalId":88835,"journal":{"name":"Biophysical reviews and letters","volume":"12 1","pages":"151-161"},"PeriodicalIF":0.0,"publicationDate":"2017-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1793048017500084","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46946918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-07-02DOI: 10.1142/S1793048017500059
K. Das, P. Roy, Subhabrata Ghosh, S. Maiti
This paper deals with an eco-epidemiological approach with disease circulating through the predator species. Disease circulation in the predator species can be possible by contact as well as by external sources. Here, we try to discuss the role of external source of infection along with nutritional value on system dynamics. To establish our findings, we have worked out the local and global stability analysis of the equilibrium points with Hopf bifurcation analysis associated with interior equilibrium point. The ecological consequence by ecological basic reproduction number as well as the disease basic reproduction number or basic reproductive ratio are obtained and we have analyzed the community structure of the particular system with the help of ecological and disease basic reproduction numbers. Further we pay attention to the chaotic dynamics which is produced by disease circulating in predator species by contact. Our numerical simulations reveal that eco-epidemiological system without external source of infection induced chaotic dynamics for increasing force of infection due to contact, whereas in the presence of external source of infection, it exhibits stable solution. It is also observed that nutritional value can prevent chaotic dynamics. We conclude that chaotic dynamics can be controlled by the external source of infection as well as nutritional value. We apply basic tools of nonlinear dynamics such as Poincare section and maximum Lyapunov exponent to investigate chaotic behavior of the system.
{"title":"External Source of Infection and Nutritional Efficiency Control Chaos in a Predator–Prey Model with Disease in the Predator","authors":"K. Das, P. Roy, Subhabrata Ghosh, S. Maiti","doi":"10.1142/S1793048017500059","DOIUrl":"https://doi.org/10.1142/S1793048017500059","url":null,"abstract":"This paper deals with an eco-epidemiological approach with disease circulating through the predator species. Disease circulation in the predator species can be possible by contact as well as by external sources. Here, we try to discuss the role of external source of infection along with nutritional value on system dynamics. To establish our findings, we have worked out the local and global stability analysis of the equilibrium points with Hopf bifurcation analysis associated with interior equilibrium point. The ecological consequence by ecological basic reproduction number as well as the disease basic reproduction number or basic reproductive ratio are obtained and we have analyzed the community structure of the particular system with the help of ecological and disease basic reproduction numbers. Further we pay attention to the chaotic dynamics which is produced by disease circulating in predator species by contact. Our numerical simulations reveal that eco-epidemiological system without external source of infection induced chaotic dynamics for increasing force of infection due to contact, whereas in the presence of external source of infection, it exhibits stable solution. It is also observed that nutritional value can prevent chaotic dynamics. We conclude that chaotic dynamics can be controlled by the external source of infection as well as nutritional value. We apply basic tools of nonlinear dynamics such as Poincare section and maximum Lyapunov exponent to investigate chaotic behavior of the system.","PeriodicalId":88835,"journal":{"name":"Biophysical reviews and letters","volume":"12 1","pages":"87-115"},"PeriodicalIF":0.0,"publicationDate":"2017-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1793048017500059","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49419229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-06-01DOI: 10.1142/S1793048017500047
S. Singh, Prabha Sharma, Phool Singh
We present a mathematical model to study the growth of a solid tumor in the presence of regular doses of lymphocytes. We further extend it to take care of the periodic behavior of the lymphocytes, which are used for stimulating the immune system. Cell carrying capacity has been specified and a cell kill rate under immunotherapy is used to take care of how different metabolisms will react to the treatment. We analyze our model with respect to its stability and its sensitivity to the various parameters used.
{"title":"Stability of Tumor Growth Under Immunotherapy: A Computational Study","authors":"S. Singh, Prabha Sharma, Phool Singh","doi":"10.1142/S1793048017500047","DOIUrl":"https://doi.org/10.1142/S1793048017500047","url":null,"abstract":"We present a mathematical model to study the growth of a solid tumor in the presence of regular doses of lymphocytes. We further extend it to take care of the periodic behavior of the lymphocytes, which are used for stimulating the immune system. Cell carrying capacity has been specified and a cell kill rate under immunotherapy is used to take care of how different metabolisms will react to the treatment. We analyze our model with respect to its stability and its sensitivity to the various parameters used.","PeriodicalId":88835,"journal":{"name":"Biophysical reviews and letters","volume":"12 1","pages":"69-85"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1793048017500047","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45436590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-03-28DOI: 10.1142/S1793048017500035
S. Vijaya, E. Rekha, J. J. Singh
This paper presents the nonlinear dynamics of a one-prey and one-predator harvesting model with precise in nature as well as imprecise in biological phenomena parameters. We derived the conditions for boundedness, the equilibrium point, and stability analysis. Both precise and imprecise models showed stable, unstable, and saddle-point states. The stability analysis revealed the existence of biological and bionomic equilibria. In this study, we found the optimal harvesting policy for both prey and predator species. Finally, numerical experiments were performed with various parameter values to observe the variation of equilibrium states.
{"title":"Nonlinear Dynamics of a Prey-Predator Model Using Precise and Imprecise Harvesting Phenomena with Biological Parameters","authors":"S. Vijaya, E. Rekha, J. J. Singh","doi":"10.1142/S1793048017500035","DOIUrl":"https://doi.org/10.1142/S1793048017500035","url":null,"abstract":"This paper presents the nonlinear dynamics of a one-prey and one-predator harvesting model with precise in nature as well as imprecise in biological phenomena parameters. We derived the conditions for boundedness, the equilibrium point, and stability analysis. Both precise and imprecise models showed stable, unstable, and saddle-point states. The stability analysis revealed the existence of biological and bionomic equilibria. In this study, we found the optimal harvesting policy for both prey and predator species. Finally, numerical experiments were performed with various parameter values to observe the variation of equilibrium states.","PeriodicalId":88835,"journal":{"name":"Biophysical reviews and letters","volume":"12 1","pages":"39-68"},"PeriodicalIF":0.0,"publicationDate":"2017-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1793048017500035","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43760329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-03-27DOI: 10.1142/S1793048017500011
M. Shahinyan, M. Mikaelyan, M. R. Darbinyan, P. O. Vardevanyan
The effect of electromagnetic irradiation with extremely high radio frequencies on several parameters of albumin water-saline solutions has been studied and the changes invoked by this irradiation after long time of its effect were observed. It was shown that the electromagnetic irradiation with 51.8GHz frequency, which is resonant for water, is preserved up to 48h after which the system returns to the initial state. It was shown as well that albumin thermostability also enhances and it is preserved during 48h, after that the system tends to return to the initial state.
{"title":"Time-Dependent Changes of Albumin Water Solutions After Irradiation by Electromagnetic Waves with Extremely High Radio Frequencies","authors":"M. Shahinyan, M. Mikaelyan, M. R. Darbinyan, P. O. Vardevanyan","doi":"10.1142/S1793048017500011","DOIUrl":"https://doi.org/10.1142/S1793048017500011","url":null,"abstract":"The effect of electromagnetic irradiation with extremely high radio frequencies on several parameters of albumin water-saline solutions has been studied and the changes invoked by this irradiation after long time of its effect were observed. It was shown that the electromagnetic irradiation with 51.8GHz frequency, which is resonant for water, is preserved up to 48h after which the system returns to the initial state. It was shown as well that albumin thermostability also enhances and it is preserved during 48h, after that the system tends to return to the initial state.","PeriodicalId":88835,"journal":{"name":"Biophysical reviews and letters","volume":"12 1","pages":"11-17"},"PeriodicalIF":0.0,"publicationDate":"2017-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1793048017500011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42449284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-03-27DOI: 10.1142/S1793048016300024
Hema Chandra Kotamarthi, Sri Rama Koti Ainavarapu
Protein mechanics is a key component of many cellular and sub-cellular processes. The current review focuses on recent studies from our laboratory that probe the effect of sequence on the mechanical stability of structurally similar proteins and the unfolding mechanisms of multi-domain periplasmic binding proteins. Ubiquitin and small ubiquitin-related modifiers (SUMOs) are structurally similar and possess different mechanical stabilities, ubiquitin being stronger than SUMOs as revealed from their unfolding forces. These differences are plausibly due to the variation in number of inter-residue contacts. The unfolding potential widths determined from the pulling speed-dependent studies revealed that SUMOs are mechanically more flexible than ubiquitin. This flexibility of SUMOs plays a role in ligand binding and our single-molecule studies on SUMO interaction with SUMO binding motifs (SBMs) have shown that ligand binding decreases the SUMO flexibility and increases its mechanical stability. Studies on multi-domain periplasmic binding proteins have revealed that the unfolding energy landscape of these proteins is complex and they follow kinetic partitioning between two-state and multiple three-state pathways.
{"title":"Mechanical Unfolding Studies on Single-Domain SUMO and Multi-Domain Periplasmic Binding Proteins","authors":"Hema Chandra Kotamarthi, Sri Rama Koti Ainavarapu","doi":"10.1142/S1793048016300024","DOIUrl":"https://doi.org/10.1142/S1793048016300024","url":null,"abstract":"Protein mechanics is a key component of many cellular and sub-cellular processes. The current review focuses on recent studies from our laboratory that probe the effect of sequence on the mechanical stability of structurally similar proteins and the unfolding mechanisms of multi-domain periplasmic binding proteins. Ubiquitin and small ubiquitin-related modifiers (SUMOs) are structurally similar and possess different mechanical stabilities, ubiquitin being stronger than SUMOs as revealed from their unfolding forces. These differences are plausibly due to the variation in number of inter-residue contacts. The unfolding potential widths determined from the pulling speed-dependent studies revealed that SUMOs are mechanically more flexible than ubiquitin. This flexibility of SUMOs plays a role in ligand binding and our single-molecule studies on SUMO interaction with SUMO binding motifs (SBMs) have shown that ligand binding decreases the SUMO flexibility and increases its mechanical stability. Studies on multi-domain periplasmic binding proteins have revealed that the unfolding energy landscape of these proteins is complex and they follow kinetic partitioning between two-state and multiple three-state pathways.","PeriodicalId":88835,"journal":{"name":"Biophysical reviews and letters","volume":"12 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2017-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1793048016300024","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49233366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-03-01DOI: 10.1142/S1793048017500023
T. Kar, Soovoojeet Jana
In this paper we have proposed and analyzed a simple three-dimensional mathematical model related to malaria disease. We consider three state variables associated with susceptible human population, infected human population and infected mosquitoes, respectively. A discrete delay parameter has been incorporated to take account of the time of incubation period with infected mosquitoes. We consider the effect of insecticide control, which is applied to the mosquitoes. Basic reproduction number is figured out for the proposed model and it is shown that when this threshold is less than unity then the system moves to the disease-free state whereas for higher values other than unity, the system would tend to an endemic state. On the other hand if we consider the system with delay, then there may exist some cases where the endemic equilibrium would be unstable although the numerical value of basic reproduction number may be greater than one. We formulate and solve the optimal control problem by considering insecticide as the control variable. Optimal control problem assures to obtain better result than the noncontrol situation. Numerical illustrations are provided in support of the theoretical results.
{"title":"Dynamical Behavior of a Malaria Model with Discrete Delay and Optimal Insecticide Control","authors":"T. Kar, Soovoojeet Jana","doi":"10.1142/S1793048017500023","DOIUrl":"https://doi.org/10.1142/S1793048017500023","url":null,"abstract":"In this paper we have proposed and analyzed a simple three-dimensional mathematical model related to malaria disease. We consider three state variables associated with susceptible human population, infected human population and infected mosquitoes, respectively. A discrete delay parameter has been incorporated to take account of the time of incubation period with infected mosquitoes. We consider the effect of insecticide control, which is applied to the mosquitoes. Basic reproduction number is figured out for the proposed model and it is shown that when this threshold is less than unity then the system moves to the disease-free state whereas for higher values other than unity, the system would tend to an endemic state. On the other hand if we consider the system with delay, then there may exist some cases where the endemic equilibrium would be unstable although the numerical value of basic reproduction number may be greater than one. We formulate and solve the optimal control problem by considering insecticide as the control variable. Optimal control problem assures to obtain better result than the noncontrol situation. Numerical illustrations are provided in support of the theoretical results.","PeriodicalId":88835,"journal":{"name":"Biophysical reviews and letters","volume":"12 1","pages":"19-38"},"PeriodicalIF":0.0,"publicationDate":"2017-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1793048017500023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43071194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-10-17DOI: 10.1142/S1793048016500041
M. Chakroun, M. H. B. Ghozlen
Automotive shocks involve various tiers’ speed for different human body tissues. Knowing the behavior of these tissues, including muscles, in different vibration frequency is therefore necessary. The muscle has viscoelatic properties. Dynamically, this material has variable mechanical properties depending on the vibration frequency. A novel technique is being employed to examine the variation of the mechanical impedance of pork muscle as a function of frequency. A force is imposed on the lower surface of the sample and acceleration is measured on its upper surface. These two parameters are measured using sensors. The sample is modeled by Kelvin–Voigt model. These measures allow deducing the change in the mechanical impedance modulus (/Zexp/ = /Force: Acceleration/) of pork muscle as a function of vibration frequency. The measured impedance has a resonance of approximately 60Hz. Best-fit parameters of theoretical impedance can be deduced by superposition with the experiment result. The variation of Young’s modulus and internal damping of pig’s muscle as a function of frequency are determined. The results obtained between 5Hz and 30Hz are the same as determined by Aimedieu and al in 2003, therefore validating our technique. The Young’s modulus of muscle increases with the frequency, on the other hand, we note a rating decrease of internal damping.
{"title":"Measurement of Young’s Modulus and Internal Damping of Pork Muscle in Dynamic Mode","authors":"M. Chakroun, M. H. B. Ghozlen","doi":"10.1142/S1793048016500041","DOIUrl":"https://doi.org/10.1142/S1793048016500041","url":null,"abstract":"Automotive shocks involve various tiers’ speed for different human body tissues. Knowing the behavior of these tissues, including muscles, in different vibration frequency is therefore necessary. The muscle has viscoelatic properties. Dynamically, this material has variable mechanical properties depending on the vibration frequency. A novel technique is being employed to examine the variation of the mechanical impedance of pork muscle as a function of frequency. A force is imposed on the lower surface of the sample and acceleration is measured on its upper surface. These two parameters are measured using sensors. The sample is modeled by Kelvin–Voigt model. These measures allow deducing the change in the mechanical impedance modulus (/Zexp/ = /Force: Acceleration/) of pork muscle as a function of vibration frequency. The measured impedance has a resonance of approximately 60Hz. Best-fit parameters of theoretical impedance can be deduced by superposition with the experiment result. The variation of Young’s modulus and internal damping of pig’s muscle as a function of frequency are determined. The results obtained between 5Hz and 30Hz are the same as determined by Aimedieu and al in 2003, therefore validating our technique. The Young’s modulus of muscle increases with the frequency, on the other hand, we note a rating decrease of internal damping.","PeriodicalId":88835,"journal":{"name":"Biophysical reviews and letters","volume":"11 1","pages":"109-116"},"PeriodicalIF":0.0,"publicationDate":"2016-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S1793048016500041","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64047755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：