Nothing Special   »   [go: up one dir, main page]

Skip to main content
Log in

Modelling intra-host competition between malaria parasites strains

  • Published:
Computational and Applied Mathematics Aims and scope Submit manuscript

Abstract

An intra-host epidemiological model is formulated for the co-infection of drug-sensitive and drug-resistant malaria parasites to examine the impact of aggressive treatment on the effect of competitive release in an infected host. The analysis of the existence of equilibrium and their stability of the model is conducted, and the results reveal that the intra-host competition and treatment play a key role in the prevalence of drug-resistant strains. The mathematical outcomes qualitatively match the experimental fact, that the rapid elimination of drug-resistant strains could promote the very evolution it is intended to retard.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Subscribe and save

Springer+ Basic
$34.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or eBook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8

Similar content being viewed by others

References

  • Anderson R, May R (1991) Infectious disease of humans. Oxford University Press, Oxford

    Google Scholar 

  • Anderson R, May R, Gupta S (1989) Non-linear phenomena in host–parasite interactions. Parasitology 99:S59–S79

    Article  Google Scholar 

  • Arnot D (1998) Clone multiplicity of plasmodium falciparum infections in individuals exposed to variable levels of disease transmission. Trans R Soc Trop Med Hyg 92:580–585

    Article  Google Scholar 

  • Balzarini J, Pelemans H, Karlsson A, De Clercq E, Kleim J-P (1996) Concomitant combination therapy for HIV infection preferable over sequential therapy with 3TC and non-nucleoside reverse transcriptase inhibitors. Proc Nat Acad Sci 93:13152–7

    Article  Google Scholar 

  • Bushman M, Morton L, Duah N, Quashie N, Abuaku B et al (2016) Within-host competition and drug resistance in the human malaria parasite Plasmodium falciparum. Proc Biol Sci 283:20153038

    Article  Google Scholar 

  • de Roode J, Culleton R, Bell A, Read A (2004) Competitive release of drug resistance following drug treatment of mixed Plasmodium chabaudi infections. Malar J 3:33–39

    Article  Google Scholar 

  • Greaves M, Maley C (2012) Clonal evolution in cancer. Nature 481:306–313

    Article  Google Scholar 

  • Hansen J, Day T (2014) Coinfection and evolution of drug resistance. J Evol Biol 27:2595–2604

    Article  Google Scholar 

  • Hansen E, Woods R, Read A (2017) How to use a chemotherapeutic agent when resistance to it threatens the patient. PLoS Biol 15:e2001110

    Article  Google Scholar 

  • Hasting I, Donneily M (2005) The impact of antimalaria drug resistance mutations on parasite fitness, and its implications for the evolution of resistance. Drug Resist Updat 8:43–50

    Article  Google Scholar 

  • Hastings I (1997) A model for the origins and spread of drug resistance. Parasitology 115:133–141

    Article  Google Scholar 

  • Hastings I, D’Alessandro U (2000) Modelling a predictable disaster: the rise and spread of drug-resistant malaria. Parasitol Today 16:340–347

    Article  Google Scholar 

  • Huijben S, Nelson W, Wargo A, Sim D, Drew D, Read A (2010) Chemotherapy, within-host ecology and the fitness of drug-resistant malaria parasite. Evolution 64:2952–2968

    Google Scholar 

  • Huijben S, Bell A, Sim D, Tomasello D, Mideo N, Day T, Read A (2013) Aggressive chemotherapy and the selection of drug resisant pathogens. PLOS Path 9:e1003578

    Article  Google Scholar 

  • Kommineni S, Bretl D, Lam V, Chakraborty R, Hayward M, Simpson P et al (2015) Bacteriocin production augments niche competition by enterococci in the mammalian gastrointestinal tract. Nature 526:719–722

    Article  Google Scholar 

  • Legros M, Bonhoeffer S (2016) A combined within-host and between-hosts modelling framework for the evolution of resistance to antimalarial drugs. J R Soc Interface 13:20160148

    Article  Google Scholar 

  • Li Y, Ruan S, Xiao D (2011) The within-host dynamics of malaria infection with immune response. Math Bios Eng 8:999–1018

    Article  MathSciNet  Google Scholar 

  • Lipsitch M, Samore M (2002) Antimicrobial use and antimicrobial resistance: a population perspective. Emerg Infect Dis 8:347–354

    Article  Google Scholar 

  • Lukens AK, Ross LS, Heidebrecht R et al (2014) Harnessing evolutionary fitness in plasmodium falciparum for drug discovery and suppressing resistance. Proc Natl Acad Sci 111:799–804

    Article  Google Scholar 

  • Mackinnon M (2005) Drug resistance models for malaria. Acta Trop 94:207–217

    Article  Google Scholar 

  • Mackinnon M, Hastings I (1998) The evolution of multiple drug resistance in malaria parasites. Trans R Soc Trop Med Hyg 92:188–195

    Article  Google Scholar 

  • Mason D, Mckenzie F, Bossert W (1999) The blood-state dynamics of mixed plasmodium malariae-plasmodium falciparum infections. J Theor Biol 198:546–566

    Article  Google Scholar 

  • Mckenzie F, Bossert W (1997) The dynamics of plasmodium falciparum blood-state infections. J Theor Biol 188:127–140

    Article  Google Scholar 

  • Mitchell J, Carr T (2010) Ocillations in an intra-host model of plasmodium falciparum malaria due to cross-reactive immume response. Bull Math Biol 72:590–610

    Article  MathSciNet  Google Scholar 

  • Molineaux L, Dietz K (1999) Review of intra-host models of malaria. Parassitologia 41:221–231

    Google Scholar 

  • Parida P , Sarma K , Borkakoty B , Mohapatra PK (2016) Structure and functional differentiation of PfCRT mutation in chloroquine resistance (CQR) in Plasmodium falciparum Malaria. Curr Top Malaria

  • Pollitt L, Mideo N, Drew D (2011) Competition and the evolution of reproductive restraint in malaria parasites. Am Nat 177:358–367

    Article  Google Scholar 

  • Read A, Taylor L (2001) The ecology of genetically diverse infections. Science 292:1099–1102

    Article  Google Scholar 

  • Read A, Day T, Huijben S (2011) The evolution of drug resistance and the curious orthodoxy of aggressive chemotherapy. Proc Natl Acad Sci 108:10871–10877

    Article  Google Scholar 

  • Recker M, Gupta S (2006) Conflicting immune responses can prolong the length of infection in Plasmodium falciparum malaria. Bull Math Biol 68:821–835

    Article  MathSciNet  Google Scholar 

  • Recker M, Nee S, Bull P, Kinyanjul S, Marsh K, Newbold C, Gupta S (2004) Transient crossreactive immune responses can orchestrate antigenic variation in malaria. Nature 188:555–558

    Article  Google Scholar 

  • Roche-Lestienne C, Preudhomme C (2003) Mutations in the ABL kinase domain pre-exist the onset of imatinib treatment. Semin Hematol 40:80–82

    Article  Google Scholar 

  • van den Driessche P, Watmough J (2002) Reproduction numbers and sub-threshold endemic equilibria for compartmental models of disease transmission. Math Biosci 180:29–48

    Article  MathSciNet  Google Scholar 

  • Wale N, Sim D, Jones M, Day Salathe R, T, Read A (2017) Resource limitation prevents the emerge of drug resistance by intensifying with-hose comptetion. Early edn. Proc Natl Acad Sci

  • Walliker D, Hunt P, Babiker H (2005) Fitness of drug-resistant malaria parasites. Acta Trop 94:251–259

    Article  Google Scholar 

  • Wargo A, Huijben S, de Roode J, Shepherd J, Read A (2007) Competitive release and facilitation of drug-resistant parasites after therapeutic chemotherapy in a rodent malaria model. Proc Natl Acad Sci 104:19914–19919

    Article  Google Scholar 

  • World Health Organization (2017) World malaria report 2017. World Health Organization

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Chuncheng Wang.

Additional information

Communicated by Florence Hubert.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Appendix

Appendix

Proof

(Proof of Theorem 2) The Jacobi matrix J(E) of right hand side of (2) at E is

$$\begin{aligned} J(E)=\left( \begin{array}{ccc}-\beta _1 I_s-\beta _2 I_r-d_1&{}-\beta _1 S&{}-\beta _2 S\\ \alpha \beta _1 I_s+p \alpha \beta _2I_r&{}\alpha \beta _1 S -d_2-\mu &{}p \alpha \beta _2 S\\ (1-p)\alpha \beta _2 I_r&{}0&{}(1-p)\alpha \beta _2 S-d_3\end{array}\right) . \end{aligned}$$

At \(P_0\), the eigenvalues of \(J(P_0)\) are

$$\begin{aligned} -d_1,\quad \frac{\varLambda \alpha \beta _1 }{d_1}-d_2-\mu ,\quad \frac{\varLambda \alpha \beta _2(1-p) }{d_1}-d_3 \end{aligned}$$

These quantities are negative whenever \(R_0<1\). At \(\tilde{P}=(\tilde{S},\tilde{I}_s,0)\),

$$\begin{aligned} J(\tilde{P})=\left( \begin{array}{ccc}-\beta _1 \tilde{I}_s-d_1&{}-\beta _1 \tilde{S}&{}-\beta _2 \tilde{S}\\ \alpha \beta _1 \tilde{I}_s&{}0&{}p \alpha \beta _2 \tilde{S}\\ 0&{}0&{}(1-p)\alpha \beta _2 \tilde{S}-d_3\end{array}\right) . \end{aligned}$$

The stability of \(E_1\) is determined by the eigenvalue \((1-p)\alpha \beta _2 \tilde{S}-d_3\), which is also equal to \(\frac{(1-p)(d_2 +\mu )\beta _2}{\beta _1}-d_3\). If \(R_2 < R_1\), then this quantity is always less than 0. For \(\hat{P}\), one has

$$\begin{aligned} J(\hat{P})=\left( \begin{array}{ccc}-\frac{\varLambda }{\hat{S}}&{} -\beta _1\hat{S}&{}-\beta _2\hat{S}\\ \frac{d_2\hat{I}_s}{\hat{S}}&{}\alpha \beta _1 \hat{S} -d_2-\mu &{}p \alpha \beta _2 \hat{S}\\ (1-p)\alpha \beta _2 \hat{I}_r&{}0&{}0\end{array}\right) . \end{aligned}$$

The characteristic equation of \(J(\hat{P})\) is given by

$$\begin{aligned} \lambda ^3+A\lambda ^2+B\lambda +C=0. \end{aligned}$$

where

$$\begin{aligned} \begin{aligned} A=&\,\,d_1R_2+\frac{T_1}{\beta _2},\quad C=\frac{d_1d_3(R_2-1)T_1}{\beta _2}\\ B=&\,\,\frac{d_1R_2T_1}{\beta _2}+\frac{p\beta _1d_1d_2d_3(R_2-1)}{(1-p)T_2}+\frac{d_1d_3(R_2-1)T_1}{T_2},\\ T_1=&\,\beta _2(d_2+\mu )-\beta _1d_3/(1-p),\quad T_2=\,\beta _2(d_2+\mu )-\beta _1d_3 \end{aligned} \end{aligned}$$

It follows from (3) that

$$\begin{aligned} \alpha \beta _1 \hat{S} -d_2-\mu =\frac{\beta _1d_3}{\beta _2(1-p)}-(d_2+\mu )<0. \end{aligned}$$

and therefore, \(T_2>T_1>0\), \(A>0\), \(B>0\) and \(C>0\). Since

$$\begin{aligned} \begin{aligned} D&:=AB-C\\&=\frac{d_1R_2T_1A}{\beta _2}+\frac{d_1d_3(R_2-1)}{T_2\beta _2(1-p)}\left[ p\beta _1\beta _2d_1d_2R_2 +\beta _2d_1R_2T_1(1-p)+p\beta _1T_1(d_2-d_3)\right] \end{aligned} \end{aligned}$$

the Routh-Hurwitz criterion tells that \(\hat{P}\) is locally asymptotically stable if and only if \(D>0\). \(\square \)

Proof

(Proof of Theorem 4) The Jacobi matrix J(E) of right hand side of (2) is

$$\begin{aligned} J(E)=\left( \begin{array}{ccc}-\beta _1 I_s-\beta _2 I_r-d_1&{}-\beta _1 S&{}-\beta _2 S\\ \alpha \beta _1 I_s+p \alpha \beta _2I_r&{}\alpha \beta _1 S -\gamma _1 I_r-d_2-\mu &{}p \alpha \beta _2 S-\gamma _1 I_s\\ (1-p)\alpha \beta _2 I_r&{}-\gamma _2 I_r&{}(1-p)\alpha \beta _2 S-\gamma _2 I_s-d_3\end{array}\right) . \end{aligned}$$

At \(P_0\), the eigenvalues of \(J(P_0)\) are

$$\begin{aligned} -d_1,\quad \frac{\alpha \beta _1 \varLambda }{d_1}-d_2-\mu ,\quad \frac{(1-p)\alpha \beta _2 \varLambda }{d_1}-d_3 \end{aligned}$$

which are negative whenever \(R_0<1\). At \(\tilde{P}=(\tilde{S},\tilde{I}_s,0)\),

$$\begin{aligned} J(\tilde{P})=\left( \begin{array}{ccc}-\beta _1 \tilde{I}_s-d_1&{}-\beta _1 \tilde{S}&{}-\beta _2 \tilde{S}\\ \alpha \beta _1 \tilde{I}_s&{}0&{}p \alpha \beta _2 \tilde{S}-\gamma _1 \tilde{I}_s\\ 0&{}0&{}(1-p)\alpha \beta _2 \tilde{S}-\gamma _2 \tilde{I}_s-d_3\end{array}\right) . \end{aligned}$$

The stability of \(\tilde{P}\) is determined by the eigenvalue \((1-p)\alpha \beta _2 \tilde{S}-\gamma _2 \tilde{I}_s-d_3\), which is equal to \(\frac{(1-p)d_2\beta _2}{\beta _1}-\frac{\gamma _2(\varLambda \alpha \beta _1-d_1(d_2+\mu ))}{\beta _1(d_2+\mu )}-d_3\). Recall that \(d_2<d_3\) and \(\beta _1>\beta _2\) due to fitness cost of resistant strain. Then, this quantity is always less than 0.

At \(P^*=(S^*,I_s^*,I_r^*)\), we have

$$\begin{aligned} J(E_2)=\left( \begin{array}{ccc}-\beta _1 I_s^*-\beta _2 I_r^*-d_1&{}-\beta _1 S^*&{}-\beta _2 S^*\\ \alpha \beta _1 I_s^*+p \alpha \beta _2I_r^*&{}\alpha \beta _1 S^* -\gamma _1 I_r^*-d_2-\mu &{}p \alpha \beta _2 S^*-\gamma _1 I_s^*\\ (1-p)\alpha \beta _2 I_r^*&{}-\gamma _2 I_r^*&{}(1-p)\alpha \beta _2 S^*-\gamma _2 I_s^*-d_3\end{array}\right) . \end{aligned}$$

The eigenvalues of \(J(P^*)\) are given by zeros of a third order polynomial. However, we will not provide the detailed expression of characteristic equation for its complexity. The expression of \(J(P^*)\) is enough for carrying out numerical simulations.

In order to show the occurrence of fixed point bifurcation, we change the order of equations of system (1), and let \(I_r(t)=x, I_s(t)=y, S(t)=z\). Then,

$$\begin{aligned} \left\{ \begin{aligned} x'=&\,(1-p)\alpha \beta _2 x z-\gamma _2 x y-d_3 x\\ y'=&\,\alpha \beta _1 y z+p\alpha \beta _2 x z-\gamma _1 x y-(d_2+\mu ) y\\ z'=&\,\varLambda -\beta _1 y z-\beta _2 x z-d_1 z \end{aligned} \right. \end{aligned}$$
(9)

Shifting the fixed point \(P_0=(\frac{\varLambda }{d_1},0,0)\) through \({\overline{x}}=x,{\overline{y}}=y,\overline{z}=z-\frac{\varLambda }{d_1}\), we have

$$\begin{aligned} \left\{ \begin{aligned} {\overline{x}}'=&\,((1-p)\alpha \beta _2 \frac{\varLambda }{d_1}-d_3) {\overline{x}}+(1-p)\alpha \beta _2 {\overline{x}} {\overline{z}}-\gamma _2 {\overline{x}} {\overline{y}}\\ {\overline{y}}'=&\,p\alpha \beta _2 \frac{\varLambda }{d_1} {\overline{x}}+ (\alpha \beta _1 \frac{\varLambda }{d_1}-(d_2+\mu )){\overline{y}}+ \alpha \beta _1 {\overline{y}} {\overline{z}}+p\alpha \beta _2 {\overline{x}} {\overline{z}}- \gamma _1 {\overline{x}} {\overline{y}}\\ {\overline{z}}'=&\,-\beta _2 \frac{\varLambda }{d_1} {\overline{x}}-\beta _1 \frac{\varLambda }{d_1} {\overline{y}} -d_1 {\overline{z}}-\beta _1 {\overline{y}} {\overline{z}}-\beta _2 {\overline{x}} {\overline{z}} \end{aligned} \right. \end{aligned}$$
(10)

Let \(d_3^*=(1-p)\alpha \beta _2 \frac{\varLambda }{d_1}\) and \(\xi =d_3^*-d_3\) be the bifurcation parameter. The Jacobian matrix of system (10) at (0, 0, 0) when \(\xi =0\) is

$$\begin{aligned} J\big |_{(0,0,0)}=\left( \begin{array}{ccc}0&{}0&{}0\\ \frac{p \alpha \beta _2 \varLambda }{d_1}&{}\frac{\alpha \beta _1 \varLambda }{d_1}-(d_2+\mu )&{}0\\ -\frac{\beta _2 \varLambda }{d_1}&{}-\frac{\beta _1 \varLambda }{d_1}&{}-d_1\end{array}\right) \end{aligned}$$

Accordingly, its eigenvalues are \( \lambda _1=0, \lambda _2=\frac{\alpha \beta _1 \varLambda }{d_1}-(d_2+\mu ), \lambda _3=-d_1\), and the corresponding eigenvectors are

$$\begin{aligned} \left( \begin{array}{c}1\\ a\\ b\end{array}\right) , \left( \begin{array}{c}0\\ 1\\ c\end{array}\right) , \left( \begin{array}{c}0\\ 0\\ 1\end{array}\right) \end{aligned}$$

with \(a=\frac{p \alpha \beta _2 \varLambda }{d_1 (d_2+\mu )-\alpha \beta _1 \varLambda }, b=-\frac{1}{d_1}\left( \frac{\beta _2 \varLambda (d_1 (d_2+\mu )-\alpha \beta _1 \varLambda )+ \varLambda ^2 \alpha \beta _1 \beta _2 p}{d_1(d_1 (d_2+\mu ) - \alpha \beta _1 \varLambda )}\right) , c=\frac{\beta _1 \varLambda }{d_1 (d_2+\mu )-\alpha \beta _1 \varLambda -d_1^2}\).

Make the following change of variables

$$\begin{aligned} \left( \begin{array}{c}{\overline{x}}\\ {\overline{y}}\\ \overline{z}\end{array}\right) =T\left( \begin{array}{c}u\\ v\\ w\end{array}\right) \end{aligned}$$
(11)

where T is the invertible matrix whose columns are the three eigenvectors obtained above. Then,

$$\begin{aligned} \left( \begin{array}{c}u\\ v\\ w\end{array}\right) '=\left( \begin{array}{ccc}0&{}0&{}0\\ 0&{}\frac{\alpha \beta _1 \varLambda }{d_1}-d_2&{}0\\ 0&{}0&{}-d_1\end{array}\right) \left( \begin{array}{c}u\\ v\\ w\end{array}\right) + \left( \begin{array}{c}g_1(u,v,w,\xi )\\ g_2(u,v,w,\xi )\\ g_3(u,v,w,\xi )\end{array}\right) \end{aligned}$$

where

$$\begin{aligned} \begin{aligned} g_1(u,v,w,\xi )&=\xi u+((1-p)\alpha \beta _2 b -a \gamma _2)u^2+((1-p)\alpha \beta _2 b -\gamma _2)uv+(1-p)\alpha \beta _2 u w\\ g_2(u,v,w,\xi )&=-a \xi u+(-(1-p)\alpha \beta _2 a b + a^2 \gamma _2+\alpha \beta _1 a b + p \alpha \beta _2 b - a \gamma _1)u^2\\&\quad +(-(1-p)\alpha \beta _2 a b + a \gamma _2 + \alpha \beta _1 a c + \alpha \beta _1 b + p \alpha \beta _2 b c - \gamma _1)uv\\&\quad +(-a(1-p)\alpha \beta _2 + \alpha \beta _1 a + p \alpha \beta _2)uw+\alpha \beta _1 c v^2 + \alpha \beta _1 v w \\ g_3(u,v,w,\xi )&=(2ac-b)\xi u+ ((ac-b) ((1-p)\alpha \beta _2 b - a \gamma _2){-}c(\alpha \beta _1 a b {+}p \alpha \beta _2 b {-} a \gamma _1)\\&\quad -(\beta _1 a b + \beta _2 b))u^2 +((ac-b)((1-p) \alpha \beta _2 b - \gamma _2) \\&\quad -c(\alpha \beta _1 a c+ \alpha \beta _1 b + p \alpha \beta _2 b c -\gamma _1)-(\beta _1 a c + \beta _1 b + \beta _2 c))u v\\&\quad +((ac-b)((1-p) \alpha \beta _2)-c(\alpha \beta _1 a+p \alpha \beta _2)-(\beta _1 a+\beta _2))u w \\&\quad -(c^2 \alpha \beta _1 + c \beta _1)v^2-(c \alpha \beta _1+\beta _1)v w \end{aligned} \end{aligned}$$

Denote

$$\begin{aligned}&A=0,~B=\left( \begin{array}{cc}\lambda _2&{}0\\ 0&{}\lambda _3\end{array}\right) , ~f(u,v,w,\xi )\\&\quad =g_1(u,v,w,\xi ),~~g(u,v,w,\xi )= \left( \begin{array}{c}g_2(u,v,w,\xi )\\ g_3(u,v,w,\xi )\end{array}\right) \end{aligned}$$

Assume the center manifold takes the form of

$$\begin{aligned} v= & {} h_1(u,\xi )=a_1 u^2+a_2 u \xi + a_3 \xi ^2 + o(3)\\ w= & {} h_2(u,\xi )=b_1 u^2+b_2 u \xi + b_3 \xi ^2 + o(3) \end{aligned}$$

It then follows that

$$\begin{aligned} N(h)\triangleq D_u h(u,\xi )(A u +f(u, h_1, h_2 \xi ))-B h -g(u, h_1, h_2, \xi )=0. \end{aligned}$$

After some symbolic manipulations, we have

$$\begin{aligned} \begin{aligned} a_1&=- \frac{1}{\lambda _2}(-(1-p)\alpha \beta _2 a b + a^2 \gamma _2 + \alpha \beta _1 a b + p \alpha \beta _2 b - a \gamma _1)\\ a_2&=\frac{a}{\lambda _2},\quad a_3=0\\ b_1&= - \frac{1}{\lambda _3}((ac-b)((1-p)\alpha \beta _2 b - a \gamma _2)-c(\alpha \beta _1 a b +p \alpha \beta _2 b+ a \gamma _1)-(\beta _1 a b + \beta _2 b))\\ b_2&= - \frac{2ac-b}{\lambda _3}, \quad b_3=0 \end{aligned} \end{aligned}$$

Consequently, the restricted equation of (1) on the center manifold is given by

$$\begin{aligned} u'=\xi u+r u^2 +(a_1 s+t b_1)u^3+(a_2 s + t b_2)u^2 \xi \end{aligned}$$

where

$$\begin{aligned} r=(1-p)\alpha \beta _2 b - a \gamma _2, \quad s=(1-p)\alpha \beta _2 b - \gamma _2,\quad t=(1-p)\alpha \beta _2 b. \end{aligned}$$

\(\square \)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Song, T., Wang, C. & Tian, B. Modelling intra-host competition between malaria parasites strains. Comp. Appl. Math. 39, 48 (2020). https://doi.org/10.1007/s40314-020-1072-5

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s40314-020-1072-5

Keywords

Mathematics Subject Classification

Navigation