NEWS

Monday, 22 IUN 2022

LINEAR DYNAMICS, Miercuri 22.06.2022, ora 10.00, sala A27

Monday, 15 OCT 2021

16th International Symposium on Geometric Function Theory and Applications (GFTA 2021), 15-18 October 2021

Research papers

2020

1. P.N. Agrawal, A.M. Acu, R. Ruchi, q-Generalized Bernstein-Durrmeyer Polynomials, Journal of Mathematical Inequalities, Volume: 14 Issue: 1 Pages: 211-235 Published: MAR 2020. http://jmi.ele-math.com/14-15/q-generalized-Bernstein-Durrmeyer-polynomials

2. Laurian Suciu, On operators with two-isometric liftings, Complex Analysis and Operator Theory, 14:5, 1-16, 2020. https://link.springer.com/article/10.1007/s11785-019-00960-9

3. Witold Majdak, Laurian Suciu, Brownian type parts of operators in Hilbert spaces, Results in Mathematics, 75:5, 1-23, 2020. https://link.springer.com/article/10.1007%2Fs00025-019-1130-8

2019

1. A. Ratiu, A.M. Acu, T. Acar, D.F. Sofonea, Certain positive linear operators with better approximation properties, Mathematical Methods in the applied sciences, Volume: 42 Issue: 16 Special Issue: SI Pages: 5133-5142 Published: NOV 15 2019 https://onlinelibrary.wiley.com/doi/abs/10.1002/mma.5243

2. A.M. Acu, T. Acar, C.V. Muraru, V.A. Radu, Some approximation properties by a class of bivariate operators, Mathematical Methods in The Applied Sciences, Volume: 42 Issue: 16 Special Issue: SI Pages: 5551-5565 Published: NOV 15 2019. https://onlinelibrary.wiley.com/doi/abs/10.1002/mma.5515

3. A.M. Acu, H. Gonska, Classical Kantorovich operators revisited, Ukrainian Mathematical Journal, Volume: 71 Issue: 6, Pages: 843-852 Published: NOV 2019 https://link.springer.com/article/10.1007/s11253-019-01683-y

4. A.M. Acu, I. Rasa, Estimates for the differences of positive linear operators and their derivatives, Numerical Algorithms, (2019). https://link.springer.com/article/10.1007/s11075-019-00809-4

5. Neer, Trapti; Acu, Ana Maria; Agrawal, P. N., Degree of approximation by Chlodowsky variant of Jakimovski-Leviatan-Durrmeyer type operators, Revista De La Real Academia De Ciencias Exactas Fisicas Y Naturales Serie A-Matematicas, Volume: 113 Issue: 4 Pages: 3445-3459 Published: OCT 2019. https://link.springer.com/article/10.1007/s13398-019-00709-1

6. T. Garg, A.M. Acu, P.N. Agrawal, Weighted approximation and GBS of Chlodowsky-Szasz-Kantorovich type operators, Analysis and Mathematical Physics, Volume: 9 Issue: 3 Pages: 1429-1448 Published: SEP 2019 https://link.springer.com/article/10.1007%2Fs13324-018-0246-4

7. A.M. Acu, O. Dogru, C.V. Muraru, V.A. Radu, Approximation properties of certain Bernstein-Stancu type operators, Journal of Mathematical Inequalities, Volume: 13 Issue: 3 Pages: 687-702 Published: SEP 2019. http://jmi.ele-math.com/13-46/Approximation-properties-of-certain-Bernstein-Stancu-type-operators

8. A.M. Acu, V. Gupta, G. Tachev, Better Numerical Approximation by Durrmeyer Type Operators, Results in Mathematics, Volume: 74 Issue: 3 Article Number: UNSP 90 Published: SEP 2019 https://link.springer.com/article/10.1007/s00025-019-1019-6?shared-article-renderer

9. Rahman, Shagufta; Mursaleen, Mohammad; Acu, Ana Maria, Approximation properties of lambda-Bernstein-Kantorovich operators with shifted knots, Mathematical Methods in the Applied Sciences, Volume: 42 Issue: 11 Pages: 4042-4053 Published: JUL 30 2019 https://onlinelibrary.wiley.com/doi/abs/10.1002/mma.5632

10. T. Garg, A.M. Acu, P.N. Agrawal, Further results concerning some general Durrmeyer type operators, Revista De La Real Academia De Ciencias Exactas Fisicas Y Naturales Serie A-Matematicas, Volume: 113 Issue: 3 Pages: 2373-2390 Published: JUL 2019 https://link.springer.com/article/10.1007/s13398-019-00628-1

11. A.M. Acu, T. Acar, V.A. Radu, Approximation by modified U-n (rho) operators, Revista De La Real Academia De Ciencias Exactas Fisicas Y Naturales Serie A-Matematicas, Volume: 113 Issue: 3 Pages: 2715-2729 P ublished: JUL 2019 https://link.springer.com/article/10.1007/s13398-019-00655-y

12. Vijay Gupta, Gancho Tachev, Ana-Maria Acu, Modified Kantorovich operators with better approximation properties, Numerical Algorithms, Volume: 81 Issue: 1 Pages: 125-149 Published: MAY 2019 https://link.springer.com/article/10.1007/s11075-018-0538-7

13. N. Rao, A. Wafi, A.M. Acu, q-Szasz-Durrmeyer Type Operators Based on Dunkl Analogue, Complex Analysis and Operator Theory, Volume: 13 Issue: 3 Pages: 915-934 Published: APR 2019 https://link.springer.com/article/10.1007/s11785-018-0816-3

14. A.M. Acu, N. Manav, A. Ratiu, Convergence Properties of Certain Positive Linear Operators, Results in Mathematics, Volume: 74 Issue: 1 Article Number: UNSP 8 Published: MAR 2019 https://link.springer.com/article/10.1007/s00025-018-0931-5

15. Acu, Ana-Maria; Radu, Voichita Adriana, About the Iterates of Some Operators Depending on a Parameter and Preserving the Affine Functions, Iranian Journal of Science and Technology Transaction A-Science, Volume: 43 Issue: A1 Pages: 265-271 Published: FEB 2019 https://link.springer.com/article/10.1007/s40995-017-0461-0

16. V. Gupta, A.M. Acu, On Difference of Operators with Different Basis Functions, FILOMAT Volume: 33 Issue: 10 Pages: 3023-3034 Published: 2019 http://journal.pmf.ni.ac.rs/filomat/index.php/filomat/article/view/9535 "> http://journal.pmf.ni.ac.rs/filomat/index.php/filomat/article/view/9535

17. A.M. Acu, P.N. Agrawal, D. Kumar, Approximation properties of modified q-Bernstein-Kantorovich operators, Communications Faculty of Sciences University of Ankara-Series A1 Mathematics and Statistics, Volume: 68 Issue: 2 Pages: 2170-2197 Published: 2019 http://static.dergipark.org.tr/article-download/9222/f102/9527/5d25bf28cbe38.pdf?"> http://static.dergipark.org.tr/article-download/9222/f102/9527/5d25bf28cbe38.pdf?

18. A.M. Acu, P.N. Agrawal, Better approximation of functions by genuine Bernstein-Durrmeyer type operators, Carpathian Journal of Mathematics, Volume: 35 Issue: 2 Pages: 125-136 Published: 2019 https://www.jstor.org/stable/26898763?seq=1

19. P.N. Agrawal, A.M. Acu, M. Sidharth, Approximation degree of a Kantorovich variant of Stancu operators based on Polya-Eggenberger distribution, Revista De La Real Academia De Ciencias Exactas Fisicas Y Naturales Serie A-Matematicas, Volume: 113 Issue: 1 Pages: 137-156 Published: JAN 2019 https://link.springer.com/article/10.1007/s13398-017-0461-0

20. Pooja Gupta, Ana Maria Acu, P.N. Agrawal, Jakimovski-Leviatan operators of Kantorovich type involving multiple Appell polynomials, Georgian Mathematical Journal, 2019, DOI: 10.1515/gmj-2019-2013 https://www.degruyter.com/view/journals/gmj/ahead-of-print/article-10.1515-gmj-2019-2013/article-10.1515-gmj-2019-2013.xml

21. Witold Majdak and Laurian Suciu, Brownian isometric parts of concave operators, New York J. Math. 25, 1067–1090, 2019. http://nyjm.albany.edu/j/2019/25-46.html

22. Catalin Badea and Laurian Suciu, Similarity problems, Folner sets and isometric representations of amenable semigroups, Mediterranean Journal of Mathematics 16: 5, 2019. https://doi.org/10.1007/s00009-018-1294-6

23. Catalin Badea and Laurian Suciu, The Cauchy dual and 2-isometric liftings of concave operators, Journal of Math. Anal. and Appl. 472, 1458-1474, 2019. https://doi.org/10.1016/j.jmaa.2018.12.002

24. N.A. Secelean, M. Zhou, Generalized F-Contractions on Product of Metric Spaces, Mathematics 2019, 7, 1040; 1-8; https://www.mdpi.com/2227-7390/7/11/1040/html

25. M. Zhou, X.L. Liub, N.A. Secelean, On coincidence and common fixed point theorems of eight self-maps satisfying an F_M-contraction condition, Nonlinear Analysis: Modelling and Control 2019, Vol. 24, No. 6,1001–1018 https://pdfs.semanticscholar.org/5f5d/999280d24d02dd18cd75aacda25890e538bd.pdf?_ga=2.87196632.176953674.1588599116-2127475333.1588425489

26. N.A. Secelean, S. Mathew, D. Wardowski, New fixed point results in quasi-metric spaces and applications in fractals theory, Advances in Difference Equations 2019, 2019:177, 1-23, https://doi.org/10.1186/s13662-019-2119-z

2018

1. Florin Sofonea, Ioan Tincu, Acu Ana Maria, Convex sequences of higher order, Filomat 32:13 (2018) http://journal.pmf.ni.ac.rs/filomat/index.php/filomat/article/view/7477

2. A.M. Acu, Nesibe Manav, Florin Sofonea, Approximation properties of λ-Kantorovich operators, Journal of Inequalities and Applications, 2018:202, https://doi.org/10.1186/s13660-018-1795-7

3. Ana Maria Acu, Tuncer Acar and Nesibe Manav, Approximation of functions by genuine Bernstein-Durrmeyer type operators, Journal of Mathematical Inequalities, 12(4), 975-987, 2018. http://jmi.ele-math.com/12-74/Approximation-of-functions-by-genuine-Bernstein-Durrmeyer-type-operators

4. Sheetal Deshwal, Ana Maria Acu and P.N. Agrawal, Pointwise approximation Bezier variant of an operator based on Laguerre polynomials, Journal of Mathematical Inequalities, 12(3), 2018, 693–707 http://jmi.ele-math.com/12-53/Pointwise-approximation-by-Bezier-variant-of-an-operator-based-on-Laguerre-polynomials

5. S. Deshwal, A.M. Acu, P.N. Agrawal, Rate of convergence of q-analogue of a class of new Bernstein type operators, Miskolc Mathematical Notes, 19(1) (2018), 211–234 http://real.mtak.hu/87327/1/2265.pdf

6. A.M. Acu, C. Muraru, Certain Approximation Properties of Srivastava Gupta operators, Journal of Mathematical Inequalities, Volume 12, Number 2 (2018), 583–595 http://jmi.ele-math.com/12-44/Certain-approximation-properties-of-Srivastava-Gupta-operators

7. T Neer, AM Acu, P Agrawal, Approximation of functions by bivariate q-Stancu-Durrmeyer type operators, Mathematical Communications, 23(2018), 161–180. https://www.mathos.unios.hr/mc/index.php/mc/article/view/2410

8. A.M. Acu, V. Gupta, On Baskakov-Szasz-Mirakyan-type operators preserving exponential type functions, Positivity, 22(3), 2018, 919–929, https://link.springer.com/article/10.1007/s11117-018-0553-x

9. AM Acu, V Gupta, N Malik, Local and Global Approximation for Certain (p, q)-Durrmeyer Type Operators, Complex Analysis and Operator Theory, Volume: 12 Issue: 8, 1973-1989, 2018, https://doi.org/10.1007/s11785-017-0714-0

10. Ana Maria Acu, V. Radu, C. Muraru, On the monotonicity of q-Schurer-Stancu type polynomials, Miskolc Mathematical Notes, 19(1), (2018), 19-28, http://mat76.mat.uni-miskolc.hu/mnotes/article/1785

11. N.A. Secelean, Suzuki \psi F-contractions and some fixed point results, Carpathian Journal of Mathematics, Vol. 34 (2018), No.1, 93-102 https://www.carpathian.cunbm.utcluj.ro/article/suzuki-%D1%B1-f-contractions-fixed-point-results/

2017

1. Manjari Sidharth, Ana-Maria Acu, P.N. Agrawal, Chlodowsky-Szasz-Appel type operators for functions of two variables, Annals of Functional Analysis 8(4). 2017, 446-459. https://projecteuclid.org/euclid.afa/1495677675

2. T. Neer, A.M. Acu, P.N. Agrawal, Bezier variant of genuine-Durrmeyer type operators based on Polya distribution, Carpathian Journal of Mathematics, Vol. 33, No 1, 2017, Pages: 73-86. https://www.carpathian.cunbm.utcluj.ro/article/bezier-variant-genuine-durrmeyer-type-operators-based-polya-distribution/

3. A.M. Acu, Properties and applications of Pn-simple functionals, Positivity ISSN: 1385-1292, DOI 10.1007/s11117-016-0420-6, 21 (1), 2017, 283-297. https://link.springer.com/article/10.1007/s11117-016-0420-6

4. Ana Maria Acu, P.N. Agrawal, Trapti Neer, Approximation properties of the modified Stancu operators, Numerical Functional Analysis and Optimization, Doi:10.1080/01630563.2016.1248564, 38 (3), Pages: 279-292, 2017 https://www.tandfonline.com/doi/abs/10.1080/01630563.2016.1248564

5. Young Chel Kwun , Ana-Maria Acu, Arif Rafiq, Voichita Adriana Radu, Faisal Ali and Shin Min Kang, Bernstein-Stancu type operators which preserve polynomials, J. Computational Analysis and Applications, 23(4), 2017, 758-770.) http://www.eudoxuspress.com/244/JOCAAA-2017-VOL-23.pdf

6. A.M. Acu, H. Gonska, Generalized Alomari functionals, Mediterranean Journal of Mathematics, 14(1), 2017, Article Number: UNSP 1, https://link.springer.com/article/10.1007/s00009-016-0833-2

7. A.M. Acu, V. Gupta, Direct results for certain summation-integral type Baskakov-Szasz operators, Results in Mathematics, 72(3), 2017, 1161–1180, DOI: 10.1007/s00025-016-0603-2 https://link.springer.com/article/10.1007/s00025-016-0603-2

8. V. Gupta, A.M. Acu, D.F. Sofonea, Approximation Baskakov type Polya-Durrmeyer operators, Applied Mathematics and Computations, 294( 1), 2017, 318–331 https://www.sciencedirect.com/science/article/abs/pii/S0096300316305720

9. Arun Kajla, Ana Maria Acu, and P. N. Agrawal, Baskakov–Szász-type operators based on inverse Pólya–Eggenberger distribution, Annals of Functional Analysis 8 (1), 2017, 106-123. https://projecteuclid.org/euclid.afa/1477918638

10. Dan Barbosu, Ana-Maria Acu, Carmen Violeta Muraru, Some bivariate Durrmeyer operators based on q-integers, Jourmal of Mathematical Inequalities, 11( 1), 2017, 59–75 http://jmi.ele-math.com/11-06/Some-bivariate-Durrmeyer-operators-based-on-q-integers

11. D. Bărbosu, A.M. Acu, C. V. Muraru, On certain GBS-Durrmeyer operators based on q-integers,Turkish Journal of Mathematics, 41(2) (2017), 368 – 380 https://dergipark.org.tr/en/pub/tbtkmath/issue/35834/401624

12. Catalin Badea and Laurian Suciu, Harnack and Shmul'yan preorder relations for Hilbert space contractions, Indagationes Mathematicae 28 (4), 892-912, 2017, https://doi.org/10.1016/j.indag.2017.06.012

13. Laurian Suciu, Ergodic behaviors of the regular operator means, Banach Journal of Mathematical Analysis, Vol. 11, No. 2, 239-265, 2017. https://projecteuclid.org/euclid.bjma/1484363107

14. Catalin Badea, Laurian Suciu, and Dan Timotin, Classes of contractions and Harnack domination, Revista Matematica Iberoamericana, 33 (2), 469-488, 2017. https://www.ems-ph.org/journals/show_abstract.php?issn=0213-2230&vol=33&iss=2&rank=4

15. N.A. Secelean, D. Wardowski, New Fixed Point Tools in Non-metrizable Spaces, Results. Math. Vol. 72 (2017), 919–935, Issue 1-2, https://link.springer.com/article/10.1007/s00025-017-0688-2

16. R. Balu, S. Mathew, N.A. Secelean, Separation properties of (n, m)-IFS attractors, Communications in Nonlinear Science and Numerical Simulation, Vol. 51 (2017), 160- 168, http://doi.org/10.1016/j.cnsns.2017.04.009

17. Petrica Dicu, Alina Totoi, Inclusion properties regarding classes of meromorphic p-valent functions, involving the operator J^n_{p,\lambda}, Commun. Korean Math. Soc., Vol. 32, No. 4(2017), pp. 971-977. https://www.koreascience.or.kr/article/JAKO201732839400520.page

2016

1. A.M. Acu, I. Rasa, New estimates for the differences of positive linear operators, Numerical Algorithms, 73(3), 775–789, 2016. https://link.springer.com/article/10.1007/s11075-016-0117-8

2. Shin Min Kang, Arif Rafiq, Ana-Maria Acu, Faisal Ali, Young Chel Kwun, Some approximation properties of (p, q) -Bernstein operators, Journal of Inequalities and Applications, 2016, Article 169. https://journalofinequalitiesandapplications.springeropen.com/articles/10.1186/s13660-016-1111-3

3. A.M. Acu, C. Muraru, V. Radu, F. Sofonea, Some approximation properties of a Durrmeyer variant of q-Bernstein–Schurer operators, Mathematical Methods in the Applied Sciences, 39(18), 2016, 5636–5650. https://onlinelibrary.wiley.com/doi/abs/10.1002/mma.3949

4. Ana Maria Acu, Heiner Gonska, Composite Bernstein Cubature, Banach Journal of Mathematical Analysis, Banach Journal of Mathematical Analysis, Vol. 10, No.2, 235-250, 2016 https://projecteuclid.org/euclid.bjma/1456246278

5. Shin Min Kang, Ana Maria Acu, Arif Rafiq and Young Chel Kwun, On q-analogue of Stancu-Schurer-Kantorovich operators based on q-Riemann integral, Journal of Computational Analysis and Applications, Vol. 21, No. 3, 2016, 564-577. http://www.eudoxuspress.com/244/VOLUME-21-JOCAAA-2016.pdf

6. Laurian Suciu, Estimations of the operator resolvent by higher order Cesaro means, Results in Mathematics 69(3), pp. 457-475, 2016. https://link.springer.com/article/10.1007/s00025-016-0533-z

7. Witold Majdak, Mostafa Mbekhta, and Laurian Suciu, Operators intertwining with isometries and Brownian parts of 2-isometries, Linear Algebra and its Applications 509 (15), 168-190, 2016. https://www.sciencedirect.com/science/article/abs/pii/S0024379516302762

8. Alexandru Aleman and Laurian Suciu, On ergodic operator means in Banach spaces, Integral Equations and Operator Theory, vol. 85 pp. 259-287, 2016. https://doi.org/10.1007/s00020-016-2298-x

9. Mostafa Mbekhta and Laurian Suciu, Partial isometries and the conjecture of C. K. Fong and S. K. Tsui, Journal of Mathematical Analysis and Applications Vol. 437, pp. 431-444, 2016. https://doi.org/10.1016/j.jmaa.2015.12.057

10. N.A. Secelean, D. Wardowski, \psi F-Contractions: Not Necessarily Nonexpansive Picard Operators, Results. Math., Vol. 70 (2016), Issue 3, 415–43, https://link.springer.com/article/10.1007/s00025-016-0570-7

11. N.A. Secelean, Weak F-contractions and some fixed point results, Bulletin of the Iranian Mathematical Society, Vol. 42 (2016), Issue 3, 779-798 http://bims.iranjournals.ir/article_812.html

2015

1. Ana Maria Acu, F. Sofonea, D. Barbosu, Note on a q-analogue of Stancu-Kantorovich operators, Miskolc Mathematical Notes, Vol. 16, no.1, 2015, 3-15. http://real.mtak.hu/87799/

2. Ana Maria Acu, Improvement of Gruss and Ostrowski Type Inequalities, Filomat, 29:9, 2015, 2027-2035 http://journal.pmf.ni.ac.rs/filomat/index.php/filomat/article/view/921

3. Ana Maria Acu, Heiner Gonska, Weighted Ostrowski-Gruss type inequalities, Stud. Univ. Babes-Bolyai Math., 60(2015), No. 2, 183–192 http://www.cs.ubbcluj.ro/~studia-m/2015-2/03-Acu-Gonska-final.pdf

4. Shin Min Kang, Ana Maria Acu, Arif Rafiq, Young Chel Kwun, Approximation properties of q-Kantorovich-Stancu operator , Journal of Inequalities and Applications, Article Number: 211, Published: Jun 27 2015 https://link.springer.com/article/10.1186/s13660-015-0729-x

5. Ana Maria Acu, Muraru Carmen , Approximation Properties of Bivariate Extension of q-Bernstein–Schurer–Kantorovich operators, Results in Mathematics, 67 (3) , 265-279, 2015, DOI: 10.1007/s00025-015-0441-7 https://link.springer.com/article/10.1007/s00025-015-0441-7

6. Ana Maria Acu, Stancu–Schurer–Kantorovich operators based on q-integers, Applied Mathematics and Computation, 259, 896–907, 2015, DOI: 10.1016/j.amc.2015.03.032 https://www.sciencedirect.com/science/article/abs/pii/S0096300315003379

7. Michael Lin, David Shoikhet, and Laurian Suciu, Remarks on uniform ergodic theorems, Acta Sci. Math. (Szeged) Vol. 81, pp. 251-283, 2015. DOI: 10.14232/actasm-012-307-4 http://pub.acta.hu/acta/showCustomerArticle.action?id=40193&dataObjectType=article

8. Michael Lin and Laurian Suciu, Poisson's equation for mean ergodic operators, Contemporary Mathematics Vol. 636, pp. 141-148, 2015.

9. N.A. Secelean, Generalized F-iterated function systems on product of metric spaces, Journal of Fixed Point Theory and Applications, 17 (2015) 575–595, DOI: 10.1007/s11784-015-0235-2 https://link.springer.com/article/10.1007/s11784-015-0235-2

10. A. Ratiu, N. Minculete, Several refinements and counterparts of Radon’s inequality, Mathematica Bohemica, 140(1), 71-80, 2015. http://mb.math.cas.cz/full/140/1/mb140_1_6.pdf

2014

1. Ana Maria Acu, Maria Daniela Rusu, New results concerning Chebyshev-Grusstype inequalities via discrete oscillations, Applied Mathematics and Computation, 243, pp. 585-593, 2014 https://www.sciencedirect.com/science/article/abs/pii/S0096300314008443

2. Mostafa Mbekhta and Laurian Suciu, Quasi-isometries associated to Acontractions, Linear Algebra and its Applications Vol. 459, pp. 430-453, 2014. https://doi.org/10.1016/j.laa.2014.07.016

3. Laurian Suciu and Nicolae Suciu, Borel-Carathéodory and Fan Type Inequalities for Hilbert space bicontractions, Complex Analysis and Operator Theory Vol. 8, Issue 1, pp. 227-241, 2014. https://doi.org/10.1007/s11785-013-0291-9

4. E.C. Popa, N.A. Secelean, Estimates for the constants of Landau and Lebesgue via some inequalities for the Wallis ratio, Journal of Computational and Applied Mathematics, Vol. 269 (2014), 68-74, DOI: 10.1016/j.cam.2014.03.020 https://www.sciencedirect.com/science/article/pii/S0377042714001691

5. N.A. Secelean, Generalized Iterated Function Systems on the space l^{\infty}(X), Journal of Mathematical Analysis and Applications, Vol. 410, Issue 2, 15. Feb. 2014, 847-858, DOI:10.1016/j.jmaa.2013.09.007 https://www.sciencedirect.com/science/article/pii/S0022247X13008196

6. M. Olaru, N.A. Secelean, Vector comparison operators in cone metric spaces, Mathematical Report, Vol. 16 (66), No.3 (2014), 431-442. http://imar.ro/journals/Mathematical_Reports/Pdfs/2014/3/6.pdf

7. N.A. Secelean, Invariant measure associated with a Generalized Countable Iterated Function System, Mediterranean Journal of Mathematics, 11 (2014), 361-372, DOI 10.1007/s00009-013-0300-2 https://link.springer.com/article/10.1007/s00009-013-0300-2