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arxiv: 1907.06171 · v1 · pith:2MZ3KR5Jnew · submitted 2019-07-14 · 🧬 q-bio.QM · q-bio.BM

Weighted persistent homology for osmolyte molecular aggregation and hydrogen-bonding network analysis

Pith reviewed 2026-05-24 21:55 UTC · model grok-4.3

classification 🧬 q-bio.QM q-bio.BM
keywords persistent homologyosmolyteTMAOureamolecular aggregationhydrogen-bonding networkradial distribution functiontopological data analysis
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The pith

Localized and interactive persistent homology models distinguish TMAO's concentration-dependent local networks from urea's clusters and global circles.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper applies two weighted persistent homology approaches to molecular configurations of TMAO and urea solutions. Localized models track how circle elements in local networks change with osmolyte concentration. Interactive models generate a persistent radial distribution function that reproduces traditional RDF peaks while adding local interaction detail. These topological measures are presented as a way to capture aggregation differences that may underlie the osmolytes' opposing effects on protein folding. The work focuses on filtration-scale features at 4–12 Å to separate local from longer-range structures.

Core claim

From the localized persistent homology models, TMAO shows local network structures whose circle elements increase in total number and decrease in relative size with concentration, while urea shows local clusters around 6 Å and a few global circle elements at around 12 Å; the interactive PRDF recovers the same physical properties as the traditional RDF while also characterizing local interaction information, with clear differences at the first peak near 4 Å and in the second peak region from 5 Å to 10 Å.

What carries the argument

Localized persistent homology (LPH) and interactive persistent homology (IPH) applied to weighted molecular point clouds, producing persistent radial distribution functions (PRDF) at global and local scales.

If this is right

  • Circle count and size trends provide a quantitative topological signature for osmolyte aggregation that scales with concentration.
  • PRDF at local filtration scales supplies interaction detail beyond what global RDF captures.
  • The reported separation of local clusters versus global circles offers a structural basis for comparing TMAO stabilization and urea denaturation effects.
  • The same LPH and IPH constructions can be applied to other osmolyte or solvent systems to generate comparable topological descriptors.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • If the topological signatures prove robust across force fields, they could serve as order parameters for coarse-grained models of osmolyte-protein interactions.
  • Tracking how PRDF local peaks evolve along molecular dynamics trajectories might reveal transient network rearrangements not visible in time-averaged RDF.
  • The distinction between local and global circle elements suggests a route to classify aggregation in multicomponent biomolecular mixtures.

Load-bearing premise

The weighting functions chosen for the localized and interactive models correctly encode the relevant physical interactions (hydrogen-bonding and molecular size) without introducing artifacts that would alter the reported differences in circle counts or peak positions.

What would settle it

Direct comparison of the reported PRDF first-peak heights at 4 Å and second-peak behavior between 5–10 Å against independently measured experimental radial distribution functions for TMAO and urea solutions at matching concentrations.

Figures

Figures reproduced from arXiv: 1907.06171 by D Vijay Anand, Kelin Xia, Yuguang Mu.

Figure 1
Figure 1. Figure 1: A schematic representation of the localized persistent homology (LPH) analysis. The red circle (a sphere in 3D) specifies [PITH_FULL_IMAGE:figures/full_fig_p005_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Illustration of interactions in global-scale and local-scale interactive persistent homology (IPH). In global-scale IPH [PITH_FULL_IMAGE:figures/full_fig_p006_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: The local persistent barcodes for TMAO and urea aggregation. TMAO and urea molecules are coarse-grained as their [PITH_FULL_IMAGE:figures/full_fig_p008_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: The comparison of average β1 PBNs for TMAO and urea using three different cutoff radii namely., Rc = 9˚A, 12˚A and 15˚A respectively. The β1 PBNs are averaged over all the frames and all molecules in each frame. It can be seen that, TMAO and urea show dramatically different local topological characteristics. 8 [PITH_FULL_IMAGE:figures/full_fig_p008_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: The comparison of average persistent entropies for TMAO and urea using three different cutoff radii, i.e., [PITH_FULL_IMAGE:figures/full_fig_p009_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: The comparison of average β1 PBNs for hydrogen bonding networks from TMAO and urea using two different cutoff radii, i.e., Rc = 7˚A and Rc = 9˚A. The coarse-grained representation of water as its oxygen atom is considered. The PBNs are averaged over all the molecules and configuration numbers. It can be seen that, TMAO and urea show very different topological characteristics. concentrations. It has much sm… view at source ↗
Figure 7
Figure 7. Figure 7: The comparison of average β1 PEs for hydrogen-bonding networks from TMAO and urea systems using two different cutoff radii, i.e., Rc = 7˚A and Rc = 9˚A. The PEs are averaged over all the water molecules in each frames, thus a total 101 PEs are obtained for each simulation. It can be seen that, the average PE decreases with the concentration for both TMAO and urea. However, the PE variance for urea systemat… view at source ↗
Figure 8
Figure 8. Figure 8: The comparison of global-scale and local-scale PRDFs for both TMAO and UREA. The PRDF of N-O is examined in [PITH_FULL_IMAGE:figures/full_fig_p012_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: The comparison of average β0 PBNs for hydrogen-bonding networks of TMAO and urea systems. The N-O pair interaction network is considered for analysis. The comparison of average β0 PEs from the IPH analysis of TMAO and urea systems. For each configuration, a PE value can be calculated, thus a total 101 PEs are obtained for each simulation. It can be seen that, the average PE increases with the concentration… view at source ↗
read the original abstract

It has long been observed that trimethylamin N-oxide (TMAO) and urea demonstrate dramatically different properties in a protein folding process. Even with the enormous theoretical and experimental research work of the two osmolytes, various aspects of their underlying mechanisms still remain largely elusive. In this paper, we propose to use the weighted persistent homology to systematically study the osmolytes molecular aggregation and their hydrogen-bonding network from a local topological perspective. We consider two weighted models, i.e., localized persistent homology (LPH) and interactive persistent homology (IPH). From the localized persistent homology models, we have found that TMAO and urea have very different local topology. TMAO shows local network structures. With the concentration increase, the circle elements in these networks show a clear increase in their total numbers and a decrease in their relative sizes. In contrast, urea shows two types of local topological patterns, i.e., local clusters around 6 \AA~ and a few global circle elements at around 12 \AA. From the interactive persistent homology models, it has been found that our persistent radial distribution function (PRDF) from the global-scale IPH has same physical properties as the traditional radial distribution function (RDF). Moreover, PRDFs from the local-scale IPH can also be generated and used to characterize the local interaction information. Other than the clear difference of the first peak value of PRDFs at filtration size 4\AA, TMAO and urea also shows very different behaviors at the second peak region from filtration size 5\AA~ to 10 \AA.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 2 minor

Summary. The paper applies two weighted persistent homology models—localized persistent homology (LPH) and interactive persistent homology (IPH)—to analyze molecular aggregation and hydrogen-bonding networks in TMAO and urea solutions. Using LPH, it reports that TMAO forms local network structures whose circle elements increase in number and decrease in relative size with rising concentration, whereas urea exhibits local clusters near 6 Å and sparse global circles near 12 Å. Using IPH, it introduces a persistent radial distribution function (PRDF) that is stated to recover the same physical properties as the conventional RDF while additionally capturing local interaction details, with noted differences in first-peak values at 4 Å filtration and behavior in the 5–10 Å region.

Significance. If the weighting schemes prove robust, the work offers a topological complement to standard RDF analysis that can distinguish concentration-dependent local network motifs in osmolytes, potentially clarifying mechanisms behind their opposing effects on protein stability. The explicit construction of PRDF from the global-scale IPH filtration provides a direct consistency check with RDF, which is a methodological strength when the underlying distances are preserved.

major comments (1)
  1. [LPH/IPH model definitions] LPH/IPH model definitions (abstract and methods): the weighting functions that encode hydrogen-bonding and molecular size are introduced without any cross-validation against independent observables such as coordination numbers, experimental RDF peak positions, or unweighted control filtrations. Because the reported distinctions—TMAO circle-count increase versus urea 6 Å clusters and 12 Å global circles, as well as PRDF peak differences—are generated directly by these weights, the absence of such checks makes the physical interpretation load-bearing and currently unsupported.
minor comments (2)
  1. [Abstract] Abstract: the statements that PRDF “has same physical properties as” RDF and that local-scale PRDFs “can also be generated” are purely qualitative; no quantitative metric (e.g., integrated absolute deviation or peak-position error) is supplied.
  2. [Abstract] Abstract: no information is given on the number of independent trajectories, system sizes, or concentration sampling used to generate the persistence diagrams, nor are error bars or variability measures reported for circle counts or PRDF peaks.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the constructive review and for noting the potential of our approach as a topological complement to RDF analysis. We address the single major comment below.

read point-by-point responses
  1. Referee: [LPH/IPH model definitions] LPH/IPH model definitions (abstract and methods): the weighting functions that encode hydrogen-bonding and molecular size are introduced without any cross-validation against independent observables such as coordination numbers, experimental RDF peak positions, or unweighted control filtrations. Because the reported distinctions—TMAO circle-count increase versus urea 6 Å clusters and 12 Å global circles, as well as PRDF peak differences—are generated directly by these weights, the absence of such checks makes the physical interpretation load-bearing and currently unsupported.

    Authors: We thank the referee for highlighting the need for explicit validation of the weighting schemes. The weights are constructed from standard physical parameters in the methods: hydrogen-bonding weights use donor-acceptor distance and angle cutoffs consistent with typical H-bond geometry (~2.8 Å), while molecular-size weights are taken from the atomic radii in the underlying simulation force field. The global-scale IPH PRDF recovering the same physical properties as the conventional RDF (reported in the results) already provides an internal consistency check that the weighting preserves overall distribution features. We nevertheless agree that additional cross-checks against coordination numbers, literature experimental RDF peak positions, and unweighted control filtrations would strengthen the physical grounding of the local distinctions. We will incorporate these comparisons in the revised manuscript (e.g., a new subsection and supplementary figure showing weighted versus unweighted filtrations together with peak-position references). revision: yes

Circularity Check

0 steps flagged

No significant circularity; empirical application of weighted PH models to simulation data.

full rationale

The paper defines LPH and IPH weighting schemes, applies them to osmolyte trajectory data, and reports observed differences in circle counts, sizes, and PRDF peaks. The statement that global-scale PRDF recovers RDF properties is a post-hoc consistency check on the same distance data rather than a first-principles derivation or fitted prediction. No equations reduce by construction to their inputs, no parameters are fit on a subset then relabeled as predictions, and no load-bearing self-citations or uniqueness theorems appear in the supplied text. The central claims remain independent empirical observations from the chosen models.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 0 invented entities

The central claims rest on the assumption that the chosen weighting functions faithfully represent physical interactions and that the observed persistence features are not artifacts of the filtration or simulation protocol. No new physical constants or particles are introduced.

free parameters (1)
  • weighting function parameters
    The localized and interactive models require explicit weighting functions whose functional form and scale parameters are chosen to encode molecular size and interaction strength; these are free parameters fitted or selected to produce the reported topological differences.
axioms (1)
  • domain assumption The underlying molecular dynamics trajectories accurately represent the physical system at the simulated concentrations and temperatures.
    All topological features are computed on simulation data whose fidelity is presupposed.

pith-pipeline@v0.9.0 · 5826 in / 1474 out tokens · 19327 ms · 2026-05-24T21:55:39.267670+00:00 · methodology

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Reference graph

Works this paper leans on

117 extracted references · 117 canonical work pages · 4 internal anchors

  1. [1]

    Software available at http://www.mrzv.org/software/ dionysus

    Dionysus: the persistent homology software. Software available at http://www.mrzv.org/software/ dionysus

  2. [2]

    M. J. Abraham, T. Murtola, R. Schulz, S. P´ all, J. C. Smith, B. Hess, and E. Lindahl. GROMACS: High performance molecular simulations through multi-level parallelism from laptops to supercomputers. SoftwareX, 1:19–25, 2015

  3. [3]

    Ahmed, B

    M. Ahmed, B. T. Fasy, and C. Wenk. Local persistent homology based distance between maps. In Proceedings of the 22nd ACM SIGSPATIAL International Conference on Advances in Geographic In- formation Systems, pages 43–52. ACM, 2014

  4. [4]

    Bak´ o, A

    I. Bak´ o, A. Bencsura, K. Hermannson, S. B´ alint, T. Gr´ osz, V. Chihaia, and J. Ol´ ah. Hydrogen bond network topology in liquid water and methanol: a graph theory approach. Physical Chemistry Chemical Physics, 15(36):15163–15171, 2013

  5. [5]

    Bak´ o, T

    I. Bak´ o, T. Megyes, S. B´ alint, T. Gr´ osz, and V. Chihaia. Water–methanol mixtures: topology of hydrogen bonded network. Physical Chemistry Chemical Physics , 10(32):5004–5011, 2008

  6. [6]

    Bandyopadhyay, S

    D. Bandyopadhyay, S. Mohan, S. K. Ghosh, and N. Choudhury. Molecular dynamics simulation of aqueous urea solution: is urea a structure breaker? The Journal of Physical Chemistry B, 118(40):11757– 11768, 2014

  7. [7]

    Baskakov and D

    I. Baskakov and D. W. Bolen. Forcing thermodynamically unfolded proteins to fold. Journal of Biological Chemistry, 273(9):4831–4834, 1998

  8. [8]

    I. V. Baskakov, R. Kumar, G. Srinivasan, Y. S. Ji, D. W. Bolen, and E. B. Thompson. Trimethylamine N-oxide-induced cooperative folding of an intrinsically unfolded transcription-activating fragment of human glucocorticoid receptor. Journal of Biological Chemistry , 274(16):10693–10696, 1999

  9. [9]

    P. W. Bates, G. W. Wei, and Shan Zhao. Minimal molecular surfaces and their applications. Journal of Computational Chemistry , 29(3):380–91, 2008

  10. [10]

    Bauer, M

    U. Bauer, M. Kerber, and J. Reininghaus. Distributed computation of persistent homology. Proceedings of the Sixteenth Workshop on Algorithm Engineering and Experiments (ALENEX) , 2014

  11. [11]

    G. Bell, A. Lawson, J. Martin, J. Rudzinski, and C. Smyth. Weighted persistent homology. arXiv preprint arXiv:1709.00097, 2017

  12. [12]

    Bendich, D

    P. Bendich, D. Cohen-Steiner, H. Edelsbrunner, J. Harer, and D. Morozov. Inferring local homology from sampled stratified spaces. In Foundations of Computer Science, 2007. FOCS’07. 48th Annual IEEE Symposium on, pages 536–546. IEEE, 2007. 13

  13. [13]

    Bendich, H

    P. Bendich, H. Edelsbrunner, and M. Kerber. Computing robustness and persistence for images. IEEE Transactions on Visualization and Computer Graphics , 16:1251–1260, 2010

  14. [14]

    Bendich, E

    P. Bendich, E. Gasparovic, J. Harer, R. Izmailov, and L. Ness. Multi-scale local shape analysis and feature selection in machine learning applications. In Neural Networks (IJCNN), 2015 International Joint Conference on, pages 1–8. IEEE, 2015

  15. [15]

    Bendich, B

    P. Bendich, B. Wang, and S. Mukherjee. Local homology transfer and stratification learning. In Pro- ceedings of the twenty-third annual ACM-SIAM symposium on Discrete Algorithms , pages 1355–1370. SIAM, 2012

  16. [16]

    H. J. C. Berendsen, D. van der Spoel, and R. van Drunen. GROMACS: a message-passing parallel molecular dynamics implementation. Computer physics communications, 91(1-3):43–56, 1995

  17. [17]

    Binchi, E

    J. Binchi, E. Merelli, M. Rucco, G. Petri, and F. Vaccarino. jholes: A tool for understanding biological complex networks via clique weight rank persistent homology. Electronic Notes in Theoretical Computer Science, 306:5–18, 2014

  18. [18]

    P. Bubenik. Statistical topological data analysis using persistence landscapes. The Journal of Machine Learning Research, 16(1):77–102, 2015

  19. [19]

    Bubenik and P

    P. Bubenik and P. T. Kim. A statistical approach to persistent homology. Homology, Homotopy and Applications, 19:337–362, 2007

  20. [20]

    Buchet, F

    M. Buchet, F. Chazal, Steve Y. Oudot, and D. R. Sheehy. Efficient and robust persistent homology for measures. Computational Geometry, 58:70–96, 2016

  21. [21]

    Z. X. Cang, L. Mu, and G. W. Wei. Representability of algebraic topology for biomolecules in machine learning based scoring and virtual screening. PLoS computational biology, 14(1):e1005929, 2018

  22. [22]

    Z. X. Cang and G. W. Wei. Analysis and prediction of protein folding energy changes upon mutation by element specific persistent homology. Bioinformatics, 33(22):3549–3557, 2017

  23. [23]

    Z. X. Cang and G. W. Wei. Integration of element specific persistent homology and machine learning for protein-ligand binding affinity prediction. International journal for numerical methods in biomedical engineering, page 10.1002/cnm.2914, 2017

  24. [24]

    Z. X. Cang and G. W. Wei. TopologyNet: Topology based deep convolutional and multi-task neural networks for biomolecular property predictions. PLOS Computational Biology , 13(7):e1005690, 2017

  25. [25]

    Carlsson

    G. Carlsson. Topology and data. Am. Math. Soc, 46(2):255–308, 2009

  26. [26]

    Carlsson, T

    G. Carlsson, T. Ishkhanov, V. Silva, and A. Zomorodian. On the local behavior of spaces of natural images. International Journal of Computer Vision , 76(1):1–12, 2008

  27. [27]

    Carlsson, A

    G. Carlsson, A. Zomorodian, A. Collins, and L. J. Guibas. Persistence barcodes for shapes. International Journal of Shape Modeling , 11(2):149–187, 2005

  28. [28]

    Cazals, F

    F. Cazals, F. Proust, R. P. Bahadur, and J. Janin. Revisiting the voronoi description of protein–protein interfaces. Protein Science, 15(9):2082–2092, 2006

  29. [29]

    T. V. Chalikian and K. J. Breslauer. Thermodynamic analysis of biomolecules: a volumetric approach. Current opinion in structural biology , 8(5):657–664, 1998

  30. [30]

    Chandler

    D. Chandler. Introduction to Modern Statistical Mechanics . Oxford University Press, 1987

  31. [31]

    Chintakunta, T

    H. Chintakunta, T. Gentimis, R. Gonzalez-Diaz, M. J. Jimenez, and H. Krim. An entropy-based persis- tence barcode. Pattern Recognition, 48(2):391–401, 2015. 14

  32. [32]

    Choi and M

    J. Choi and M. Cho. Ion aggregation in high salt solutions. II. spectral graph analysis of water hydrogen- bonding network and ion aggregate structures. The Journal of chemical physics , 141(15):154502, 2014

  33. [33]

    Choi and M

    J. Choi and M. Cho. Ion aggregation in high salt solutions. IV. graph-theoretical analyses of ion aggregate structure and water hydrogen bonding network. The Journal of chemical physics , 143(10):104110, 2015

  34. [34]

    Choi and M

    J. Choi and M. Cho. Ion aggregation in high salt solutions. VI. spectral graph analysis of chaotropic ion aggregates. The Journal of chemical physics , 145(17):174501, 2016

  35. [35]

    J. H. Choi, H. Lee, H. R. Choi, and M. Cho. Graph theory and ion and molecular aggregation in aqueous solutions. Annual review of physical chemistry , 69:125–149, 2018

  36. [36]

    J. A. B. da Silva, F. G. B. Moreira, V. M. L. dos Santos, and R. L. Longo. On the hydrogen bond networks in the water–methanol mixtures: topology, percolation and small-world. Physical Chemistry Chemical Physics, 13(14):6452–6461, 2011

  37. [37]

    R. J. M. Dawson. Homology of weighted simplicial complexes. Cahiers de Topologie et G´ eom´ etrie Diff´ erentielle Cat´ egoriques, 31(3):229–243, 1990

  38. [38]

    Di Fabio and C

    B. Di Fabio and C. Landi. A Mayer-Vietoris formula for persistent homology with an application to shape recognition in the presence of occlusions. Foundations of Computational Mathematics, 11:499–527, 2011

  39. [39]

    V. M. L. dos Santos, F. G. B. Moreira, and R. L. Longo. Topology of the hydrogen bond networks in liquid water at room and supercritical conditions: a small-world structure. Chemical physics letters , 390(1):157–161, 2004

  40. [40]

    Edelsbrunner

    H. Edelsbrunner. Weighted alpha shapes , volume 92. University of Illinois at Urbana-Champaign, Department of Computer Science, 1992

  41. [41]

    Edelsbrunner and P

    H. Edelsbrunner and P. Koehl. The geometry of biomolecular solvation. Combinatorial and computa- tional geometry, 52:243–275, 2005

  42. [42]

    Edelsbrunner, D

    H. Edelsbrunner, D. Letscher, and A. Zomorodian. Topological persistence and simplification. Discrete Comput. Geom., 28:511–533, 2002

  43. [43]

    Essmann, L

    U. Essmann, L. Perera, M. L. Berkowitz, T. Darden, H. Lee, and L. G. Pedersen. A smooth particle mesh Ewald method. The Journal of chemical physics , 103(19):8577–8593, 1995

  44. [44]

    B. T. Fasy, J. Kim, F. Lecci, and C. Maria. Introduction to the r package tda. arXiv preprint arXiv:1411.1830, 2014

  45. [45]

    B. T. Fasy and B. Wang. Exploring persistent local homology in topological data analysis. In Acoustics, Speech and Signal Processing (ICASSP), 2016 IEEE International Conference on , pages 6430–6434. IEEE, 2016

  46. [46]

    X. Feng, K. L. Xia, Y. Y. Tong, and G. W. Wei. Multiscale geometric modeling of macromolecules II: lagrangian representation. Journal of Computational Chemistry , 34:2100–2120, 2013

  47. [47]

    Frosini and C

    P. Frosini and C. Landi. Persistent Betti numbers for a noise tolerant shape-based approach to image retrieval. Pattern Recognition Letters, 34(8):863–872, 2013

  48. [48]

    Gameiro, Y

    M. Gameiro, Y. Hiraoka, S. Izumi, M. Kramar, K. Mischaikow, and V. Nanda. Topological measurement of protein compressibility via persistence diagrams. preprint, 2013

  49. [49]

    Ganguly, P

    P. Ganguly, P. Boserman, N. F. van der Vegt, and J. E. Shea. Trimethylamine N-oxide counteracts urea denaturation by inhibiting protein–urea preferential interaction. Journal of the American Chemical Society, 140(1):483–492, 2017. 15

  50. [50]

    Ganguly, T

    P. Ganguly, T. Hajari, J. E. Shea, and N. F. A. van der Vegt. Mutual exclusion of urea and trimethy- lamine N-oxide from amino acids in mixed solvent environment.The journal of physical chemistry letters, 6(4):581–585, 2015

  51. [51]

    Ganguly, N

    P. Ganguly, N. F. van der Vegt, and J. E. Shea. Hydrophobic association in mixed urea–TMAO solutions. The journal of physical chemistry letters , 7(15):3052–3059, 2016

  52. [52]

    R. Ghrist. Barcodes: the persistent topology of data. Bulletin of the American Mathematical Society , 45(1):61–75, 2008

  53. [53]

    Giusti, R

    C. Giusti, R. Ghrist, and D. S. Bassett. Twos company, three (or more) is a simplex. Journal of computational neuroscience, 41(1):1–14, 2016

  54. [54]

    Guibas, D

    L. Guibas, D. Morozov, and Q. M´ erigot. Witnessed k-distance. Discrete & Computational Geometry , 49(1):22–45, 2013

  55. [55]

    B. Hess, H. Bekker, H. J. C. Berendsen, and J. G. E. M. Fraaije. Lincs: a linear constraint solver for molecular simulations. Journal of computational chemistry , 18(12):1463–1472, 1997

  56. [56]

    Hiraoka, T

    Y. Hiraoka, T. Nakamura, A. Hirata, E. G. Escolar, K. Matsue, and Y. Nishiura. Hierarchical structures of amorphous solids characterized by persistent homology. Proceedings of the National Academy of Sciences, 113(26):7035–7040, 2016

  57. [57]

    Horak, S Maletic, and M

    D. Horak, S Maletic, and M. Rajkovic. Persistent homology of complex networks. Journal of Statistical Mechanics: Theory and Experiment , 2009(03):P03034, 2009

  58. [58]

    H. W. Horn, W. C. Swope, J. W. Pitera, J. D. Madura, T. J. Dick, G. L. Hura, and T. Head-Gordon. Development of an improved four-site water model for biomolecular simulations: TIP4P-Ew.The Journal of chemical physics , 120(20):9665–9678, 2004

  59. [59]

    Hunger, N

    J. Hunger, N. Ottosson, K. Mazur, M. Bonn, and H. J. Bakker. Water-mediated interactions between trimethylamine-N-oxide and urea. Physical Chemistry Chemical Physics , 17(1):298–306, 2015

  60. [60]

    Idrissi, M

    A. Idrissi, M. Gerard, P. Damay, M. Kiselev, Y. Puhovsky, E. Cinar, P. Lagant, and G. Vergoten. The effect of urea on the structure of water: A molecular dynamics simulation. The Journal of Physical Chemistry B, 114(13):4731–4738, 2010

  61. [61]

    P. M. Kasson, A. Zomorodian, S. Park, N. Singhal, L. J. Guibas, and V. S. Pande. Persistent voids a new structural metric for membrane fusion. Bioinformatics, 23:1753–1759, 2007

  62. [62]

    K. M. Kast, J. Brickmann, S. M. Kast, and R. S. Berry. Binary phases of aliphatic n-oxides and water: Force field development and molecular dynamics simulation. The Journal of Physical Chemistry A , 107(27):5342–5351, 2003

  63. [63]

    H Lee, H. Kang, M. K. Chung, B. Kim, and D. S. Lee. Persistent brain network homology from the perspective of dendrogram. Medical Imaging, IEEE Transactions on , 31(12):2267–2277, Dec 2012

  64. [64]

    Y. T. Liao, A. C. Manson, M. R. DeLyser, W. G. Noid, and P. S. Cremer. Trimethylamine N-oxide stabilizes proteins via a distinct mechanism compared with betaine and glycine. Proceedings of the National Academy of Sciences , 114(10):2479–2484, 2017

  65. [65]

    X. Liu, Z. Xie, and D. Y. Yi. A fast algorithm for constructing topological structure in large data. Homology, Homotopy and Applications , 14:221–238, 2012

  66. [66]

    C. Maria. Filtered complexes. In GUDHI User and Reference Manual . GUDHI Editorial Board, 2015

  67. [67]

    Meersman, D

    F. Meersman, D. Bowron, A. K. Soper, and M. H. J. Koch. An X-ray and neutron scattering study of the equilibrium between trimethylamine N-oxide and urea in aqueous solution. Physical Chemistry Chemical Physics, 13(30):13765–13771, 2011. 16

  68. [68]

    Z. Y. Meng, D. V. Anand, Y. P. Lu, J. Wu, and K. L. Xia. Weighted persistent homology for biomolecular data analysis. arXiv preprint arXiv:1903.02890 , 2019

  69. [69]

    Merelli, M

    E. Merelli, M. Rucco, P. Sloot, and L. Tesei. Topological characterization of complex systems: Using persistent entropy. Entropy, 17(10):6872–6892, 2015

  70. [70]

    Mischaikow, M Mrozek, J

    K. Mischaikow, M Mrozek, J. Reiss, and A. Szymczak. Construction of symbolic dynamics from exper- imental time series. Physical Review Letters, 82:1144–1147, 1999

  71. [71]

    Mischaikow and V

    K. Mischaikow and V. Nanda. Morse theory for filtrations and efficient computation of persistent homology. Discrete and Computational Geometry , 50(2):330–353, 2013

  72. [72]

    J. R. Munkres. Elements of algebraic topology . CRC Press, 2018

  73. [73]

    Perseus: the persistent homology software

    Vidit Nanda. Perseus: the persistent homology software. Software available at http://www.sas.upenn. edu/~vnanda/perseus

  74. [74]

    D. D. Nguyen, Z. X. Cang, K. D. Wu, M. L. Wang, Y. Cao, and G. Wei. Wei. Mathematical deep learning for pose and binding affinity prediction and ranking in D3R Grand Challenges. Journal of computer-aided molecular design, 33(1):71–82, 2019

  75. [75]

    D. D. Nguyen, T. Xiao, M. L. Wang, and G. W. Wei. Rigidity strengthening: A mechanism for protein– ligand binding. Journal of chemical information and modeling , 57(7):1715–1721, 2017

  76. [76]

    Niyogi, S

    P. Niyogi, S. Smale, and S. Weinberger. A topological view of unsupervised learning from noisy data. SIAM Journal on Computing , 40:646–663, 2011

  77. [77]

    Oleinikova, N

    A. Oleinikova, N. Smolin, I. Brovchenko, A. Geiger, and Roland Winter. Formation of spanning wa- ter networks on protein surfaces via 2D percolation transition. The journal of physical chemistry B , 109(5):1988–1998, 2005

  78. [78]

    Pachauri, C

    D. Pachauri, C. Hinrichs, M.K. Chung, S.C. Johnson, and V. Singh. Topology-based kernels with applica- tion to inference problems in alzheimer’s disease. Medical Imaging, IEEE Transactions on, 30(10):1760– 1770, Oct 2011

  79. [79]

    Panuszko, P

    A. Panuszko, P. Bruzdziak, J. Zielkiewicz, D. Wyrzykowski, and J. Stangret. Effects of urea and trimethylamine-N-oxide on the properties of water and the secondary structure of hen egg white lysozyme. The Journal of Physical Chemistry B , 113(44):14797–14809, 2009

  80. [80]

    Paul and G

    S. Paul and G. N. Patey. Structure and interaction in aqueous urea-trimethylamine-N-oxide solutions. Journal of the American Chemical Society , 129(14):4476–4482, 2007

Showing first 80 references.