Phanourios Tamamis Lab

Texas A&M University

Computational Study and Design of Biomolecular and Material Systems




Lab Members





Our Approach, Goals and Research Problems of Interest

Computational methods, including molecular dynamics (MD) simulations and free energy calculations, are increasingly becoming powerful tools in the study and design of biomolecular and material systems. Despite the continuous advancement of experimental methods, computational tools have proved to be of utmost importance to fill crucial “gaps”, obtain information that is not accessible from experiments, solve critical problems in biology, health, and the environments, and can also leading to novel advanced materials and therapeutics.


Our lab uncovers or modulates biological interactions, designs novel peptide-materials and clay-materials, and investigates biological self-assembly, through the use of simulations, and the development of novel computational tools combining structure and energetic analysis, as well as optimization or virtual screening-based principles.


Phanourios Tamamis



Assistant Professor


Artie McFerrin Department of Chemical Engineering


Department of Materials Science and Engineering

(affiliated faculty)



Texas A&M University



Lab Office: 330 GERB,

Teaching Office: 225 JEB


3122 TAMU, College Station,

TX 77843

Phone: 979-862-1610

Fax: 979-845-6446


Our research currently focuses on the following four areas:


• Computational design of functional peptide- and protein- based materials with applications in biomedicine and the environment.

Peptide-fibril forming biological materials are highly promising materials for several reasons, including their ease of fabrication and potential biocompatibility. Yet, their functionalization to bind to single ions and compounds (e.g., to serve as sorbents or drug carriers) relied on trial-and-error approaches and remained a highly challenging problem. Our lab has been developing novel tools for the simulation-based design of novel peptide nanomaterials. Our research is primarily aiming to develop novel biological and bioinspired materials for tissue-engineering and drug-carrier applications.


• Study of interactions between clay-based materials and toxic compounds. 

Clays can bind tightly various toxic chemicals within their interlayers, and were shown to be safe for short-term human and animal consumption. Our lab uses simulations and has been developing novel computational tools to study the structure and dynamics of toxic compounds binding to clays. In addition, our research is primarily aiming to develop novel advanced clay-based materials with improved sorption properties for particular toxic compounds.


• Study of interactions between proteins with modified RNAs, DNAs or small compounds.

Computational methods are becoming increasingly powerful tools in delineating biomolecular interactions owing to the difficulties associated with using experimental techniques for solving particular problems. One such problem our lab has been investigating involves understanding interactions between RNA and DNA modifications with proteins, which play a vital role in biology, health and diseases. A second problem our lab has been investigating involves the use of docking refinement methods to predict high-accuracy compound-protein structures. We have been developing a novel computational docking-refinement protocol, which nearly exhaustively searches a compound’s binding site using a suite of physics-based innovative features.


• Study of amyloid formation and inhibition as a potential therapeutic avenue for neurodegenerative diseases.

Protein aggregation and amyloid self-assembly occurs in many diseases, including Alzheimer’s, Parkinson’s and diabetes type 2. Tamamis lab has been investigating the fundamentals of amyloid inhibition and is aiming to design novel inhibitors.




Phanourios Tamamis - Bio

Phanourios Tamamis received his B.S. degree in 2006 (excellent; top academic performance) and Ph.D. degree in 2010 from the Physics Department of the University of Cyprus, and was recognized as the top Cypriot undergraduate researcher in 2006. During his undergraduate, graduate and early-postdoctoral studies, he was supervised by Professor Georgios Archontis. After finishing his Ph.D. studies, from 2010 until 2012, Phanourios Tamamis served as a Postdoctoral Fellow at the University of Cyprus, and as a Short-term Fulbright scholar at the University of California at Riverside and Princeton University, under the co-supervision of Professors Dimitrios Morikis and Christodoulos A. Floudas. He was recognized as an “Outstanding Young Researcher” in the 2012 Computational Biophysics to Systems Biology conference. In 2013, he joined the lab of Professor Christodoulos A. Floudas at the Chemical and Biological Engineering Department of Princeton University as a Postdoctoral Research Associate. In 2015, he joined the Chemical Engineering Department of Texas A&M University as an Assistant Professor. Tamamis’ lab addresses key problems at the intersection of computational biophysics, physical chemistry and biomolecular engineering. Among other, Tamamis’ lab has been developing pioneering tools enabling the study of modified RNAs and DNAs with proteins, facilitating the use of computers to functionalize-peptide materials as tissue engineering agents or drug nanocarriers, investigation amyloid inhibition, and enlightening how clays can be used and be improved to be applied sorbents mitigating toxic compounds’ exposure. He received awards for both his research and teaching. Tamamis’ lab research is currently supported by the NSF and the NIH.



Announcements and News


Please contact us if you are interested in joining Tamamis’ lab as a graduate or an undergraduate student.


Key stories from 2022

• Tamamis lab has welcomed two new graduate students, Anastasia Vlachou and Kendall Lilly.


Key stories from 2021

• Tamamis lab received new funding from NSF on the design of novel cancer drug nanocarriers.

• Tamamis lab has welcomed two new graduate students, Juanita Pombo Garcia and Gaelen Brown.

• Tamamis lab has welcomed three new undergraduate students, Madeline Demny, Kendall Lilly  and Carter Priest on May 2021. Carter Priest is co-advised with Dr. Sreeram Vaddiraju.

• Congratulations to Asuka A. Orr who graduated from our lab with a PhD.

• Tamamis lab has published a paper in collaboration with Dr. Adler-Abramovich’ lab at Tel Aviv University on the protection of oxygen-sensitive enzymes by a peptide hydrogel.

• Tamamis lab published a paper in collaboration with Dr. Phillips’ lab at Texas A&M University on the use of montmorillonite clays as sorbents for PFAS.

• Tamamis lab published a paper in collaboration with Dr. Phillips’ and Dr. Pistikopoulos labs on the use of minimalistic simulations and a model to understand and predict chemical adsorption onto montmorillonite clays.

• Tamamis lab published two papers in collaboration with Dr. Gazit’s lab at Tel Aviv University on self-assembled systems mimicking hydrolysis and for multifunctional packings.

• Tamamis lab published a paper in collaboration with Dr. Jayaraman’s and Safe’s labs on hydroxylated chalcones as Aryl Hydrocarbon Receptor Agonists.



Key stories from 2020

Busra Ozguney joined Tamamis lab as a PhD student.

• Tamamis lab published nine papers in 2020. Our computational research was performed in collaboration with several experimental labs, including Drs. Phillips’, Safe’s and Jayaraman’s lab at Texas A&M University, Dr. Contreras’ lab at UT Austin, Dr. Gazit’s lab at Tel Aviv University, Dr. Mitraki’s lab at the University of Crete, and Dr. Gkikas’ lab at U. Mass. Lowell.

• Tamamis lab received funding from the NSF, on the study of RNA modifications with key protein readers and erasers.



Lab Members

Graduate students


Busra Ozguney


Anastasia Vlachou


Juanita Pombo Garcia


Gaelen Brown


Kendall Lilly



Undergraduate students




Madeline Demny


Carter Priest












Compstatin analogs, US Patent 9, 512, 180, 2016.


Amyloid peptide scaffolds coordinate with alzheimer's disease drugs. US Patent 62, 757, 384, 2018.



Peer-Reviewed Papers and Book Chapters

Publications of Tamamis lab

1. Hearon SE, Orr AA, Moyer H, Wang M, Tamamis P, Phillips TD. Montmorillonite clay-based sorbents decrease the bioavailability of per- and polyfluoroalkyl substances (PFAS) from soil and their translocation to plants. Environ Res. 2021;205:112433.


2. Orr AA, Wang M, Beykal B, Ganesh HS, Hearon SE, Pistikopoulos EN, Phillips TD, Tamamis P. Combining Experimental Isotherms, Minimalistic Simulations, and a Model to Understand and Predict Chemical Adsorption onto Montmorillonite Clays. ACS Omega. 2021;6(22):14090-14103


3. Chen Y, Yang Y, Orr AA, Makam P, Redko B, Haimov E, Wang Y, Shimon LJW, Rencus-Lazar S, Ju M, Tamamis P, Dong H, Gazit E. Self-Assembled Peptide Nano-Superstructure towards Enzyme Mimicking Hydrolysis. Angew Chem Int Ed Engl. 2021;60:17164-17170


4. Tao K, Orr AA, Hu W, Makam P, Zhang J, Geng Q, Li B, Jakubowski JM, Wang Y, Tamamis P, Yang R, Mei D, Gazit E. EDTA-mimicking amino acid-metal ion coordination for multifunctional packings. J. Mater. Chem. A, 2021, Advance Article. DOI: 10.1039/D1TA03985G.


5. Aviv M, Cohen-Gerassi D, Orr AA, Misra R, Arnon ZA, Shimon LJW, Shacham-Diamand Y, Tamamis P, Adler-Abramovich L. Modification of a Single Atom Affects the Physical Properties of Double Fluorinated Fmoc-Phe Derivatives. Int J Mol Sci. 2021; 22: 9634.


6. Park H, Jin UH, Karki K, Allred C, Davidson LA, Chapkin RS, Orr AA, Nowshad F, Jayaraman A, Tamamis P, Safe S. Hydroxylated Chalcones as Aryl Hydrocarbon Receptor Agonists: Structure-Activity Effects. Toxicol Sci. 2021;180:148-159


7. Wang M, Orr AA, Jakubowski JM, Bird KE, Casey CM, Hearon SE, Tamamis P, Phillips TD. Enhanced adsorption of per- and polyfluoroalkyl substances (PFAS) by edible, nutrient-amended montmorillonite clays. Water Res. 2021;188:116534


8. Ben-Zvi O, Grinberg I, Orr AA, Noy D, Tamamis P, Yacoby I, Adler-Abramovich L. Protection of Oxygen-Sensitive Enzymes by Peptide Hydrogel. ACS Nano. 2021; 15: 6530–6539.


9. Orr AA, Yang J, Sule N, Chawla R, Hull KG, Zhu M, Romo D, Lele PP, Jayaraman A, Manson MD, Tamamis P. Molecular Mechanism for Attractant Signaling to DHMA by E. coli Tsr. Biophys J., 2020, 118: 492-504.


10. Orr AA, He S, Wang M, Goodall A, Hearon SE, Phillips TD, Tamamis P. Insights into the interactions of bisphenol and phthalate compounds with unamended and carnitine-amended montmorillonite clays. Computers & Chemical Engineering, 2020, 143: 107063.


11. Chen Y, Orr AA, Tao K, Wang Z, Ruggiero A, Shimon LJW, Schnaider L, Goodall A, Rencus-Lazar S, Gilead S, Slutsky I, Tamamis P, Tan Z, Gazit E. High-Efficiency Fluorescence through Bioinspired Supramolecular Self-Assembly. ACS Nano. 2020, 14: 2798-2807.


12. Tao K, Orr AA, Tian Z, Makam P, Gilead S, Si M, Rencus-Lazar S, Qu S, Zhang M, Tamamis P, Gazit P. Enhanced Fluorescence for Bioassembly by Environment-Switching Doping of Metal Ions. Adv. Funct. Mater. 2020: 1909614.


13. Gonzalez-Rivera JC, Orr AA, Engels SM, Jakubowski JM, Sherman MW, O'Connor KN, Matteson T, Woodcock BC, Contreras LM, Tamamis P. Computational evolution of an RNA-binding protein towards enhanced oxidized-RNA binding. Computational and Structural Biotechnology Journal, 2020, 18: 137-152.


14. Jonnalagadda SVR, Gerace AJ, Thai K, Johnson J, Tsimenidis K, Jakubowski JM, Shen C, Henderson KJ, Tamamis P, Gkikas M. Amyloid Peptide Scaffolds Coordinate with Alzheimer's Disease Drugs. J Phys Chem B. 2020, 124: 487-503.


15. Kokotidou C, Tamamis P, Mitraki A. Amyloid-Like Peptide Aggregates. Peptide-based Biomaterials. 2020: 217-268.


16. Jakubowski JM, Orr AA, Le DA, Tamamis P. Interactions between Curcumin Derivatives and Amyloid-β Fibrils: Insights from MD Simulations. J Chem Inf Model. 2019, 60: 289-305. 


17. Kokotidou C, Jonnalagadda SVR, Orr AA, Vrentzos G, Kretsovali A, Tamamis P, Mitraki A. Designer Amyloid Cell-Penetrating Peptides for Potential Use as Gene Transfer Vehicles. Biomolecules. 2019 10(1). pii: E7.


18. Wang M, Orr AA, He S, Dalaijamts C, Weihsueh AC, Tamamis P, Phillips TD. Montmorillonites Can Tightly Bind Glyphosate and Paraquat Reducing Toxin Exposures and Toxicity. ACS Omega 2019, 4, 18: 17702-17713.


19. Park H, Jin UH, Orr AA, Echegaray SP, Davidson LA, Allred CD, Chapkin RS, Jayaraman A, Lee K, Tamamis P, Safe S. Isoflavones as Ah Receptor Agonists in Colon-Derived Cell Lines: Structure-Activity Relationships. Chem Res Toxicol. 2019, 32: 2353-2364.


20. Kokotidou C, Tamamis P, Mitraki A. SelfAssembling Amyloid Sequences as Scaffolds for Material Design: A Case Study of Building Blocks Inspired From the Adenovirus Fiber Protein. Macromolecular Symposia, 2019, 386: 1900005.


21.  Yoon K, Chen CC, Orr AA, Barreto PN, Tamamis P, Safe S. Activation of COUP-TFI by a Novel Diindolylmethane Derivative. Cells, 2019, 8: 220.


22. Jonnalagadda SVR, Kokotidou C, Orr AA, Fotopoulou E, Henderson KJ, Choi CH, Lim WT, Choi SJ, Jeong HK, Mitraki A, Tamamis P. Computational Design of Functional Amyloid Materials with Cesium Binding, Deposition and Capture Properties. J Phys Chem B. 2018, 122: 7555-7568.


23. Keasar C. et al. An analysis and evaluation of the WeFold collaborative for protein structure prediction and its pipelines in CASP11 and CASP12. Scientific Reports 2018, 8: 9939.


24. Mohan RR, Wilson M, Gorham RD Jr, Harrison RES, Morikis VA, Kieslich CA, Orr AA, Coley AV, Tamamis P, Morikis D. Virtual Screening of Chemical Compounds for Discovery of Complement C3 Ligands. ACS Omega, 2018, 3: 6427–6438.


25. Kokotidou C, Jonnalagadda SVR, Orr AA, Seoane-Blanco M, Apostolidou CP, van Raaij MJ, Kotzabasaki M, Chatzoudis A, Jakubowski JM, Mossou E, Forsyth VT, Mitchell EP, Bowler MW, Llamas-Saiz AL, Tamamis P, Mitraki A. A Novel Amyloid Designable Scaffold and Potential Inhibitor Inspired by GAIIG of Amyloid Beta and the HIV-1 V3 loop. FEBS Lett. 2018, 592: 1777–1788


26.  Jin UH, Park H, Li X, Davidson LA, Allred C, Patil B, Jayaprakasha G, Orr AA, Mao L, Chapkin RS, Jayaraman A, Tamamis P, Safe S. Structure-Dependent Modulation of Aryl Hydrocarbon Receptor-Mediated Activities by Flavones. Toxicological Sciences, 2018,164: 205-217.


27. Orr AA, Shaykhalishahi H, Mirecka EA, Jonnalagadda SVR, Hoyer W, Tamamis P*. Elucidating the Multi-Targeted Anti-Amyloid Activity and Enhanced Islet Amyloid Polypeptide Binding of β-wrapins. Computers & Chemical Engineering, 2018, 116: 322-332.


28. Orr AA, Jayaraman A, Tamamis P. Molecular Modeling of Chemoreceptor: Ligand Interactions. Methods in Molecular Biology, 2018, 1729: 353-372.


29. Orr AA, Gonzalez-Rivera JC, Wilson M, Bhikha PR, Wang D, Contreras LM, Tamamis P. A high-throughput and rapid computational method for screening of RNA post-transcriptional modifications that can be recognized by target proteins. Methods, 2018, 143: 34-47.


30. Jonnalagadda SVR, Ornithopoulou E, Orr AA, Mossou E, Forsyth E, Mitchell EP, Bowler MW, Mitraki A, Tamamis P. Computational Design of Amyloid Self-Assembling Peptides Bearing Aromatic Residues and the Cell Adhesive Motif Arg-Gly-Asp. Molecular Systems Design & Engineering, 2017, 2(3): 321-335.


31. Orr AA, Wördehoff MM. Hoyer W, Tamamis P. Uncovering the Binding and Specificity of β-Wrapins for Amyloid-β and α-Synuclein. Journal of Physical Chemistry B, 2016, 120 (50): 12781–12794.


32. Deidda G, Jonnalagadda SVR, Spies JW, Ranella A, Mossou E, Forsyth VT, Mitchell EP, Bowler MW, Tamamis P, Mitraki A.  Self-assembled amyloid peptides with Arg-Gly-Asp (RGD) motifs as scaffolds for tissue engineering. ACS Biomaterials Science & Engineering, 2017, 3(7): 1404–1416.


33. Cheng Y, Jin UH, Davidson LA, Chapkin RS, Jayaraman A, Tamamis P, Orr A, Allred C, Denison MS, Soshilov A, Weaver E, Safe S. Microbial-Derived 1,4-Dihydroxy-2-naphthoic Acid and Related Compounds as Aryl Hydrocarbon Receptor Agonists/Antagonists: Structure-Activity Relationships and Receptor Modeling. Toxicological Sciences, 2017, 155 (2): 458-473.


34. Khoury GA, Smadbeck J, Kieslich CA, Koskosidis AJ, Guzman YA, Tamamis P, Floudas CA.  Princeton_TIGRESS 2.0: High refinement consistency and net gains through support vector machines and molecular dynamics in double-blind predictions during the CASP11 experiment. Proteins 2017, 85(6):1078-1098.


35. Kieslich CA, Tamamis P, Guzman YA, Onel M, Floudas CA. Highly Accurate Structure-Based Prediction of HIV-1 Coreceptor Usage Suggests Intermolecular Interactions Driving Tropism. PLoS One. 2016, 11(2): e0148974.



Publications from Dr. Tamamis’ graduate and postgraduate studies

36. Gorham RD Jr, Forest DL, Khoury GA, Beecher CN, Tamamis P, Archontis G, Larive CK, Floudas C A, Radeke M J, Johnson LV, Morikis D. New compstatin peptides containing N-terminal extensions and non-natural amino acids exhibit potent complement inhibition and improved solubility characteristics. Journal of Medicinal Chemistry, 2015, 58(2): 814-826.


37. Tamamis P, Floudas CA. Elucidating a Key Anti-HIV-1 and Cancer-Associated Axis: The Structure of CCL5 (Rantes) in Complex with CCR5. Scientific Reports, 2014, 4: 5447.


38. Tamamis P, Floudas CA. Elucidating a Key Component of Cancer Metastasis: CXCL12 (SDF-1α) Binding to CXCR4. Journal of Chemical Information and Modeling, 2014, 54 (4): 1174-1188.


39. Tamamis P, Floudas CA. Molecular Recognition of CCR5 by an HIV-1 gp120 V3 Loop. PLoS ONE 2014, 9 (4): e95767.


40. Tamamis P, Terzaki, K, Kassinopoulos M, Mastrogiannis L,  Mossou E,  Forsyth VT, Mitchell EP,  Mitraki A,  Archontis G. Self-Assembly of an Aspartate-Rich Sequence from the Adenovirus Fibre Shaft: Insights from Molecular Dynamics Simulations and Experiments. Journal of Physical Chemistry B, 2014, 118 (7): 1765-1774.


41.  Khoury GA, Smadbeck J, Tamamis P, Vandris AC, Kieslich CA, Floudas CA Forcefield_NCAA: Ab Initio Charge Parameters to Aid in the Discovery and Design of Therapeutic Proteins and Peptides with Unnatural Amino Acids and Their Application to Complement Inhibitors of the Compstatin Family. ACS Synthetic Biology, 2014, 3(12): 855–869.


42. Khoury GA, Tamamis P, Pinnaduwage N, Smadbeck J, Kieslich CA, Floudas CA. Princeton_TIGRESS: Protein geometry refinement using simulations and support vector machines. Proteins, 2014, 82 (5): 794-814.


43. Tamamis P, Kasotakis E,  Archontis G, Mitraki A. Combination of Theoretical and Experimental Approaches for the Design and Study of Fibril-forming Peptides. In Protein Design: Methods and Applications. Methods in Molecular Biology, 2014, 1216: 53-70.


44. Tamamis P, Kieslich CA, Nikiforovich GV, Woodruff TM, Morikis D, Archontis G. Insights into the Mechanism of C5aR Inhibition by PMX53 via Implicit Solvent Molecular Dynamics Simulations and Docking. BMC Biophysics, 2014, 7: 5.


45. Gorham RD Jr, Forest DL, Tamamis P, López de Victoria A, Kraszni  M, Kieslich CA, Banna CD, Bellows-Peterson ML, Larive CK, Floudas CA, Archontis G, Johnson LV, Morikis D. Novel compstatin family peptides inhibit complement activation by drusen-like deposits in human retinal pigmented epithelial cell cultures. Experimental Eye Research, 2013, 116: 96-108.


46. Tamamis P, Floudas CA. Molecular Recognition of CXCR4 by a Dual Tropic HIV-1 gp120 V3 Loop. Biophysical Journal, 2013, 105 (6): 1502-1514.


47. Lopez de Victoria, A, Tamamis P, Kieslich, CA, Morikis, D. Insights into the Structure, Correlated Motions, and Electrostatic Properties of two HIV-1 gp120 V3 loops. PLoS ONE 2012, 7 (11): e49925.


48. Kieslich CA, Tamamis P, Gorham RD Jr, Lopez de Victoria A, Sausman N, Archontis G, Morikis D. Exploring protein-protein and protein-ligand interactions in the immune system using molecular dynamics and continuum electrostatics. Current Physical Chemistry 2012, 2 (4): 324-343.


49. Tamamis P, Lopez de Victoria A, Gorham RD, Bellows-Peterson ML, Pierou P, Floudas CA, Morikis D, Archontis G. Molecular Dynamics in Drug Design: New Generations of Compstatin Analogs. Chemical Biology & Drug Design 2012, 79 (5): 703-718.


50. Tamamis P, Pierou P, Mytidou C, Floudas CA, Morikis D, Archontis G. Design of a modified mouse protein with ligand binding properties of its human analog by molecular dynamics simulations: The case of C3 inhibition by compstatin. Proteins, 2011, 79 (11): 3166-3179.


51. Pieridou G, Avgousti-Menelaou C, Tamamis P, Archontis G, Hayes SC. UV Resonance Raman Study of TTR(105-115) Structural Evolution as a Function of Temperature. Journal of Physical Chemistry B, 2011, 115 (14): 4088-4098.


52. Tamamis P, Archontis G. Amyloid-like Self-Assembly of a Dodecapeptide Sequence from the Adenovirus Fiber Shaft: Perspectives from Molecular Dynamics Simulations. Journal of Non-Crystalline Solids, 2011, 357 (2): 717-722.


53. Tamamis P, Morikis D, Floudas CA, Archontis G. Species specificity of the complement inhibitor compstatin investigated by all-atom molecular dynamics simulations. Proteins, 2010, 78 (12): 2655-2667.


54. Tamamis P, Kasotakis E, Mitraki A, Archontis G. Amyloid-like Self-Assembly of Peptide Sequences from the Adenovirus Fiber Shaft: Insights from Molecular Dynamics Simulations. Journal of Physical Chemistry B, 2009, 113 (47): 15639-15647.


55. Tamamis P, Adler-Abramovich L, Reches M, Marshall K, Sikorski P, Serpell L, Gazit E, Archontis G. Self-Assembly of Phenylalanine Oligopeptides: Insights from Experiments and Simulations. Biophysical Journal, 2009, 96 (12): 5020-5029.





Tamamis lab has received support from:

- the National Institutes for Health,

Ø National Institute on Aging

Computational Design of Novel β-wrapins Targeting and Sequestering Amyloid-β, α-synuclein and IAPP

Ø National Institute of Environmental Health Sciences

Comprehensive Tools and Models for Addressing Exposure to Mixtures During Environmental Emergency-Related Contamination Events


- the National Science Foundation

Ø URoL: Epigenetics 1: Collaborative Research: Novel epitransciptomics tools to understand and modulate interactions of modified RNAs with protein readers and erasers

Ø NSF-BSF: Computational and Experimental Design of Novel Peptide Nanocarriers for Cancer Drugs


In addition, Tamamis lab has received support (startup funding, seed funding and T3 funding) from Texas A&M University andTexas A&M engineering experiment station.




We provide the following programs/files which can be useful to other researchers in the academic community:

1) Input files for the calculation of residue-pairwise interaction free energies for β-wrapin : amyloidogenic protein complexes. The files correspond to β-wrapin HI18 in complex with IAPP. Input simulation files for the project are available upon request.