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2017
Haymet, ADJ, Wilson PW.  2017.  The Workman-Reynolds "Freezing Potential": A new look at the inherent physical process. Journal of Molecular Liquids. 228:243-246.   10.1016/j.molliq.2016.07.081   AbstractWebsite

Recent published results and a re-analysis of existing measurements of the Workman-Reynolds Freezing Potential allow a redefinition the electric potential created when ice grows into a dilute salt solution. The entire process is largely determined by the solubility and diffusivity of the ion species being incorporated differentially into the ice lattice. This new look at the Workman-Reynolds effect shows that the voltage itself is of secondary interest, and rather it is the time to reach peak voltage, which is of paramount interest in the study of the mechanism. (C) 2016 Elsevier B.V. All rights reserved.

2016
Wilson, PW, Haymet ADJ.  2016.  The effect of stirring on the heterogeneous nucleation of water and of clathrates of tetrahydrofuran/water mixtures. Condensed Matter Physics. 19   10.5488/cmp.19.23602   AbstractWebsite

The statistics of liquid-to-crystal nucleation are measured for both water and for clathrate-forming mixtures of tetrahydrofuran (THF) and water using an automatic lag time apparatus (ALTA). We measure the nucleation temperature using this apparatus in which a single sample is repeatedly cooled, nucleated and thawed. The effect of stirring on nucleation has been evaluated numerically and is discussed. We find that stirring of the solution makes no difference to the nucleation temperature of a given solution in a given tube.

Bryk, T, Haymet ADJ.  2016.  Profiles of electrostatic potential across the water-vapor, ice-vapor and ice-water interfaces. Condensed Matter Physics. 19   10.5488/cmp.19.13607   AbstractWebsite

Ice-water, water-vapor interfaces and ice surface are studied by molecular dynamics simulations with the SPC/E model of water molecules having the purpose to estimate the profiles of electrostatic potential across the interfaces. We have proposed a methodology for calculating the profiles of electrostatic potential based on a trial particle, which showed good agreement for the case of electrostatic potential profile of the water-vapor interface of TIP4P model calculated in another way. The measured profile of electrostatic potential for the pure ice-water interface decreases towards the liquid bulk region, which is in agreement with simulations of preferential direction of motion of Li+ and F- solute ions at the liquid side of the ice-water interface. These results are discussed in connection with the Workman-Reynolds effect.

2012
Wilson, PW, Haymet ADJ.  2012.  The Spread of Nucleation Temperatures of a Sample of Supercooled Liquid Is Independent of the Average Nucleation Temperature. Journal of Physical Chemistry B. 116:13472-13475.   10.1021/jp308177b   AbstractWebsite

The stochastic nature of the nucleation of a supercooled solution is not always realized or well-defined. There exists an inherent spread of nucleation temperatures of any given sample which is repeatedly supercooled, frozen, and then thawed, in the Same container, even when the nucleation is occurring at the same site Classical nucleation theory predicts such a:Spread but does not provide any molecular level interpretation for the value of the spread and thus it has been the subject of some speculation. This report shows that there is a lower limit to the value of the spread which is related neither to the efficiency of the best nucleation site nor the number of times the sample is cooled and the nucleation temperature measured.

2011
Maeda, N, Wells D, Becker NC, Hartley PG, Wilson PW, Haymet ADJ, Kozielski KA.  2011.  Development of a high pressure automated lag time apparatus for experimental studies and statistical analyses of nucleation and growth of gas hydrates. Review of Scientific Instruments. 82   10.1063/1.3602926   AbstractWebsite

Nucleation in a supercooled or a supersaturated medium is a stochastic event, and hence statistical analyses are required for the understanding and prediction of such events. The development of reliable statistical methods for quantifying nucleation probability is highly desirable for applications where control of nucleation is required. The nucleation of gas hydrates in supercooled conditions is one such application. We describe the design and development of a high pressure automated lag time apparatus (HP-ALTA) for the statistical study of gas hydrate nucleation and growth at elevated gas pressures. The apparatus allows a small volume (approximate to 150 mu l) of water to be cooled at a controlled rate in a pressurized gas atmosphere, and the temperature of gas hydrate nucleation, T(f), to be detected. The instrument then raises the sample temperature under controlled conditions to facilitate dissociation of the gas hydrate before repeating the cooling-nucleation cycle again. This process of forming and dissociating gas hydrates can be automatically repeated for a statistically significant (>100) number of nucleation events. The HP-ALTA can be operated in two modes, one for the detection of hydrate in the bulk of the sample, under a stirring action, and the other for the detection of the formation of hydrate films across the water-gas interface of a quiescent sample. The technique can be applied to the study of several parameters, such as gas pressure, cooling rate and gas composition, on the gas hydrate nucleation probability distribution for supercooled water samples. (C) 2011 American Institute of Physics. [doi:10.1063/1.3602926]

2010
Wilson, PW, Haymet ADJ.  2010.  Effect of Ice Growth Rate on the Measured Workman-Reynolds Freezing Potential between Ice and Dilute NaCl Solutions. Journal of Physical Chemistry B. 114:12585-12588.   10.1021/jp105001c   AbstractWebsite

Workman-Reynolds freezing potentials have been measured across the interface between ice and dilute NaCl solutions as a function of ice growth rate for three salt concentrations. Growth rates of up to 40 pm s(-1) are used, and it is found that the measured voltage peaks at rates of similar to 25 mu m center dot s(-1). Our initial results indicate that the freezing potential can be used as a probe into various aspects of the DC electrical resistance of ice as a function of variables such as salt concentration.

Wilson, PW, Osterday KE, Heneghan AF, Haymet ADJ.  2010.  Type I Antifreeze Proteins Enhance Ice Nucleation above Certain Concentrations. Journal of Biological Chemistry. 285:34741-34745.   10.1074/jbc.M110.171983   AbstractWebsite

In this study, we examined the effects that antifreeze proteins have on the supercooling and ice-nucleating abilities of aqueous solutions. Very little information on such nucleation currently exists. Using an automated lag time apparatus and a new analysis, we show several dilution series of Type I antifreeze proteins. Our results indicate that, above a concentration of similar to 8 mg/ml, ice nucleation is enhanced rather than hindered. We discuss this unexpected result and present a new hypothesis outlining three components of polar fish blood that we believe affect its solution properties in certain situations.

Wilson, PW, Haymet ADJ.  2010.  Hydrate formation and re-formation in nucleating THF/water mixtures show no evidence to support a "memory" effect. Chemical Engineering Journal. 161:146-150.   10.1016/j.cej.2010.04.047   AbstractWebsite

There are many reports in the chemical engineering literature citing a 'memory' effect in association with nucleation of clathrate hydrates. Some researchers appeal to this memory effect in order to explain the apparent reduction in induction time for hydrates formed repetitively from supercooled solutions. It is suggested that for various species of clathrate in liquid-liquid or gas-liquid systems, such as THF/water, CO(2)/water and hydrocarbon gas/water, the 'memory' effect results from water which is obtained from melted hydrates possessing a "modified" structure which allows easier hydrate re-formation. We provide here data from several series of measurements of the stochastic nature of THF-water hydrate formation using an automatic lag time apparatus. Our data supports the existing molecular understanding of nucleation and does not require any appeal to a memory effect. (C) 2010 Elsevier B.V. All rights reserved.

2009
Wilson, PW, Osterday K, Haymet ADJ.  2009.  The Effects of Electric Field on Ice Nucleation May be Masked by the Inherent Stochastic Nature of Nucleation. Cryoletters. 30:96-99. AbstractWebsite

We use an automatic lag time apparatus to show that an electric field of 5* 10(4) Vm(-1) appears to have no effect on the nucleation of supercooled water. Previously reported effects at similar magnitude fields are most likely due to the inherent stochastic nature of liquid to solid nucleation.

Wilson, PW, Haymet ADJ.  2009.  Effect of solutes on the heterogeneous nucleation temperature of supercooled water: an experimental determination. Physical Chemistry Chemical Physics. 11:2679-2682.   10.1039/b817585c   AbstractWebsite

We investigate the effect of solute concentration on the heterogeneous ice nucleation temperature (T(het)) of aqueous solutions of both NaCl and D-glucose. An automatic lag time apparatus (ALTA) technique allows the dependence of T(het) on solute concentration to be determined with statistical significance. Our results point to the solute-induced lowering of T(het) being a factor of two times the equivalent melting point depression at any fixed concentration, the same factor reported for homogeneous nucleation experiments with small molecular weight solutes.

2008
Wilson, PW, Haymet ADJ.  2008.  Workman-Reynolds freezing potential measurements between ice and dilute salt solutions for single ice crystal faces. Journal of Physical Chemistry B. 112:11750-11755.   10.1021/jp804047x   AbstractWebsite

Workman-Reynolds freezing potentials have been measured for the first time across the interface between single crystals of ice 1h and dilute electrolyte solutions. The measured electric potential is a strictly nonequilibrium phenomenon and a function of the concentration of salt, freezing rate, orientation of the ice crystal, and time. When all these factors are controlled, the voltage is reproducible to the extent expected with ice growth experiments. Zero voltage is obtained with no growth or melting. For rapidly grown ice I h basal plane in contact with a solution of 10(-4) M NaCl the maximum voltage exceeds 30 V and decreases to zero at. both high and low salt concentrations. These single-crystal experiments explain much of the data captured on this remarkable phenomenon since 1948.

2007
Wierzbicki, A, Dalal P, Cheatham Iii TE, Knickelbein JE, Haymet ADJ, Madura JD.  2007.  Antifreeze Proteins at the Ice/Water Interface: Three Calculated Discriminating Properties for Orientation of Type I Proteins. Biophysical Journal. 93:1442-1451.   10.1529/biophysj.107.105189   AbstractWebsite

Antifreeze proteins (AFPs) protect many plants and organisms from freezing in low temperatures. Of the different AFPs, the most studied AFP Type I from winter flounder is used in the current computational studies to gain molecular insight into its adsorption at the ice/water interface. Employing molecular dynamics simulations, we calculate the free energy difference between the hydrophilic and hydrophobic faces of the protein interacting with ice. Furthermore, we identify three properties of Type I “antifreeze” proteins that discriminate among these two orientations of the protein at the ice/water interface. The three properties are: the “surface area” of the protein; a measure of the interaction of the protein with neighboring water molecules as determined by the number of hydrogen bond count, for example; and the side-chain orientation angles of the threonine residues. All three discriminants are consistent with our free energy results, which clearly show that the hydrophilic protein face orientations toward the ice/water interface, as hypothesized from experimental and ice/vacuum simulations, are incorrect and support the hypothesis that the hydrophobic face is oriented toward the ice/water interface. The adsorption free energy is calculated to be 2–3 kJ/mol.

2005
Wilson, PW, Lester D, Haymet ADJ.  2005.  Heterogeneous nucleation of clathrates from supercooled tetrahydrofuran (THF)/water mixtures, and the effect of an added catalyst. Chemical Engineering Science. 60:2937-2941.   10.1016/j.ces.2004.12.047   AbstractWebsite

The statistics of liquid-to-crystal nucleation are measured for clathrate-forming mixtures of tetrahydrofuran (THF) and water using an automatic lag time apparatus (ALTA). We measure the nucleation temperature using this new apparatus in which a single sample is repeatedly cooled, nucleated and thawed. This is done for a series of tetrahydrofuran concentrations and in several different sample tubes since the nucleation is heterogeneous and so occurring on the tube wall. The measurements are also done at the same concentrations and tubes but with an added catalyst, a single crystal of silver iodide. (c) 2005 Elsevier Ltd. All rights reserved.

Smith, EJ, Bryk T, Haymet ADJ.  2005.  Free energy of solvation of simple ions: Molecular-dynamics study of solvation of Cl- and Na+ in the ice/water interface. Journal of Chemical Physics. 123   10.1063/1.1953578   AbstractWebsite

Molecular-dynamics simulations of Cl- and Na+ ions are performed to calculate ionic solvation free energies in both bulk simple point-charge/extended water and ice 1 h at several different temperatures, and at the basal ice 1 h/water interface. For the interface we calculate the free energy of "transfer" of the ions across the ice/water interface. For the ions in bulk water in the NPT ensemble at 298 K and 1 atm, results are found to be in good agreement with experiments, and with other simulation results. Simulations performed in the NVT ensemble are shown to give equivalent solvation free energies, and this ensemble is used for the interfacial simulations. Solvation free energies of Cl- and Na+ ions in ice at 150 K are found to be similar to 30 and similar to 20 kcal mol(-1), respectively, less favorable than for water at room temperature. Near the melting point of the model the solvation of the ions in water is the same (within statistical error) as that measured at room temperature, and in the ice is equivalent and similar to 10 kcal mol(-1) less favorable than the liquid. The free energy of transfer for each ion across ice/water interface is calculated and is in good agreement with the bulk observations for the Cl- ion. However, for the model of Na+ the long-range electrostatic contribution to the free energy was more negative in the ice than the liquid, in contrast with the results observed in the bulk calculations. (c) 2005 American Institute of Physics.

Wilson, PW, Haymet ADJ.  2005.  Nucleation from a supercooled binary mixture studied by crossed polarizers. Journal of Physical Chemistry A. 109:11354-11357.   10.1021/jp052830a   AbstractWebsite

Polarized light passing through a supercooled binary liquid mixture sample is analyzed during the moment of the nucleation of the crystal phase to determine whether the stable equilibrium crystal is nucleated, or whether a transient phase of different composition or broken-symmetry is formed. This experiment is performed for the particular case of heterogeneous nucleation of a supercooled clathrate-forming liquid mixture, tetrahydrofuran (THF)/water, compared with ice nucleating from pure supercooled water. The new experimental results are consistent with the hypothesis that the equilibrium clathrate hydrate crystal is nucleated directly, with no transient phase detected on the time scale of these experiments.

Haymet, ADJ, Bryk T, Smith EJ.  2005.  Solute Ions at Ice/Water InterfaceIonic Soft Matter: Modern Trends in Theory and Applications. 206( Henderson D, Holovko M, Trokhymchuk A, Eds.).:333-359.: Springer Netherlands   10.1007/1-4020-3659-0_13   Abstract

A molecular dynamics study of the I h ice/water interface and the behavior of solute ions at the basal ice/water interface is presented. The excess stress at the interface of pure ice and pure water is discussed. We compare the solvation of Na + and Cl − solute ions in bulk water and ice, and discuss their behavior at the ice/vacuum interface. The free energy profiles for Na + and Cl − ions across the ice/water interface is estimated from calculations of potential of mean force.

2004
Engel-Cox, JA, Hoff RM, Haymet ADJ.  2004.  Recommendations on the use of satellite remote-sensing data for urban air quality. Journal of the Air & Waste Management Association. 54:1360-1371. AbstractWebsite

In the last 5 yr, the capabilities of earth-observing satellites and the technological tools to share and use satellite data have advanced sufficiently to consider using satellite imagery in conjunction with ground-based data for urban-scale air quality monitoring. Satellite data can add synoptic and geospatial information to ground-based air quality data and modeling. An assessment of the integrated use of ground-based and satellite data for air quality monitoring, including several short case studies, was conducted. Findings identified current U.S. satellites with potential for air quality applications, with others available internationally and several more to be launched within the next 5 yr; several of these sensors are described in this paper as illustrations. However, use of these data for air quality applications has been hindered by historical lack of collaboration between air quality and satellite scientists, difficulty accessing and understanding new data, limited resources and agency priorities to develop new techniques, ill-defined needs, and poor understanding of the potential and limitations of the data. Specialization in organizations and funding sources has limited the resources for cross-disciplinary projects. To successfully use these new data sets requires increased collaboration between organizations, streamlined access to data, and resources for project implementation.

Bryk, T, Haymet ADJ.  2004.  Charge separation at the ice/water interface: a molecular dynamics simulation study of solute ions at the ice basal plane. Journal of Molecular Liquids. 112:47-50.   10.1016/s0167-7322(03)00274-5   AbstractWebsite

The behavior of Na+ and Cl- ions over a total time of 1.5 ns ice basal plane/vacuum interface is simulated with the SPC/E model of water molecules at a temperature close to the coexistence point. It is found that the Na+ ion stays for almost the whole simulation time in the top broad ice surface layer, while Cl- ion penetrates through the top layer and settles in the subsurface layer. Running coordination numbers calculated every 60 ps show on average seven nearest neighbors for the Cl- ion, while the Na+ ion is surrounded mostly by five nearest water molecules. A tendency to melt is observed for the surface ice layers with the solute ions inside. (C) 2003 Elsevier B.V. All rights reserved.

Heneghan, AF, Moore HJ, Lee TR, Haymet ADJ.  2004.  Statistics of heterogeneous nucleation of supercooled aqueous solutions in a self-assembled monolayer-coated container. Chemical Physics Letters. 385:441-445.   10.1016/j.cplett.2004.01.025   AbstractWebsite

Repeated heterogeneous nucleation of a single, unchanging aqueous sample of water in a container coated by a self-assembled monolayer (SAM) is studied using our automated lag-time apparatus showing that coating the walls of the sample container with the SAM decreases the average supercooled temperature (DeltaT(50%)) to colder temperatures, indicating that nucleation in an unmodified glass container takes place on the container walls in the absence of a substrate or impurities. Adding an AgI crystal increases DeltaT(50%) to the same warm temperature, whether the container is SAM-coated or not, suggesting that nucleation takes place on the surface of the added crystal. (C) 2004 Elsevier B.V. All rights reserved.

2003
Tomczak, MM, Hincha DK, Crowe JH, Harding MM, Haymet ADJ.  2003.  The effect of hydrophobic analogues of the type I winter flounder antifreeze protein on lipid bilayers. Febs Letters. 551:13-19.   10.1016/s0014-5793(03)00843-3   AbstractWebsite

The effect of four synthetic analogues of the 37-residue winter flounder type I antifreeze protein (AFP), which contain four Val, Ala or Ile residues in place of Thr residues at positions 2, 13, 24 and 37 and two additional salt bridges, on the binary lipid system prepared from a 1:1 mixture of the highly unsaturated DGDG and saturated DMPC has been determined using FTIR spectroscopy. In contrast to the natural protein, which increases the thermotropic phase transition, the Thr, Val and Ala analogues decreased the thermotropic phase transitions of the liposomes by 2.2degreesC, 3.4degreesC and 2.4degreesC, while the Ile analogue had no effect on the transition. Experiments performed using perdeuterated DMPC showed that the Ala and Thr peptides interacted preferentially with the DGDG in the lipid mixture, while the Val peptide showed no preference for either lipid. The results are consistent with interactions involving the hydrophobic face of type I AFPs and model bilayers, i.e. the same face of the protein that is responsible for antifreeze properties. The different effects correlate with the helicity of the peptides and suggest that the solution conformation of the peptides has a significant role in determining the effects of the peptides on thermotropic membrane phase transitions. (C) 2003 Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies.

Rick, SW, Haymet ADJ.  2003.  Dielectric constant and proton order and disorder in ice Ih: Monte Carlo computer simulations. Journal of Chemical Physics. 118:9291-9296.   10.1063/1.1568337   AbstractWebsite

The dielectric properties of ice Ih are studied using a Monte Carlo algorithm for sampling over proton configurations. The algorithm makes possible the calculation of the dielectric constant and other properties of the proton-disordered crystal. Results are presented for three classical models of water, two commonly used nonpolarizable models (SPC/E and TIP4P) and a polarizable model (TIP4P-FQ). (C) 2003 American Institute of Physics.

Heneghan, AF, Haymet ADJ.  2003.  Liquid-to-crystal heterogeneous nucleation: bubble accelerated nucleation of pure supercooled water. Chemical Physics Letters. 368:177-182.   10.1016/s0009-2614(02)01835-3   AbstractWebsite

Bubble formation in a single sample of pure water, held in the sample holder of our automated lag-time apparatus, is shown to lead to accelerated liquid-to-crystal heterogeneous nucleation. This phenomenon shifts the entire probability distribution for heterogeneous nucleation, together with the average lag-time , to significantly warmer temperatures. In the linear supercooling experiment analyzed here, this is equivalent to reducing the average time to nucleation. Using a single assumption tested in previous work, the entire 'nucleation curve' is extracted from a single experiment. (C) 2002 Elsevier Science B.V. All rights reserved.

Wilson, PW, Heneghan AF, Haymet ADJ.  2003.  Ice nucleation in nature: supercooling point (SCP) measurements and the role of heterogeneous nucleation. Cryobiology. 46:88-98.   10.1016/s0011-2240(02)00182-7   AbstractWebsite

In biological systems, nucleation of ice from a supercooled aqueous solution is a stochastic process and always heterogeneous. The average time any solution may remain supercooled is determined only by the degree of supercooling and heterogeneous nucleation sites it encounters. Here we summarize the many and varied definitions of the so-called "supercooling point," also called the "temperature of crystallization" and the "nucleation temperature," and exhibit the natural, inherent width associated with this quantity. We describe a new method for accurate determination of the supercooling point, which takes into account the inherent statistical fluctuations of the value. We show further that many measurements on a single unchanging sample are required to make a statistically valid measure of the supercooling point. This raises an interesting difference in circumstances where such repeat measurements are inconvenient, or impossible, for example for live organism experiments. We also discuss the effect of solutes on this temperature of nucleation. Existing data appear to show that various solute species decrease the nucleation temperature somewhat more than the equivalent melting point depression. For non-ionic solutes the species appears not to be a significant factor whereas for ions the species does affect the level of decrease of the nucleation temperature. (C) 2003 Elsevier Science (USA). All rights reserved.

Ulander, J, Haymet ADJ.  2003.  Permeation across hydrated DPPC lipid bilayers: Simulation of the titrable amphiphilic drug valproic acid. Biophysical Journal. 85:3475-3484.   10.1016/s0006-3495(03)74768-7   AbstractWebsite

Valproic acid is a short branched fatty acid used as an anticonvulsant drug whose therapeutic action has been proposed to arise from membrane-disordering properties. Static and kinetic properties of valproic acid interacting with fully hydrated dipalmitoyl phosphatidylcholine lipid bilayers are studied using molecular-dynamics simulations. We calculate spatially resolved free energy profiles and local diffusion coefficients using the distance between the bilayer and valproic acid respective centers-of-mass along the bilayer normal as reaction coordinate. To investigate the pH dependence, we calculate profiles for the neutral valproic acid as well as its water-soluble anionic conjugate base valproate. The local diffusion constants for valproate/valproic acid along the bilayer normal are found to be similar to10(-6) to 10(-5) cm(2) s(-1). Assuming protonation of valproic acid upon association with - or insertion into - the lipid bilayer, we calculate the permeation coefficient to be similar to2.0 10(-3) cm s(-1), consistent with recent experimental estimates of fast fatty acid transport. The ability of the lipid bilayer to sustain local defects such as water intrusions stresses the importance of going beyond mean field and taking into account correlation effects in theoretical descriptions of bilayer translocation processes.

Harding, MM, Anderberg PI, Haymet ADJ.  2003.  'Antifreeze' glycoproteins from polar fish. European Journal of Biochemistry. 270:1381-1392.   10.1046/j.1432-1033.2003.03488.x   AbstractWebsite

Antifreeze glycoproteins (AFGPs) constitute the major fraction of protein in the blood serum of Antarctic notothenioids and Arctic cod. Each AFGP consists of a varying number of repeating units of (Ala-Ala-Thr) (n), with minor sequence variations, and the disaccharide beta-d-galactosyl-(1-->3)-alpha-N-acetyl-d-galactosamine joined as a glycoside to the hydroxyl oxygen of the Thr residues. These compounds allow the fish to survive in subzero ice-laden polar oceans by kinetically depressing the temperature at which ice grows in a noncolligative manner. In contrast to the more widely studied antifreeze proteins, little is known about the mechanism of ice growth inhibition by AFGPs, and there is no definitive model that explains their properties. This review summarizes the structural and physical properties of AFGPs and advances in the last decade that now provide opportunities for further research in this field. High field NMR spectroscopy and molecular dynamics studies have shown that AFGPs are largely unstructured in aqueous solution. While standard carbohydrate degradation studies confirm the requirement of some of the sugar hydroxyls for antifreeze activity, the importance of following structural elements has not been established: (a) the number of hydroxyls required, (b) the stereochemistry of the sugar hydroxyls (i.e. the requirement of galactose as the sugar), (c) the acetamido group on the first galactose sugar, (d) the stereochemistry of the beta-glycosidic linkage between the two sugars and the alpha-glycosidic linkage to Thr, (e) the requirement of a disaccharide for activity, and (f) the Ala and Thr residues in the polypeptide backbone. The recent successful synthesis of small AFGPs using solution methods and solid-phase chemistry provides the opportunity to perform key structure-activity studies that would clarify the important residues and functional groups required for activity. Genetic studies have shown that the AFGPs present in the two geographically and phylogenetically distinct Antarctic notothenioids and Arctic cod have evolved independently, in a rare example of convergent molecular evolution. The AFGPs exhibit concentration dependent thermal hysteresis with maximum hysteresis (1.2 degreesC at 40 mg.mL(-1)) observed with the higher molecular mass glycoproteins. The ability to modify the rate and shape of crystal growth and protect cellular membranes during lipid-phase transitions have resulted in identification of a number of potential applications of AFGPs as food additives, and in the cryopreservation and hypothermal storage of cells and tissues.