A first test of the hypothesis of biogenic magnetite-based heterogeneous ice-crystal nucleation in cryopreservation

An outstanding biophysical puzzle is focused on the apparent ability of weak, extremely low-frequency oscillating magnetic fields to enhance cryopreservation of many biological tissues. A recent theory holds that these weak magnetic fields could be inhibiting ice-crystal nucleation on the nanocrystals of biological magnetite (Fe₃O₄, an inverse cubic spinel) that are present in many plant and animal tissues by causing them to oscillate. In this theory, magnetically-induced mechanical oscillations disrupt the ability of water molecules to nucleate on the surface of the magnetite nanocrystals. However, the ability of the magnetite crystal lattice to serve as a template for heterogeneous ice crystal nucleation is as yet unknown, particularly for particles in the 10–100 nm size range. Here we report that the addition of trace-amounts of finely-dispersed magnetite into ultrapure water samples reduces strongly the incidence of supercooling, as measured in experiments conducted using a controlled freezing apparatus with multiple thermocouples. SQUID magnetometry was used to quantify nanogram levels of magnetite in the water samples. We also report a relationship between the volume change of ice, and the degree of supercooling, that may indicate lower degassing during the crystallization of supercooled water. In addition to supporting the role of ice-crystal nucleation by biogenic magnetite in many tissues, magnetite nanocrystals could provide inexpensive, non-toxic, and non-pathogenic ice nucleating agents needed in a variety of industrial processes, as well as influencing the dynamics of ice crystal nucleation in many natural environments.     

Magnetic fields at extremely low-frequency (50 Hz, 0.8 mT) can induce the uptake of intracellular calcium levels in osteoblasts

Several studies have been undertaken to elucidate the effects of electromagnetic field (EMF) on intracellular calcium ([Ca²⁺]_i) in the past 20 years. However, still there were controversies of electromagnetic pollution within the scientific community. In this work, we studied the effects of alternative magnetic fields on intracellular calcium. Osteoblastic cells were used as a model both to test the hypothesis that extremely low-frequency (ELF) magnetic fields can alter the concentrations of the intracellular calcium, and to examine the ‘window’ effect predicted by our previous theoretical work. The outcome of this experiment demonstrated that 50 Hz, 0.8 mT magnetic field can induce the uptake of [Ca²⁺]_i in osteoblasts. The empirical evidences of the specified window effects of [Ca²⁺]_i in osteoblastic cells were reported for the first time in this work.     

Water balance of over-wintering beetles in relation to strategies for cold tolerance

The vapour pressure of the haemolymph of a supercooled insect is higher than the vapour pressure of the haemolymph of a frozen insect at the same temperature. The aim of the study was to see whether this may affect the water loss of freeze-avoiding and freezetolerant, over-wintering beetles. The rates of water loss were determined on freeze-tolerant Pytho depressus larvae and Upis ceramboides adults. Within each species one group was kept supercooled whereas another group was frozen. All groups were incubated at-5°C. Both species displayed significantly lower rates of water loss when they were frozen than when they were supercooled. Values of respiratory rate and water loss of freeze-avoiding and freeze-tolerant species were compared to corresponding values of desert beetles. The results indicate that the freeze-avoiding species have lower rates of cuticular water loss than freeze-tolerant species. This indicates that the freeze-avoiding species have developed more efficient water-saving mechanisms than freeze-tolerant species. The reason for this may be that the haemolymph in frozen animals will be in vapour pressure equlibrium with the ice in the hibernaculum and thus there is no danger of desiccation during winter. The supercooled insects will have a vapour pressure of the haemolymph that is higher than the vapour pressure of water in the surrounding air and will thus lose water.Abbreviations BW body weight - BW_i initial body weight - BW_t body weight at time t - P vapour pressure difference between the water in the haemolymph and the water in the air - DWL_t dry weight loss at time t - M _w rate of metabolic water production - MF_w mol fraction of water, in the haemolymph - MO₂ rate of oxygen consumption - Osm osmolality of the haemolymph - P _a vapour pressure of water in the air - P _h vapour pressure of water in the haemolymph - P _w vapour pressure of pure water - Q a constant (2,02 1 oxygen per g fat metabolized) relating oxygen consumption to dry weight loss when fat is metabolized - R a constant (1,89 1 oxygen per g water produced) relating metabolic water production to oxygen consumption when fat is metabolized - R _dwl rate of dry weight loss - RH relative humidity of the air - RWC_i initial relative water content measured by weighing - RWC_t relative water content at time t - STP standard temperature and pressure     

Retarded Charge–Carrier Recombination in Photoelectrochemical Cells from Plasmon‐Induced Resonance Energy Transfer

N‐type metal oxides such as hematite (α‐Fe₂O₃) and bismuth vanadate (BiVO₄) are promising candidate materials for efficient photoelectrochemical water splitting; however, their short minority carrier diffusion length and restricted carrier lifetime result in undesired rapid charge recombination. Herein, a 2D arranged globular Au nanosphere (NS) monolayer array with a highly ordered hexagonal hole pattern (hereafter, Au array) is introduced onto the surface of photoanodes comprised of metal oxide films via a facile drying and transfer‐printing process. Through plasmon‐induced resonance energy transfer, the Au array provides a strong electromagnetic field in the near‐surface area of the metal oxide film. The near‐field coupling interaction and amplification of the electromagnetic field suppress the charge recombination with long‐lived photogenerated holes and simultaneously enhance the light harvesting and charge transfer efficiencies. Consequently, an over 3.3‐fold higher photocurrent density at 1.23 V versus reversible hydrogen electrode (RHE) is achieved for the Au array/α‐Fe₂O₃. Furthermore, the high versatility of this transfer printing of Au arrays is demonstrated by introducing it on the molybdenum‐doped BiVO₄ film, resulting in 1.5‐fold higher photocurrent density at 1.23 V versus RHE. The tailored metal film design can provide a potential strategy for the versatile application in various light‐mediated energy conversion and optoelectronic devices.     

EVIDENCE OF SYNCHRONIZATION OF NEURONAL ACTIVITY OF MOLLUSCAN BRAIN GANGLIA INDUCED BY ALTERNATING 50 Hz APPLIED MAGNETIC FIELD

Experimental evidence for the appearance of synchronized bioelectric activity in neurons under applied extremely low frequency (ELF) magnetic fields is shown. We have studied the synchronizing process by recording the intracellular bioelectric activity from pairs of neurons randomly chosen from the brain ganglia of the snail Helix aspersa. The recordings were made in real time under exposure to sinusoidal low frequency (50 Hz) weak (B₀=1–15 mT) magnetic fields. Synchronization was observed in 27% of the pairs tested. A linear dependence of the firing frequency f with the energy density of the applied magnetic field (i.e., f∝B₀²) was presented. The ability of low frequency sinusoidal weak magnetic fields to promote “magnetic synchronization” is exciting and opens new avenues for induced electromagnetic field bioeffects.     

Modelling of β-d-glucopyranose ring distortion in different force fields: a metadynamics study

Modelling of carbohydrate conformations is a challenging task for force field developers. Three carbohydrate force fields, namely GLYCAM06, GROMOS 45a4 and OPLS were evaluated. Free energies of different ring conformations of β-d-glucopyranose were calculated using metadynamics in vacuum as well as in explicitly modelled water. All three force fields model the ⁴C₁ conformation as the most stable by at least 6 kJ/mol, as compared to other conformations. Interconversion from the ⁴C₁ to any other conformation is associated with a barrier of no lower than 26 kJ/mol. The free energy surface calculated in the GLYCAM06 force field is in remarkably good agreement with the recent Car-Parrinello metadynamics study. The effect of a water environment is relatively low and analogous in all tested force fields. Namely, the presence of water stabilizes the upper-left (^3,OB) versus bottom-right (B_3,O) area of Stoddard’s plot, relative to the situation in vacuum. Comparison of free and potential surfaces is also provided for vacuum calculations.     

Cold hardiness and deep supercooling in xylem of shagbark hickory

Differential thermal analysis, differential scanning calorimetry, pulsed nuclear magnetic resonance spectroscopy, and low temperature microscopy are utilized to investigate low temperature freezing points or exotherms which occur near −40 C in the xylem of cold-acclimated shagbark hickory (Carya ovata L.). Experiments using these methods demonstrate that the low temperature exotherm results from the freezing of cellular water in a manner predicted for supercooled dilute aqueous solutions. Heat release on freezing, nuclear magnetic resonance relaxation times, and freezing and thawing curves for hickory twigs all point to a supercooled fraction in the xylem at subfreezing temperatures. Calorimetric and low temperature microscopic analyses indicate that freezing occurs intracellularly in the xylem ray parenchyma. The supercooled fraction is found to be extremely stable, even at temperatures only slightly above the homogeneous nucleation temperature for water (−38 C). Xylem water is also observed to be resistant to dehydration when exposed to 80% relative humidity at 20 C. D₂O exchange experiments find that only a weak kinetic barrier to water transport exists in the xylem rays of shagbark hickory.     

Static and extremely low frequency electromagnetic field exposure: Reported effects on the circadian production of melatonin

The circadian rhythm of melatonin production (high melatonin levels at night and low during the day) in the mammalian pineal gland is modified by visible portions of the electromagnetic spectrum, i.e., light, and reportedly by extremely low frequency (ELF) electromagnetic fields as well as by static magnetic field exposure. Both light and non-visible electromagnetic field exposure at night depress the conversion of serotonin (5HT) to melatonin within the pineal gland. Several reports over the last decade showed that the chronic exposure of rats to a 60 Hz electric field, over a range of field strengths, severely attenuated the nighttime rise in pineal melatonin production; however, more recent studies have not confirmed this initial observation. Sinusoidal magnetic field exposure also has been shown to interfere with the nocturnal melatonin forming ability of the pineal gland although the number of studies using these field exposures is small. On the other hand, static magnetic fields have been repeatedly shown to perturb the circadian melatonin rhythm. The field strengths in these studies were almost always in the geomagnetic range (0.2 to 0.7 Gauss or 20 to 70 μtesla) and most often the experimental animals were subjected either to a partial rotation or to a total inversion of the horizontal component of the geomagnetic field. These experiments showed that several parameters in the indole cascade in the pineal gland are modified by these field exposures; thus, pineal cyclic AMP levels, N-acetyltransferase (NAT) activity (the rate limiting enzyme in pineal melatonin production), hydroxyindole-O-methyltransferase (HIOMT) activity (the melatonin forming enzyme), and pineal and blood melatonin concentrations were depressed in various studies. Likewise, increases in pineal levels of 5HT and 5-hydroxyindole acetic acid (5HIAA) were also seen in these glands; these increases are consistent with a depressed melatonin synthesis. The mechanisms whereby non-visible electromagnetic fields influence the melatonin forming ability of the pineal gland remain unknown; however, the retinas in particular have been theorized to serve as magnetoreceptors with the altered melatonin cycle being a consequence of a disturbance in the neural biological clock, i.e., the suprachiasmatic nuclei (SCN) of the hypothalamus, which generates the circadian melatonin rhythm. The disturbances in pineal melatonin production induced by either light exposure or non-visible electromagnetic field exposure at night appear to be the same but whether the underlying mechanisms are similar remains unknown.     

人体电磁兼容系统与电磁场处理水--Ⅲ.电磁水对人体电磁场的作用

《人体电磁兼容系统与电磁场处理水》一文分三篇写。第一篇“Ⅰ.人体电磁兼容系统”,讨论了人体体内电磁场;第二篇“Ⅱ·电磁水的特性”,讨论了电磁水的电磁场。二文均已发表于《生物磁学》。本文是第三篇,讨论电磁水电磁场对人体电磁场的作用,重点阐明饮用电磁水后,主要是电磁水的电磁场作为入射场与体内场发生迭加作用,产生耦合电磁场,从而实现其对体内场的调节作用,达到维系身体健康的目的。由于有关水的问题非常复杂,动态性强,故大多数关于耦合场的研究均服从于“统计学规律”。     

The effect of pulsed electromagnetic field therapy on food sensitivity

Abstract

Owing to the involvement of the immune system in the etiology of food sensitivity, and because pulsed electromagnetic field therapy is associated with beneficial immunologic changes, it was hypothesized that pulsed electromagnetic fields may have a beneficial effect on food sensitivity. A small pilot study was carried out in patients suffering from food sensitivity, with the antigen leukocyte antibody test being employed to index the degree of food sensitivity in terms of the number of foods to which each patient reacted. It was found that a 1-week course of pulsed electromagnetic field therapy, consisting of one hour’s treatment per day, resulted in a reduction in the mean number of reactive foods of 10.75 (p?<?0.05). On the basis of these results, a larger study is warranted.     

Activity and stability comparison of immobilized NADH oxidase on multi-walled carbon nanotubes,carbon nanospheres,and single-walled carbon nanotubes

Nanomaterials have been studied widely as the supporting materials for enzyme immobilization because in theory, they can provide low diffusion resistance and high surface/volume ratio. Common immobilization methods, such as physical adsorption, covalent binding, crosslinking, and encapsulation, often cause problems in enzyme leaching, 3D structure change and strong mass transfer resistance. We have previously demonstrated a site-specific enzyme immobilization method, which is based on the specific interaction between a His-tagged enzyme and functionalized single-walled carbon nanotubes (SWCNTs), that can overcome the foresaid constraints. In this work, we broadened the use of this immobilization approach by applying it on other nanomaterials, including multi-walled carbon nanotubes and carbon nanospheres. Both supporting materials were modified with N_α,N_α-bis(carboxymethyl)-l-lysine hydrate prior to enzyme immobilization. The resulting nanomaterial–enzyme conjugates could maintain 78–87% of the native enzyme activity and showed significantly better stability than the free enzyme. When compared with the SWCNT–enzyme conjugate, we found that the size variance among these supporting nanomaterials may affect factors such as surface curvature, surface coverage and particle mobility, which in turn results in differences in the activity and stability among these immobilized biocatalysts.     

Nano-Scale Pollutants: Fate in Irish Surface and Drinking Water Regulatory Systems

Nano-functionalized products such as UV protective paints additives, antimicrobial food packaging, and fuel additives offering reduced CO₂ emissions have the potential to secure a significant Irish market share in the near future. This scoping study gives a first estimation of nanomaterial surface water concentrations and population ingestional exposure through drinking water resulting from these products. As nanomaterial behavior in wastewater treatment plants (WWTPs) and water treatment plants (WTPs) is currently unclear, bridging data relating to potentially relevant materials (pharmaceuticals and metal removal efficiencies in WWTPs; pathogen removal efficiencies in WTPs) are employed in this study. Mean nanomaterial removal efficiencies of 59.8% and 70.2% were predicted for Irish WWTPs, between 96.95% and 0% for Irish WTPs. Predicted nano-scale TiO₂ concentrations in surface waters (resulting from exterior paints) were 2 orders of magnitude greater than that of Ag (resulting from food packaging) and CeO₂ (resulting from fuel additives), respectively. Predicted surface and drinking water concentrations were unlikely to pose any ecotoxicological or human health risk, although nano-scale TiO₂ and Ag may warrant monitoring as part of standard surface water monitoring schemes. Future research should be directed toward characterizing the behavior of different categories of nanomaterials within WWTP processes.     

Laser Raman investigation of intact single muscle fibers on the state of water in muscle tissue

Laser Raman spectroscopy has been used to investigate the state of water in intact single muscle fibers of the giant barnacle (Balanus nulilus). The spectra in the region of the O-H (or O-²H) stretching modes of water in unfrozen fibers show that there is no appreciable difference between the shape and relative intensity of the Raman bands due to the water molecules located inside a muscle fiber and those of the corresponding bands in the spectrum of pure water. The presence of significant amounts of “structured” intracellular water, greater than approx. 5% of the total water content, in these fibers is thus excluded. The Raman spectra of frozen fibers have also been recorded in order to evaluate the amount of intracellular water which remains unfrozen at temperatures below the normal freezing point of water. We have been able to reproduce these spectra by assuming that the spectrum of a frozen fiber is the sum of the individual spectra of water and ice. To calculate the amount of unfrozen water from these curve fittings, it was also necessary to determine the intensities of the water and ice Raman bands relative to one another. We have found the I(ice)/I(water) ratio is 1.07 ± 0.01 for H₂O and 1.05 ± 0.03 for ²H₂O With these figures, we have calculated that for a fiber with a normal water content of 80%, 20% of the water molecules remain in the supercooled state at ?5°C, which corresponds to 1 g of water per of fiber dry weight. This amount of bound water was also found to be independent of the water content of the fibers.     

Patterns of distribution and abundance of chitons of the genus Ischnochiton in intertidal boulder fields

Abstract Chitons of the genus Ischnochiton are found predominantly on the undersurfaces of boulders, compared with other intertidal or subtidal habitats. They therefore appear to be habitat‐specialists at this scale. This, combined with the fact that boulder fields are relatively sparse compared with other intertidal habitats, makes these animals vulnerable to natural and anthropogenic disturbances. In addition, many species of Ischnochiton are relatively rare and appear to have very patchy abundances, making them likely to have very specific requirements for habitat. We need to understand the habitat requirements in order to manage, conserve and restore disturbed habitats. The present study was carried out at three intertidal boulder fields separated along approximately 200 km of the coast of New South Wales, Australia, centred around Sydney. The boulder fields were representative of those found in this region. The boulders were made of different materials: shale in the north, sandstone in Sydney and quartzitic sandstone in the south. Some boulders in each boulder field were covered by up to 0.4 m of water during low tide. The study showed that the seven species examined were overdispersed among boulders in each of these three intertidal boulder fields. Most boulders did not have associated chitons, but there were very large abundances on a very small number of boulders. Chitons were also overdispersed among boulders that they occupied. These patterns were consistent among shores and among species, even though patterns of abundance were extremely different among different species. These species appear therefore to show specific requirements for habitat at a small spatial scale, using only a small proportion of potential patches of habitat (i.e. boulders) in any place. Extremely patchy patterns of dispersion can be caused by variation in patterns of recruitment, mortality or behavioural responses to habitat or other species. Before performing experiments to investigate such processes, it is useful to test hypotheses of association with habitat using mensurative experiments to identify environmental correlates that might explain the observed patterns. In the present study, sizes of boulders and the associated sessile and mobile assemblages were proposed as mechanisms that could affect dispersion of chitons among boulders. None of these factors, however, showed strong associations with abundances of chitons. The lack of support of these models rules out some features of habitat to which species of Ischnochiton might respond, thereby precluding manipulative experiments involving these features, which are unlikely to be involved in the very patchy patterns of dispersion of species of Ischnochiton.     

CO2 emissions from an undrained tropical peatland: Interacting influences of temperature,shading and water table depth

Emission of CO₂ from tropical peatlands is an important component of the global carbon budget. Over days to months, these fluxes are largely controlled by water table depth. However, the diurnal cycle is less well understood, in part, because most measurements have been collected daily at midday. We used an automated chamber system to make hourly measurements of peat surface CO₂ emissions from chambers root‐cut to 30 cm. We then used these data to disentangle the relationship between temperature, water table and heterotrophic respiration (R_het). We made two central observations. First, we found strong diurnal cycles in CO₂ flux and near‐surface peat temperature (<10 cm depth), both peaking at midday. The magnitude of diurnal oscillations was strongly influenced by shading and water table depth, highlighting the limitations of relying on daytime measurements and/or a single correction factor to remove daytime bias in flux measurements. Second, we found mean daily R_het had a strong linear relationship to the depth of the water table, and under flooded conditions, R_het was small and constant. We used this relationship between R_het and water table depth to estimate carbon export from both R_het and dissolved organic carbon over the course of a year based on water table records. R_het dominates annual carbon export, demonstrating the potential for peatland drainage to increase regional CO₂ emissions. Finally, we discuss an apparent incompatibility between hourly and daily average observations of CO₂ flux, water table and temperature: water table and daily average flux data suggest that CO₂ is produced across the entire unsaturated peat profile, whereas temperature and hourly flux data appear to suggest that CO₂ fluxes are controlled by very near surface peat. We explore how temperature‐, moisture‐ and gas transport‐related mechanisms could cause mean CO₂ emissions to increase linearly with water table depth and also have a large diurnal cycle.     

Permeability changes of connexin32 hemi channels reconstituted in liposomes induced by extremely low frequency, low amplitude magnetic fields

The effect of extremely low frequency and low amplitude magnetic fields on gap junctional permeability was investigated by using reconstituted connexin32 hemi channel in liposomes. Cytochrome c was loaded inside these proteoliposomes and its reduction upon addition of ascorbate in the bulk aqueous phase was adopted as the index of hemi channel permeability. The permeability rate of the hemi channels, expressed as ΔA/min, was dependent on the incubation temperature of proteoliposomes. The effect of exposures to magnetic fields at different frequencies (7, 13 and 18 Hz) and amplitudes (50, 50 and 70 μT, respectively), and at different temperatures (16, 18 and 24 °C) was studied. Only the exposure of proteoliposomes to 18-Hz (B_acpeak and B_dc=70 μT) magnetic field for 60 min at 16±0.4 °C resulted in a significant enhancement of the hemi channel permeability from ΔA/min=0.0007±0.0002 to ΔA/min=0.0010±0.0001 (P=0.030). This enhancement was not found for magnetic field exposures of liposomes kept at the higher temperatures tested. Temperature appears to influence lipid bilayer arrangement in such a way as being capable to mask possible effects induced by the magnetic field. Although the observed effect was very low, it seems to confirm the applicability of our model previously proposed for the interaction of low frequency electromagnetic fields with lipid membrane.     

Assessment of an anti-scale low-frequency electromagnetic field device on drinking water biofilms

Abstract

Low intensity and very low-frequency electromagnetic fields (EMF) used for preventing scaling in water distribution systems were tested for the first time for their potential impact on drinking water biofilms. The assays were carried out in laboratory-scale flow-through reactors that mimic water distribution systems. The drinking water biofilms were not directly exposed to the core of the EMF generator and only subjected to waterborne electromagnetic waves. The density and chlorine susceptibility of nascent or mature biofilms grown under exposure to EMF were evaluated in soft and hard water. This EMF treatment was able to modify CaCO₃ crystallization but it did not significantly affect biofilms. Indeed, over all the tested conditions, there was no significant change in cell number, or in the integrity of the cells (membrane, culturability), and no measurable effect of chlorine on the biofilm.     

Molecular simulation and experimental studies on the interfacial properties of a mixed surfactant SDS/C4mimBr

Mixed surfactants have potential applications in various fields. The understanding and prediction of their macro- and microscopic properties are of great importance in the designing of these materials. We used molecular dynamics (MD) and experiments to study the interfacial tension and the microscopic structures of the sodium dodecyl sulfate (SDS)/C₄mimBr mixed surfactant at the water/hexane interface. The interfacial tension, density profile, radial distribution function (RDF), orientation distribution of the tails and order parameters have been examined. It seems that the addition of C₄mimBr decreased the interfacial tension; a higher C₄mimBr concentration resulted in a thicker interface, a smaller droplet, and more disordered SDS tails. The competition between free volume and electrostatic shielding seems to be the primary mechanism behind these phenomena.     

Growth characteristics of mung beans and water convolvuluses exposed to 425‐MHz electromagnetic fields

Effects of high‐frequency, continuous wave (CW) electromagnetic fields on mung beans (Vigna radiata L.) and water convovuluses (Ipomoea aquatica Forssk.) were studied at different growth stages (pre‐sown seed and early seedling). Specifically, the effects of the electromagnetic source's power and duration (defined as power‐duration level) on the growth of the two species were studied. Mung beans and water convolvuluses were exposed to electromagnetic fields inside a specially designed chamber for optimum field absorption, and the responses of the seeds to a constant frequency at various power levels and durations of exposure were monitored. The frequency used in the experiments was 425 MHz, the field strengths were 1 mW, 100 mW, and 10 W, and the exposure durations were 1, 2, and 4 h. Results show that germination enhancement is optimum for the mung beans at 100 mW/1 h power‐duration level, while for water convolvuluses the optimum germination power‐duration level was 1 mW/2 h. When both seed types were exposed at the early sprouting phase with their respective optimum power‐duration levels for optimum seed growth, water convolvuluses showed growth enhancement while mung bean sprouts showed no effects. Water content analysis of the seeds suggests thermal effects only at higher field strength. Bioelectromagnetics 31:519–527, 2010. © 2010 Wiley‐Liss, Inc.     

The surface properties of some silicone and fluorosilicone coating materials immersed in seawater

Changes in the surface properties of some silicone elastomers (General Electric RTV11, RTV160 and RTV655) and fluorosilicones (‐(Si(CH₃)((CH₂)₃‐O(CH₂)₂(CF₂)_XCF₃)‐O)_n‐, x = 5,7,9) on prolonged immersion in water (distilled water, artificial seawater, filtered and unfiltered seawater) have been investigated using measurements of advancing and receding contact angles, of surface roughness and of water uptake. Considerable increases in hydrophilicity and surface rugosity are attributed mainly to surface structural rearrangements accompanying absorption of water; these effects are greater for the fluorosilicones and the rugosity of RTV160 also increased considerably. Observations of early marine settlement (up to 16 weeks in flowing seawater), visualised by scanning electron microscopy, showed patchy attachment mainly of bacteria and microalgae while mature biofilms were formed on the poly(methylmethacrylate) controls. Although settlement was least on RTV11 and greatest on the fluorosilicones, the range of variation was small relative to the differences in the long‐term fouling resistance of the materials. The design requirements for fouling resistance of a smooth, soft, uniform surface are supported.