Evidence of extensive multispecies macrofouling in Eckström's topknot Zeugopterus regius (Bonnaterre, 1788), Pleuronectiformes, Scophthalmidae.

Diverse and extensive macrofouling of the left-hand (eyed) side has been observed in multiple films and photographs of different specimens of Eckström's topknot Zeugopterus regius. Identified foulers include macroalgae and tunicates. Photographs of unfouled specimens and preserved juveniles have also been inspected. Macrofouling is not universal in this species; unfouled fish were observed around the strongly tidal British Isles, whereas the worst-fouled topknots were seen in the eutrophic, microtidal northern Adriatic.

Simulations of mode-selective photonic lanterns for efficient coupling of starlight into the single-mode regime.

In ground-based astronomy, starlight distorted by the atmosphere couples poorly into single-mode waveguides, but a correction by adaptive optics, even if only partial, can boost coupling into the few-mode regime, allowing the use of photonic lanterns to convert into multiple single-mode beams. Corrected wavefronts result in focal patterns that couple mostly with circularly symmetric waveguide modes. A mode-selective photonic lantern is hence proposed to convert multimode light into a subset of single-mode waveguides of the standard photonic lantern, thereby reducing the required number of outputs. We ran simulations to show that only two out of the six waveguides of a 1×6 photonic lantern carry >95% of the coupled light to the outputs at D/r0<10 if the wavefront is partially corrected and the photonic lantern is made mode selective.

Visualization and Manipulation of Bilayer Graphene Quantum Dots with Broken Rotational Symmetry and Nontrivial Topology.

Electrostatically defined quantum dots (QDs) in Bernal stacked bilayer graphene (BLG) are a promising quantum information platform because of their long spin decoherence times, high sample quality, and tunability. Importantly, the shape of QD states determines the electron energy spectrum, the interactions between electrons, and the coupling of electrons to their environment, all of which are relevant for quantum information processing. Despite its importance, the shape of BLG QD states remains experimentally unexamined. Here we report direct visualization of BLG QD states by using a scanning tunneling microscope. Strikingly, we find these states exhibit a robust broken rotational symmetry. By using a numerical tight-binding model, we determine that the observed broken rotational symmetry can be attributed to low energy anisotropic bands. We then compare confined holes and electrons and demonstrate the influence of BLG's nontrivial band topology. Our study distinguishes BLG QDs from prior QD platforms with trivial band topology.

Does the common topknot Zeugopterus punctatus (Teleosteii: Pleuronectiformes: Scophthalmidae) use a novel Venturi-effect attachment mechanism? A testable hypothesis.

Common topknots (Zeugopterus punctatus) attach to vertical rock surfaces and overhangs. It has been speculated that attachment is by a suction cup, with the median (anal, dorsal) fins providing a peripheral seal. Here the authors propose that the attachment is actually based on a Venturi effect. The rear portions of the median fins continually move in a fan-like fashion (at c. 4 cycles per second). This movement produces a tailward fluid flow that ventilates the shallow underbody space between the fish and its rocky substratum. The anterior portions of the median fins seal the space laterally, but the space is open anterior (beneath the raised head) and posterior to the sea. The mid-underbody space likely has a lower cross-sectional area than does the front intake or rear exit, so flow should be faster (and pressure lower) within it than outside, thus providing pressure gradient suction. Topknots attach to rough and heavily biofouled surfaces, presumably because the high numbers of fin rays and their associated membranes plus fine muscle control allow effective sealing. The attachment ability is shared by all members of the flatfish tribe Phrynorhombini; it can be related to anatomical peculiarities and constitutes a probable synapomorphy for this clade.

"The things that people can't see" The impact of TBI on relationships: an interpretative phenomenological analysis.

Objective: To explore the impact of TBI on couple relationships, from the perspective of both injured and uninjured partners in the relationship.Method: In-depth, semi-structured interviews were conducted with six uninjured women and five of their male partners living with TBI for between four and eight years who had attended a tertiary neurorehabilitation service. The principles of Interpretative Phenomenological Analysis (IPA) were used to analyze the data.Results: The three major themes emerged. Broken Bonds: "those special things just between the two of us" captures the emotional fallout from TBI on each individual and on the relationship; New Dynamics: "like oil and water" describes the effect of individual changes on relationship dynamics in general, on sexuality, conflict and family life; Moving Forward Together: "We figure it out" describes coping strategies in maintaining relationships post-TBI including hope, time, understanding TBI and positive reappraisal.Conclusions: This research provides an in-depth, phenomenological account of couples' experiences of the impact of TBI on relationships, including the perspectives of both TBI survivors and their partners. The three major themes that emerged capture the stresses that impinge on relationships post-TBI and confirms the importance of supportive clinical interventions for couples as an essential component of neurorehabilitation.

Visualizing the Effect of an Electrostatic Gate with Angle-Resolved Photoemission Spectroscopy.

Electrostatic gating is pervasive in materials science, yet its effects on the electronic band structure of materials has never been revealed directly by angle-resolved photoemission spectroscopy (ARPES), the technique of choice to noninvasively probe the electronic band structure of a material. By means of a state-of-the-art ARPES setup with submicron spatial resolution, we have investigated a heterostructure composed of Bernal-stacked bilayer graphene (BLG) on hexagonal boron nitride and deposited on a graphite flake. By voltage biasing the latter, the electric field effect is directly visualized on the valence band as well as on the carbon 1s core level of BLG. The band gap opening of BLG submitted to a transverse electric field is discussed and the importance of intra layer screening is put forward. Our results pave the way for new studies that will use momentum-resolved electronic structure information to gain insight on the physics of materials submitted to the electric field effect.

The locomotor system of the ocean sunfish Mola mola (L.): role of gelatinous exoskeleton, horizontal septum, muscles and tendons.

Adult ocean sunfish are the heaviest living teleosts. They have no axial musculature or caudal fin. Propulsion is by unpaired dorsal and anal fins; a pseudocaudal fin ('clavus') acts as a rudder. Despite common perception, young sunfish are active predators that swim quickly, beating their vertical fins in unison to generate lift-based propulsion and attain cruising speeds similar to salmon and marlin. Here we show that the thick subcutaneous layer (or 'capsule'), already known to provide positive buoyancy, is also crucial to locomotion. It provides two compartments, one for dorsal fin musculature and one for anal fin muscles, separated by a thick, fibrous, elastic horizontal septum that is bound to the capsule itself, the roof of the skull and the dorsal surface of the short vertebral column. The compartments are braced sagittally by bony haemal and neural spines. Both fins are powered by white muscles distributed laterally and red muscles located medially. The anal fin muscles are mostly aligned dorso-ventrally and have origins on the septum and haemal spines. Dorsal fin muscles vary in orientation; many have origins on the capsule above the skull and run near-horizontally and some bipennate muscles have origins on both capsule and septum. Such bipennate muscle arrangements have not been described previously in fishes. Fin muscles have hinged tendons that pass through capsular channels and radial cartilages to insertions on fin rays. The capsule is gelatinous (89.8% water) with a collagen and elastin meshwork. Greasy in texture, calculations indicate capsular buoyancy is partly provided by lipid. Capsule, septum and tendons provide elastic structures likely to enhance muscle action and support fast cruising.

Crying a river: how much salt-laden jelly can a leatherback turtle really eat?

Leatherback turtles (Dermochelys coriacea) are capital breeders that accumulate blubber (33 kJ g-1 wet mass) by hyperphagia on a gelatinous diet at high latitudes; they breed in the tropics. A jellyfish diet is energy poor (0.1-0.2 kJ g-1 wet mass) so leatherbacks must ingest large quantities. Two published estimates of feeding rate [50% body mass day-1 (on Rhizostoma pulmo) and 73% body mass day-1 (on Cyanea capillata)] have been criticised as too high. Jellyfish have high salt and water contents that must be removed to access organic material and energy. Most salt is removed (as NaCl) by paired lachrymal salt glands. Divalent ions are lost via the gut. In this study, the size of adult salt glands (0.622 kg for a 450 kg turtle; relatively three times the size of salt glands in cheloniid turtles) was measured for the first time by computed tomography scanning. Various published values for leatherback field metabolic rate, body fluid composition and likely blubber accumulation rates are combined with known jellyfish salt, water and organic compositions to calculate feasible salt gland secretion rates and feeding rates. The results indicate that leatherbacks can produce about 10-15 ml secretion g-1 salt gland mass h-1 (tear osmolality 1800 mOsm kg-1). This will permit consumption of 80% body mass day-1 of Ccapillata Calculations suggest that leatherbacks will find it difficult/impossible to accumulate sufficient blubber for reproduction in a single feeding season. Rapid jellyfish digestion and short gut transit times are essential.

Dual pO2/pCO2 fibre optic sensing film.

A fibre optic multi-sensor has been developed for biomedical sensing applications using a tip coating solution sensitive to both oxygen and carbon dioxide. An oxygen sensitive phosphorescence quenching complex based on platinum octaethylporphyrin (PtOEP) was combined with a carbon dioxide sensitive phosphorescence compound based on 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS). When excited by blue light (470 nm), the resultant coating had two fluorescent peaks at 515 nm (green) and 645 nm (red) which responded to partial pressure of CO2 and O2 respectively. The sensor was tested in vitro and shown to be able to measure CO2 and O2 simultaneously and in real time, with calibration constants of 0.0384 kPa-1 and 0.309 kPa-1 respectively. The O2 sensitive peak received some overlap from the 515 nm peak (0.38% of peak intensity) as well as some cross-sensitivity (maximum, 5.1 kPa pCO2 gave a measurement equivalent to 0.43 kPa of O2, a ratio of 0.08 : 1). However, these effects can be subtracted from measurements and no significant cross-sensitivity or overlap was seen in CO2 measurements from O2. This novel compound presents great potential for use in medical sensors and we expect it to be important to a wide range of future applications.

Fiber-optic fluorescence-quenching oxygen partial pressure sensor using platinum octaethylporphyrin.

The development and bench testing of a fiber-optic oxygen sensor is described. The sensor is designed for measurement of tissue oxygen levels in the mucosa of the digestive tract. The materials and construction are optimized for insertion through the mouth for measurement in the lower esophagus. An oxygen-sensitive fluorescence-quenching film was applied as a solution of platinum octaethylporphyrin (PtOEP) poly(ethyl methacrylate) (PEMA) and dichloromethane and dip coated onto the distal tip of the fiber. The sensor was tested by comparing relative fluorescence when immersed in liquid water at 37°C, at a range of partial pressures (0-101 kPa). Maximum relative fluorescence at most oxygen concentrations was seen when the PtOEP concentration was 0.1 g.L-1, four layers of coating solution were applied, and a fiber core radius of 600 µm was selected, giving a Stern-Volmer constant of 0.129 kPa-1. The performance of the sensor is suitable for many in vivo applications, particularly mucosal measurements. It has sufficient sensitivity, is sterilizable, and is sufficiently flexible and robust for insertion via the mouth without damage to the probe or risk of harm to the patient.

Topsy-turvy: turning the counter-current heat exchange of leatherback turtles upside down.

Counter-current heat exchangers associated with appendages of endotherms feature bundles of closely applied arteriovenous vessels. The accepted paradigm is that heat from warm arterial blood travelling into the appendage crosses into cool venous blood returning to the body. High core temperature is maintained, but the appendage functions at low temperature. Leatherback turtles have elevated core temperatures in cold seawater and arteriovenous plexuses at the roots of all four limbs. We demonstrate that plexuses of the hindlimbs are situated wholly within the hip musculature, and that, at the distal ends of the plexuses, most blood vessels supply or drain the hip muscles, with little distal vascular supply to, or drainage from the limb blades. Venous blood entering a plexus will therefore be drained from active locomotory muscles that are overlaid by thick blubber when the adults are foraging in cold temperate waters. Plexuses maintain high limb muscle temperature and avoid excessive loss of heat to the core, the reverse of the accepted paradigm. Plexuses protect the core from overheating generated by muscular thermogenesis during nesting.

Noise analysis for CCD-based ultraviolet and visible spectrophotometry.

We present the results of a detailed analysis of the noise behavior of two CCD spectrometers in common use, an AvaSpec-3648 CCD UV spectrometer and an Ocean Optics S2000 Vis spectrometer. Light sources used include a deuterium UV/Vis lamp and UV and visible LEDs. Common noise phenomena include source fluctuation noise, photoresponse nonuniformity, dark current noise, fixed pattern noise, and read noise. These were identified and characterized by varying light source, spectrometer settings, or temperature. A number of noise-limiting techniques are proposed, demonstrating a best-case spectroscopic noise equivalent absorbance of 3.5×10(-4) AU for the AvaSpec-3648 and 5.6×10(-4) AU for the Ocean Optics S2000 over a 30 s integration period. These techniques can be used on other CCD spectrometers to optimize performance.

Large-scale movements in European badgers: has the tail of the movement kernel been underestimated?

Characterizing patterns of animal movement is a major aim in population ecology, and yet doing so at an appropriate spatial scale remains a major challenge. Estimating the frequency and distances of movements is of particular importance when species are implicated in the transmission of zoonotic diseases. European badgers (Meles meles) are classically viewed as exhibiting limited dispersal, and yet their movements bring them into conflict with farmers due to their potential to spread bovine tuberculosis in parts of their range. Considerable uncertainty surrounds the movement potential of badgers, and this may be related to the spatial scale of previous empirical studies. We conducted a large-scale mark-recapture study (755 km(2); 2008-2012; 1935 capture events; 963 badgers) to investigate movement patterns in badgers, and undertook a comparative meta-analysis using published data from 15 European populations. The dispersal movement (>1 km) kernel followed an inverse power-law function, with a substantial 'tail' indicating the occurrence of rare long-distance dispersal attempts during the study period. The mean recorded distance from this distribution was 2.6 km, the 95 percentile was 7.3 km and the longest recorded was 22.1 km. Dispersal frequency distributions were significantly different between genders; males dispersed more frequently than females, but females made proportionally more long-distance dispersal attempts than males. We used a subsampling approach to demonstrate that the appropriate minimum spatial scale to characterize badger movements in our study population was 80 km(2), substantially larger than many previous badger studies. Furthermore, the meta-analysis indicated a significant association between maximum movement distance and study area size, while controlling for population density. Maximum long-distance movements were often only recorded by chance beyond the boundaries of study areas. These findings suggest that the tail of the badger movement distribution is currently underestimated. The implications of this for understanding the spatial ecology of badger populations and for the design of disease intervention strategies are potentially significant.

Human junctophilin-2 undergoes a structural rearrangement upon binding PtdIns(3,4,5)P3 and the S101R mutation identified in hypertrophic cardiomyopathy obviates this response.

JP2 (junctophilin-2) is believed to hold the transverse tubular and jSR (junctional sarcoplasmic reticulum) membranes in a precise geometry that facilitates excitation-contraction coupling in cardiomyocytes. We have expressed and purified human JP2 and shown using electron microscopy that the protein forms elongated structures ~15 nm long and 2 nm wide. Employing lipid-binding assays and quartz crystal microbalance with dissipation we have determined that JP2 is selective for PS (phosphatidylserine), with a Kd value of ~0.5 µM, with the N-terminal domain mediating this interaction. JP2 also binds PtdIns(3,4,5)P3 at a different site than PS, resulting in the protein adopting a more flexible conformation; this interaction is modulated by both Ca(2+) and Mg(2+) ions. We show that the S101R mutation identified in patients with hypertrophic cardiomyopathy leads to modification of the protein secondary structure, forming a more flexible molecule with an increased affinity for PS, but does not undergo a structural transition in response to binding PtdIns(3,4,5)P3. In conclusion, the present study provides new insights into the structural and lipid-binding properties of JP2 and how the S101R mutation may have an effect upon the stability of the dyad organization with the potential to alter JP2-protein interactions regulating Ca(2+) cycling.

Structure, material characteristics and function of the upper respiratory tract of the pygmy sperm whale.

Cetaceans are neckless, so the trachea is very short. The upper respiratory tract is separate from the mouth and pharynx, and the dorsal blowhole connects, via the vestibular and nasopalatine cavities, directly to the larynx. Toothed cetaceans (Odontoceti) are capable of producing sounds at depth, either for locating prey or for communication. It has been suggested that during dives, air from the lungs and upper respiratory tract can be moved to the vestibular and nasal cavities to permit sound generation to continue when air volume within these cavities decreases as ambient pressure rises. The pygmy sperm whale, Kogia breviceps, is a deep diver (500-1000 m) that is known to produce hunting clicks. Our study of an immature female shows that the upper respiratory tract is highly asymmetrical: the trachea and bronchi are extremely compressible, whereas the larynx is much more rigid. Laryngeal and tracheal volumes were established. Calculations based on Boyle's Law imply that all air from the lungs and bronchi would be transferred to the larynx and trachea by a depth of 270 m and that the larynx itself could not accommodate all respiratory air mass at a depth of 1000 m. This suggests that no respiratory air would be available for vocalisation. However, the bronchi, trachea and part of the larynx have a thick vascular lining featuring large, thin-walled vessels. We propose that these vessels may become dilated during dives to reduce the volume of the upper respiratory tract, permitting forward transfer of air through the larynx.

A comparative study of the speeds attained by captive cheetahs during the enrichment practice of the "cheetah run".

The enrichment practice of the "cheetah run" is becoming increasingly popular within zoological institutions as a method to enrich captive cheetahs. A lure moving at speed represents an artificial prey item that the cursorial cheetah can pursue, therefore allowing it to perform an important hunting behavior within a captive setting. This study was conducted in order to highlight how employing different forms of this type of enrichment may influence its efficacy. This is important in relation to the future development of an optimum type of "cheetah run" enrichment which maximizes the potential beneficial effects and therefore positively impacts upon cheetah welfare in captivity. Video recordings were carried out at three separate institutions (Fota Wildlife Park, Ireland; Ann van Dyk Cheetah Centre, South Africa; Cheetah Conservation Fund, Namibia). Randomization tests were carried out to compare the highest speeds attained between males and females, trained and untrained cheetahs and also between the three institutions. Females and trained individuals reached significantly higher speeds compared with males and untrained individuals, respectively. The only significant difference between the three institutions was between the Ann van Dyk Cheetah Centre and the Cheetah Conservation Fund, where cheetahs at the Ann van Dyk center reached significantly higher speeds. The current study represents the first detailed study of any aspect of the "cheetah run" across multiple institutions. It also includes the first quantification of the speed of cheetahs in captivity in relation to differing enrichment practices.

Food transport in Reptilia: a comparative viewpoint.

Reptilia exploit a large diversity of food resources from plant materials to living mobile prey. They are among the first tetrapods that needed to drink to maintain their water homeostasis. Here were compare the feeding and drinking mechanisms in Reptilia through an empirical approach based on the available data to open perspectives in our understanding of the evolution of the various mechanisms determined in these Tetrapoda for exploiting solid and liquid food resources. This article is part of the theme issue 'Food processing and nutritional assimilation in animals'.

Shape and material characteristics of the trachea in the leatherback sea turtle promote progressive collapse and reinflation during dives.

The leatherback turtle regularly undertakes deep dives and has been recorded attaining depths in excess of 1200 m. Its trachea is an almost solid, elliptical-section tube of uncalcified hyaline cartilage with minimal connective tissue between successive rings. The structure appears to be advantageous for diving and perfectly designed for withstanding repeated collapse and reinflation. This study applies Boyle's law to the respiratory system (lungs, trachea and larynx) and estimates the changes in tracheal volume during a dive. These changes are subsequently compared with the results predicted by a corresponding finite element (FE) structural model, itself based on laboratory studies of the trachea of an adult turtle. Boyle's law predicts that the lungs will collapse first during the initial stages of a dive with tracheal compression beginning at much deeper depths after complete air mass expulsion from the lungs. The FE model reproduces the changes extremely well (agreeing closely with Boyle's law estimations) and provides visual representation of the deformed tracheal luminal area. Initially, the trachea compresses both ventrally and dorsally before levelling ventrally. Bulges are subsequently formed laterally and become more pronounced at deeper depths. The geometric configuration of the tracheal structure confers both homogeneity and strength upon it, which makes it extremely well suited for enduring repeated collapse and re-expansion. The structure actually promotes collapse and is an adaptation to the turtle's natural environment in which large numbers of deep dives are performed annually.

Pleated turtle escapes the box--shape changes in Dermochelys coriacea.

Typical chelonians have a rigid carapace and plastron that form a box-like structure that constrains several aspects of their physiology and ecology. The leatherback sea turtle, Dermochelys coriacea, has a flexible bony carapace strengthened by seven longitudinal ridges, whereas the plastron is reduced to an elliptical outer bony structure, so that the ventrum has no bony support. Measurements of the shell were made on adult female leatherbacks studied on the feeding grounds of waters off Nova Scotia (NS) and on breeding beaches of French Guiana (FG) to examine whether foraging and/or breeding turtles alter carapace size and/or shape. NS turtles exhibited greater mass and girth for a given curved carapace length (CCL) than FG turtles. Girth:CCL ratios rose during the feeding season, indicating increased girth. Measurements were made of the direct (straight) and surface (curved) distances between the medial longitudinal ridge and first right-hand longitudinal ridge (at 50% CCL). In NS turtles, the ratio of straight to curved inter-ridge distances was significantly higher than in FG turtles, indicating distension of the upper surfaces of the NS turtles between the ridges. FG females laid 11 clutches in the breeding season; although CCL and curved carapace width remained stable, girth declined between each nesting episode, indicating loss of mass. Straight to curved inter-ridge distance ratios did not change significantly during the breeding season, indicating loss of dorsal blubber before the onset of breeding. The results demonstrate substantial alterations in size and shape of female D. coriacea over periods of weeks to months in response to alterations in nutritional and reproductive status.

"Not a whole woman": an interpretative phenomenological analysis of the lived experience of women's body image and sexuality following amputation.

Background: Lower-limb amputations can lead to depression, performance anxiety, altered body image, relationships and sexual well-being. However, there is little published literature investigating how people experience changes to body image and their sexuality post-amputation and minimal literature exploring sexuality specifically from the female perspective post-amputation.Purpose: To gain an in-depth understanding of women's experience of sexuality and body image following amputation of a lower limb to inform rehabilitation and clinical practice.Method: Semi-structured interviews with female amputees (n = 9) were conducted to collect rich contextual data. This qualitative data was analysed using Interpretative Phenomenological Analysis (IPA).Results: Three superordinate themes emerged from IPA data analysis: "I don't like the way I am", which illustrated participants' changed relationship with their embodied selves, "Broken/not wanted" which reflected changes participants experienced in their romantic relationships, and "Same but different" which related to participants' changed societal roles as women.Discussion: Participants' accounts highlighted experiences of decreased sexual well-being, disrupted body image, stigmatisation and resilience. These accounts point to the potential utility of compassion focused approaches in therapeutic intervention, as well as the necessity for health professionals to involve spouses in sexual rehabilitation conversations and encourage patient-led peer support networks.Implications for rehabilitationPsychosexual assessment following limb loss involving open-ended questions will likely capture issues of sexual well-being as well as functioning, ensuring that interventions are comprehensive, targeted and relevant to the individual.Women struggle with reconciling their post-amputation kinetic representations of their selves to new ways of functioning, which may impact body image and prosthesis uptake.Compassion focused psychotherapeutic interventions could be effective in addressing problematic coping strategies post-amputation such as avoidance and disengagement while enhancing more self-compassionate coping styles.Couples distressed about their relationship may not engage in problem-solving discussions around sexuality, highlighting the necessity for health professionals to involve spouses in sexual rehabilitation conversations and interventions.Supporting the creation of gendered, peer-led groups to address issues related to sexual well-being is likely to improve overall quality of life for these individuals.