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A 54-year-old man was referred to the Princess of Wales Hospital, Bridgend, United Kingdom, for evaluation of corneal opacities found on routine eye examination. He was asymptomatic and had no history of contact lens wear. Past ophthalmic, medical, and drug history were unremarkable. Of note, the patient reported having taken various brands of multivitamins over the preceding 3 years. He did not smoke tobacco, but he had a history of smoking cannabis in the past. He denied alcohol excess. The patient reported that his siblings and mother all had recent eye examinations and no signs of corneal opacities. His mother denied drug use during pregnancy. The patient was observed over a period of 2 months, with no change in appearance of the stromal opacities.

Aims The significance of the ‘clicky hip’ in neonatal and infant examination remains controversial with recent conflicting papers reigniting the debate. We aimed to quantify rates of developmental dysplasia of the hip (DDH) in babies referred with ‘clicky hips’ to our dedicated DDH clinic. Patients and Methods A three-year prospective cohort study was undertaken between 2014 and 2016 assessing the diagnosis and treatment outcomes of all children referred specifically with ‘clicky hips’ as the primary reason for referral to our dedicated DDH clinic. Depending on their age, they were all imaged with either ultrasound scan or radiographs. Results There were 69 ‘clicky hip’ referrals over the three-year period. This represented 26.9% of the total 257 referrals received in that time. The mean age at presentation was 13.6 weeks (1 to 84). A total of 19 children (28%) referred as ‘clicky hips’ were noted to have hip abnormalities on ultrasound scan, including 15 with Graf Type II hips (7 bilateral), one Graf Type III hip, and three Graf Type IV hips. Of these, ten children were treated with a Pavlik harness, with two requiring subsequent closed reduction in theatre; one child was treated primarily with a closed reduction and adductor tenotomy. In total, 11 (15.9%) of the 69 ‘clicky hip’ referrals required intervention with either harness or surgery. Conclusion Our study provides further evidence that the ‘clicky hip’ referral can represent an underlying diagnosis of DDH and should, in our opinion, always lead to further clinical and radiological assessment. In the absence of universal ultrasound screening, we would encourage individual units to carefully assess their own outcomes and protocols for ‘clicky hip’ referrals and tailor ongoing service provision to local populations and local referral practices. Cite this article: Bone Joint J 2018;100-B:1249–52.

The ability to control the mechanical properties of cell culture environments is known to influence cell morphology, motility, invasion and differentiation. The present work shows that it is possible to control the mechanical properties of collagen gels by manipulating gelation conditions near the sol gel transition. This manipulation is accomplished by performing gelation in two stages at different temperatures. The mechanical properties of the gel are found to be strongly dependent on the duration and temperature of the first stage. In the second stage the system is quickly depleted of free collagen which self assembles into a highly branched network characteristic of gelation at the higher temperature (37 °C). An important aspect of the present work is the use of advanced rheometric techniques to assess the transition point between viscoelastic liquid and viscoelastic solid behaviour which occurs upon establishment of a sample spanning network at the gel point. The gel time at the stage I temperature is found to indicate the minimum time that the gelling collagen sample must spend under stage I conditions before the two stage gelation procedure generates an enhancement of mechanical properties. Further, the Fractional Maxwell Model is found to provide an excellent description of the time-dependent mechanical properties of the mature collagen gels.

This fundus photograph (fig 1) shows a branch retinal vein occlusion in a 34 year old woman. She presented with four …

A laboratory characterization of cohesive sediment has been carried out in which data obtained from standard sedimentation and rheological measurements were combined in a determination of the critical solid concentration for the detection of elasticity in a weakly cohesive suspension. The corresponding storage modulus and shear stress are very critical in any in situ rheometry of sediments, especially in the study of mud-water surface erosion in a flume. Sedimentation results showed that particle size distribution rather than surface treatment controlled the rheological behavior of the suspension while the critical solid concentration for the appearance of three-dimensional space-filling network, showing some measurable elasticity in the suspension, occurred in the region of 0.015. This parallel between the consolidation behavior and shear rheology development for the flocculating system has been established. This technique could be an adjunct to the laboratory characterization of cohesive sediments for the estimation of critical shear stress for surface erosion, especially in a typical flume experiment under water wave pressure.

We report simulations of the formation of a giant disc galaxy from cosmological initial conditions. Two sets of initial conditions are used, initially smooth density for both gas and stars, representing the Warm dark Matter scenario, and an initially fluctuating density representing the standard spectrum for the Cold dark Matter scenario. For the WDM initial conditions, the galaxy has a population of long lived dwarf satellites at z = 0, with orbits close to a plane coincident with that of the giant galaxy disc. The detailed properties of these dwarfs mimic closely the observed properties of Local Group dwarfs with respect to mass, and kinematics. However they do not have individual dark matter halos, but orbit in the nearly spherical dark matter halo of the giant galaxy. The reason for this is that the initial population of dwarf dark matter haloes, which form during the initial collapse phase, all merge into the halo of the giant galaxy within a few to several Gyears, while the long lived dwarfs form as a secondary population by gravitational collapse of high angular momentum gas in the outer reaches of the giants proto-galactic disc. Due to their late formation and their more distant orbits, they survive until the present epoch as individual dwarf galaxies at radii 20-50kpc from the giants centre. For CDM initial conditions there are many more dwarf satellites at z = 0, some of which form early on as gas condensations in DM sub-halos, and survive with these individual DM halos till z = 0 due to their being sufficiently well bound to avoid merging with the main galaxy. However even in this case some second generation satellites form as initially gas only objects, just as for the smooth initial conditions of WDM.

To report on the complications associated with the use of intravitreal triamcinolone acetonide (IVTA) in a tertiary referral hospital setting. A retrospective case series review of all IVTA injections carried out over a period of 30 months. One hundred and thirty IVTA injections were performed; nine with limited local follow-up were excluded. Thus, 121 injections (108 patients, 114 eyes) were included in the study. Triamcinolone (4 mg) was used in all cases. Indications were diabetic macular oedema (n=41 eyes), retinal vein occlusions (n=27), postoperative cystoid macular oedema (n=24), exudative age-related macular degeneration (n=16), and others (n=6). No intraoperative complications were recorded. Postoperative intraocular pressure (IOP) readings of 22, 28, 35, and 40 mmHg or higher were recorded in 46.5, 29.8, 12.3, and 7.9% of eyes, respectively. IOP elevation was treated with antiglaucoma medication in all but one eye (0.9%) that required trabeculectomy and one (0.9%) that required vitrectomy with cataract extraction for suspected phacoanaphylactic glaucoma. Two eyes (1.8%) developed retinal detachment; both had previously been treated for retinal breaks. One eye (0.9%) developed culture-positive endophthalmitis. Significant morbidity is associated with IVTA injection; clinicians should be aware when considering treatment options.

Of all the large interferometric gravitational-wave detectors, the German/British project GEO600 is the only one which uses dual recycling. During the four weeks of the international S4 data-taking run it reached an instrumental duty cycle of 97% with a peak sensitivity of 7 × 10-22 Hz-1/2 at 1 kHz. This paper describes the status during S4 and improvements thereafter.

The problems and challenges involved in in situ measurement of dynamic mechanical properties of non-rigid mud bed under water wave pressure have been investigated. A detailed preliminary investigation on a natural mud was carried out in a flume-generating monochromatic water waves at a fixed frequency in which dynamic bulk density profile, water turbidity and viscoelastic parameters from the bed response to plane shear waves, were measured with a specially designed measuring device. The device, which is based on the analysis of the characteristics of shear wave field generated within the mud bed, was used in situ at a frequency of 619 Hz. The effect of water wave pressure on the bed was picked up at a fixed location in the form of shear wave pattern for analysis using Fast Fourier Signal Processing technique. The shear wave velocity through the mud and the phase difference between shear stress and shear strain at the wave-generating surface of the device were simultaneously measured. A phase angle of about 18° was obtained for the mud with evidence of bed weakening by up to 57% within the surface wave amplitude that showed no mud surface erosion. The problems inherent in carrying out this type of investigation are also discussed alongside the result obtained that demonstrated the capability of this technique in this type of application.

This paper discusses the differences between the results of various measurements of the effective tensile strength (F c ) of liquids in experiments involving a pulse of tension (‘negative pressure’) created by the reflection of a pressure pulse at a boundary. Using a modified ‘bullet-piston’ (B-P) pulse reflection apparatus, measurements presented herein show that degassed, deionized water is capable of sustaining tensions an order of magnitude greater than previously reported in B-P work. Results are also reported for a series of Newtonian silicone oils which show a similar dependence of F c on the shear viscosity (μ) as a previous study though the absolute values of F c are greater.

Purpose: To determine whether topical ketorolac (Acular) is more effective than artificial tears in treating the signs and symptoms of idiopathic episcleritis. Methods: In this prospective, randomised, double-blind study, 38 eyes of 37 patients presenting with idiopathic episcleritis were allocated to receive either topical ketorolac (0.5%) or artificial tears three times a day for 3 weeks. The severity of patients' signs (episcleral injection and the number of clock hours affected) were recorded at weekly intervals. Patients' symptoms (perceived redness and pain scores) were recorded using a daily diary. Results: There was no significant difference in the ophthalmic signs between the two groups at each assessment, including intensity of episcleral injection and the number of clock hours affected. No significant difference was found in the time to halve the baseline redness intensity scores (4.4 vs 6.1 days, P=0.2) or pain scores (3.6 vs 4.3 days, P=0.55). Significantly more patients on ketorolac reported stinging at the first follow-up visit (P Conclusion: Topical ketorolac is not significantly better than artificial tears in treating the signs or symptoms of idiopathic episcleritis.

The GEO 600 laser interferometer with 600 m armlength is currently being commissioned as a part of a worldwide network of gravitational wave detectors. Due to the use of advanced technologies such as signal recycling and multiple pendulum suspensions with a monolithic last stage the anticipated sensitivity of GEO 600 is close to the initial sensitivity of km baseline detectors. This paper describes the status of the detector as of November 2003 with special emphasis on its performance during the first serious data-taking periods and on the experimental challenges encountered during the commissioning of the dual-recycled detector.

This paper reports the first measurements of the effective tensile strength (or ‘cavitation threshold’) Fc, of degassed samples of a commercial multigrade engine oil over a range of temperatures, T, which are representative of those encountered under normal automotive engine operating conditions (in the range 20° C ≤ T ≤ 140°C). Also reported are the values of Fc obtained for Newtonian silicone oils over a range of shear viscosities. In the experiments reported herein, samples of liquid are subjected to dynamic stressing by a rapid pressure—tension cycle, this being a feature of the conditions experienced by an engine oil within a dynamically loaded journal bearing. The method used herein to estimate Fc avoids reliance upon direct measurements of substantial dynamic negative pressures using transducers which are designed for use in the range of positive pressures.

This paper addresses discrepancies between the results of different measurements of the effective tensile strength (Fc) of liquids, in experiments in which a pulse of tension (or `negative pressure') is created by the reflection of a pressure pulse at a suitable boundary. We show that a key feature of the pressure records previously reported in such experiments may have been misinterpreted. The first complete account of such pressure records reported here offers an explanation for the order-of-magnitude discrepancies in Fc which arise in work involving instruments such as the `Bullet-Piston' (B-P) pulse-reflection apparatus (Temperley H N V and Trevena D H 1987 J. Phys. D: Appl. Phys. 20 1080). We also report a new method of estimating Fc in a modified B-P apparatus and the results obtained indicate that samples of degassed, deionized water can sustain tensions which are an order-of-magnitude greater than previously reported in B-P work. Results are also reported for work involving samples of Newtonian silicone oils, for which the dependence of Fc on shear viscosity, µ, found in this work confirms that of an earlier study although the absolute values of Fc are found to be considerably greater than previously reported.

A simulation is described in which the numerical galaxy formed compares favourably in every measurable respect with contemporary bright spiral galaxies, including the formation of a distinct stellar bulge and large scale spiral arm shocks in the gas component. This is achieved in spite of the fact that only idealized proto{galactic initial conditions were used, and only simple phenomenological prescriptions for the physics of the interstellar medium (ISM) and star formation were implemented. In light of the emphasis in recent literature on the importance of the link between galaxy formation and models of the universe on cosmological scales, on the details of the physics of the ISM and star formation, and on apparent problems therein, the implications of this result are discussed.

This paper describes experiments in which a shock wave, emanating from the collapse of a cavitation bubble, causes a second bubble to collapse, thereby producing a liquid jet. A comparison of the jets formed by bubble collapse in dilute solutions of polyacrylamide and polyethylene oxide, and in their Newtonian counterparts, shows that in the polymer solutions liquid jet development is markedly suppressed. The implications of these findings are discussed in the context of cavitation damage.

We describe a microprocessor-controlled rheometer is described in which resonance-bandwidth and (separate) pulse-velocity measurements yield the complex shear modulus, G * , of systems undergoing gelation. The underlying theory is shown to be appropriate to systems characterized at the gel point by a frequency independent loss tangent. Here the usual limitations of resonance-bandwidth measurements are avoided and a correction factor for viscoelastic-dispersion errors in pulse measurements is obtained. Preliminary results for a gel system are presented.

Between January 1987 and December 1988 there were 7575 births in the Swansea maternity unit. Of these 823 (10.9%) were considered to be at ‘high risk’ for developmental dysplasia of the hip (DDH). Static ultrasound examination was performed in each case and the results classified on the basis of the method of Graf. A total of 117 type III–IV hips in 83 infants was splinted using the Aberdeen splint. Radiographs of these hips were taken at six and 12 months. Hilgenreiner’s measurements of the acetabular angle were made in all cases and the development of the femoral capital epiphysis was assessed by measuring the epiphyseal area. The effect of splintage on the acetabular angle and the epiphyseal area between the normal and abnormal splinted hips was compared. Radiographs of 16 normal infants (32 normal unsplinted hips) were used as a control group. This cohort has now been followed up for a minimum of nine years. There have been no complications as a result of splintage. The failure rate was 1.7% or 0.25 per 1000 live births. No statistical difference was found when comparing the effect of splintage on the acetabular angle and epiphyseal area between normal and abnormal splinted hips and normal unsplinted hips. Our study has shown that while the Aberdeen splint had a definite but small failure rate, it was safe in that it did not produce avascular necrosis. The current conventional view that a low rate of splintage is always best is therefore brought into question if the Aberdeen splint is chosen for the management of neonatal DDH.

It is shown that a mechanical stress relaxation spectrum may be obtained directly from measurements of the dispersion of shear waves in viscoelastic media. The effectiveness of this spectrum, in terms of its sensitivity and accuracy in parametrizing distributions of stress relaxation in the frequency domain, is demonstrated with reference to several published spectra. Of the three different forms of stress relaxation spectrum which may be obtained directly from oscillatory shear measurements, only that based on the group and phase velocities of shear waves is found adequate in terms of sensitivity to the presence of adjacent relaxation mechanisms in the systems considered herein.

An instrument which exploits the `tube-arrest' technique of subjecting a column of liquid to tension by dynamic stressing is described. In this apparatus two tension pulses are produced, one ab initio within the liquid, the other by free-surface reflection of a cavitation-generated shock wave. A method of deriving the tensile strength of a liquid from measurements of the velocity of these pulses is presented, and previous assumptions concerning the origin of tension in the `tube-arrest' technique are critically examined. The initial tension pulse is shown not to arise at the bottom of the liquid column as has been assumed hitherto, and the means by which cavitation is exploited to study the production of liquid jets by shock wave-bubble interaction are explained.

A study of viscoelastic shear wave dispersion in a simulated gelation process involving mechanically self-similar nodal networks is reported. The network formed at the gel point (the infinite network cluster, or `critical gel') shares a common structural feature of smaller network clusters and the onset of a recognizably `gel-like' feature is shown to occur when the characteristic wavelength of the network cluster becomes twice that of an individual node. It is shown that, during gelation, the dispersion of shear waves can be exploited to assess the proximity of a system to an equivalent `critical gel' state at any single frequency, thereby identifying the smallest length scale at which gel-like characteristics are established prior to the gel point. In this way, and for the first time, a rheometrical basis is established for examining the gel-like, self-similar characteristics of pre-gel point viscoelastic liquid systems, in terms of the gel equation but in the absence of a frequency-independent loss tangent. Experiments are reported for a critical gel in which the high-frequency wave dispersion is in good agreement with theory.

In Duketon, a mafic‐dominated rock sequence surrounds a felsic‐epiclastic rock sequence. D1 L‐S tectonites in the ma = fic‐dominated sequence are absent from the felsic rocks suggesting that these epiclastics were deposited post‐D1, on top of older greenstones. In the older greenstones, the linear shape of the Christmas Well orebody, together with auriferous quartz veins deformed by L‐S tectonites in the mineralised corridor through Hack Well, implies that the D1 fabric‐forming event strongly influenced the shape of the orebodies and probably the timing of mineralisation.

An experimental study of the origin and hitherto unexplored structure of the pressure - tension cycles accompanying the cavitation of liquids under dynamic stressing by tension is presented. The results of this study are relevant to certain problems in engineering and medicine, and the potential for application of the improved `tube-arrest' apparatus described here to those fields is considered.

The use of intravitreal vascular endothelial growth factor (VEGF) inhibitor medications has widened considerably to include indications affecting females of reproductive age. We present our experiences following intravitreal injection of bevacizumab during the first trimester of unrecognised pregnancies in four women. All our patients were inadvertently exposed to bevacizumab within the first trimester when placental growth and fetal organogenesis take place. There were three cases of pregnancy without complication and one case of complicated pregnancy in which there was a significant past obstetric history. This case series provides further insights into intravitreal injection of bevacizumab in early pregnancy. There is insufficient information to suggest that such use is safe, nor is there definitive evidence to suggest that it causes harm. We advise that ophthalmologists discuss pregnancy with women of childbearing age undergoing intraocular anti-VEGF injections. Should a woman become pregnant, counselling is needed to explain the potential risks and benefits, and the limited available data relating to the use of these agents in early pregnancy.

A new technique involving high-frequency shear wave interferometry has been used to investigate the viscoelastic properties of gels formed from aqueous dispersions of a synthetic hectorite-type clay colloid. The technique facilitates studies of stress relaxation phenomena under a range of strains and strain rates, in both linear and nonlinear deformation regimes. Measurements of the group and phase velocities of frequency-multiplexed shear waves, conducted in the presence and absence of steady shear fields, provide visco elastic-solid-like relaxation spectra. Under shear, the relaxation spectra indicate a trend to fluidization of the system as shear rate increases. A viscoelastic solid model is used to interpret the wave dispersion and the results, which constitute the first rheometrical exploitation of the `beat' phenomenon, support conclusions drawn from light scattering and small-angle neutron scattering studies concerning the origin of viscoelasticity in this system.