Culture, diversity and inclusion: a survey of British Hip Society members.

AIM: To explore the perceptions and experiences of members of the British Hip Society (BHS) as they relate to culture, diversity and inclusion in the professional sphere. METHOD: BHS members participated in an anonymised online survey in 2021. Quantitative and qualitative data were collected on demographics, professional experiences and perceptions of workplace culture. Members provided suggestions for improving working culture and supporting inclusivity. RESULTS: A 45% response rate (n=217) was achieved. Most respondents were male consultant surgeons, of white ethnicity. Almost a quarter of respondents reported experiencing barriers to career progression within the hip subspecialty. Experience of barriers was more common among women and those of non-white ethnicity. Several members experienced an elitist, exclusive culture in the BHS which is closed to outsiders. Thematic analysis of textual data revealed narratives which portray the perception of the society as a closed-door society, and described a clique culture in orthopaedics, and the pervasiveness of discrimination and banter. CONCLUSION: We found that barriers to inclusion and diversity exist within the professional society. Exploring the narratives around these has informed strategies to overcome them and has shaped future BHS initiatives. To ensure our patients receive the best possible surgical care, it is vital that those with the skills and expertise to deliver it, are supported by the Society and feel a sense of belonging and representation.

Time-integral iteration method for two-dimensional anomalous transport.

A methodology is developed to describe time-dependent phenomena associated with nonlocal transport in complex, two-dimensional geometries. It is an extension of the ''iterative method" introduced previously to solve steady-state transport problems [Maggs and Morales, Phys. Rev. E 99, 013307 (2019)10.1103/PhysRevE.99.013307], and it is based on the ''jumping particle" concepts associated with the continuous-time random walk (CTRW) model. The method presented explicitly evaluates the time integral contained in the CTRW master equation. A modified version of the Mittag-Leffler function is used for the waiting-time probability distributions to incorporate memory effects. Calculations of the propagation of ''anomalous transport waves" in various systems, with and without memory, illustrate the technique.

Nonlocal transport in bounded two-dimensional systems: An iterative method.

The concept of transport mediated through the dynamics of "jumping" particles is used to develop an iterative method for obtaining steady-state solutions to the nonlocal transport equation in two dimensions. The technique is self-adjoint and capable of correctly treating spatially nonuniform, asymmetric systems. An appropriate reduced version of the iteration method is used to compare with results obtained with a self-adjoint one-dimensional transport matrix approach [Maggs and Morales, Phys. Rev. E 94, 053302 (2016)10.1103/PhysRevE.94.053302]. The transport "jump" probability distribution functions are based on Lévy α-stable distributions. The technique can handle the entire Lévy α-parameter range from one (Lorentz distributions) to two (Gaussian distributions). Cases with α=2 (standard diffusion) are used to establish the validity of the iterative method. The capabilities of the iterative method are demonstrated by presenting examples from systems with various source configurations, boundary shapes, boundary conditions, and spatial variations in parameters.

Confirmation of specificity of reactivity in a solid phase ELISA for the detection of hepatitis E viral antigen improves utility of the assay.

Genotype 3 hepatitis E virus (HEV) can lead to persistent infections in immunocompromised hosts. A recently available commercial assay for the detection of HEV antigen (HEV-Ag ELISA, Wantai diagnostics) may enable the study of HEV-Ag dynamics in such persistent infections, however currently there is no confirmatory test available. We generated a putative neutralising reagent from a pool of four convalescent blood donor samples and explored neutralising activity against HEV antigens from clinical samples, HEV tissue-culture and virus-like particles. Using this neutralisation method we were able to differentiate true reactivity from non-specific reactivity in plasma, stool and urine samples. This could also facilitate the introduction of HEV-Ag detection as a screening assay or the study of HEV-Ag in different body fluids.

United Kingdom national paediatric bilateral project: Results of professional rating scales and parent questionnaires.

OBJECTIVES: This fourteen-centre project used professional rating scales and parent questionnaires to assess longitudinal outcomes in a large non-selected population of children receiving simultaneous and sequential bilateral cochlear implants. METHODS: This was an observational non-randomized service evaluation. Data were collected at four time points: before bilateral cochlear implants or before the sequential implant, one year, two years, and three years after. The measures reported are Categories of Auditory Performance II (CAPII), Speech Intelligibility Rating (SIR), Bilateral Listening Skills Profile (BLSP) and Parent Outcome Profile (POP). RESULTS: Thousand and one children aged from 8 months to almost 18 years were involved, although there were many missing data. In children receiving simultaneous implants after one, two, and three years respectively, median CAP scores were 4, 5, and 6; median SIR were 1, 2, and 3. Three years after receiving simultaneous bilateral cochlear implants, 61% of children were reported to understand conversation without lip-reading and 66% had intelligible speech if the listener concentrated hard. Auditory performance and speech intelligibility were significantly better in female children than males. Parents of children using sequential implants were generally positive about their child's well-being and behaviour since receiving the second device; those who were less positive about well-being changes also generally reported their children less willing to wear the second device. CONCLUSION: Data from 78% of paediatric cochlear implant centres in the United Kingdom provide a real-world picture of outcomes of children with bilateral implants in the UK. This large reference data set can be used to identify children in the lower quartile for targeted intervention.

United Kingdom national paediatric bilateral project: Demographics and results of localization and speech perception testing.

OBJECTIVES: To assess longitudinal outcomes in a large and varied population of children receiving bilateral cochlear implants both simultaneously and sequentially. METHODS: This observational non-randomized service evaluation collected localization and speech recognition in noise data from simultaneously and sequentially implanted children at four time points: before bilateral cochlear implants or before the sequential implant, 1 year, 2 years, and 3 years after bilateral implants. No inclusion criteria were applied, so children with additional difficulties, cochleovestibular anomalies, varying educational placements, 23 different home languages, a full range of outcomes and varying device use were included. RESULTS: 1001 children were included: 465 implanted simultaneously and 536 sequentially, representing just over 50% of children receiving bilateral implants in the UK in this period. In simultaneously implanted children the median age at implant was 2.1 years; 7% were implanted at less than 1 year of age. In sequentially implanted children the interval between implants ranged from 0.1 to 14.5 years. Children with simultaneous bilateral implants localized better than those with one implant. On average children receiving a second (sequential) cochlear implant showed improvement in localization and listening in background noise after 1 year of bilateral listening. The interval between sequential implants had no effect on localization improvement although a smaller interval gave more improvement in speech recognition in noise. Children with sequential implants on average were able to use their second device to obtain spatial release from masking after 2 years of bilateral listening. Although ranges were large, bilateral cochlear implants on average offered an improvement in localization and speech perception in noise over unilateral implants. CONCLUSION: These data represent the diverse population of children with bilateral cochlear implants in the UK from 2010 to 2012. Predictions of outcomes for individual patients are not possible from these data. However, there are no indications to preclude children with long inter-implant interval having the chance of a second cochlear implant.

Self-adjoint integral operator for bounded nonlocal transport.

An integral operator is developed to describe nonlocal transport in a one-dimensional system bounded on both ends by material walls. The "jump" distributions associated with nonlocal transport are taken to be Lévy α-stable distributions, which become naturally truncated by the bounding walls. The truncation process results in the operator containing a self-consistent, convective inward transport term (pinch). The properties of the integral operator as functions of the Lévy distribution parameter set [α,γ] and the wall conductivity are presented. The integral operator continuously recovers the features of local transport when α=2. The self-adjoint formulation allows for an accurate description of spatial variation in the Lévy parameters in the nonlocal system. Spatial variation in the Lévy parameters is shown to result in internally generated flows. Examples of cold-pulse propagation in nonlocal systems illustrate the capabilities of the methodology.

The upgraded Large Plasma Device, a machine for studying frontier basic plasma physics.

In 1991 a manuscript describing an instrument for studying magnetized plasmas was published in this journal. The Large Plasma Device (LAPD) was upgraded in 2001 and has become a national user facility for the study of basic plasma physics. The upgrade as well as diagnostics introduced since then has significantly changed the capabilities of the device. All references to the machine still quote the original RSI paper, which at this time is not appropriate. In this work, the properties of the updated LAPD are presented. The strategy of the machine construction, the available diagnostics, the parameters available for experiments, as well as illustrations of several experiments are presented here.

The Exeter Contemporary flanged cemented acetabular component in primary total hip arthroplasty.

AIMS: We report on the outcome of the Exeter Contemporary flanged cemented all-polyethylene acetabular component with a mean follow-up of 12 years (10 to 13.9). This study reviewed 203 hips in 194 patients. 129 hips in 122 patients are still in situ; 66 hips in 64 patients were in patients who died before ten years, and eight hips (eight patients) were revised. Clinical outcome scores were available for 108 hips (104 patients) and radiographs for 103 hips (100 patients). PATIENTS AND METHODS: A retrospective review was undertaken of a consecutive series of 203 routine primary cemented total hip arthroplasties (THA) in 194 patients. RESULTS: There were no acetabular component revisions for aseptic loosening. Acetabular revision was undertaken in eight hips. In four hips revision was necessitated by periprosthetic femoral fractures, in two hips by recurrent dislocation, in one hip for infection and in one hip for unexplained ongoing pain. Oxford and Harris hip scores demonstrated significant clinical improvement (all p < 0.001). Radiolucent lines were present in 37 (36%) of the 103 acetabular components available for radiological evaluation. In 27 of these, the line was confined to zone 1. No component had migrated. CONCLUSION: Kaplan-Meier survivorship, with revision for aseptic loosening as the endpoint, was 100% at 12.5 years and for all causes was 97.8% (95% confidence interval 95.6 to 100) when 40 components remained at risk. The Exeter Contemporary flanged cemented acetabular component demonstrates excellent survivorship at 12.5 years. TAKE HOME MESSAGE: The Exeter Contemporary flanged cemented acetabular component has excellent clinical outcomes and survivorship when used with the Exeter stem in total hip arthroplasty.

Laboratory study of avalanches in magnetized plasmas.

It is demonstrated that a novel heating configuration applied to a large and cold magnetized plasma allows the study of avalanche phenomena under controlled conditions. Intermittent collapses of the plasma pressure profile, associated with unstable drift-Alfvén waves, exhibit a two-slope power-law spectrum with exponents near -1 at lower frequencies and in the range of -2 to -4 at higher frequencies. A detailed mapping of the spatiotemporal evolution of a single avalanche event is presented.

Isotropic model of fractional transport in two-dimensional bounded domains.

A two-dimensional fractional Laplacian operator is derived and used to model nonlocal, nondiffusive transport. This integro-differential operator appears in the long-wavelength, fluid description of quantities undergoing non-Brownian random walks without characteristic length scale. To study bounded domains, a mask function is introduced that modifies the kernel in the fractional Laplacian and removes singularities at the boundary. Green's function solutions to the fractional diffusion equation are presented for the unbounded domain and compared to the one-dimensional Cartesian approximations. A time-implicit numerical integration scheme is presented to study fractional diffusion in a circular disk with azimuthal symmetry. Numerical studies of steady-state reveal temperature profiles in which the heat flux and temperature gradient are in the same direction, i.e., uphill transport. The response to off-axis heating, scaling of confinement time with system size, and propagation of cold pulses are investigated.

Modification of turbulent transport with continuous variation of flow shear in the large plasma device.

Continuous control over azimuthal flow and shear in the edge of the Large Plasma Device (LAPD) has been achieved using a biasable limiter which has allowed a careful study of the effect of flow shear on pressure-gradient-driven turbulence and transport in the LAPD. The LAPD rotates spontaneously in the ion diamagnetic direction; positive limiter bias first reduces, then minimizes (producing a near-zero shear state), and finally reverses the flow into the electron diamagnetic direction. Degradation of particle confinement is observed in the minimum shearing state and a reduction in the turbulent particle flux is observed with increasing shearing in both flow directions. Near-complete suppression of the turbulent particle flux is observed for shearing rates comparable to the turbulent autocorrelation rate measured in the minimum shear state. Turbulent flux suppression is dominated by amplitude reduction in low-frequency (<10 kHz) density fluctuations. An increase in fluctuations for the highest shearing states is observed with the emergence of a coherent mode which does not lead to net particle transport. The variations of density fluctuations are fit well with power laws and compare favorably to simple models of shear suppression of transport.

Origin of Lorentzian pulses in deterministic chaos.

Pulses having a temporal Lorentzian shape arise naturally from topological changes in flow trajectories or phase-space orbits associated with deterministic chaos. The pulses can appear as random intermittent events in the time series of observable quantities, and they are the cause of exponential frequency power spectra previously observed in magnetically confined plasmas and various nonlinear systems.

Systematic review: the role of liver transplantation in the management of hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is a major cause of morbidity and mortality worldwide. Liver transplantation offers a potential cure for this otherwise devastating disease. The selection of the most appropriate candidates is paramount in an era of graft shortage. AIM: To review systematically the role of liver transplantation in the management of HCC in current clinical practice. METHODS: An electronic literature search using PUBMED (1980-2010) was performed. Search terms included HCC, hepatoma, liver cancer, and liver transplantation. RESULTS: Liver transplantation is a highly successful treatment for HCC, in patients within Milan criteria (MC), defined as a solitary tumour ≤50 mm in diameter or ≤3 tumours ≤30 mm in diameter in the absence of extra-hepatic or vascular spread. Other eligibility criteria for liver transplantation are also used in clinical practice, such as the University of California, San Francisco criteria, with outcomes comparable to MC. Loco-regional therapies have a role in the bridging treatment of HCC by minimising wait-list drop-out secondary to tumour progression. Beyond MC, encouraging results have been demonstrated for patients with down-staged tumours. Post-liver transplantation, there is no evidence to support a specific immunosuppressive regimen. In the context of an insufficient cadaveric donor pool to meet demand, the role of adult living donation may be increasingly important. CONCLUSIONS: Liver transplantation offers a curative therapy for selected patients with HCC. The optimisation of eligibility criteria is paramount to ensure that maximum benefit is accrued. Although wait-list therapies have been incorporated into clinical practice, additional high quality data are required to support this strategy.

Generality of deterministic chaos, exponential spectra, and Lorentzian pulses in magnetically confined plasmas.

The dynamics of transport at the edge of magnetized plasmas is deterministic chaos. The connection is made by a previous survey [M. A. Pedrosa et al., Phys. Rev. Lett. 82, 3621 (1999)] of measurements of fluctuations that is shown to exhibit power spectra with exponential frequency dependence over a broad range, which is the signature of deterministic chaos. The exponential character arises from Lorentzian pulses. The results suggest that the generalization to complex times used in studies of deterministic chaos is a representation of Lorentzian pulses emerging from the chaotic dynamics.

Family needs of parents of children and youth with cerebral palsy.

BACKGROUND: Understanding the needs of families of children and youth with cerebral palsy (CP) is important for family-centred services. The aims of this study were to identify: (1) differences in the number and types of family needs expressed by parents based on the age and gross motor function level of their children with CP; (2) the most frequent family needs; and (3) needs that differ on gross motor function level. METHODS: A total of 501 parents (77.6% mothers) of children and youth with CP completed a modified version of a Family Needs Survey and a demographic questionnaire. Children's gross motor function level was classified using the Gross Motor Function Classification System. RESULTS: Total number of family needs differed based on gross motor function level (P < 0.001) but not age. Parents of children/youth who use wheeled mobility expressed the highest number of family needs, while parents of children/youth who walk without restrictions expressed the fewest needs. Family needs for Information (P= 0.001), Support (P= 0.001), Community Services (P < 0.001) and Finances (P < 0.001) differed based on children's gross motor function level. Over 50% of parents expressed family needs for information on current and future services, planning for the future, help in locating community activities and more personal time. Parents of children and youth who use wheeled mobility were more likely to express the need for help in paying for home modifications, equipment, services and locating sitters, respite care providers and community activities. CONCLUSIONS: The gross motor function of children/youth with CP has implications for collaboration with families to identify needs and co-ordinate services. Health professionals have a role to assist families with information needs and locating community services and leisure activities. Family needs for future planning suggest that health professionals should assist families to prepare for key periods in the lives of their children with CP.

Role of reactive metabolites in drug-induced hepatotoxicity.

Drugs are generally converted to biologically inactive forms and eliminated from the body, principally by hepatic metabolism. However, certain drugs undergo biotransformation to metabolites that can interfere with cellular functions through their intrinsic chemical reactivity towards glutathione, leading to thiol depletion, and functionally critical macromolecules, resulting in reversible modification, irreversible adduct formation, and irreversible loss of activity. There is now a great deal of evidence which shows that reactive metabolites are formed from drugs known to cause hepatotoxicity, such as acetaminophen, tamoxifen, isoniazid, and amodiaquine. The main theme of this article is to review the evidence for chemically reactive metabolites being initiating factors for the multiple downstream biological events culminating in toxicity. The major objectives are to understand those idiosyncratic hepatotoxicities thought to be caused by chemically reactive metabolites and to define the role of toxic metabolites.

Management of autoimmune liver disease.

The management of autoimmune liver disease can be very challenging. The presentation and natural history of these disorders is highly variable and can be asymptomatic, acute or chronic. Diagnosis requires the skilled interpretation of serological markers and histological changes and sometimes of biliary tract imaging. The major treatment options are immunosuppressive therapy (steroids and azathioprine) in autoimmune hepatitis (AIH) and ursodeoxycholic acid in cholestatic conditions although other treatments continue to be developed and tested. The complications of these diseases, in particular hepatocellular carcinoma and, in PSC, cholangiocarcinoma, remain difficult to monitor or prevent. Liver transplantation remains the only therapeutic option for end stage of liver disease and determining the optimum time for a patient to undergo this procedure requires a sophisticated judgment of the risks and benefits of the procedure as they pertain to an individual patient.

Spontaneous thermal waves in a magnetized plasma.

Coherent temperature oscillations corresponding to thermal (diffusion) waves are observed to be spontaneously excited in a narrow temperature filament embedded in a large, but colder, magnetized plasma. The parallel and transverse propagation properties of the waves satisfy the predictions of the classical transport theory based on Coulomb collisions. The frequency of the oscillations meets the conditions for a quarter-wave thermal resonator. This is the plasma version of thermal resonators used in the study of other states of matter.

Exponential frequency spectrum in magnetized plasmas.

Measurements of a magnetized plasma with a controlled electron temperature gradient show the development of a broadband spectrum of density and temperature fluctuations having an exponential frequency dependence at frequencies below the ion cyclotron frequency. The origin of the exponential frequency behavior is traced to temporal pulses of Lorentzian shape. Similar exponential frequency spectra are also found in limiter-edge plasma turbulence associated with blob transport. This finding suggests a universal feature of magnetized plasma turbulence leading to nondiffusive, cross-field transport, namely, the presence of Lorentzian shaped pulses.