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Ureteroscopy is a minimally invasive surgical procedure for the removal of kidney stones. A ureteroscope, containing a hollow, cylindrical working channel, is inserted into the patient's kidney. The renal space proximal to the scope tip is irrigated, to clear stone particles and debris, with a saline solution that flows in through the working channel. We consider the fluid dynamics of irrigation fluid within the renal pelvis, resulting from the emerging jet through the working channel and return flow through an access sheath. Representing the renal pelvis as a two-dimensional rectangular cavity, we investigate the effects of flow rate and cavity size on flow structure and subsequent clearance time of debris. Fluid flow is modelled with the steady incompressible Navier–Stokes equations, with an imposed Poiseuille profile at the inlet boundary to model the jet of saline, and zero-stress conditions on the outlets. The resulting flow patterns in the cavity contain multiple vortical structures. We demonstrate the existence of multiple solutions dependent on the Reynolds number of the flow and the aspect ratio of the cavity using complementary numerical simulations and particle image velocimetry experiments. The clearance of an initial debris cloud is simulated via solutions to an advection–diffusion equation and we characterise the effects of the initial position of the debris cloud within the vortical flow and the Péclet number on clearance time. With only weak diffusion, debris that initiates within closed streamlines can become trapped. We discuss a flow manipulation strategy to extract debris from vortices and decrease washout time.
The aim of this research was to look at the emergence of wearable technology and the internet of things (IoT) and their current and potential use in the health and care area. There is a wide and ever-expanding range of wearables, devices, apps, data aggregators and platforms allowing the measurement, tracking and aggregation of a multitude of health and lifestyle measures, information and behaviours. The use and application of such technology and the corresponding richness of data that it can provide bring the health and care insurance market both potential opportunities and challenges. Insurers across a range of fields are already engaging with this type of technology in their proposition designs in areas such as customer engagement, marketing and underwriting. However, it seems like we are just at the start of the journey, on a learning curve to find the optimal practical applications of such technology with many aspects as yet untried, tested or indeed backed up with quantifiable evidence. It is clear though that technology is only part of the solution, on its own it will not engage or change behaviours and insurers will need to consider this in terms of implementation and goals. In the first weeks of forming this working party, it became evident that the potential scope of this technology, the information already out there and the pace of development of it, is almost overwhelming. With many yet-unanswered questions the paper focuses on pulling together in one place relevant information for the consideration of the health and care actuary, and also to open the reader’s eyes to potential future innovations by drawing on use of the technology in other markets and spheres, and the “science fiction–like” new technology that is just around the corner. The paper explores:
an overview of wearables and IoT and available measures,
examples of how this technology is currently being used,
risks and challenges,
future technology developments and
what this may mean for the future of insurance.
Insurers who engage now are likely to be on an evolving business case model and product development journey, over which they can build up their understanding and interpretation of the data that this technology can provide. An exciting area full of potential – when and how will you get involved?
Background: Recent research has supported the efficacy of schema therapy as a treatment for personality disorders. A group format has been developed (group schema therapy; GST), which has been suggested to improve both the clinical and cost-effectiveness of the treatment. Aims: Efficacy studies of GST need to assess treatment fidelity. The aims of the present study were to improve, describe and evaluate a fidelity measure for GST, the Group Schema Therapy Rating Scale – Revised (GSTRS-R). Method: Following a pilot study on an initial version of the scale (GSTRS), items were revised and guidelines were modified in order to improve the reliability of the scale. Students highly experienced with the scale rated recorded GST therapy sessions using the GSTRS-R in addition to a group cohesion measure, the Harvard Community Health Plan Group Cohesiveness Scale – II (GCS-II). The scores were used to assess internal consistency and inter-rater reliability. Discriminant validity was assessed by comparing the scores on the GSTRS-R with the GCS-II. Results: The GSTRS-R displayed substantial internal consistency and inter-rater reliability, and adequate discriminate validity, evidenced by a weak positive correlation with the GCS-II. Conclusions: Overall, the GSTRS-R is a reliable tool that may be useful for evaluating therapist fidelity to GST model, and assisting GST training and supervision. Initial validity was supported by a weak association with GCS-II, indicating that although associated with cohesiveness, the instrument also assesses factors specific to GST. Limitations are discussed.
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.
Gyro-phase drift is a guiding center drift that is directly dependent on the charging rate limit of dust grains. The effect of introducing a gyro-phase-dependence on the grain charge leads to two orthogonal components of guiding-center drift. One component, referred to here as grad-q drift, results from the time-varying, gyro-phase angle dependent, in-situ-equilibrium grain charge, assuming that the grain charging is instantaneous. For this component, the grain is assumed to be always in its in-situ-equilibrium charge state and this state gyro-synchronously varies with respect to the grain's average charge state. The other component, referred to here as the gyro-phase drift, arises from any non-instantaneous-charging-induced modification of the diamagnetic drift and points in the direction of -∇RLd (where RLd is the grain gyro-radius), i.e. the direction associated with increasing magnitude of in-situ-equilibrium charge state. For this component, the grain gyro-synchronously undercharges and overcharges with respect to its gyro-synchronously varying, in-situ-equilibrium charge state. These characteristics are illustrated with a single-particle code for predicting grain trajectory that demonstrates how gyro-phase drift magnitude and direction could be exploited, using an extended version of the presented model, as sensitive indicators of the charging time of dust grains because of the cumulative effect of the ever-changing charge state of a grain making repeated excursions in inhomogeneous plasma over many gyro-periods.
If a magnetized-orbit-charged grain encounters any abrupt inhomogeneity in plasma conditions during a gyro-orbit, such that the resulting in-situ equilibrium charge is significantly different between these regions (q1/q2 ~ 2, where q1 is the in-situ equilibrium charge on one side of the inhomogeneity, q2 is the in-situ equilibrium charge on the other side, and q1 < q2 < 0), then the capacitive effects of charging and discharging of the dust grain can result in a modification to the orbit-averaged grain trajectory, i.e. gyro-phase drift. The special case of q1/q2 is notioned for the purpose of illustrating the utility of the method. An analytical expression is derived for the grain velocity, assuming a capacitor approximation to the OML charging model. For cases in which a strong electric field suddenly appears in the wake or at the space-plasma-to-crater interface from solar wind and/or ultraviolet illumination and in which a magnetic field permeates an asteroid, comet, or moon, this model could contribute to the interpretation of the distribution of fields and particles.
The neurocognitive deficits and other correlates of problem gambling are also observable in individuals with lower cognitive abilities, suggesting that a low IQ may be a determinant of problem gambling. There has been very little research into this possibility. This study aimed to investigate the characteristics associated with problem gambling in a large population-based study in England, with a particular focus on IQ.
The Adult Psychiatric Morbidity Survey (APMS) 2007 comprised detailed interviews with 7403 individuals living in private households in England. Problem gambling was ascertained using a questionnaire based on DSM-IV criteria. Verbal IQ was estimated using the National Adult Reading Test (NART). Confounders included socio-economic and demographic factors, common mental disorders, impulsivity, smoking, and hazardous drug and alcohol use.
More than two-thirds of the population reported engaging in some form of gambling in the previous year, but problem gambling was rare [prevalence 0.7%, 95% confidence interval (CI) 0.5–1.0]. The odds of problem gambling doubled with each standard deviation drop in estimated verbal IQ [adjusted odds ratio (OR) 2.1, 95% CI 1.3–3.4, p = 0.003], after adjusting for other characteristics associated with problem gambling including age, sex, socio-economic factors, drug and alcohol dependence, smoking, impulsivity and common mental disorders. There was no strong relationship observed between IQ and non-problem gambling.
People with lower IQs may be at a higher risk of problem gambling. Further work is required to replicate and study the mechanisms behind these findings, and may aid the understanding of problem gambling and inform preventative measures and interventions.
The Australian Square Kilometre Array Pathfinder (ASKAP) will give us an unprecedented opportunity to investigate the transient sky at radio wavelengths. In this paper we present VAST, an ASKAP survey for Variables and Slow Transients. VAST will exploit the wide-field survey capabilities of ASKAP to enable the discovery and investigation of variable and transient phenomena from the local to the cosmological, including flare stars, intermittent pulsars, X-ray binaries, magnetars, extreme scattering events, interstellar scintillation, radio supernovae, and orphan afterglows of gamma-ray bursts. In addition, it will allow us to probe unexplored regions of parameter space where new classes of transient sources may be detected. In this paper we review the known radio transient and variable populations and the current results from blind radio surveys. We outline a comprehensive program based on a multi-tiered survey strategy to characterise the radio transient sky through detection and monitoring of transient and variable sources on the ASKAP imaging timescales of 5 s and greater. We also present an analysis of the expected source populations that we will be able to detect with VAST.
Foraminiferal analyses of 404 contiguous samples, supported by diatom, lithologic, geochronologic and seismic data, reveal both rapid and gradual Holocene paleoenvironmental changes in an 8.21-m vibracore taken from southern Pamlico Sound, North Carolina. Data record initial flooding of a latest Pleistocene river drainage and the formation of an estuary 9000 yr ago. Estuarine conditions were punctuated by two intervals of marine influence from approximately 4100 to 3700 and 1150 to 500 cal yr BP. Foraminiferal assemblages in the muddy sand facies that accumulated during these intervals contain many well-preserved benthic foraminiferal species, which occur today in open marine settings as deep as the mid shelf, and significant numbers of well-preserved planktonic foraminifera, some typical of Gulf Stream waters. We postulate that these marine-influenced units resulted from temporary destruction of the southern Outer Banks barrier islands by hurricanes. The second increase in marine influence is coeval with increased rate of sea-level rise and a peak in Atlantic tropical cyclone activity during the Medieval Climate Anomaly. This high-resolution analysis demonstrates the range of environmental variability and the rapidity of coastal change that can result from the interplay of changing climate, sea level and geomorphology in an estuarine setting.
Strain field distribution in a naval platform under dry-dock conditions is complex and represents the cumulative response from residual stress (“locked in” during fabrication of materials and formation of the structure) and static loading stress (e.g., dry-dock loading). The magnitude and distribution of stress fields are a significant concern for the Canadian Navy, where the superposition of applied stresses on residual stresses may adversely affect the performance, safe operational envelope, and service life of naval platforms. Stress analysis was conducted on Canada’s VICTORIA Class submarines using a portable miniature X-ray diffractometer (mXRD) under dry-dock conditions. This paper introduces the concept of “residential stress” as it applies to submarine platforms and discusses the methodology for performing stress analysis with a portable mXRD. The evolution of residential stress during routine pressure hull repairs to Canada’s VICTORIA Class submarines is discussed. In particular, the recent replacement of the diesel exhaust hull and back-up valves on one of the submarines, as well as a pressure hull plate extraction-insertion-weld procedure on another, is discussed.
Significant deterioration to the historic expedition huts of the Ross Sea region of Antarctica has occurred during the past decades from exposure to the polar environment. One type of deterioration that has affected all of the huts is a chemical attack resulting in a defibration of wood. Wood surfaces have a rough, fuzzy appearance and consist of white to yellow-brown masses of detached fibers. The damage is commonly associated with areas where water with dissolved salts is absorbed by wood. As moisture evaporates from the wood surface, exceedingly high concentrations of salt accumulate. Chemical reactions within the wood cause a corrosive degradation on the middle lamella region of the woody cell wall (the area located between cells that cements them together) and may gradually degrade all cell-wall layers. As the deterioration progresses, cells continue to separate and the wood is converted into masses of detached and eroded wood fibers. In advanced stages of attack, the wood structure and integrity is severely compromised. This paper describes the defibration process, reports locations on Ross Island where the damage is severe, and discusses methods to control the problem. Successful preservation of these important historic structures and cultural objects depends on a more complete understanding of the unique deterioration processes underway and on implementation of effective strategies to conserve the huts.
To survive in Antarctica, early explorers of Antarctica's Heroic Age erected wooden buildings and brought in large quantities of supplies. The introduction of wood and other organic materials may have provided new nutrient sources for fungi that were indigenous to Antarctica or were brought in with the materials. From 30 samples taken from Discovery Hut, 156 filamentous fungi were isolated on selective media. Of these, 108 were screened for hydrolytic activity on carboxymethyl cellulose, of which 29 demonstrated activities. Endo-1, 4-β-glucanase activity was confirmed in the extracellular supernatant from seven isolates when grown at 4°C, and also when they were grown at 15°C. Cladosporium oxysporum and Geomyces sp. were shown to grow on a variety of synthetic cellulose substrates and to use cellulose as a nutrient source at temperate and cold temperatures. The research findings from the present study demonstrate that Antarctic filamentous fungi isolated from a variety of substrates (wood, straw, and food stuffs) are capable of cellulose degradation and can grow well at low temperatures.
We present a patient with an inflammatory pseudotumour of the neck with multifocal sites in the head and chest responding to steroids. A review of the literature revealed that this is the first case of a pseudotumour with multiple sites in the head and neck as revealed by 2-fluorodeoxyglucose(FDG) PET scan imaging.
Early explorers to Antarctica built wooden huts and brought huge quantities of supplies and equipment to support their geographical and scientific studies for several years. When the expeditions ended and relief ships arrived, a rapid exodus frequently allowed only essential items to be taken north. The huts and thousands of items were left behind. Fuel depots with unused containers of petroleum products, asbestos materials, and diverse chemicals were also left at the huts. This investigation found high concentrations of polyaromatic hydrocarbons in soils under and around the historic fuel depots, including anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, chrysene, fluorene, and pyrene, as well as benzo[a]anthracene, benzo[a]pyrene, and fluoranthene, which are recognized carcinogens. Asbestos materials within the huts have been identified and extensive amounts of fragmented asbestos were found littering the ground around the Cape Evans hut. These materials are continually abraded and fragmented as tourists walk over them and the coarse scoria breaks and grinds down the materials. A chemical spill, within the Cape Evans hut, apparently from caustic substances from one of the scientific experiments, has caused an unusual deterioration and defibration on affected woods. Although these areas are important historic sites protected by international treaties, the hazardous waste materials left by the early explorers should be removed and remedial action taken to restore the site to as pristine a condition as possible. Recommendations are discussed for international efforts to study and clean up these areas, where the earliest environmental pollution in Antarctica was produced.
By virtue of their planetary-scale magnetic fields, the Earth and all of the gas giants in our solar system possess solar-wind deformed magnetospheres. The magnetic polar regions of these “magnetic planets” produce intense, aurora-related radio emission from solar-wind powered electron currents. Simple scaling laws suggest that Jovian-mass planets close to their host stars should produce radio emission; detecting such emission would be the first direct detection of many of these planets. We describe searches using the Very Large Array (VLA) for radio emission from the planets orbiting HD 114762, 70 Vir, and τ Boo. Our limits are just above those predicted for the planetary emissions. We discuss the possibilities for more stringent limits and the implications that the existing observations have for the planets' radio emissions, and hence on the planetary magnetic fields and stellar wind environments.
In cases of thyroid surgery that require a drain post-operatively, the authors suggest the subcutaneous tunnelling of the drain to exit in the bra-strap line. This simple but effective technique hides the potentially unsightly resultant scars that may be of concern to women wearing clothes that expose the upper chest and lower neck. The bra-strap line can be easily found in the patient and the authors have found no additional complications with exiting the drain at this site.