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Analysis of optical spectroscopy and photometry of the type I X-ray bursting system UW CrB
Get PDFUW Coronae Borealis (UW CrB) is a low mass X-ray binary that shows both Type 1 X-ray and optical bursts, which typically last for 20 s. The system has a binary period of close to 2 hours and
is thought to have a relatively high inclination due to the presence of an eclipse in the optical light curve. There is also evidence that an asymmetric disc is present in the system, which precesses every
5.5 days based on changes in the depth of the eclipse. In this paper, we present optical photometry and spectroscopy of UW CrB taken over 2 years. We update the orbital ephemeris using observed optical eclipses and refine the orbital period to 110.97680(1) min. A total of 17 new optical bursts are presented, with 10 of these bursts being resolved temporally. The average e-folding time of 19 ± 3s for the bursts is consistent with the previously found value. Optical bursts are observed during a
previously identified gap in orbital phase centred on ϕ = 0.967, meaning the reprocessing site is not eclipsed as previously thought. Finally, we find that the apparent P-Cygni profiles present in some of the atomic lines in the optical spectra are due to transient absorption
Judicial discourses about journalism in journalism-related judgments in the United Kingdom (UK) since Reynolds
Get PDFIn the 1999 case of Reynolds v Times Newspapers, a qualified privilege defence was developed to libel action. However, section 4 of the Defamation Act 2013 abolished the defence and replaced it with a new defence of ‘publication on a matter of public interest'. This paper combines n-gram and qualitative approaches to analysing discourses about journalism in 228 journalism-related judgments since Reynolds. Findings suggest a fluctuating increase in cases, particularly in those involving defamation and libel, and a rise in non-news organisations as sole or primary defendants. The acknowledgement of journalism's right to freedom of expression in judicial discourses of journalism weakened over time, placing an increasing emphasis on journalism's responsibilities, ethics, and its watchdog role, particularly after 2013. These changes suggest courts’ evolving interpretations of journalism and related issues, reflecting legal values that could significantly impact journalistic practices, with alarming implications for media freedom in the United Kingdom
Unlocking planetesimal magnetic field histories: A refined, versatile model for thermal evolution and dynamo generation
Get PDFThe thermal and magnetic histories of planetesimals provide unique insights into the formation and evolution of Earth’s building blocks. These histories can be gleaned from meteorites by using numerical models to translate measured properties into planetesimal behaviour. In this paper, we present a new 1D planetesimal thermal evolution and dynamo generation model. This magnetic field generation model is the first of a differentiated, mantled planetesimal that includes both mantle convection and sub-eutectic core solidification. We have improved fundamental aspects of mantle heat transport by including a more detailed viscosity model and stagnant lid convection parametrisations consistent with internal heating. We have also added radiogenic heating from 60Fe in the metallic Fe-FeS core. Additionally, we implement a combined thermal and compositional buoyancy flux, as well as the latest magnetic field scaling laws to predict magnetic field strengths during the planetesimal’s thermal evolution until core solidification is complete. We illustrate the consequences of our model changes with an example run for a 500 km radius planetesimal. These effects include more rapid erosion of core thermal stratification and longer duration of mantle convection compared to previous studies. The additional buoyancy from core solidification has a marginal effect on dynamo strength, but for some initial core sulfur contents it can prevent cessation of the dynamo when mantle convection ends. Our model can be used to investigate the effects of individual parameters on dynamo generation and constrain properties of specific meteorite parent bodies. Combined, these updates mean this model can predict the most reliable and complete magnetic field history for a planetesimal to date, so is a valuable tool for deciphering planetesimal behaviour from meteorite properties
Editorial
Get PDFIssue 9 of Hillary Place Papers, centred on the theme Global Research Journeys, drawing from a record number of submissions, explores the varied trajectories PGR and MA researchers undertake—personal, cultural, methodological, and professional. Contributors include MA and postgraduate research (PGR)
students from multiple disciplines and international contexts. Featured articles address topics such as parental engagement in education during the COVID-19 pandemic in India, decolonising English Language Teaching in Mexico, ESL grammar instruction in Vietnam, and identity formation through migration and part-time doctoral study. Several papers examine institutional and pedagogical development, including a co-authored piece on designing a PGR-facing employment strategy and a critical review of Specialist Mathematics Schools in England. The issue also includes two conference reports, capturing reflections from presenters at the Leeds-Hull MA TESOL Conference and the 17th Research Students’ Education Conference. Together, these contributions highlight how research journeys are shaped by context, identity, and critical inquiry and, in line with the journal’s mission to offer a platform for emerging researchers, has enabled our authors to explore those issues in our supportive publishing space
Challenges in managing public spaces in work unit communities in China: A case study of Xiangshao village
Get PDFPublic space management has gained rising attention across the world in recent years. However, existing studies have mainly focused on Western countries. The research on public space management in China is scarce. This paper investigates the issues and challenges associated with managing public space and how stakeholders deal with challenges that affect the effectiveness of public space management in the Chinese context. This qualitative research is built on observations and interviews from a specific case, including three groups of stakeholders: the community, the property management company, and the residents. The research found three challenges of the current practice: the difficulty of accepting new policies, the influence of the governance structure, and the process dimensions of management. These challenges are intertwined together and hinder the effectiveness of day-to-day maintenance and long-term management. This paper proposes a benchmark that will contribute to the theoretical development of public space management and will be a valuable tool for similar research across different contexts. The research findings suggest that the coordination and cooperation between different stakeholders and the establishment of a holistic management approach offer the potential for an effective and future-proof public space and environment
Mid-infrared group IV nanowire laser
Get PDFSemiconductor nanowires have shown great potential for enabling ultracompact lasers for integrated photonics platforms. Despite the impressive progress in developing nanowire lasers, their integration into Si photonics platforms remains challenging largely because of the use of III-V and II-VI semiconductors as gain media. Recently, group IV nanowires, particularly direct bandgap GeSn nanowires capable of emitting above 2 μm, have emerged as promising cost-effective gain media for Si-compatible nanowire lasers, but there has been no successful demonstration of lasing from this seemingly promising nanowire platform. Herein, we report the experimental observation of lasing above 2 μm from a single bottom-up grown GeSn nanowire. By harnessing strain engineering and optimized cavity designs simultaneously, the single GeSn nanowire achieves an amplified material gain that can sufficiently overcome minimized optical losses, resulting in single-mode lasing with an ultralow threshold of ~5.3 kilowatts per square centimeter. Our finding paves the way for all–group IV mid-infrared photonic-integrated circuits with Si-compatible lasers for on-chip classical and quantum applications
Global assessment of health utilities associated with pneumococcal disease in children—targeted literature reviews
Get PDFBackground
Pneumococcal disease can significantly impact the quality of life (QoL) of children. Health utilities are used to measure the disease burden and calculate quality-adjusted life year (QALY) estimates. These estimates provide critical inputs in economic evaluations of pneumococcal vaccines in children.
Objectives
This study aimed to synthesize utility values used in cost-utility analyses (CUAs) of pediatric pneumococcal vaccines and to summarize published utility studies on pneumococcal disease and post-meningitis sequelae (PMS) in children on a global scale.
Methods
Two targeted literature reviews were conducted to identify CUAs of pediatric pneumococcal vaccines and original studies on health utilities of pneumococcal disease and PMS. Both literature reviews identified relevant studies using published reviews, supplemented by de novo searches conducted in MEDLINE in June 2024 to cover periods not included in those reviews. References from published literature reviews on QoL of pneumococcal disease and CUAs were screened to identify additional original utility studies. Health utility values applied in the CUAs were summarized and the source studies for these utilities were reviewed. For original utility studies, methods and utility estimates were summarized for each condition.
Results
The study identified 45 CUAs of pediatric pneumococcal vaccines in North America and Europe published from 2004 to 2024, and 21 original utility studies on pneumococcal disease or PMS in children published globally from 1994 to 2017. QALY decrement was the most common utility input in CUAs. Most CUAs referenced an earlier CUA for utility inputs, which were often sourced from one or two original utility studies for each health state. Most source studies were published more than two decades ago; some common source studies were conducted in adults. Utility estimates from original studies showed considerable variability, with ranges of −0.330 to 0.6882 for meningitis, −0.331 to 0.93 for non-meningitis invasive pneumococcal disease (IPD), −0.054 to 0.71 for inpatient pneumonia, 0.412–0.82 for outpatient pneumonia, 0.389–0.97 for acute otitis media (AOM)/simple AOM, 0.434–0.540 for recurrent AOM, −0.33 to 0.89 for neurological deficits, and 0.217–0.97 for hearing loss. Variability in methods, including in the surveyed population, utility elicitation method, and use of different country-specific preference weights, substantially impacted utility values. Overall, the methods were not suitable for temporary health states. Additionally, many studies used instruments that have not been validated in children.
Conclusions
Original utility studies demonstrated that pneumococcal disease and PMS are associated with impaired QoL in children; however, there was considerable variability in utility estimates across studies, reflecting the inherent methodological challenges in estimating utilities for acute diseases in children. Most CUAs referenced previous CUAs for health utility values, which were sourced from a limited number of outdated original utility studies. Contemporary data and methods adapted for acute diseases in children are needed for future studies. Given the significance of health utilities in the economic valuations of new pneumococcal vaccines, utility values should be carefully selected in CUAs, considering alternative sources and assumptions
Comparative Assessment of Turbulence Models for Predicting Square Cyclone Separator Performance
Get PDFAs with conventional cyclones, the gas-particle flow within a square cyclone is characterized by the consistent presence of turbulence. Therefore, selecting an appropriate turbulence model to accurately predict cyclone performance is crucial. This paper presents the findings of a computational fluid dynamics (CFD) study that assesses the impact of various turbulence models on the flow field, collection efficiency, and pressure drop predictions within square cyclone separators. In the simulation of the flow field, an investigation was conducted into five turbulence models falling under the Reynolds Averaged Navier-Stokes category, namely the Spalart-Allmaras, standard k–ε, RNG k–ε, standard k–ω, and Reynolds Stress models. Each turbulence model was coupled with a discrete phase model to represent solid particle flow within a square cyclone. The solution of the flow and particle transport equations was conducted using the software Ansys Fluent (version 21.1). Except for the flow field, for which experimental data were unavailable, the calculations were validated by comparing the predicted results for the square cyclone overall and grade efficiencies, and the pressure drop, with values from the literature. The findings of this simulation investigation demonstrate that all tested turbulence models exhibit comparable qualitative trends in predicting the tangential and axial velocity profiles. However, when evaluated in quantitative terms, the RNG k-ε model tends to overpredict both the tangential and axial velocities compared to the other models. Conversely, in the majority of cases, the k–ε standard turbulence model tends to underpredict these velocities in comparison to the other models. Regarding the predictions of the square cyclone performance, the Reynolds Stress Model is particularly noteworthy among the five turbulence models examined. It provides qualitative and quantitative closer agreement with the experimental data regarding the overall collection, grade efficiencies, and pressure drop. In general, while all models produced qualitatively similar trends in square cyclone performance predictions, the Reynolds Stress Model yielded the closest agreement with the experimental results, both qualitatively and quantitatively
Response adaptive randomisation in clinical trials: Current practice, gaps and future directions.
Get PDFIntroduction: Adaptive designs (ADs) offer clinical trials flexibility to modify design aspects based on accumulating interim data. Response adaptive randomisation (RAR) adjusts treatment allocation according to interim results, favouring promising treatments. Despite scientific appeal, RAR adoption lags behind other ADs. Understanding methods and applications could provide insights and resources and reveal future research needs. This study examines RAR application, trial results and achieved benefits, reporting gaps, statistical tools and concerns, while highlighting examples of effective practices. Methods: RAR trials with comparative efficacy, effectiveness or safety objectives, classified at least phase I/II, were identified via statistical literature, trial registries, statistical resources and researcher-knowledge. Search spanned until October 2023, including results until February 2024. Analysis was descriptive and narrative. Results: From 652 articles/trials screened, 65 planned RAR trials (11 platform trials) were identified, beginning in 1985 and gradually increasing through to 2023. Most trials were in oncology (25%) and drug-treatments (80%), with 63% led by US teams. Predominantly Phase II (62%) and multi-arm (63%), 85% used Bayesian methods, testing superiority hypotheses (86%). Binary outcomes appeared in 55%, with a median observation of 56 days. Bayesian RAR algorithms were applied in 83%. However, 71% of all trials lacked clear details on statistical implementation. Subgroup-level RAR was seen in 23% of trials. Allocation was restricted in 51%, and 88% was included a burn-in period. Most trials (85%) planned RAR alongside other adaptations. Of trials with results, 92% used RAR, but over 50% inadequately reported allocation changes. A mean 22% reduction in sample size was seen, with none over-allocating to ineffective arms. Conclusion: RAR has shown benefits in conditions like sepsis, COVID-19 and cancer, enhancing effective treatment allocation and saving resources. However, complexity, costs and simulation need limit wider adoption. This review highlights RAR's benefits and suggests enhancing statistical tools to encourage wider adoption in clinical research
Synthesis of quinoline liquid crystals by inverse electron demand Diels-Alder cycloaddition
Get PDFTetrahydroquinolines (THQ) cycloadducts, as well as their oxidation to the corresponding quinolines are reported. THQs were achieved through the Inverse Electron Demand [4 + 2]-Diels–Alder (IEDDA) cycloaddition. The [4 + 2]-IEDDA cycloadducts were obtained through a three-component reaction involving aromatic aldehydes, amines and pyrano dienophile, in the presence of TEMPOL (4-hydroxy-2,2,6,6-tetramethylpiperydine-1-oxyl), trifluoroacetic acid and acetonitrile, in low yields 90 %. The thermal behavior of the THQs and quinolines was studied using DSC and POM techniques. The final quinolines exhibited an amorphous appearance with vitreous, glossy, and brittle characteristics. Through POM studies only one quinoline displayed stable liquid crystal behavior with a glass transition temperature (Tg) and glassy nematic mesophase at room temperature was assigned, without no thermal decomposition detected after cycles of heating and cooling
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