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Repeated Tidal Interactions Between Stars and Supermassive Black Holes: Mass Transfer, Stability, and Implications for Repeating Partial Tidal Disruption Events
Get PDFStars orbiting supermassive black holes can generate recurring accretion flares in repeating partial tidal disruption events (TDEs). Here, we develop an efficient formalism for analyzing the time-dependent response of a star to the removal of a fraction (≲10%) of its mass. This model predicts that mass loss results in a decrease in the average density of low-mass (≲0.7M⊙) stars. In contrast, higher-mass stars exhibit an increase in their average density, such that the change is more pronounced for larger mass losses, and stars with masses ∼1.5−2M⊙ experience the largest such increase. We predict that the final energy of the star post-mass-loss (i.e., the “surviving core”) is effectively given by the binding energy of the original star interior to the radius from which mass is removed, i.e., the final core energy is agnostic to the process that removes the mass and—as a corollary—tidal heating is comparatively insignificant. We find excellent agreement between our predictions and one-dimensional Eulerian simulations of a star undergoing mass loss, and three-dimensional Lagrangian simulations of partial TDEs. We conclude that (1) partially disrupted stars are not significantly heated via tidal dissipation, (2) evolved and moderately massive (≳1.5M⊙) stars can most readily survive many repeated stripping events, and (3) progressively dimmer flares—observed in some repeating partial TDE candidates—could be explained by the increase in the density of the star post-mass-loss
Trends in mortality due to haemophagocytic lymphohistiocytosis across 29 European countries from 2011 to 2021: a retrospective, international, population-based study
Get PDFBackground
Previous research has suggested that the incidence of haemophagocytic lymphohistiocytosis is increasing in Europe. We aimed to examine rates of mortality due to haemophagocytic lymphohistiocytosis across 29 European countries from 2011 to 2021.
Methods
In this retrospective, population-based, descriptive study, we applied to EUROSTAT for publicly available death certificate data for mortality due to haemophagocytic lymphohistiocytosis in countries in Europe. We defined haemophagocytic lymphohistiocytosis mortality as any death recorded with ICD-10 codes of D76.1 or D76.2 as the underlying cause. We calculated age-specific and sex-specific death registration rates from Jan 1, 2011, to Dec 31, 2021, for each country and used Poisson regression to compare Europe-wide rates over time. We used direct standardisation to compare rates between countries. We also searched Scopus Analytics to establish the number of haemophagocytic lymphohistiocytosis publications for each country from Jan 1, 2000, to June 11, 2024, and analysed the correlation between mortality rates and research activity measured by the number of relevant publications.
Findings
Of 34 European countries that provided data, five were excluded from the analysis because the data had been censored due to small numbers of deaths. Analysis of 3345 deaths from the remaining 29 countries showed that crude haemophagocytic lymphohistiocytosis mortality increased from 3·9 per 10 000 000 person-years in 2011, to 6·6 per 10 000 000 person-years population in 2021. The age–sex-standardised mortality rate across Europe was 4·7 (95% CI 3·0–6·4) per 10 000 000 person-years, with the highest recorded rate in France (10·1, 0·0–27·3) and the lowest in Romania (0·5, 0·0–13·6). Crude mortality rates were highest in infants aged 0–4 years (17·5, 95% CI 16·1–19·0) and adults aged 80–85 years (15·6, 13·7–17·6). Mortality was higher in male than in female individuals (adjusted rate ratio 1·5, 95% CI 1·4–1·6). Increased haemophagocytic lymphohistiocytosis-related research activity often occurred in countries with higher rates of mortality recorded due to haemophagocytic lymphohistiocytosis than countries with lower rates (Pearson's correlation coefficient 0·4968; p=0·012).
Interpretation
Recorded rates of mortality due to haemophagocytic lymphohistiocytosis have nearly doubled over the past decade in Europe. Deaths were most common at the extremes of age and were more common in male than in female individuals. Age-standardised rates between countries differed substantially, suggesting potential under-recognition of the diagnosis of haemophagocytic lymphohistiocytosis. There is a need to increase awareness among clinicians together with implementation of evidence-based guidelines for diagnosis and urgent treatment.
Funding
Medical Research Council Rare Disease Platform Node for Histiocytic Disorders
Matrix-directed therapy losartan to identify the effect on the bone resorption marker carboxy-terminal crosslink of type I collagen telopeptide (CTX) in older adolescents and adults with osteogenesis imperfecta recruited from secondary care sites: the ‘MOI-A’ study; a randomised, phase 2/pilot, dose-escalating trial
Get PDFIntroduction Osteogenesis imperfecta (OI) is the most common inherited cause of bone fragility (approximately 1 in 16 000). People with OI suffer bone fragility causing fractures, pain and deformity; sarcopenia causing fatigue and poor endurance; aortic root dilatation and hearing loss. No drug currently has market authorisation to treat OI in Europe. Current standard-of-care is multidisciplinary, with pharmacological interventions—primarily bisphosphonates—directed at increasing bone mass; however, such interventions are of equivocal efficacy. The structural damage that can accumulate as a result of repeated fractures over time may not be reversible. The lack of a treatment with clearly defined efficacy in terms of reducing fracture frequency or the sarcopenia, that is increasingly recognised in this condition, leads to the consideration of alternatives based on what is known about the molecular pathophysiology of the condition. For reasons that are currently unclear, transforming growth factor beta (TGFβ) pathway signalling is increased in OI, and both studies in mouse models and more recently also in humans suggest that reducing TGFβ pathway signalling could be of benefit in OI. This demonstrator project tests the hypothesis that losartan, an antihypertensive agent known to reduce circulating TGFβ, will reduce bone turnover and bone loss and have a positive effect on muscle function and quality of life in adults and older adolescents with OI.
Methods and analysis This is a phase 2/pilot, open-label, dose-escalating study. This study aims to identify the effective dose for losartan in this population to inform the design of a pivotal phase III study. The study aims to recruit 30 adolescents and adults aged 16 years and above with OI across secondary care study sites in the UK and Italy. Participants will be recruited from the patient populations attending for treatment of OI at the participating hospital sites or referred by clinicians at the Participant Identification Centres (PIC sites). Participants will be randomised to one of three ‘final doses’—25, 50 or 75 mg losartan once daily. All participants will start on 25 mg once daily. Those assigned to higher ‘final doses’ will increase in 25 mg once daily increments on day 8 and day 15 following safety assessments. The primary outcome measures are to establish the effective dose of losartan in OI patients, based on maximal reduction in the bone resorption marker carboxy-terminal crosslink of type I collagen telopeptide (CTX) over the 24-week period of the study.
Secondary outcome measures are to determine the changes in proxy efficacy outcomes for bone (turnover, mass, architecture and strength) using blood tests, high-resolution peripheral quantitative CT (HRpQCT), dual-energy X-ray absorptiometry (DXA) and muscle (strength) using the ‘Timed Up and Go’ test. In addition, the changes in quality of life, including pain and fatigue, will be evaluated by using a disease-specific tool (OI-QOL) and a validated generic tool (EQ-5D-5L-VAS)
Digital thread enabled time optimal trajectory generation for machining toolpaths
No full textThe manufacturing sector is undergoing a data-driven revolution, with standards such as ISO 10303 (STEP) enabling a seamless digital thread – enhancing productivity, sustainability, and regulatory compliance. As the complexity of manufacturing operations grows, so does the demand for end-to-end certifiable processes via interoperable, standards-based digital workflows to maintain traceability and trust – from design, through to manufacture and beyond. This study introduces a novel ISO 10303-238 (STEP-NC) compatible CNC toolpath trajectory generation framework. Uniquely, it allows feature-based customisation in the CNC interpolation stage, generating minimum time toolpaths within geometric tolerances and machine limits. The proposed method has been validated against an industrial controller, showing cycle time reductions up to 14.37%
“No one knows I exist”: a qualitative study exploring the experiences of young people and staff in UK mental health hospitals
Get PDFSupporting youth mental health is a priority; currently, one in 10 young people experience a mental health disorder. Accordingly, integrated youth health services are a focus for service development both in the United Kingdom and internationally. Less attention is given to inpatient settings and the experiences of young people who use them. This in-depth qualitative study aimed to understand the experiences of people aged 16–25 years, admitted to inpatient mental health settings, and the experiences of staff caring for them. Individual interviews with seven inpatient young people and three focus groups with staff (N = 27) were conducted. An Interpretative Phenomenological Analysis (IPA) methodology with a polyvocal design was used. Young people reported how the impact of restriction, lack of inclusion, information, and transparency affected their experiences. Relationships with other young people and staff were important while shared experiences were especially salient. Staff identified difficulties of working within a system divided into separate services while attempting to work flexibly with young people. Future practice needs to enhance relational, inclusive, and flexible working practices to optimize care delivery
Designing belonging: a spatial framework for understanding university campus experiences
No full textPurpose
This paper explores the complex relationship between university campus spatial design and students’ sense of belonging. Conceptualising campus spaces as dynamic social environments, the paper investigates how the design of educational environments fosters/hinders a sense of belonging among diverse student populations.
Design/methodology/approach
The paper employs a literature review and a reflexive thematic analysis, drawing from interdisciplinary perspectives in architecture, psychology, and anthropology.
Findings
The study develops a conceptual model of “non-belonging” to diagnose spatial design practices that generate feelings of exclusion, isolation, and detachment. Additionally, it proposes a conceptual framework for understanding students’ sense of belonging to university campuses. This spatialised framework provides theoretical insight and practical guidance for future architectural and planning approaches to create inclusive, meaningful, and contextually grounded campus environments.
Originality/value
The proposed framework integrates New Brutalism’s emphasis on community needs with spatial belonging theories focused on social practice, power, and justice. It conceptualises campus belonging across three layers: the city, the campus, and its diverse communities. Recognising the coexistence of belonging and non-belonging, it uses campus design to mediate between individual and collective identities. It also utilises digital platforms as tools for shaping campus narratives that transcend physical boundaries. The study concludes with recommendations for future research, encouraging the development of practical toolkits and models through empirical inquiry. These will support broader adoption by scholars and spatial design practitioners working across educational and urban contexts
Characterization of Iron Oxide Nanoparticles Inside the Myxococcus xanthus Encapsulin
Get PDFEncapsulins are microbial protein nanocompartments that spatially organize and sequester specific biochemical processes, including iron storage. While their protein shells have been extensively characterized, the composition and structure of their mineral cores remain less understood. Here, we use bright field transmission electron microscopy (BF TEM), high-angle annular dark-field scanning TEM (HAADF STEM), energy-dispersive X-ray (EDX), and electron energy-loss spectroscopy (EELS) in STEM to characterize the iron-containing mineral granules within the Myxococcus xanthus encapsulin system at near atomic resolution. We find that the internal nanoparticles are smaller (~2 nm) and more numerous (up to ~2200 per encapsulin) than previously reported. These nanoparticles are typically amorphous and have a composition consistent with FePO4 (measured Fe:P ratio of ≈1:1.2). Each encapsulin contains on average ~8500 iron atoms, corresponding to a volumetric density of 2.1 atoms/nm3. Phosphorus incorporation inhibits crystallization, whereas growth in phosphorus-free media leads to the formation of nano-crystalline goethite [α-FeO(OH)]
How pregnancy might change women’s travel behavior
Get PDFUnderstanding how to mitigate car dependency in cities has become increasingly important. Life events, such as childbirth, have been reported to influence parents' travel behavior, often leading to greater car dependency. While there is knowledge regarding changes in travel behavior among parents after childbirth, there is less knowledge about how pregnancy itself might change women’s (mothers’) travel behavior, who bear the primary burden of this event. The present study aims to explore (travel) behavioral responses of women to pregnancy. A latent class analysis was conducted using data from a survey of women (those who have recently experienced this event) in Tehran (n = 646). Employing a (retrospective) survey study, participants were asked about their daily travel behaviors, attitudes, and sociodemographic attributes before and during pregnancy. The results indicate that women show four transition patterns of their travel behavior in response to pregnancy: increasingly car-dependents, consistent walkers, transit leavers, and continual car-independents. Nearly half of respondents (increasingly car-dependents) utilized cars and walking for their trips prior to pregnancy; however, following pregnancy, there was a notable decrease in walking and an increase in car use. Quarter of respondents (consistent walkers) primarily use walking before pregnancy, and this travel behavior remains unchanged after this event. Factors such as attitudes towards travel modes, car ownership, economic level, educational attainment, and child order in household play role on respondents’ transition patterns of travel behavior following pregnancy. Results show that those experiencing greater attitudinal changes being more likely to transition away from sustainable travel modes, while those with more stable attitudes showing greater resistance to such transitions
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