Stochastic Gravity: Theory and Applications

Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel.In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime: we compute the two-point correlation functions for the linearized Einstein tensor and for the metric perturbations. Second, we discuss structure formation from the stochastic gravity viewpoint. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a quasi-static black hole.Comment: 75 pages, no figures, submitted to Living Reviews in Relativit

How do healthcare staff respond to patient experience feedback online? A typology of responses published on Care Opinion

Patients are increasingly describing their healthcare experiences publicly online. This has been facilitated by digital technology, a growing focus on transparency in healthcare and the emergence of a feedback culture in many sectors. Due to this area being previously unexplored, the objective of this study was to identify a typology of responses that healthcare staff provide on Care Opinion (www.careopinion.org.uk), a not-for-profit online platform on which patients are able to provide narrative feedback about health and social care in the UK. Framework analysis was used to qualitatively analyse a purposive sample of 486 stories regarding hospital care, and their 475 responses. Five response types were identified: non-responses, generic responses, appreciative responses, offline responses and transparent, conversational responses. The key factors that varied between these response types included the extent to which responses were specific and personal to the patient story, how much responders' embraced the transparent nature of public online discussion and whether or not responders suggested that the feedback had led to learning or impacted subsequent care delivery. Staff provide varying responses to feedback from patients online, with the response types provided being likely to have strong organisational influences. The findings offer valuable insight, advancing the relatively unexplored research area. They also have both practical and theoretical implications for those looking to enable meaningful conversations between patients and staff to help inform improvement. Future research should focus on the relationship between response type, organisational culture and the ways in which feedback is used in practice

Autoimmune and autoinflammatory mechanisms in uveitis

The eye, as currently viewed, is neither immunologically ignorant nor sequestered from the systemic environment. The eye utilises distinct immunoregulatory mechanisms to preserve tissue and cellular function in the face of immune-mediated insult; clinically, inflammation following such an insult is termed uveitis. The intra-ocular inflammation in uveitis may be clinically obvious as a result of infection (e.g. toxoplasma, herpes), but in the main infection, if any, remains covert. We now recognise that healthy tissues including the retina have regulatory mechanisms imparted by control of myeloid cells through receptors (e.g. CD200R) and soluble inhibitory factors (e.g. alpha-MSH), regulation of the blood retinal barrier, and active immune surveillance. Once homoeostasis has been disrupted and inflammation ensues, the mechanisms to regulate inflammation, including T cell apoptosis, generation of Treg cells, and myeloid cell suppression in situ, are less successful. Why inflammation becomes persistent remains unknown, but extrapolating from animal models, possibilities include differential trafficking of T cells from the retina, residency of CD8(+) T cells, and alterations of myeloid cell phenotype and function. Translating lessons learned from animal models to humans has been helped by system biology approaches and informatics, which suggest that diseased animals and people share similar changes in T cell phenotypes and monocyte function to date. Together the data infer a possible cryptic infectious drive in uveitis that unlocks and drives persistent autoimmune responses, or promotes further innate immune responses. Thus there may be many mechanisms in common with those observed in autoinflammatory disorders

Sustainable Financing of Innovative Therapies: A Review of Approaches

The process of innovation is inherently complex, and it occurs within an even more complex institutional environment characterized by incomplete information, market power, and externalities. There are therefore different competing approaches to supporting and financing innovation in medical technologies, which bring their own advantages and disadvantages. This article reviews value- and cost-based pricing, as well direct government funding, and cross-cutting institutional structures. It argues that performance-based risk-sharing agreements are likely to have little effect on the sustainability of financing; that there is a role for cost-based pricing models in some situations; and that the push towards longer exclusivity periods is likely contrary to the interests of industry

Stochastic Gravity: Theory and Applications

Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel. In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime, compute the two-point correlation functions of these perturbations and prove that Minkowski spacetime is a stable solution of semiclassical gravity. Second, we discuss structure formation from the stochastic gravity viewpoint. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a black hole and describe the metric fluctuations near the event horizon of an evaporating black holeComment: 100 pages, no figures; an update of the 2003 review in Living Reviews in Relativity gr-qc/0307032 ; it includes new sections on the Validity of Semiclassical Gravity, the Stability of Minkowski Spacetime, and the Metric Fluctuations of an Evaporating Black Hol

Guidance on stakeholder engagement practices to inform the development of areawide vector control methods

This is the final version. Available from the publisher via the DOI in this record.British Academ

Vanzacaftor–tezacaftor–deutivacaftor for children aged 6–11 years with cystic fibrosis (RIDGELINE Trial VX21-121-105): an analysis from a single-arm, phase 3 trial

BACKGROUND: In phase 2 trials in people with cystic fibrosis aged 18 years and older, vanzacaftor–tezacaftor–deutivacaftor has been shown to be a safe and effective, once-daily cystic fibrosis transmembrane conductance regulator (CFTR) modulator. Restoring normal CFTR function early in life has the potential to prevent manifestations of cystic fibrosis. We aimed to evaluate the safety, tolerability, efficacy, and pharmacokinetics of vanzacaftor–tezacaftor–deutivacaftor in children with cystic fibrosis aged 6–11 years. METHODS: In this multicentre, single-arm, phase 3 trial (RIDGELINE Trial VX21-121-105), participants were enrolled across 33 clinical sites that care for children with cystic fibrosis in eight countries (Australia, France, Germany, Netherlands, Sweden, Switzerland, the UK, and the USA). Eligible participants were aged 6–11 years with at least one elexacaftor–tezacaftor–ivacaftor-responsive CFTR variant, FEV1 % predicted of 60% or higher, and stable cystic fibrosis as determined by investigators. Before study treatment, participants were either on stable elexacaftor–tezacaftor–ivacaftor for at least 28 days before screening or received the combination for a 4-week run-in period. Participants then received vanzacaftor–tezacaftor–deutivacaftor (<40 kg bodyweight: vanzacaftor 12 mg, tezacaftor 60 mg, and deutivacaftor 150 mg orally as three fixed-dose combination tablets once daily; ≥40 kg bodyweight: vanzacaftor 20 mg, tezacaftor 100 mg, and deutivacaftor 250 mg orally as two fixed-dose combination tablets once daily (manufactured by Patheon Pharmaceuticals, Cincinnati, OH, USA) from day 1 for 24 weeks. The primary endpoint was safety and tolerability, as measured by adverse events, vital signs, clinical laboratory values, electrocardiograms, and pulse oximetry. Endpoints were analysed in all participants who received at least one dose of vanzacaftor–tezacaftor–deutivacaftor. This trial is registered with ClinicalTrials.gov, NCT05422222, and evaluation of the 6–11-year-old cohort is complete. FINDINGS: Between Feb 6 and May 18, 2023, 83 children were screened, of whom five were not eligible, and 78 children aged 6-11 years received at least one dose of vanzacaftor–tezacaftor–deutivacaftor. Median age was 9·3 years (IQR 7·6–10·4), 34 (44%) of 78 participants were female, 44 (56%) were male, 71 (91%) were White, one (1%) was Black or African American, and one (1%) was of multiple races. The analysis for these data was completed on Dec 15, 2023. Median exposure of participants to vanzacaftor–tezacaftor–deutivacaftor was 168 days (IQR 166–170). 75 (96%) of 78 participants had adverse events, all of which were mild or moderate; the most common events were generally consistent with cystic fibrosis manifestations, including, cough (36 [46%]), pyrexia (16 [21%]), headache (14 [18%]), infective pulmonary exacerbation of cystic fibrosis (13 [17%]), and oropharyngeal pain (13 [17%]). Serious adverse events occurred in six (8%) participants (two had infective pulmonary exacerbation, one of whom also had failure to thrive; one participant each had adenovirus infection, constipation, pulmonary function test decreased, and cough), and one (1%) participant discontinued due to adverse events of cough and fatigue that were considered possibly related to study drug. INTERPRETATION: Vanzacaftor–tezacaftor–deutivacaftor was safe and well tolerated and maintained FEV1 % predicted from elexacaftor–tezacaftor–ivacaftor baseline with further improved CFTR function. Improvements in CFTR function compared with baseline elexacaftor–tezacaftor–ivacaftor values demonstrate the potential opportunity to restore normal physiology early and prevent development or progression of cystic fibrosis. Nearly all participants had sweat chloride below the diagnostic threshold for cytstic fibrosis (<60 mmol/L) and more than half had normal levels (<30 mmol/L). Additional long-term data in children with cystic fibrosis are being collected in an open-label extension study to demonstrate clinical benefits and safety. These findings will inform health-care providers and people with cystic fibrosis regarding the benefits of early initiation of CFTR modulators. FUNDING: Vertex Pharmaceuticals

MicroRNA-Mediated Positive Feedback Loop and Optimized Bistable Switch in a Cancer Network Involving miR-17-92

MicroRNAs (miRNAs) are small, noncoding RNAs that play an important role in many key biological processes, including development, cell differentiation, the cell cycle and apoptosis, as central post-transcriptional regulators of gene expression. Recent studies have shown that miRNAs can act as oncogenes and tumor suppressors depending on the context. The present work focuses on the physiological significance of miRNAs and their role in regulating the switching behavior. We illustrate an abstract model of the Myc/E2F/miR-17-92 network presented by Aguda et al. (2008), which is composed of coupling between the E2F/Myc positive feedback loops and the E2F/Myc/miR-17-92 negative feedback loop. By systematically analyzing the network in close association with plausible experimental parameters, we show that, in the presence of miRNAs, the system bistability emerges from the system, with a bistable switch and a one-way switch presented by Aguda et al. instead of a single one-way switch. Moreover, the miRNAs can optimize the switching process. The model produces a diverse array of response-signal behaviors in response to various potential regulating scenarios. The model predicts that this transition exists, one from cell death or the cancerous phenotype directly to cell quiescence, due to the existence of miRNAs. It was also found that the network involving miR-17-92 exhibits high noise sensitivity due to a positive feedback loop and also maintains resistance to noise from a negative feedback loop

Growth hormone responsive neural precursor cells reside within the adult mammalian brain

The detection of growth hormone (GH) and its receptor in germinal regions of the mammalian brain prompted our investigation of GH and its role in the regulation of endogenous neural precursor cell activity. Here we report that the addition of exogenous GH significantly increased the expansion rate in long-term neurosphere cultures derived from wild-type mice, while neurospheres derived from GH null mice exhibited a reduced expansion rate. We also detected a doubling in the frequency of large (i.e. stem cell-derived) colonies for up to 120 days following a 7-day intracerebroventricular infusion of GH suggesting the activation of endogenous stem cells. Moreover, gamma irradiation induced the ablation of normally quiescent stem cells in GH-infused mice, resulting in a decline in olfactory bulb neurogenesis. These results suggest that GH activates populations of resident stem and progenitor cells, and therefore may represent a novel therapeutic target for age-related neurodegeneration and associated cognitive decline

MOSAIC (MOthers' Advocates In the Community): protocol and sample description of a cluster randomised trial of mentor mother support to reduce intimate partner violence among pregnant or recent mothers

Background : Intimate partner violence (IPV) is prevalent globally, experienced by a significant minority of women in the early childbearing years and is harmful to the mental and physical health of women and children. There are very few studies with rigorous designs which have tested the effectiveness of IPV interventions to improve the health and wellbeing of abused women. Evidence for the separate benefit to victims of social support, advocacy and non-professional mentoring suggested that a combined model may reduce the levels of violence, the associated mental health damage and may increase a woman\u27s health, safety and connection with her children. This paper describes the development, design and implementation of a trial of mentor mother support set in primary care, including baseline characteristics of participating women.Methods/Design : MOSAIC (MOtherS\u27 Advocates In the Community) was a cluster randomised trial embedded in general practice and maternal and child health (MCH) nursing services in disadvantaged suburbs of Melbourne, Australia. Women who were pregnant or with infants, identified as abused or symptomatic of abuse, were referred by IPV-trained GPs and MCH nurses from 24 general practices and eight nurse teams from January 2006 to December 2007. Women in the intervention arm received up to 12 months support from trained and supported non-professional mentor mothers. Vietnamese health professionals also referred Vietnamese women to bilingual mentors in a sub-study. Baseline and follow-up surveys at 12 months measured IPV (CAS), depression (EPDS), general health (SF-36), social support (MOS-SF) and attachment to children (PSI-SF). Significant development and piloting occurred prior to trial commencement. Implementation interviews with MCH nurses, GPs and mentors assisted further refinement of the intervention. In-depth interviews with participants and mentors, and follow-up surveys of MCH nurses and GPs at trial conclusion will shed further light on MOSAIC\u27s impact.Discussion : Despite significant challenges, MOSAIC will make an important contribution to the need for evidence of effective partner violence interventions, the role of non-professional mentors in partner violence support services and the need for more evaluation of effective health professional training and support in caring for abused women and children among their populations.<br /