Lattice quantum gravity with scalar fields

We consider the four-dimensional Euclidean dynamical triangulations lattice model of quantum gravity based on triangulations of $S^{4}$. We couple it minimally to a scalar field in the quenched approximation. Our results suggest a multiplicative renormalization for the mass of the scalar field which is consistent with the shift symmetry of the discretized lattice action. We discuss the possibility of measuring the mass anomalous dimension and the gravitational binding energy between two scalar test particles, where a negative bound state energy would imply that this model has an attractive gravitational force.Comment: 1+6 pages, proceedings for the 36th International Symposium on Lattice Field Theory (22-28 July 2018). v2 -- Added one reference and fixed a typo. Comments welcome

Model of Transcriptional Activation by MarA in Escherichia coli

We have developed a mathematical model of transcriptional activation by MarA in Escherichia coli, and used the model to analyze measurements of MarA-dependent activity of the marRAB, sodA, and micF promoters in mar-rob- cells. The model rationalizes an unexpected poor correlation between the mid-point of in vivo promoter activity profiles and in vitro equilibrium constants for MarA binding to promoter sequences. Analysis of the promoter activity data using the model yielded the following predictions regarding activation mechanisms: (1) MarA activation of the marRAB, sodA, and micF promoters involves a net acceleration of the kinetics of transitions after RNA polymerase binding, up to and including promoter escape and message elongation; (2) RNA polymerase binds to these promoters with nearly unit occupancy in the absence of MarA, making recruitment of polymerase an insignificant factor in activation of these promoters; and (3) instead of recruitment, activation of the micF promoter might involve a repulsion of polymerase combined with a large acceleration of the kinetics of polymerase activity. These predictions are consistent with published chromatin immunoprecipitation assays of interactions between polymerase and the E. coli chromosome. A lack of recruitment in transcriptional activation represents an exception to the textbook description of activation of bacterial sigma-70 promoters. However, use of accelerated polymerase kinetics instead of recruitment might confer a competitive advantage to E. coli by decreasing latency in gene regulation.Comment: 30 pages, 2 figure

Threats to safe transitions from hospital to home: a consensus study in North West London primary care.

BACKGROUND: Transitions between healthcare settings are vulnerable points for patients. AIM: To identify key threats to safe patient transitions from hospital to primary care settings. DESIGN AND SETTING: Three-round web-based Delphi consensus process among clinical and non-clinical staff from 39 primary care practices in North West London, England. METHOD: Round 1 was a free-text idea-generating round. Rounds 2 and 3 were consensus-obtaining rating rounds. Practices were encouraged to complete the questionnaires at team meetings. Aggregate ratings of perceived level of importance for each threat were calculated (1-3: 'not important', 4-6: 'somewhat important', 7-9: 'very important'). Percentage of votes cast for each patient or medication group were recorded; consensus was defined as ≥75%. RESULTS: A total of 39 practices completed round 1, 36/39 (92%) completed round 2, and 30/36 (83%) completed round 3. Round 1 identified nine threats encompassing problems involving communication, service organisation, medication provision, and patients who were most at risk. 'Poor quality of handover instructions from secondary to primary care teams' achieved the highest rating (mean rating at round 3 = 8.43) and a 100% consensus that it was a 'very important' threat. Older individuals (97%) and patients with complex medical problems taking >5 medications (80%) were voted the most vulnerable. Anticoagulants (77%) were considered to pose the greatest risk to patients. CONCLUSION: This study identified specific threats to safe patient transitions from hospital to primary care, providing policymakers and healthcare providers with targets for quality improvement strategies. Further work would need to identify factors underpinning these threats so that interventions can be tailored to the relevant behavioural and environmental contexts in which these threats arise

A population survey on beliefs around cervical cancer screening: determining the barriers and facilitators associated with attendance

Background: Cervical screening saves approximately 5000 lives annually in England. However, screening rates have been falling continuously, and coverage in London is particularly low (64.7%). While demographic predictors of uptake have been well researched, there has been less thorough investigation of the individual barriers and facilitators which predict cervical screening attendance. Understanding modifiable factors influencing attendance can guide the design of effective interventions to increase cervical screening uptake. The aim of this study was to understand the demographic, and individual factors associated with self-reported attendance at cervical screening in London. Methods: The study used an online survey of 500 women in London (June-July 2017). The survey included self-reported measures of past attendance, demographic variables (including age, household income, ethnicity), past experience variables, and individual variables (list of potential barriers and facilitators developed based on the Theoretical Domains Framework and existing literature, which included: environmental context and resources, perceived risk, anticipated pain/embarrassment). Participants were categorised into regular attenders and non-regular attenders. Backwards stepwise logistic regression investigated the barriers and facilitators predicting past attendance. Demographic variables with significant differences between regular and non-regular attenders were added to the final regression model. Results: Of women who had previously been invited (n = 461, age range: 25–65), 34.5% (n = 159) were classified as non-regular attenders, and 65.5% (n = 302) as regular attenders. The individual barriers and facilitators predicting attendance were: cervical screening priority, memory, environmental context and resources, and intention. The only demographic variables related to regular attendance were relationship status (married/civil partnership having higher rates than single) and higher household income. Relationship status was not significant when adjusting for barriers and facilitators. Those who have ever been sexually active or who have had an STI in the past were significantly more likely to be regular attenders. Conclusions: The study shows the importance of individual barriers and facilitators in predicting self-reported cervical screening attendance. Household income was the only significant demographic variable when combined with the individual variables. Interventions targeting priority, memory, and practical barriers affecting environmental context may be expected to be effective an increasing attendance

Tensor renormalization group study of 3D principal chiral model

We study the three-dimensional $SU(2)$ principal chiral model (PCM) using different tensor renormalization group methods based on the triad and anisotropic decomposition of the tensor. The tensor network representation is formulated based on the character expansion of the Boltzmann weight. We compare the average action obtained using these two tensor network algorithms and confirm that the resulting critical coupling and exponent are comparable with the recent estimations from the Monte Carlo methods.Comment: eight pages, six figure

A systematic review of interventions to improve breast cancer screening health behaviours

Whilst breast cancer screening has been implemented in many countries, uptake is often suboptimal. Consequently, several interventions targeting non-attendance behaviour have been developed. This systematic review aims to appraise the successes of interventions, identifying and comparing the specific techniques they use to modify health behaviours. A literature search (PROSPERO CRD42020212090) between January 2005 and December 2020 using PubMed, Medline, PsycInfo, EMBASE and Google Scholar was conducted. Studies which investigated patient-facing interventions to increase attendance at breast cancer screening appointments were included. Details regarding the intervention delivery, theoretical background, and contents were extracted, as was quantitative data on the impact on attendance rates, compared to control measures. Interventions were also coded using the Behavioural Change Techniques (BCT) Taxonomy. In total fifty-four studies, detailing eighty interventions, met the inclusion criteria. Only 50% of interventions reported a significant impact on screening attendance. Thirty-two different BCTs were used, with 'prompts/cues' the most commonly incorporated (77.5%), however techniques from the group 'covert learning' had the greatest pooled effect size 0.12 (95% CI 0.05-0.19, P < 0·01, I2 = 91.5%). 'Problem solving' was used in the highest proportion of interventions that significantly increased screening attendance (69.0%). 70% of the interventions were developed using behavioural theories. These results show interventions aimed at increasing screening uptake are often unsuccessful. Commonly used approaches which focus upon explaining the consequences of not attending mammograms were often ineffective. Problem solving, however, has shown promise. These techniques should be investigated further, as should emerging technologies which can enable interventions to be feasibly translated at a population-level

Detection of low-level promoter activity within open reading frame sequences of Escherichia coli

The search for promoters has largely been confined to sequences upstream of open reading frames (ORFs) or stable RNA genes. Here we used a cloning approach to discover other potential promoters in Escherichia coli. Chromosomal fragments of ∼160 bp were fused to a promoterless lacZ reporter gene on a multi-copy plasmid. Eight clones were deliberately selected for high activity and 105 clones were selected at random. All eight of the high-activity clones carried promoters that were located upstream of an ORF. Among the randomly-selected clones, 56 had significantly elevated activity. Of these, 7 had inserts which also mapped upstream of an ORF, while 49 mapped within or downstream of ORFs. Surprisingly, the eight promoters selected for high activity matched the canonical σ(70) −35 and −10 sequences no better than sequences from the randomly-selected clones. For six of the nine most active sequences with orientations opposite to that of the ORF, chromosomal expression was detected by RT–PCR, but defined transcripts were not detected by northern analysis. Our results indicate that the E.coli chromosome carries numerous −35 and −10 sequences with weak promoter activity but that most are not productively expressed because other features needed to enhance promoter activity and transcript stability are absent