Differential birefringence in Bragg gratings in multicore fiber under transverse stress

We present experimental measurements of the peak splitting of the reflection spectra of fiber Bragg gratings as a result of birefringence induced by transverse loading of a multicore fiber. Measurements show that the splitting is a function of the applied load and the direction of the load relative to the azimuth of the fiber. A model for calculating the stress in the fiber that is due to an applied load is in good agreement with our experimental observations

Dynamic two-axis curvature measurement using multicore fiber Bragg gratings interrogated by arrayed waveguide gratings

We describe the use of arrayed waveguide gratings (AWGs) in the interrogation of fiber Bragg gratings (FBGs) for dynamic strain measurement. The ratiometric AWG output was calibrated in a static deflection experiment over a ±200 με range. Dynamic strain measurement was demonstrated with a FBG in a conventional single-mode fiber mounted on the surface of a vibrating cantilever and on a piezoelectric actuator, giving a resolution of 0.5 με at 2.4 kHz. We present results of this technique extended to measure the dynamic differential strain between two FBG pairs within a multicore fiber. An arbitrary cantilever oscillation of the multicore fiber was determined from curvature measurements in two orthogonal axes at 1125 Hz with a resolution of 0.05 m-1. © 2006 Optical Society of America

Improving the management of open tibia fractures, Malawi.

To assess the impact of an open fracture intervention bundle on clinical management and patient outcomes of adults in Malawi with open tibia fractures. We conducted a before-and-after implementation study in Malawi in 2021 and 2022 to assess the impact of an open fracture intervention bundle, including a national education course for clinical officers and management guidelines for open fractures. We recruited 287 patients with open tibia fractures. The primary outcome was a before-and-after comparison of the self-reported short musculoskeletal function assessment score, a measure of patient function. Secondary outcomes included clinical management; and clinician knowledge and implementation evaluation outcomes of 57 health-care providers attending the course. We also constructed multilevel regression models to investigate associations between clinical knowledge, patient function, and implementation evaluation before and after the intervention. The median patient function score at 1 year was 6.8 (interquartile range, IQR: 1.5 to 14.5) before intervention and 8.4 (IQR: 3.8 to 23.2) after intervention. Compared with baseline scores, we found clinicians' open fracture knowledge scores improved 1 year after the intervention was implemented (mean posterior difference: 1.6, 95% highest density interval: 0.9 to 2.4). However, we found no difference in most aspects of clinicians' open fracture management practice. Despite possible improvement in clinician knowledge and positive evaluation of the intervention implementation, our study showed that there was no overall improvement in clinical management, and weak evidence of worsening patient function 1 year after injury, after implementation of the open fracture intervention bundle

Protocol for a prospective cohort study of open tibia fractures in Malawi with a nested implementation of open fracture guidelines.

Background: Road traffic injury (RTI) is the largest cause of death amongst 15-39-year-old people worldwide, and the burden of injuries such as open tibia fractures are rapidly increasing in Malawi. This study aims to investigate disability and economic outcomes of people with open tibia fractures in Malawi and improve these with locally delivered implementation of open fracture guidelines. Methods: This is a prospective cohort study describing function, quality of life and economic burden of open tibia fractures in Malawi. In total, 160 participants will be recruited across six centres and will be followed-up with face-to-face interviews at six weeks, three months, six months and one year following injury. The primary outcome will be function at one year measured by the short musculoskeletal functional assessment (SMFA) score. Secondary outcomes will include quality of life measured by EuroQol EQ-5D-3L, catastrophic loss of income and implementation outcomes (acceptability, adoption, appropriateness, costs, feasibility, fidelity, penetration, and sustainability) at one year. A nested pilot pre-post implementation study of an interventional bundle for all open fractures will be developed based on other implementation studies from low- and middle-income countries (LMICs). Regression analysis will be used to model and investigate associations between SMFA score and fracture severity, infection and the pre- and post-training course period. Outcome: This prospective cohort study will report patient reported outcomes from open tibia fractures in low-resource settings. Subsequent detailed evaluation of both the clinical and implementation components of the study will promote sustainability of improved open fractures management in the study sites and further scale-up of open fracture management guidelines. Ethics: Ethics approval has been obtained from the Liverpool School of Tropical Medicine and College of Medicine Research and Ethics committee

Functional outcomes and quality of life at 1-year follow-up after an open tibia fracture in Malawi: a multicentre, prospective cohort study

Background: Injuries are a major cause of disability globally and injury incidence is rapidly increasing, largely due to road traffic injuries in low-income and middle-income countries. Current estimates of the scale and consequences of disability from injury are largely based on modelling studies, with a scarcity of empirical evidence from severe injuries in low-income countries. We aimed to better understand the outcomes for individuals with open tibia fractures in Malawi. Methods: In this multicentre, prospective cohort study, adults (aged ≥18 years) with open tibia fractures were systematically recruited at six hospitals in Malawi (two tertiary hospitals and four district hospitals). Follow-up lasted at least 1 year, during which in-person follow-up reviews were done at 6 weeks, 3 months, 6 months, and 1 year post-injury. The primary outcome was function at 1 year post-injury, measured by the Short Musculoskeletal Functional Assessment (SMFA) score. Secondary outcomes included quality-adjusted life-years (QALYs; as determined via the European Quality of Life 5-Dimensions 3-Levels [EQ-5D-3L] survey) and fracture-related infection at 1 year post-injury. Multilevel regression models investigated associations between SMFA score, EQ-5D-3L, baseline factors, and orthopaedic management. Findings: Between Feb 12, 2021, and March 14, 2022, 287 participants were enrolled (median age 34 years [IQR 25–44]; 84% male). The most common mode of injury was road traffic injuries (194 [68%] of 287). Overall, 268 (93%) participants had debridement; of the 63 participants who were debrided in district hospitals, 47 (75%) had the procedure under local or no anaesthesia. Following substantial declines by 6 weeks after injury, function and quality of life had not recovered by 1 year post-injury for participants with Gustilo grade I–II fractures (posterior mean SMFA at 1 year: 10·5, 95% highest density interval [HDI]: 9·5–11·6; QALYs: 0·73, 95% HDI: 0·66–0·80) nor Gustilo grade III fractures (posterior mean SMFA at 1 year: 14·9, 95% HDI: 13·4–16·6; QALYs: 0·67, 95% HDI: 0·59–0·75). For all fracture grades, intramedullary nailing substantially improved function and quality of life at 1 year post-injury. Delayed definitive fixation after 5 days had 5-times greater odds of infection compared with early management within 2 days (adjusted odds ratio: 5·1, 95% CI 1·8–16·1; p=0·02). Interpretation: Adults with open tibia fractures in Malawi have poor function and quality of life in the 1 year following injury. Centralised orthopaedic surgical management, including early definitive fixation and intramedullary nailing for more severe injuries, might improve outcomes. Funding: Wellcome Trust

Short Timescale Evolution of the Polarized Radio Jet during V404 Cygni's 2015 Outburst

We present a high time resolution, multi-frequency linear polarization analysis of Very Large Array (VLA) radio observations during some of the brightest radio flaring (~1 Jy) activity of the 2015 outburst of V404 Cygni. The VLA simultaneously captured the radio evolution in two bands (each with two 1 GHz base-bands), recorded at 5/7 GHz and 21/26 GHz, allowing for a broadband polarimetric analysis. Given the source's high flux densities, we were able to measure polarization on timescales of ~13 minutes, constituting one of the highest temporal resolution radio polarimetric studies of a black hole X-ray binary (BHXB) outburst to date. Across all base-bands, we detect variable, weakly linearly polarized emission (<1%) with a single, bright peak in the time-resolved polarization fraction, consistent with an origin in an evolving, dynamic jet component. We applied two independent polarimetric methods to extract the intrinsic electric vector position angles and rotation measures from the 5 and 7 GHz base-band data and detected a variable intrinsic polarization angle, indicative of a rapidly evolving local environment or a complex magnetic field geometry. Comparisons to the simultaneous, spatially-resolved observations taken with the Very Long Baseline Array at 15.6 GHz, do not show a significant connection between the jet ejections and the polarization state.Comment: 24 pages, 9 figures, accepted by MNRA

Simple and effective bacterial-based intratumoral cancer immunotherapy

Background We describe intratumoral injection of a slow-release emulsion of killed mycobacteria (complete Freund’s adjuvant (CFA)) in three preclinical species and in human cancer patients. Methods Efficacy and safety were tested in mammary tumors in mice, in mastocytomas in mice and dogs, and in equine melanomas. In mice, survival, tumor growth, and tumor infiltration by six immune cell subsets (by flow cytometry) were investigated and analyzed using Cox proportional hazards, a random slopes model, and a full factorial model, respectively. Tumor growth and histology were investigated in dogs and horses, as well as survival and tumor immunohistochemistry in dogs. Tumor biopsies were taken from human cancer patients on day 5 (all patients) and day 28 (some patients) of treatment and analyzed by histology. CT scans are provided from one patient. Results Significantly extended survival was observed in mouse P815 and 4T1 tumor models. Complete tumor regressions were observed in all three non-human species (6/186 (3%) of mouse mastocytomas; 3/14 (21%) of canine mastocytomas and 2/11 (18%) of equine melanomas). Evidence of systemic immune responses (regression of non-injected metastases) was also observed. Analysis of immune cells infiltrating mastocytoma tumors in mice showed that early neutrophil infiltration was predictive of treatment benefit. Analysis of the site of mastocytoma regression in dogs weeks or months after treatment demonstrated increased B and T cell infiltrates. Thus, activation of the innate immune system alone may be sufficient for regression of some injected tumors, followed by activation of the acquired immune system which can mediate regression of non-injected metastases. Finally, we report on the use of CFA in 12 human cancer patients. Treatment was well tolerated. CT scans showing tumor regression in a patient with late-stage renal cancer are provided. Conclusion Our data demonstrate that intratumoral injection of CFA has major antitumor effects in a proportion of treated animals and is safe for use in human cancer patients. Further trials in human cancer patients are therefore warranted. Our novel treatment provides a simple and inexpensive cancer immunotherapy, immediately applicable to a wide range of solid tumors, and is suitable to patients in developing countries and advanced care settings.g Canberra trial: Canberra Hospital Private Practice Fund, Janice and Ron Parker Fund. Mouse preclinical studies: Lea Chapuis Memorial Fund. Canine preclinical studies: The John and Mary Kibble Trust (grants CT22492, CT21335) and the William Peter Richards Bequest for research into veterinary pathology. CSEC, ERA, and AAA was supported by Australian Government Research Training Program Stipend Scholarships. CSEC and K-MS were supported by Max Lindemann Memorial Foundation, Miam

IMG-06. PREDICTING SURVIVAL FROM PERFUSION AND DIFFUSION MRI BY MACHINE LEARNING

INTRODUCTION Magnetic Resonance Imaging (MRI) is routinely used in the assessment of children’s brain tumours. Reduced diffusion and increased perfusion on MRI are commonly associated with higher grade but there is a lack of quantitative data linking these parameters to survival. Machine learning is increasingly being used to develop diagnostic tools but its use in survival analysis is rare. In this study we combine quantitative parameters from diffusion and perfusion MRI with machine learning to develop a model of survival for paediatric brain tumours. METHOD: 69 children from 4 centres (Birmingham, Liverpool, Nottingham, Newcastle) underwent MRI with diffusion and perfusion (dynamic susceptibility contrast) at diagnosis. Images were processed to form ADC, cerebral blood volume (CBV) and vessel leakage correction (K2) parameter maps. Parameter mean, standard deviation and heterogeneity measures (skewness and kurtosis) were calculated from tumour and whole brain and used in iterative Bayesian survival analysis. The features selected were used for k-means clustering and differences in survival between clusters assessed by Kaplan-Meier and Cox-regression. RESULTS Bayesian analysis revealed the 5 top features determining survival to be tumour volume, ADC kurtosis, CBV mean, K2 mean and whole brain CBV mean. K-means clustering using these features showed two distinct clusters (high- and low-risk) which bore significantly different survival characteristics (Hazard Ratio = 5.6). DISCUSSION AND CONCLUSION Diffusion and perfusion MRI can be used to aid the prediction of survival in children’s brain tumours. Tumour perfusion played a particularly important role in predicting survival despite being less routinely measured than diffusion

Accurate water maser positions from HOPS

We report on high spatial resolution water maser observations, using the Australia Telescope Compact Array, towards water maser sites previously identified in the H2O southern Galactic Plane Survey (HOPS). Of the 540 masers identified in the single-dish observations of Walsh et al. (2011), we detect emission in all but 31 fields. We report on 2790 spectral features (maser spots), with brightnesses ranging from 0.06 Jy to 576 Jy and with velocities ranging from −238.5 to +300.5 kms−1. These spectral features are grouped into 631 maser sites. We have compared the positions of these sites to the literature to associate the sites with astrophysical objects. We identify 433 (69 per cent) with star formation, 121 (19 per cent) with evolved stars and 77 (12 per cent) as unknown. We find that maser sites associated with evolved stars tend to have more maser spots and have smaller angular sizes than those associated with star formation. We present evidence that maser sites associated with evolved stars show an increased likelihood of having a velocity range between 15 and 35 kms−1 compared to other maser sites. Of the 31 non-detections, we conclude they were not detected due to intrinsic variability and confirm previous results showing that such variable masers tend to be weaker and have simpler spectra with fewer peaks