Adaptive designs in dermatology clinical trials: Current status and future perspectives

Current drug development strategies present many challenges that can impede drug approval by regulatory agencies. Alternative study models, such as adaptive trial designs, have recently sparked interest, as they provide a flexible and more efficient approach in conducting clinical trials. Adaptive trial designs offer several potential benefits over traditional randomized controlled trials, which include decrease in costs, reduced clinical development time and limiting exposure of patients to potentially ineffective treatments allowing completion of studies with fewer patients. This article explores the current use of adaptive trial designs in non-oncologic skin diseases and highlights the most common types of adaptive designs used in the field. We also review the operational challenges and statistical considerations associated with such designs and propose clinical development strategies to successfully implement adaptive designs. The article also proposes instances where adaptive trial designs are particularly beneficial, and other situations where they may not be very useful.

Measurement of the ^{140}Ce(n,γ) Cross Section at n_TOF and Its Astrophysical Implications for the Chemical Evolution of the Universe

^{140}Ce(n,γ) is a key reaction for slow neutron-capture (s-process) nucleosynthesis due to being a bottleneck in the reaction flow. For this reason, it was measured with high accuracy (uncertainty ≈5%) at the n_TOF facility, with an unprecedented combination of a high purity sample and low neutron-sensitivity detectors. The measured Maxwellian averaged cross section is up to 40% higher than previously accepted values. Stellar model calculations indicate a reduction around 20% of the s-process contribution to the Galactic cerium abundance and smaller sizeable differences for most of the heavier elements. No variations are found in the nucleosynthesis from massive stars.

Fetal diagnosis and management of pulmonary artery sling: A case series

OBJECTIVE

Pulmonary artery sling is a rare congenital anomaly accounting for 2% of all patients with vascular anomalies that cause airway obstruction. In the normal heart, the left (LPA) and right (RPA) pulmonary arteries arise in the intrapericardial space. However, in the pulmonary artery sling, the LPA trunk arises in the extrapericardial space from the posterior aspect of the mid RPA and courses posterior to the trachea causing tracheal compression and, at times, bronchial compression. While a full spectrum of congenital cardiac pathology can be identified before birth, only a few case reports document the prenatal diagnosis of an Left pulmonary artery sling (LPAS).

METHOD

We retrospectively identified all cases of prenatal LPAS from three Canadian fetal cardiology centers (2015-2022).

RESULTS

Using the 3-vessel-tracheal view via fetal echocardiography (FE), four fetuses from three pregnancies demonstrated abnormal origin of the LPA from RPA and echogenic trachea. In one of two affected monochorionic twins coronal imaging demonstrated a significant narrowing of the large airways consistent with significant airway obstruction.

CONCLUSION

Prenatal detection of LPAS by FE is possible and should prompt an evaluation for airway obstruction in the coronal view. Investigating associated lesions and genetic testing are recommended for informed shared decision making.

Theranostic Nanoparticle Uptake in Patient Brain Tumors as Quantified by MP2RAGE T1 Mapping

PURPOSE/OBJECTIVE(S)

Modern radiation therapy techniques provide effective treatments for solid tumors, but there remain challenges with delivering high doses to elusive tumors without causing toxicity to surrounding normal tissue. Pre-clinical trials have demonstrated the theranostic properties of a recently developed gadolinium-based nanoparticle (Gd-NP). The first in-human clinical trial was conducted to assess the safety and dose tolerance of intravenous Gd-NPs in combination with whole brain radiotherapy and showed favorable results, including a significant correlation between tumor uptake and therapeutic response. The second, double-blinded, in-human clinical trial is underway in the US and aims to evaluate if brain-directed stereotactic radiation in conjunction with NPs will improve local tumor control compared to radiation alone. The current work investigates uptake patterns in brain tumors of 23 patients as quantified by magnetization prepared 2 rapid gradient echo (MP2RAGE) T1 mapping.

MATERIALS/METHODS

A phantom containing eight vials of NP-saline solutions at varying concentrations was created to examine the relationship between NP concentration and longitudinal relaxation (T1, in seconds). This relationship is known as relaxivity and is dependent on the contrast agent, field strength and T1 mapping sequence. A 3T MAGNETOM Vida scanner and MP2RAGE sequence were used to image the phantom and MP2RAGE T1 maps were calculated using Bloch equations (QMRLab software). Relaxivity was determined and applied to 23 patient T1 maps (pre- and post- Gd-NP administration) to calculate uptake on an individual tumor basis. Theranostic NP uptake was calculated for every voxel in each of 129 brain metastases and examined for patterns in quantity and distribution.

RESULTS

Average individual tumor uptake ranged from 0.02-0.12 mg/ml, where average overall uptake was equal to 0.05 mg/ml. A relationship between tumor diameter and mean NP concentration was observed and best represented by a power-based curve (R2 = 0.92). In contrast, patients with suspected placebo administration appeared to have no uptake and therefore no relationship with tumor diameter. The distribution of NP concentration within the tumor was also examined; on average, linear uptake profiles through tumor centroids (ant-post, left-right) demonstrated roughly gaussian patterns of uptake with lower concentrations at the tumor edges and higher concentrations at the tumor center. This pattern indicates robust tumor penetration and may have implications for amplifying radiation dose to hypoxic tumors.

CONCLUSION

Gd-NP uptake in brain metastases can be quantified using MP2RAGE T1 mapping. Uptake was determined for each voxel in each tumor volume, where a gaussian pattern of spatial concentrations was observed. This analysis procedure will be applied to the full data set, when available, to evaluate the impact of NP uptake (in conjunction with radiation therapy) within individual patients and individual tumors.

Tropicalization shifts herbivore pressure from seagrass to rocky reef communities

Climate-driven species redistributions are reshuffling the composition of marine ecosystems. How these changes alter ecosystem functions, however, remains poorly understood. Here we examine how impacts of herbivory change across a gradient of tropicalization in the Mediterranean Sea, which includes a steep climatic gradient and marked changes in plant nutritional quality and fish herbivore composition. We quantified individual feeding rates and behaviour of 755 fishes of the native Sarpa salpa, and non-native Siganus rivulatus and Siganus luridus. We measured herbivore and benthic assemblage composition across 20 sites along the gradient, spanning 30° of longitude and 8° of latitude. We coupled patterns in behaviour and composition with temperature measurements and nutrient concentrations to assess changes in herbivory under tropicalization. We found a transition in ecological impacts by fish herbivory across the Mediterranean from a predominance of seagrass herbivory in the west to a dominance of macroalgal herbivory in the east. Underlying this shift were changes in both individual feeding behaviour (i.e. food choice) and fish assemblage composition. The shift in feeding selectivity was consistent among temperate and warm-affiliated herbivores. Our findings suggest herbivory can contribute to the increased vulnerability of seaweed communities and reduced vulnerability of seagrass meadows in tropicalized ecosystems.

Persistent thermally driven shift in the functional trait structure of herbivorous fishes: Evidence of top-down control on the rebound potential of temperate seaweed forests?

Extreme climatic events can reshape the functional structure of ecological communities, potentially altering ecological interactions and ecosystem functioning. While these shifts have been widely documented, evidence of their persistence and potential flow-on effects on ecosystem structure following relaxation of extreme events remains limited. Here, we investigate changes in the functional trait structure - encompassing dimensions of resource use, thermal affinity, and body size - of herbivorous fishes in a temperate reef system that experienced an extreme marine heatwave (MHW) and subsequent return to cool conditions. We quantify how changes in the trait structure modified the nature and intensity of herbivory-related functions (macroalgae, turf, and sediment removal), and explored the potential flow-on effects on the recovery dynamics of macroalgal foundation species. The trait structure of the herbivorous fish assemblage shifted as a result of the MHW, from dominance of cool-water browsing species to increased evenness in the distribution of abundance among temperate and tropical guilds supporting novel herbivory roles (i.e. scraping, cropping, and sediment sucking). Despite the abundance of tropical herbivorous fishes and intensity of herbivory-related functions declined following a period of cooling after the MHW, the underlying trait structure displayed limited recovery. Concomitantly, algal assemblages displayed a lack of recovery of the formerly dominant foundational species, the kelp Ecklonia radiata, transitioning to an alternative state dominated by turf and Sargassum spp. Our study demonstrates a legacy effect of an extreme MHW and exemplified the value of monitoring phenotypic (trait mediated) changes in the nature of core ecosystem processes to predict and adapt to the future configurations of changing reef ecosystems.

Big insight from the little skate: Leucoraja erinacea as a developmental model system

The vast majority of extant vertebrate diversity lies within the bony and cartilaginous fish lineages of jawed vertebrates. There is a long history of elegant experimental investigation of development in bony vertebrate model systems (e.g., mouse, chick, frog and zebrafish). However, studies on the development of cartilaginous fishes (sharks, skates and rays) have, until recently, been largely descriptive, owing to the challenges of embryonic manipulation and culture in this group. This, in turn, has hindered understanding of the evolution of developmental mechanisms within cartilaginous fishes and, more broadly, within jawed vertebrates. The little skate (Leucoraja erinacea) is an oviparous cartilaginous fish and has emerged as a powerful and experimentally tractable developmental model system. Here, we discuss the collection, husbandry and management of little skate brood stock and eggs, and we present an overview of key stages of skate embryonic development. We also discuss methods for the manipulation and culture of skate embryos and illustrate the range of tools and approaches available for studying this system. Finally, we summarize a selection of recent studies on skate development that highlight the utility of this system for inferring ancestral anatomical and developmental conditions for jawed vertebrates, as well as unique aspects of cartilaginous fish biology.

First 80Se(n,γ) cross section measurement with high resolution in the full stellar energy range 1 eV - 100 keV and its astrophysical implications for the s-process

Most elements heavier than iron have been generated in the stellar media by means of neutron capture reactions, approximately half are produced by the slow neutron capture or s-process. Radiative neutron capture cross section measurements are of fundamental importance for the study of this mechanism. In this contribution we present a brief summary on the measurement and results for the 80Se(n,γ) cross-section. The experiment was carried out at CERN n_TOF EAR1 via the time of flight (ToF) technique, using four C6D6 scintillation detectors with very fast response. More than a hundred new resonances have been analyzed for the first time with a high accuracy. The MACS obtained at kT = 8 keV is 36% smaller than the recommended value in KADo-NiS. Some of the astrophysical implications of this result are elucidated in this contribution.

The prevalence and significance of mitral annular disjunction on clinical outcomes in patients undergoing mitral valve surgery

Funding Acknowledgements

Type of funding sources: None.

Background

Mitral annular disjunction (MAD) is a common structural abnormality involving a distinct separation of the left atrium/mitral valve annulus and myocardium continuum. MAD is commonly associated with altered mitral valve annular dynamics, increased left ventricular and mitral valve apparatus stress and potentially life threatening arrhythmias. At present there is limited data on the prevalence and significance of MAD in patients requiring mitral valve surgery.

Purpose

To ascertain the prevalence, extent and significance of MAD on a general cohort of patients with mitral valve disease who required mitral valve surgery. Primary outcomes included: duration of surgery, need for re-do operation (any cause), neurological and gastro-intestinal complications, cardiogenic shock and mortality. These were assessed during the surgical hospitalisation period.

Methods

The local cardiothoracic database within a large tertiary centre was used to identify all patients who underwent mitral valve surgery between 2013 and 2020. From this, patients who were found to have a transthoracic echocardiogram (TTE) pre and post mitral valve surgery were included. Two experienced sonographers retrospectively reviewed and analysed each TTE. The data collected included: presence, location and extent of MAD (pre and post-surgery). The local cardiothoracic database and electronic patient records were reviewed for primary outcomes.

Results

A total of 187 patients were included (age: 65.6 ± 13.7 years, 74.2% males). The most common reason for mitral valve surgery was mitral valve prolapse (31.6%), remaining aetiologies included functional MR, ischemic MR, infective endocarditis, rheumatic mitral stenosis and congenital abnormalities. Surgical intervention included: leaflet repair ± annuloplasty ring (57.2%), bio-prosthesis (19.8%) or mechanical prosthesis (23.0%). Pre surgery, MAD was present in 32.6% of all patients and was most commonly seen in patients with mitral valve prolapse (21.3%). In patients with MAD, the averaged MAD length was 8.4 ± 3.9mm (median 7 [IQR: 5-11]). Post-surgery, MAD was only identified in 2 patients, both of whom had mitral valve repair± annuloplasty ring. As seen in Table 1, there were no significant differences in clinical outcomes in patients with or without MAD.

Conclusion

MAD is common in a cohort of patients requiring mitral valve surgery. Surgical intervention is able to correct MAD in the vast majority of patients and its presence does not affect immediate post-surgical outcomes. Abstract Table 1.

Resilience of seagrass populations to thermal stress does not reflect regional differences in ocean climate

The prevalence of local adaptation and phenotypic plasticity among populations is critical to accurately predicting when and where climate change impacts will occur. Currently, comparisons of thermal performance between populations are untested for most marine species or overlooked by models predicting the thermal sensitivity of species to extirpation. Here we compared the ecological response and recovery of seagrass populations (Posidonia oceanica) to thermal stress throughout a year-long translocation experiment across a 2800-km gradient in ocean climate. Transplants in central and warm-edge locations experienced temperatures > 29°C, representing thermal anomalies > 5°C above long-term maxima for cool-edge populations, 1.5°C for central and < 1°C for warm-edge populations. Cool-edge, central and warm-edge populations differed in thermal performance when grown under common conditions, but patterns contrasted with expectations based on thermal geography. Cool-edge populations did not differ from warm-edge populations under common conditions and performed significantly better than central populations in growth and survival. Our findings reveal that thermal performance does not necessarily reflect the thermal geography of a species. We demonstrate that warm-edge populations can be less sensitive to thermal stress than cooler, central populations suggesting that Mediterranean seagrasses have greater resilience to warming than current paradigms suggest.

Strategies for the delay of surgery in the management of resectable hepatobiliary malignancies during the COVID-19 pandemic

Objective

We aimed to review data about delaying strategies for the management of hepatobiliary cancers requiring surgery during the covid-19 pandemic.

Background

Given the covid-19 pandemic, many jurisdictions, to spare resources, have limited access to operating rooms for elective surgical activity, including cancer, thus forcing deferral or cancellation of cancer surgeries. Surgery for hepatobiliary cancer is high-risk and particularly resource-intensive. Surgeons must critically appraise which patients will benefit most from surgery and which ones have other therapeutic options to delay surgery. Little guidance is currently available about potential delaying strategies for hepatobiliary cancers when surgery is not possible.

Methods

An international multidisciplinary panel reviewed the available literature to summarize data relating to standard-of-care surgical management and possible mitigating strategies to be used as a bridge to surgery for colorectal liver metastases, hepatocellular carcinoma, gallbladder cancer, intrahepatic cholangiocarcinoma, and hilar cholangiocarcinoma.

Results

Outcomes of surgery during the covid-19 pandemic are reviewed. Resource requirements are summarized, including logistics and adverse effects profiles for hepatectomy and delaying strategies using systemic, percutaneous and radiation ablative, and liver embolic therapies. For each cancer type, the long-term oncologic outcomes of hepatectomy and the clinical tools that can be used to prognosticate for individual patients are detailed.

Conclusions

There are a variety of delaying strategies to consider if availability of operating rooms decreases. This review summarizes available data to provide guidance about possible delaying strategies depending on patient, resource, institution, and systems factors. Multidisciplinary team discussions should be leveraged to consider patient- and tumour-specific information for each individual case.

Setup for the measurement of the 235U(n, f) cross section relative to n-p scattering up to 1 GeV

The neutron induced fission of 235U is extensively used as a reference for neutron fluence measurements in various applications, ranging from the investigation of the biological effectiveness of high energy neutrons, to the measurement of high energy neutron cross sections of relevance for accelerator driven nuclear systems. Despite its widespread use, no data exist on neutron induced fission of 235U above 200 MeV. The neutron facility n_TOF offers the possibility to improve the situation. The measurement of 235U(n,f) relative to the differential n-p scattering cross-section, was carried out in September 2018 with the aim of providing accurate and precise cross section data in the energy range from 10 MeV up to 1 GeV. In such measurements, Recoil Proton Telescopes (RPTs) are used to measure the neutron flux while the fission events are detected and counted with dedicated detectors. In this paper the measurement campaign and the experimental set-up are illustrated.

Monte Carlo simulations and n-p differential scattering data measured with Proton Recoil Telescopes

The neutron-induced fission cross section of 235U, a standard at thermal energy and between 0.15 MeV and 200 MeV, plays a crucial role in nuclear technology applications. The long-standing need of improving cross section data above 20 MeV and the lack of experimental data above 200 MeV motivated a new experimental campaign at the n_TOF facility at CERN. The measurement has been performed in 2018 at the experimental area 1 (EAR1), located at 185 m from the neutron-producing target (the experiment is presented by A. Manna et al. in a contribution to this conference). The 235U(n,f) cross section from 20 MeV up to about 1 GeV has been measured relative to the 1H(n,n)1H reaction, which is considered the primary reference in this energy region. The neutron flux impinging on the 235U sample (a key quantity for determining the fission events) has been obtained by detecting recoil protons originating from n-p scattering in a C2H4 sample. Two Proton Recoil Telescopes (PRT), consisting of several layers of solid-state detectors and fast plastic scintillators, have been located at proton scattering angles of 25.07° and 20.32°, out of the neutron beam. The PRTs exploit the ΔE-E technique for particle identification, a basic requirement for the rejection of charged particles from neutron-induced reactions in carbon. Extensive Monte Carlo simulations were performed to characterize proton transport through the different slabs of silicon and scintillation detectors, to optimize the experimental set-up and to deduce the efficiency of the whole PRT detector. In this work we compare measured data collected with the PRTs with a full Monte Carlo simulation based on the Geant-4 toolkit.

OP0157-HPR DISSEMINATION AND ASSESSING IMPLEMENTATION OF THE EULAR RECOMMENDATIONS FOR PATIENT EDUCATION FOR PEOPLE WITH INFLAMMATORY ARTHRITIS ACROSS EUROPE

Background:

EULAR recommendations for patient education for people with inflammatory arthritis (IA) were published in 2015.1This is the first systematic dissemination and implementation study, reporting qualitative data identifying barriers to implementation of the recommendations.

Objectives:

To (i) disseminate and assess the level of acceptability and applicability of the EULAR recommendations for patient education among healthcare professionals and rheumatologists and (ii) assess potential barriers and facilitators to their application in clinical practice.

Methods:

This was a cross-sectional study using survey methods. Survey items were developed in English and translated into 20 different languages before being distributed to health professionals by snowball sampling using an online platform. The items covered demographic information and 10-point rating scales assessing the level of acceptability and applicability of each of the eight recommendations. In addition, textual data fields were provided to assess reasons for disagreeing and barriers to implementation of the recommendations in practice. Quantitative data were analysed descriptively with agreement and applicability levels summarised as median (IQR) scores. Textual data were analysed by content analysis and presented in themes. Finally, collaborators in each country reviewed the top barriers to implementation and proposed facilitators to implementation in their respective countries.

Results:

A total of 2442 responses were recorded from 23 countries, but only 1495 contained complete data. Of complete responses, 74% were women. Most of the professionals were nurses (n=640), rheumatologists (n=369) and physiotherapists (n=232).

Table 1 presents the levels of agreement and applicability of the recommendations. For all recommendations, the level of agreement was high (median=10). However, the level of applicability was generally lower compared to each corresponding agreement level, especially for recommendation 6, which states that the effectiveness of patient education should be evaluated. Lack of an effective evaluation tool was the biggest barrier to implementation.

Table 1.

Levels of agreement and applicability of each recommendation.

AgreementApplicabilityMedianIQRMedianIQRRecommendation 11010 to 1087 to 10Recommendation 21010 to 1086 to 10Recommendation 3109 to 1087 to 10Recommendation 4108 to 1075 to 10Recommendation 5108 to 1075 to 9Recommendation 6108 to 1064 to 8Recommendation 7109 to 1085 to 8Recommendation 81010 to 1085 to 8

There were notable similarities between barriers and facilitators for implementation of the recommendations across countries. The 3 most common barriers to application were; (i) lack of time (ii) lack of training in how to provide patient education and (iii) not having enough staff to provide patient education. The most common facilitators were: tailoring the content and delivery of patient education to individual patients; training providers, and evaluating the effectiveness of patient education with individual patients.

Conclusion:

This project has disseminated the EULAR recommendations for patient education across 23 countries. There was high agreement with the recommendations among health professionals but their application to clinical practice was lower. Some barriers to application are amenable to change such as addressing training needs of health professionals and developing evaluation tools for patient education.

Figure 1.

Recommendations for patient education in inflammatory arthritis.1

References:

[1]Zangi HA, et al. EULAR recommendations for patient education for people with inflammatory arthritisAnn Rheum Dis. 2015;74:954-962.

Disclosure of Interests:

Sarah Bennett: None declared, Heidi A. Zangi: None declared, Astrid van Tubergen Consultant of: Novartis, Mwidimi Ndosi Grant/research support from: Bristol Myers Squibb, Consultant of: Janssen, Pfizer

AB1321-HPR DEVELOPING A SELF-MANAGEMENT INTERVENTION TO MANAGE JOINT HYPERMOBILITY SYNDROME AND EHLERS-DANLOS SYNDROME HYPERMOBILITY TYPE: AN ANALYSIS INFORMED BY BEHAVIOUR CHANGE THEORY

Background:

Joint Hypermobility Syndrome (JHS) and Ehlers-Danlos Syndrome Hypermobility Type (EDS-HT) are heritable disorders of connective tissue that can cause joint instability and pain and are associated with increased anxiety and depression. There is currently little UK guidance for supporting patients with JHS/EDS-HT1. The analysis presented here used the Behaviour Change Wheel (made up of the Theoretical Domains Framework (TDF) and Capability, Opportunity, Motivation and Behaviour (COM-B) model2) to identify possible intervention options to improve self-management in people with JHS/EDS-HT.

Objectives:

To determine recommendations for the components of a behaviour change intervention for people with JHS or EDS-HT.

Methods:

Data from: 1) A systematic review and thematic synthesis of the literature examining adults’ lived experiences of JHS/EDS3and 2) A thematic analysis of interview data where UK adults with JHS/EDS-HT (n=17, 14 women, 3 men) discussed the psychosocial impact of the condition on their lives4, were mapped onto the TDF and COM-B in a behavioural analysis. A modified Nominal Group Technique focus group (n=9, all women) explored which interventions identified by the TDF/COM-B mapping exercise were most important to them.

Results:

Participants prioritised a range of potential self-management interventions, including:

Education: Participants wanted greater support to improve their knowledge of JHS/EDS-HT, including self-help strategies for coping with injury, fatigue and overexertion, and how to evaluate information about their condition.

Training: In activity pacing, assertiveness and communication skills, and what to expect during pregnancy, when symptoms of JHS/EDS-HT can worsen.

Environmental restructuring and enablement:Support from occupational therapists to maintain independence at home. Enablement of access to CBT, mindfulness and emotional support.

Modelled behaviour:Positive first-person narratives that address how other patients with JHS/EDS-HT have coped with anxiety, depression, distress, fear, frustration and feelings of loss.

Conclusion:

This study is the first to apply theoretically-informed approaches to the management of JHS/EDS-HT. Through a modified nominal group technique, potential behaviour change interventions for addressing barriers to self-management have been prioritised. Discussion with participants indicated poor access to psychological support, occupational therapy and a lack of knowledge of JHS/EDS-HT. Future research with healthcare professional and patient stakeholder groups will further evaluate which intervention options would be most acceptable and feasible for the management of JHS/EDS-HT.

References:

[1]Palmer, S., Terry, R. Rimes, K.A., Clark, C., Simmonds, J. & Horwood, J. (2016). Physiotherapy management of joint hypermobility syndrome – a focus group study of patient and health professional perspectives. Physiotherapy,http://dx.doi.org/10.1016/j.physio.2015.05.001.

[2]Michie, S., van Stralen, M.M. & West, R. (2011). The behaviour change wheel: A new method for characterising and designing behaviour change interventions. Implementation Science, 6(42).

[3]Bennett, S.E., Walsh, N., Moss, T. and Palmer, S. (2019a) “The lived experience of joint hypermobility and Ehlers-Danlos Syndromes: A systematic review and thematic synthesis.”Physical Therapy Reviews, 24 (1-2). pp. 12-28. ISSN 1083-3196

[4]Bennett, S.E., Walsh, N., Moss, T. and Palmer, S. (2019b) “Understanding the psychosocial impact of Joint Hypermobility Syndrome and Ehlers-Danlos Syndrome Hypermobility Type: A qualitative interview study.”Disability and Rehabilitation. ISSN 0963-8288

Disclosure of Interests:

None declared

Ecological effects of non-native species in marine ecosystems relate to co-occurring anthropogenic pressures

Predictors for the ecological effects of non-native species are lacking, even though such knowledge is fundamental to manage non-native species and mitigate their impacts. Current theories suggest that the ecological effects of non-native species may be related to other concomitant anthropogenic stressors, but this has not been tested at a global scale. We combine an exhaustive meta-analysis of the ecological effects of marine non-native species with human footprint proxies to determine whether the ecological changes due to non-native species are modulated by co-occurring anthropogenic impacts. We found that non-native species had greater negative effects on native biodiversity where human population was high and caused reductions in individual performance where cumulative human impacts were large. On this basis we identified several marine ecoregions where non-native species may have the greatest ecological effects, including areas in the Mediterranean Sea and along the northwest coast of the United States. In conclusion, our global assessment suggests coexisting anthropogenic impacts can intensify the ecological effects of non-native species.

Measurement of the energy-differential cross-section of the 12C(n,p)12B and 12C(n,d)11B reactions at the n_TOF facility at CERN

Although the 12C(n,p)12B and 12C(n,d)11B reactions are of interest in several fields of basic and applied Nuclear Physics the present knowledge of these two cross-sections is far from being accurate and reliable, with both evaluations and data showing sizable discrepancies. As part of the challenging n_TOF program on (n,cp) nuclear reactions study, the energy differential cross-sections of the 12C(n,p)12B and 12C(n,d)11 B reactions have been measured at CERN from the reaction thresholds up to 30 MeV neutron energy. Both measurements have been recently performed at the long flight-path (185 m) experimental area of the n_TOF facility at CERN using a pure (99.95%) rigid graphite target and two silicon telescopes. In this paper an overview of the experiment is presented together with a few preliminary results.

Status and perspectives of the neutron time-of-flight facility n_TOF at CERN

Since the start of its operation in 2001, based on an idea of Prof. Carlo Rubbia [1], the neutron time of-flight facility of CERN, n_TOF, has become one of the most forefront neutron facilities in the world for wide-energy spectrum neutron cross section measurements. Thanks to the combination of excellent neutron energy resolution and high instantaneous neutron flux available in the two experimental areas, the second of which has been constructed in 2014, n_TOF is providing a wealth of new data on neutron-induced reactions of interest for nuclear astrophysics, advanced nuclear technologies and medical applications. The unique features of the facility will continue to be exploited in the future, to perform challenging new measurements addressing the still open issues and long-standing quests in the field of neutron physics. In this document the main characteristics of the n_TOF facility and their relevance for neutron studies in the different areas of research will be outlined, addressing the possible future contribution of n_TOF in the fields of nuclear astrophysics, nuclear technologies and medical applications. In addition, the future perspectives of the facility will be described including the upgrade of the spallation target, the setup of an imaging installation and the construction of a new irradiation area.

First results of the 230Th(n,f) cross section measurements at the CERN n_TOF facility

The study of neutron-induced reactions on actinides is of considerable importance for the design of advanced nuclear systems and alternative fuel cycles. Specifically, 230Th is produced from the α-decay of 234U as a byproduct of the 232Th/233U fuel cycle, thus the accurate knowledge of its fission cross section is strongly required. However, few experimental datasets exist in literature with large deviations among them, covering the energy range between 0.2 to 25 MeV. In addition, the study of the 230Th(n,f) cross-section is of great interest in the research on the fission process related to the structure of the fission barriers. Previous measurements have revealed a large resonance at En=715 keV and additional fine structures, but with high discrepancies among the cross-section values of these measurements. This contribution presents preliminary results of the 230Th(n,f) cross-section measurements at the CERN n_TOF facility. The high purity targets of the natural, but very rare isotope 230Th, were produced at JRC-Geel in Belgium. The measurements were performed at both experimental areas (EAR-1 and EAR-2) of the n_TOF facility, covering a very broad energy range from thermal up to at least 100 MeV. The experimental setup was based on Micromegas detectors with the 235U(n,f) and 238U(n,f) reaction cross-sections used as reference.

New reaction rates for the destruction of7Be during big bang nucleosynthesis measured at CERN/n_TOF and their implications on the cosmological lithium problem

New measurements of the7Be(n,α)4He and7Be(n,p)7Li reaction cross sections from thermal to keV neutron energies have been recently performed at CERN/n_TOF. Based on the new experimental results, astrophysical reaction rates have been derived for both reactions, including a proper evaluation of their uncertainties in the thermal energy range of interest for big bang nucleosynthesis studies. The new estimate of the7Be destruction rate, based on these new results, yields a decrease of the predicted cosmological7Li abundance insufficient to provide a viable solution to the cosmological lithium problem.

The 154Gd neutron capture cross section measured at the n_TOF facility and its astrophysical implications

The (n, γ) cross sections of the gadolinium isotopes play an important role in the study of the stellar nucleosynthesis. In particular, among the isotopes heavier than Fe, 154Gd together with 152Gd have the peculiarity to be mainly produced by the slow capture process, the so-called s-process, since they are shielded against the β-decay chains from the r-process region by their stable samarium isobars. Such a quasi pure s-process origin makes them crucial for testing the robustness of stellar models in galactic chemical evolution (GCE). According to recent models, the 154Gd and 152Gd abundances are expected to be 15-20% lower than the reference un-branched s-process 150Sm isotope. The close correlation between stellar abundances and neutron capture cross sections prompted for an accurate measurement of 154Gd cross section in order to reduce the uncertainty attributable to nuclear physics input and eventually rule out one of the possible causes of present discrepancies between observation and model predictions. To this end, the neutron capture cross section of 154Gd was measured in a wide neutron energy range (from thermal up to some keV) with high resolution in the first experimental area of the neutron time-of-flight facility n_TOF (EAR1) at CERN. In this contribution, after a brief description of the motivation and of the experimental setup used in the measurement, the preliminary results of the 154Gd neutron capture reaction as well as their astrophysical implications are presented.

First results of the 241Am(n,f) cross section measurement at the Experimental Area 2 of the n_TOF facility at CERN

Feasibility, design and sensitivity studies on innovative nuclear reactors that could address the issue of nuclear waste transmutation using fuels enriched in minor actinides, require high accuracy cross section data for a variety of neutron-induced reactions from thermal energies to several tens of MeV. The isotope 241Am (T1/2= 433 years) is present in high-level nuclear waste (HLW), representing about 1.8 % of the actinide mass in spent PWR UOx fuel. Its importance increases with cooling time due to additional production from the β-decay of 241Pu with a half-life of 14.3 years. The production rate of 241 Am in conventional reactors, including its further accumulation through the decay of 241Pu and its destruction through transmutation/incineration are very important parameters for the design of any recycling solution. In the present work, the 241 Am(n,f) reaction cross-section was measured using Micromegas detectors at the Experimental Area 2 of the n_TOF facility at CERN. For the measurement, the 235U(n,f) and 238U(n,f) reference reactions were used for the determination of the neutron flux. In the present work an overview of the experimental setup and the adopted data analysis techniques is given along with preliminary results.

Integrating within-species variation in thermal physiology into climate change ecology

Accurately forecasting the response of global biota to warming is a fundamental challenge for ecology in the Anthropocene. Within-species variation in thermal sensitivity, caused by phenotypic plasticity and local adaptation of thermal limits, is often overlooked in assessments of species responses to warming. Despite this, implicit assumptions of thermal niche conservatism or adaptation and plasticity at the species level permeate the literature with potentially important implications for predictions of warming impacts at the population level. Here we review how these attributes interact with the spatial and temporal context of ocean warming to influence the vulnerability of marine organisms. We identify a broad spectrum of thermal sensitivities among marine organisms, particularly in central and cool-edge populations of species distributions. These are characterized by generally low sensitivity in organisms with conserved thermal niches, to high sensitivity for organisms with locally adapted thermal niches. Important differences in thermal sensitivity among marine taxa suggest that warming could adversely affect benthic primary producers sooner than less vulnerable higher trophic groups. Embracing the spatial, temporal and biological context of within-species variation in thermal physiology helps explain observed impacts of ocean warming and can improve forecasts of climate change vulnerability in marine systems.

This article is part of the theme issue ‘Physiological diversity, biodiversity patterns and global climate change: testing key hypotheses involving temperature and oxygen’.

Evaluation design of the Social Engagement Framework for Addressing the Chronic-disease-challenge (SEFAC): a mindfulness-based intervention to promote the self-management of chronic conditions and a healthy lifestyle

BACKGROUND

The Social Engagement Framework for Addressing the Chronic-disease-challenge (SEFAC) project intends to empower citizens at risk of or with type 2 diabetes (T2DM) and/or cardiovascular disease (CVD) to self-manage their chronic conditions through the SEFAC intervention. The intervention combines the concepts of mindfulness, social engagement and information and communication technology support, in order to reduce the burden of citizens with chronic conditions and to increase the sustainability of the health system in four European countries.

METHODS

A prospective cohort study with a 6-month pre-post design will be conducted in four European countries: Croatia, Italy, the Netherlands and the United Kingdom. A total of 360 community-dwelling citizens ≥50 years of age will be recruited; 200 citizens at risk of T2DM and/or CVD in the next 10 years (50 participants in each country) and 160 citizens with T2DM and/or CVD (40 participants in each country). Effects of the intervention in terms of self-management, healthy lifestyle behavior, social support, stress, depression, sleep and fatigue, adherence to medications and health-related quality of life will be assessed. In addition, a preliminary cost-effectiveness analysis will be performed from a societal and healthcare perspective.

DISCUSSION

The SEFAC project will further elucidate whether the SEFAC intervention is feasible and (cost-) effective among citizens at risk of and suffering from T2DM and/or CVD in different settings.

TRIAL REGISTRATION

ISRCTN registry number is ISRCTN11248135 . Date of registration is 30/08/2018 (retrospectively registered).

Developing more participatory and accountable institutions for health: identifying health system research priorities for the Sustainable Development Goal-era

Health policy and systems research (HPSR) is vital to guiding global institutions, funders, policymakers, activists and implementers in developing and enacting strategies to achieve the Sustainable Development Goals. We undertook a multi-stage participatory process to identify priority research questions relevant to improving accountability within health systems. We conducted interviews (n = 54) and focus group discussions (n = 2) with policymakers from international and national bodies (ministries of health, other government agencies and technical support institutions) across the WHO regions. Respondents were asked to reflect on challenges and current policy discussions related to health systems accountability, and to identify their pressing research needs. We also conducted an overview of reviews (n = 34) to determine the current status of knowledge on health systems accountability and to identify any gaps. We extracted research questions from the policymaker interviews and focus groups (70 questions) and from the overview of reviews (112 questions), and synthesized these into 36 overarching questions. Using the online platform Co-Digital, we invited researchers from around the world to refine and then rank the questions according to research importance. The questions that emerged amongst the top priorities focused on political factors that mediate the adoption or effectiveness of accountability initiatives, processes and incentives that facilitate the acceptability of accountability mechanisms among frontline healthcare providers, and the national governance reforms and contexts that enhance provider accountability. The process revealed different underlying conceptions of social accountability and how best to promote it, with some researchers and policymakers focusing on specific interventions and others embracing a more systems-oriented approach to understanding accountability, the multiple forms that it can take, how these interact with each other and the importance of power and underlying social relations. The findings from this exercise identify HPSR funding priorities and future areas for evidence production and policy engagement.

Maturation of adenovirus primes the protein nano-shell for successful endosomal escape

The ability of adenoviruses to infect a broad range of species has spurred a growing interest in nanomedicine to use adenovirus as a cargo delivery vehicle. While successful maturation of adenovirus and controlled disassembly are critical for efficient infection, the underlying mechanisms regulating these processes are not well understood. Here, we present Atomic Force Microscopy nanoindentation and fatigue studies of adenovirus capsids at different maturation stages to scrutinize their dynamic uncoating properties. Surprisingly, we find that the early intermediate immature (lacking DNA) capsid is mechanically indistinguishable in both break force and spring constant from the mature (containing DNA) capsid. However, mature and immature capsids do display distinct disassembly pathways, as revealed by our mechanically-induced fatigue analysis. The mature capsid first loses the pentons, followed by either long-term capsid stability or abrupt and complete disassembly. However, the immature capsid has a stable penton region and undergoes a stochastic disassembly mechanism, thought to be due to the absence of genomic pressure. Strikingly, the addition of the genome alone is not sufficient to achieve penton destabilization as indicated by the penton stability of the maturation-intermediate mutant, G33A. Full penton destabilization was achieved only when the genome was present in addition to the successful maturation-linked proteolytic cleavage of preprotein VI. Therefore these findings strongly indicate that maturation of adenovirus in concert with genomic pressure induces penton destabilization and thus, primes the capsid for controlled disassembly. This latter aspect is critical for efficient infection and successful cargo delivery.

Fission program at n_TOF

Since its start in 2001 the n_TOF collaboration developed a measurement program on fission, in view of advanced fuels in new generation reactors. A special effort was made on measurement of cross sections of actinides, exploiting the peculiarity of the n_TOF neutron beam which spans a huge energy domain, from the thermal region up to GeV. Moreover fission fragment angular distributions have also been measured. An overview of the cross section results achieved with different detectors is presented, including a discussion of the 237Np case where discrepancies showed up between different detector systems. The results on the anisotropy of the fission fragments and its implication on the mechanism of neutron absorption, and in applications, are also shown.

Study of the photon strength functions and level density in the gamma decay of the n + 234U reaction

The accurate calculations of neutron-induced reaction cross sections are relevant for many nuclear applications. The photon strength functions and nuclear level densities are essential inputs for such calculations. These quantities for 235U are studied using the measurement of the gamma de-excitation cascades in radiative capture on 234U with the Total Absorption Calorimeter at n_TOF at CERN. This segmented 4π gamma calorimeter is designed to detect gamma rays emitted from the nucleus with high efficiency. This experiment provides information on gamma multiplicity and gamma spectra that can be compared with numerical simulations. The code DICEBOXC is used to simulate the gamma cascades while GEANT4 is used for the simulation of the interaction of these gammas with the TAC materials. Available models and their parameters are being tested using the present data. Some preliminary results of this ongoing study are presented and discussed.

Thermal tolerance of Mediterranean marine macrophytes: Vulnerability to global warming

The Mediterranean Sea is warming at three times the rate of the global ocean raising concerns about the vulnerability of marine organisms to climate change. Macrophytes play a key role in coastal ecosystems, therefore predicting how warming will affect these key species is critical to understand the effects of climate change on Mediterranean coastal ecosystems. We measured the physiological performance of six dominant native Mediterranean macrophytes under ten temperature treatments ranging from 12 to 34°C to examine their thermal niche, and vulnerability to projected warming in the western Mediterranean up until 2100. Among the macrophytes tested, Cymodocea nodosa was the species with the highest thermal optima and it was beyond current summer temperature. Therefore, C. nodosa may benefit from projected warming over the coming century. The optimal temperature for growth of the other species (Posidonia oceanica, Cystoseira compressa, Padina pavonica, Caulerpa prolifera, and Halimeda tuna) was lower. Similarly, the species presented different upper lethal limits, spanning at least across 5.1°C between 28.9°C (P. oceanica) and >34°C (C. nodosa). Our results demonstrate the variable physiological responses of species within the same local community to temperature changes and highlight important potential differences in climate change vulnerability, among species within coastal marine ecosystems.

804. Impact of Azithromycin Prophylaxis in Lung Transplant Recipients on the Risk of Nontuberculous Mycobacterial Infections

Background

Azithromycin has been shown to improve FEV1 in lung transplant recipients (LTR) with bronchiolitis obliterans syndrome (BOS). The impact of azithromycin use on the incidence of infections due to Mycobacterium avium complex (MAC) and M. abscessus in LTR is currently unknown.

Methods

We conducted a nested case–control study of a retrospective cohort of adult LTR transplanted between 2007 and 2017. Cases were defined as LTR with nontuberculous mycobacterial (NTM) infections due to MAC and/or M. abscessus. Controls were defined as LTR without NTM infections. NTM infection was defined by presence of pulmonary symptoms and radiographic changes (clinical criteria) in addition to positive cultures from ≥2 sputa or ≥1 bronchial specimens (microbiological criteria) according to the IDSA/ATS criteria. LTR who meet microbiological, but not clinical criteria were considered colonized and not included for analysis. Azithromycin use was defined as ≥90 days for BOS treatment.

Results

Among 538 LTR, 60% (321/538) were male and 81% (434/538) received double LTs. Indication for LT was idiopathic pulmonary fibrosis (28% [152/538]), chronic obstructive pulmonary disease (23% [121/538]), cystic fibrosis [CF] (13% [68/538]), and other (37% [197/538]). The overall incidence of NTM infections was 4.3% (23/538); of which 65.2% (15/23), 17.4% (4/23), and 17.4% (4/23) were due to MAC, M. abscessus and polymicrobial infections, respectively. Thirty-one percent (165/538) of LTR received azithromycin. LTR who received azithromycin prophylaxis had 0.21 times the odds of developing NTM infections compared with LTR who did not receive azithromycin prophylaxis (OR: 0.21, 95% CI: 0.02 – 0.86, P = 0.02). Age (P = 0.88), type of LT (P = 0.81), pretransplant NTM colonization (P = 0.46), and CF (P = 0.22) were evaluated as possible risk factors, but were not associated with increased risk of developing NTM infections in bivariable analyses. In a multivariable logistic regression model, azithromycin prophylaxis was independently associated with decreased risk of NTM infections after adjusting for CF and pretransplant NTM colonization (aOR: 0.20, 95% CI: 0.05–0.88, P = 0.01).

Conclusion

Azithromycin use was associated with lower risk of NTM infections due to M. abscessus and MAC in our LTR.

Disclosures

All authors: No reported disclosures.

Geography and island geomorphology shape fish assemblage structure on isolated coral reef systems

We quantify the relative importance of multi-scale drivers of reef fish assemblage structure on isolated coral reefs at the intersection of the Indian and Indo-Pacific biogeographical provinces. Large (>30 cm), functionally-important and commonly targeted species of fish, were surveyed on the outer reef crest/front at 38 coral reef sites spread across three oceanic coral reef systems (i.e. Christmas Island, Cocos (Keeling) Islands and the Rowley Shoals), in the tropical Indian Ocean (c. 1.126 x 106 km2). The effects of coral cover, exposure, fishing pressure, lagoon size and geographical context, on observed patterns of fish assemblage structure were modelled using Multivariate Regression Trees. Reef fish assemblages were clearly separated in space with geographical location explaining ~53 % of the observed variation. Lagoon size, within each isolated reef system was an equally effective proxy for explaining fish assemblage structure. Among local-scale variables, 'distance from port', a proxy for the influence of fishing, explained 5.2% of total variation and separated the four most isolated reefs from Cocos (Keeling) Island, from reefs with closer boating access. Other factors were not significant. Major divisions in assemblage structure were driven by sister taxa that displayed little geographical overlap between reef systems and low abundances of several species on Christmas Island corresponding to small lagoon habitats. Exclusion of geographical context from the analysis resulted in local processes explaining 47.3% of the variation, highlighting the importance of controlling for spatial correlation to understand the drivers of fish assemblage structure. Our results suggest reef fish assemblage structure on remote coral reef systems in the tropical eastern Indian Ocean reflects a biogeographical legacy of isolation between Indian and Pacific fish faunas and geomorphological variation within the region, more than local fishing pressure or reef condition. Our findings re-emphasise the importance that historical processes play in structuring contemporary biotic communities.

Accelerated Hypertriglyceridemia in Patients on Continuous Ambulatory Peritoneal Dialysis - A Preventable Abnormality

Increasing hypertriglyceridemia is a recognised complication of CAPD. To investigate the etiology lipid clearance studies using the intravenous fat tolerance test were performed in control subjects and in uremic patients before and after six months CAPD treatment. Oral carbohydrate intake was restricted and the use of hypertonic dialysate kept to a minimum. Although serum triglycerides were elevated in the uremic patients before CAPD (3.1 ± 0.3 mMol/L) no further increase occurred during therapy. Oral carbohydrate intake was restricted to 240–250 Gms/24 hrs and hypertonic dialysate to 5.7 ± 4.1% of the total. There were no significant changes in fractional removal rate of lipid. Therefore further increases in serum triglycerides in CAPD may be prevented by simple dietary manoeuvres.

Genetic diversity and kelp forest vulnerability to climatic stress

Genetic diversity confers adaptive capacity to populations under changing conditions but its role in mediating impacts of climate change remains unresolved for most ecosystems. This lack of knowledge is particularly acute for foundation species, where impacts may cascade throughout entire ecosystems. We combined population genetics with eco-physiological and ecological field experiments to explore relationships among latitudinal patterns in genetic diversity, physiology and resilience of a kelp ecosystem to climate stress. A subsequent 'natural experiment' illustrated the possible influence of latitudinal patterns of genetic diversity on ecosystem vulnerability to an extreme climatic perturbation (marine heatwave). There were strong relationships between physiological versatility, ecological resilience and genetic diversity of kelp forests across latitudes, and genetic diversity consistently outperformed other explanatory variables in contributing to the response of kelp forests to the marine heatwave. Population performance and vulnerability to a severe climatic event were thus strongly related to latitudinal patterns in genetic diversity, with the heatwave extirpating forests with low genetic diversity. Where foundation species control ecological structure and function, impacts of climatic stress can cascade through the ecosystem and, consequently, genetic diversity could contribute to ecosystem vulnerability to climate change.

Potential exposure to Australian bat lyssavirus is unlikely to prevent future bat handling among adults in South East Queensland

Despite ongoing public health messages about the risks associated with bat contact, the number of potential exposures to Australian bat lyssavirus (ABLV) due to intentional handling by members of the general public in Queensland has remained high. We sought to better understand the reasons for intentional handling among these members of the public who reported their potential exposure to inform future public health messages. We interviewed adults who resided in a defined geographic area in South East Queensland and notified potential exposure to ABLV due to intentional handling of bats by telephone between 1 January 2012 and 31 December 2013. The participation rate was 54%. Adults who reported they had intentionally handled bats in South East Queensland indicated high levels of knowledge and perception of a moderately high risk associated with bats with overall low intentions to handle bats in the future. However, substantial proportions of people would attempt to handle bats again in some circumstances, particularly to protect their children or pets. Fifty-two percent indicated that they would handle a bat if a child was about to pick up or touch a live bat, and 49% would intervene if a pet was interacting with a bat. Future public health communications should recognize the situations in which even people with highrisk perceptions of bats will attempt to handle them. Public health messages currently focus on avoidance of bats in all circumstances and recommend calling in a trained vaccinated handler, but messaging directed at adults for circumstances where children or pets may be potentially exposed should provide safe immediate management options.