92 research outputs found
Triaxiality in galaxy clusters: Mass versus Potential reconstructions
Accounting for the triaxial shapes of galaxy clusters will become important
in the context of upcoming cosmological surveys. We show that, compared to the
gas density distribution, the cluster gravitational potential can be better
characterised by a simple 3D model and is more robust against fluctuations.
Perturbations in the gas density distribution can have a substantial influence
on the derived thermodynamic properties, while cluster potentials are smooth
and well-approximated by a spheroidal model. We use a statistical sample of 85
galaxy clusters from a large cosmological hydrodynamical simulation to
investigate cluster shapes as a function of radius. In particular, we examine
the shape of isodensity and isopotential shells and analyze how it is affected
by the choice of component (gas vs. potential), substructure removal (for the
gas density) and the definition of the computation domain (interior vs.
shells). We find that the orientation and axis ratios of gas isodensity
contours are degenerate with the presence of substructures and unstable against
fluctuations. We observe that, as the derived cluster shape depends on the
method used for removing the substructures, thermodynamic properties extracted
from e.g. X-ray emissivity profiles suffer from this additional, often
underestimated bias. In contrast, the shape reconstruction of the potential is
largely unaffected by these factors and converges towards simple geometric
models for both relaxed and dynamically active clusters. The observation that
cluster potentials are better represented by simple geometrical models and
reconstructed with a low level of systematics for both dynamically active and
relaxed clusters suggests that by characterising galaxy clusters by their
potential rather than by their mass, dynamically active and relaxed clusters
could be combined in cosmological studies, improving statistics and lowering
scatter.Comment: Updated with referee's comments, revised version submitted to A&A, 16
pages, 14 figure
Paraburkholderia sabiae Uses One Type VI Secretion System (T6SS-1) as a Powerful Weapon against Notorious Plant Pathogens
Paraburkholderia sabiae LMG24235 is a nitrogen-fixing betaproteobacterium originally isolated from a root nodule of Mimosa caesalpiniifolia in Brazil. We show here that this strain effectively kills strains from several bacterial families (Burkholderiaceae, Pseudomonadaceae, Enterobacteriaceae) which include important plant pathogens in a contact-dependent manner. De novo assembly of the first complete genome of P. sabiae using long sequencing reads and subsequent annotation revealed two gene clusters predicted to encode type VI secretion systems (T6SS), which we named T6SS-1 and T6SS-3 according to previous classification methods (G. Shalom, J. G. Shaw, and M. S. Thomas, Microbiology, 153:2689-2699, 2007, https://doi.org/10.1099/mic.0.2007/006585-0). We created P. sabiae with mutations in each of the two T6SS gene clusters that abrogated their function, and the T6SS-1 mutant was no longer able to outcompete other strains in a contact-dependent manner. Notably, our analysis revealed that T6SS-1 is essential for competition against several important plant pathogens in vitro, including Burkholderia plantarii, Ralstonia solanacearum, Pseudomonas syringae, and Pectobacterium carotovorum. The 9-log reduction in P. syringae cells in the presence of P. sabiae was particularly remarkable. Importantly, in an in vivo assay, P. sabiae was able to protect potato tubers from bacterial soft rot disease caused by P. carotovorum, and this protection was partly dependent on T6SS-1. IMPORTANCE Rhizobia often display additional beneficial traits such as the production of plant hormones and the acquisition of limited essential nutrients that improve plant growth and enhance plant yields. Here, we show that the rhizobial strain P. sabiae antagonizes important phytopathogens such as P. carotovorum, P. syringae, and R. solanacearum and that this effect is due to contact-dependent killing mediated by one of two T6SS systems identified in the complete, de novo assembled genome sequence of P. sabiae. Importantly, co-inoculation of Solanum tuberosum tubers with P. sabiae also resulted in a drastic reduction of soft rot caused by P. carotovorum in an in vivo model system. This result highlights the protective potential of P. sabiae against important bacterial plant diseases, which makes it a valuable candidate for application as a biocontrol agent. It also emphasizes the particular potential of rhizobial inoculants that combine several beneficial effects such as plant growth promotion and biocontrol for sustainable agriculture
Treatment With Erythropoietin for Patients With Optic Neuritis: Long-term Follow-up.
BACKGROUND AND OBJECTIVE
Erythropoietin (EPO) is a candidate neuroprotective drug. We assessed its long-term safety and efficacy as an adjunct to methylprednisolone in patients with optic neuritis and focused on conversions to multiple sclerosis (MS).
METHODS
The TONE trial randomized 108 patients with acute optic neuritis but without previously known MS to either 33,000 IU EPO or placebo in conjunction with 1,000 mg methylprednisolone daily for 3 days. After reaching the primary end point at 6 months, we conducted an open-label follow-up 2 years after randomization.
RESULTS
The follow-up was attended by 83 of 103 initially analyzed patients (81%). There were no previously unreported adverse events. The adjusted treatment difference of peripapillary retinal nerve fiber layer atrophy in relation to the fellow eye at baseline was 1.27 µm (95% CI -6.45 to 8.98, p = 0.74). The adjusted treatment difference in low-contrast letter acuity was 2.87 on the 2.5% Sloan chart score (95% CI -7.92 to 13.65). Vision-related quality of life was similar in both treatment arms (National Eye Institute Visual Functioning Questionnaire median score [IQR]: 94.0 [88.0 to 96.9] in the EPO and 93.4 [89.5 to 97.4] in the placebo group). The rate of multiple sclerosis-free survival was 38% in the placebo and 53% in the EPO group (hazard ratio: 1.67, 95% CI 0.96 to 2.88, p = 0.068).
DISCUSSION
In line with the results at 6 months, we found neither structural nor functional benefits in the visual system of patients with optic neuritis as a clinically isolated syndrome, 2 years after EPO administration. Although there were fewer early conversions to MS in the EPO group, the difference across the 2-year window was not statistically significant.
CLASSIFICATION OF EVIDENCE
This study provides Class II evidence that for patients with acute optic neuritis, EPO as an adjunct to methylprednisolone is well tolerated and does not improve long-term visual outcomes.
TRIAL REGISTRATION INFORMATION
The trial was preregistered before commencement at clinicaltrials.gov (NCT01962571)
Artificial intelligence for clinical decision support for monitoring patients in cardiovascular ICUs: a systematic review
Background: Artificial intelligence (AI) and machine learning (ML) models continue to evolve the clinical decision support systems (CDSS). However, challenges arise when it comes to the integration of AI/ML into clinical scenarios. In this systematic review, we followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA), the population, intervention, comparator, outcome, and study design (PICOS), and the medical AI life cycle guidelines to investigate studies and tools which address AI/ML-based approaches towards clinical decision support (CDS) for monitoring cardiovascular patients in intensive care units (ICUs). We further discuss recent advances, pitfalls, and future perspectives towards effective integration of AI into routine practices as were identified and elaborated over an extensive selection process for state-of-the-art manuscripts.
Methods: Studies with available English full text from PubMed and Google Scholar in the period from January 2018 to August 2022 were considered. The manuscripts were fetched through a combination of the search keywords including AI, ML, reinforcement learning (RL), deep learning, clinical decision support, and cardiovascular critical care and patients monitoring. The manuscripts were analyzed and filtered based on qualitative and quantitative criteria such as target population, proper study design, cross-validation, and risk of bias.
Results: More than 100 queries over two medical search engines and subjective literature research were developed which identified 89 studies. After extensive assessments of the studies both technically and medically, 21 studies were selected for the final qualitative assessment.
Discussion: Clinical time series and electronic health records (EHR) data were the most common input modalities, while methods such as gradient boosting, recurrent neural networks (RNNs) and RL were mostly used for the analysis. Seventy-five percent of the selected papers lacked validation against external datasets highlighting the generalizability issue. Also, interpretability of the AI decisions was identified as a central issue towards effective integration of AI in healthcare
Building in China - Study trip of the faculty of Civil Engineering of the HTWG Konstanz 2008
Im März 2008 führte die Fakultät Bauingenieurwesen der HTWG Konstanz eine studentische Exkursion nach China durch. Auf dem Programm standen interessante Baustellen Shanghai, Nanjing, Zhenjiang und Beijing sowie der Besuch von Hochschulen. Der Exkursionsbericht beschreibt die besuchten Bauvorhaben und gibt persönliche Eindrücke der Exkursionsteilnehmer wieder.In March 2008 the faculty of civil engineering of the University of Applied Sciences Konstanz, Germany, conducted a study trip for students of civil engineering to China. Construction sites and universities in Shanghai, Nanjing, Zhenjiang and Beijing have been visited. The report describes the places seen and reflects the personal impressions of the participants
How is tailored implementation undertaken using a self-guided toolkit? Qualitative study of the ItFits-toolkit in the ImpleMentAll project
BackgroundThe process of tailored implementation is ill-defined and under-explored. The ItFits-toolkit was developed and subsequently tested as a self-guided online platform to facilitate implementation of tailored strategies for internet-based cognitive behavioural therapy (iCBT) services. In ImpleMentAll, ItFits-toolkit had a small but positive effect on the primary outcome of iCBT normalisation. This paper investigates, from a qualitative perspective, how implementation teams developed and undertook tailored implementation using the toolkit within the trial.MethodsImplementation teams in thirteen sites from nine countries (Europe and Australia) used the ItFits-toolkit for six months minimum, consistent with the trial protocol. A qualitative process evaluation was conducted. Descriptive data regarding goals, barriers, strategies, and implementation plans collected within the toolkit informed qualitative data collection in real time. Qualitative data included remote longitudinal interviews (n = 55) with implementation team members (n = 30) and observations of support calls (n = 19) with study sites. Qualitative data were analysed thematically, using a team-based approach.ResultsImplementation teams developed and executed tailored implementation projects across all steps in the toolkit process. Working in a structured way but with room for flexibility, decisions were shaped by team members' ideas and goals, iterative stakeholder engagement, internal and external influences, and the context of the ImpleMentAll project. Although teams reported some positive impacts of their projects, 'time', both for undertaking the work, and for seeing project impacts, was described as a key factor in decisions about implementation strategies and assessments of success.ConclusionThis study responds directly to McHugh et al.'s (2022) call for empirical description of what implementation tailoring looks like in action, in service settings. Self-guided facilitation of tailored implementation enables implementers in service settings to undertake tailoring within their organisations. Implementation tailoring takes considerable time and involves detailed work but can be supported through the provision of implementation science informed guidance and materials, iterative and ongoing stakeholder engagement, and working reflectively in response to external influencing factors. Directions for advancement of tailored implementation are suggested
Low-dose AtropIne for Myopia Control in Children (AIM): protocol for a randomised, controlled, double-blind, multicentre, clinical trial with two parallel arms
IntroductionMyopia is a major cause of degenerative eye disease and increases the risk of secondary visual impairment. Mitigating its progression therefore has great potential of clinically relevant benefit as shown by using highly diluted atropine eye drops in children of Asian origin. However, limited evidence is available regarding the efficacy and safety of low-dose atropine therapy in non-Asian populations. Hence, the Low-dose AtropIne for Myopia Control in Children (AIM) study will test the efficacy and safety of 0.02% atropine vs placebo in a German population.Methods and analysisAIM is a national, multicentre, prospective, randomised, placebo-controlled, double-blind trial with two parallel arms. The primary objective is to assess the efficacy of atropine 0.02% eyedrops for myopia control in children of Caucasian origin. The primary outcome is the change in cycloplegic refraction after 1 year of treatment (D/year). Secondary and tertiary outcome measures comprise the change in axial length (mm/year) in children treated with 0.02% atropine compared with placebo, the myopic progression of participants treated with 0.01% compared with 0.02% atropine (D/year and mm/year), and the safety profile of both 0.02% and 0.01% atropine. Furthermore, the myopic progression 1 year after cessation of therapy with 0.02% atropine will be evaluated. Inclusion criteria are an age of 8–12 years and myopia of −1 D to −6 D with an estimated annual myopia progression of ≥0.5 D. After randomisation, patients will receive either atropine 0.02% (arm A) or placebo eye drops (arm B) in the first year of treatment. In the second year, they will continue to receive atropine 0.02% (arm A) or switch to atropine 0.01% (arm B). In the third year, they will switch to placebo (arm A) or continue with atropine 0.01% (arm B). To achieve a statistical power of 80%, the calculated sample size is 300. The trial has started in October 2021 with a planned recruitment period of 18 months.Ethics and disseminationAIM has been approved by the Central Ethics Committee of the University Medical Center Freiburg (21-1106), local ethics committees of each participating centre and the German Federal Institute for Drugs and Medical Devices (61-3910-4044659). It complies with the Declaration of Helsinki, local laws and ICH-GCP. Results and underlying data from this trial will be disseminated through peer-reviewed publications and conference presentations.Trial registration numberNCT03865160
Scientific opportunies for bERLinPro 2020+, report with ideas and conclusions from bERLinProCamp 2019
The Energy Recovery Linac (ERL) paradigm offers the promise to generate intense electron beams of superior quality with extremely small six-dimensional phase space for many applications in the physical sciences, materials science, chemistry, health, information technology and security. Helmholtz-Zentrum Berlin started in 2010 an intensive R\&D programme to address the challenges related to the ERL as driver for future light sources by setting up the bERLinPro (Berlin ERL Project) ERL with 50 MeV beam energy and high average current. The project is close to reach its major milestone in 2020, acceleration and recovery of a high brightness electron beam. The goal of bERLinProCamp 2019 was to discuss scientific opportunities for bERLinPro 2020+. bERLinProCamp 2019 was held on Tue, 17.09.2019 at Helmholtz-Zentrum Berlin, Berlin, Germany. This paper summarizes the main themes and output of the workshop
Tailored implementation of internet-based cognitive behavioural therapy in the multinational context of the ImpleMentAll project: a study protocol for a stepped wedge cluster randomized trial.
BACKGROUND: Internet-based Cognitive Behavioural Therapy (iCBT) is found effective in treating common mental disorders. However, the use of these interventions in routine care is limited. The international ImpleMentAll study is funded by the European Union's Horizon 2020 programme. It is concerned with studying and improving methods for implementing evidence-based iCBT services for common mental disorders in routine mental health care. A digitally accessible implementation toolkit (ItFits-toolkit) will be introduced to mental health care organizations with the aim to facilitate the ongoing implementation of iCBT services within local contexts. This study investigates the effectiveness of the ItFits-toolkit by comparing it to implementation-as-usual activities. METHODS: A stepped wedge cluster randomized controlled trial (SWT) design will be applied. Over a trial period of 30 months, the ItFits-toolkit will be introduced sequentially in twelve routine mental health care organizations in primary and specialist care across nine countries in Europe and Australia. Repeated measures are applied to assess change over time in the outcome variables. The effectiveness of the ItFits-toolkit will be assessed in terms of the degree of normalization of the use of the iCBT services. Several exploratory outcomes including uptake of the iCBT services will be measured to feed the interpretation of the primary outcome. Data will be collected via a centralized data collection system and analysed using generalized linear mixed modelling. A qualitative process evaluation of routine implementation activities and the use of the ItFits-toolkit will be conducted within this study. DISCUSSION: The ImpleMentAll study is a large-scale international research project designed to study the effectiveness of tailored implementation. Using a SWT design that allows to examine change over time, this study will investigate the effect of tailored implementation on the normalization of the use of iCBT services and their uptake. It will provide a better understanding of the process and methods of tailoring implementation strategies. If found effective, the ItFits-toolkit will be made accessible for mental health care service providers, to help them overcome their context-specific implementation challenges. TRIAL REGISTRATION: ClinicalTrials.gov NCT03652883 . Retrospectively registered on 29 August 2018
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