273 research outputs found
Reversible GANs for Memory-efficient Image-to-Image Translation
The Pix2pix and CycleGAN losses have vastly improved the qualitative and
quantitative visual quality of results in image-to-image translation tasks. We
extend this framework by exploring approximately invertible architectures which
are well suited to these losses. These architectures are approximately
invertible by design and thus partially satisfy cycle-consistency before
training even begins. Furthermore, since invertible architectures have constant
memory complexity in depth, these models can be built arbitrarily deep. We are
able to demonstrate superior quantitative output on the Cityscapes and Maps
datasets at near constant memory budget
A novel SHAPE reagent enables the analysis of RNA structure in living cells with unprecedented accuracy
Due to the mounting evidence that RNA structure plays a critical role in regulating almost any physiological as well as pathological process, being able to accurately define the folding of RNA molecules within living cells has become a crucial need. We introduce here 2-aminopyridine-3-carboxylic acid imidazolide (2A3), as a general probe for the interrogation of RNA structures in vivo. 2A3 shows moderate improvements with respect to the state-of-the-art selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) reagent NAI on naked RNA under in vitro conditions, but it significantly outperforms NAI when probing RNA structure in vivo, particularly in bacteria, underlining its increased ability to permeate biological membranes. When used as a restraint to drive RNA structure prediction, data derived by SHAPE-MaP with 2A3 yields more accurate predictions than NAI-derived data. Due to its extreme efficiency and accuracy, we can anticipate that 2A3 will rapidly take over conventional SHAPE reagents for probing RNA structures both in vitro and in vivo
Learning Layer-wise Equivariances Automatically using Gradients
Convolutions encode equivariance symmetries into neural networks leading to
better generalisation performance. However, symmetries provide fixed hard
constraints on the functions a network can represent, need to be specified in
advance, and can not be adapted. Our goal is to allow flexible symmetry
constraints that can automatically be learned from data using gradients.
Learning symmetry and associated weight connectivity structures from scratch is
difficult for two reasons. First, it requires efficient and flexible
parameterisations of layer-wise equivariances. Secondly, symmetries act as
constraints and are therefore not encouraged by training losses measuring data
fit. To overcome these challenges, we improve parameterisations of soft
equivariance and learn the amount of equivariance in layers by optimising the
marginal likelihood, estimated using differentiable Laplace approximations. The
objective balances data fit and model complexity enabling layer-wise symmetry
discovery in deep networks. We demonstrate the ability to automatically learn
layer-wise equivariances on image classification tasks, achieving equivalent or
improved performance over baselines with hard-coded symmetry
Foraging behaviour of black guillemots at three Norwegian sites during the breeding season
The intensifcation of coastal development poses potential threats for coastal seabirds, and understanding their habitat use is a key factor to guide conservation and management. In sub-arctic areas, black guillemots (Cepphus grylle) use coastal habitats year-round, which makes them vulnerable to the increasing human activities in these areas. In mainland Norway, one of the speciesâ strongholds, black guillemots are red-listed after substantial population declines. However, their fnescale foraging behaviour has received little attention to date. We collected and analysed GPS tracking data from adult black guillemots at three sites located over a latitudinal gradient of 250 km in central/northern Norway. Maximum foraging ranges of 33 km at Sklinna (65°12âČN) for incubating birds, and 18 km at both Vega (65°34âČN) and Sklinna for chick-rearing birds, are among the longest reported for this species. At all three sites, foraging probability was highest in shallow waters (<50 m depth) close to the colony and declined with increasing water depth and distance from colony. However, birds from Vega also foraged over deeper waters. Kelp presence was of high importance at Sklinna, but apparently less important at RĂžst (67°26âN) and Vega. We also found distinct diferences in foraging activity across the day and with tidal height among the sites. Inter-site diferences in habitat use and foraging activity may be explained by diferences in the availability of habitats and suitable prey. Our study highlights the importance of shallow marine areas for black guillemots and shows that habitat use can vary substantially between sites. Cepphus grylle · Marine spatial planning · Habitat use · Species distribution model · Kelp forestpublishedVersio
Unravelling the skillset of point-of-care ultrasound:a systematic review
Background: The increasing number of physicians that are trained in point-of-care ultrasound (POCUS) warrants critical evaluation and improvement of current training methods. Performing POCUS is a complex task and it is unknown which (neuro)cognitive mechanisms are most important in competence development of this skill. This systematic review was conducted to identify determinants of POCUS competence development that can be used to optimize POCUS training. Methods: PubMed, Web of Science, Cochrane Library, Emcare, PsycINFO and ERIC databases were searched for studies measuring ultrasound (US) skills and aptitude. The papers were divided into three categories: âRelevant knowledgeâ, âPsychomotor abilityâ and âVisuospatial abilityâ. The âRelevant knowledgeâ category was further subdivided in âimage interpretationâ, âtechnical aspectsâ and âgeneral cognitive abilitiesâ. Visuospatial ability was subdivided in visuospatial subcategories based on the Cattell-Horn-Carroll (CHC) Model of Intelligence v2.2, which includes visuospatial manipulation and visuospatial perception. Post-hoc, a meta-analysis was performed to calculate pooled correlations. Results: 26 papers were selected for inclusion in the review. 15 reported on relevant knowledge with a pooled coefficient of determination of 0.26. Four papers reported on psychomotor abilities, one reported a significant relationship with POCUS competence. 13 papers reported on visuospatial abilities, the pooled coefficient of determination was 0.16.Conclusion: There was a lot of heterogeneity in methods to assess possible determinants of POCUS competence and POCUS competence acquisition. This makes it difficult to draw strong conclusions on which determinants should be part of a framework to improve POCUS education. However, we identified two determinants of POCUS competence development: relevant knowledge and visuospatial ability. The content of relevant knowledge could not be retrieved in more depth. For visuospatial ability we used the CHC model as theoretical framework to analyze this skill. We could not point out psychomotor ability as a determinant of POCUS competence.</p
Selection and phenotypic characterization of a core collection of <i>Brachypodium distachyon</i> inbred lines
BACKGROUND: The model grass Brachypodium distachyon is increasingly used to study various aspects of grass biology. A large and genotypically diverse collection of B. distachyon germplasm has been assembled by the research community. The natural variation in this collection can serve as a powerful experimental tool for many areas of inquiry, including investigating biomass traits. RESULTS: We surveyed the phenotypic diversity in a large collection of inbred lines and then selected a core collection of lines for more detailed analysis with an emphasis on traits relevant to the use of grasses as biofuel and grain crops. Phenotypic characters examined included plant height, growth habit, stem density, flowering time, and seed weight. We also surveyed differences in cell wall composition using near infrared spectroscopy (NIR) and comprehensive microarray polymer profiling (CoMPP). In all cases, we observed extensive natural variation including a two-fold variation in stem density, four-fold variation in ferulic acid bound to hemicellulose, and 1.7-fold variation in seed mass. CONCLUSION: These characterizations can provide the criteria for selecting diverse lines for future investigations of the genetic basis of the observed phenotypic variation
Unravelling the skillset of point-of-care ultrasound:a systematic review
Background: The increasing number of physicians that are trained in point-of-care ultrasound (POCUS) warrants critical evaluation and improvement of current training methods. Performing POCUS is a complex task and it is unknown which (neuro)cognitive mechanisms are most important in competence development of this skill. This systematic review was conducted to identify determinants of POCUS competence development that can be used to optimize POCUS training. Methods: PubMed, Web of Science, Cochrane Library, Emcare, PsycINFO and ERIC databases were searched for studies measuring ultrasound (US) skills and aptitude. The papers were divided into three categories: âRelevant knowledgeâ, âPsychomotor abilityâ and âVisuospatial abilityâ. The âRelevant knowledgeâ category was further subdivided in âimage interpretationâ, âtechnical aspectsâ and âgeneral cognitive abilitiesâ. Visuospatial ability was subdivided in visuospatial subcategories based on the Cattell-Horn-Carroll (CHC) Model of Intelligence v2.2, which includes visuospatial manipulation and visuospatial perception. Post-hoc, a meta-analysis was performed to calculate pooled correlations. Results: 26 papers were selected for inclusion in the review. 15 reported on relevant knowledge with a pooled coefficient of determination of 0.26. Four papers reported on psychomotor abilities, one reported a significant relationship with POCUS competence. 13 papers reported on visuospatial abilities, the pooled coefficient of determination was 0.16.Conclusion: There was a lot of heterogeneity in methods to assess possible determinants of POCUS competence and POCUS competence acquisition. This makes it difficult to draw strong conclusions on which determinants should be part of a framework to improve POCUS education. However, we identified two determinants of POCUS competence development: relevant knowledge and visuospatial ability. The content of relevant knowledge could not be retrieved in more depth. For visuospatial ability we used the CHC model as theoretical framework to analyze this skill. We could not point out psychomotor ability as a determinant of POCUS competence.</p
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