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1.	Filipe, A., et al. (författare) White Book on Physical and Rehabilitation Medicine in Europe Introductions, Executive Summary, and Methodology 2018 Ingår i: European Journal of Physical and Rehabilitation Medicine. - : Edizioni Minerva Medica. - 1973-9087 .- 1973-9095. ; 54:2, s. 125-155 Tidskriftsartikel (refereegranskat)abstract The White Book (WB) of Physical and Rehabilitation Medicine (PRM) in Europe is produced by the 4 European PRM Bodies (European Academy of Rehabilitation Medicine - EARM, European Society of PRM - ESPRM, European Union of Medical Specialists - PRM Section, European College of PRM-ECPRM served by the European Union of Medical Specialists-PRM Board) and constitutes the reference book for PRM physicians in Europe. It has now reached its third edition; the first was published in 1989 and the second in 2006/2007. The WB has multiple purposes, including providing a unifying framework for European countries, to inform decision-makers on European and national level, to offer educational material for PRM trainees and physicians and information about PRM to the medical community, other rehabilitation professionals and the public. The WB states the importance of PRM, a primary medical specialty that is present all over Europe, with a specific corpus disciplinae, a common background and history throughout Europe. PRM is internationally recognized and a partner of major international bodies, including the World Health Organization (WHO). PRM activities are strongly based on the documents of the United Nations (UN) and WHO, such as the Convention of the Rights of Persons with Disabilities (2006), the World Report on Disability (2011), the WHO Global Disability Action Plan 2014-2021 (2014) and the WHO initiative "Rehabilitation 2030: a call for action" (2017). The WB is organized in 4 sections, 11 chapters and some appendices. The WB starts with basic definitions and concepts of PRM and continues with why rehabilitation is needed by individuals and society. Rehabilitation focuses not only on health conditions but also on functioning. Accordingly. PRM is the medical specialty that strives to improve functioning of people with a health condition or experiencing disability. The fundamentals of PRM, the history of the PRM specialty, and the structure and activities of PRM organizations in Europe are presented, followed by a thorough presentation of the practice of PRM, i.e. knowledge and skills of PRM physicians, the clinical field of competence of PRM, the place of the PRM specialty in the healthcare system and society, education and continuous professional development of PRM physicians, specificities and challenges of science and research in PRM. The WB concludes with the way forward for the specialty: challenges and perspectives for the future of PRM.
2.	Pteridophyte Phylogeny Group, The, et al. (författare) A community-derived classification for extant lycophytes and ferns 2017 Ingår i: Journal of Systematics and Evolution. - 1674-4918 .- 1759-6831. ; 4:6, s. 563-603 Tidskriftsartikel (refereegranskat)
3.	Schuettpelz, Eric, et al. (författare) A community-derived classification for extant lycophytes and ferns 2016 Ingår i: Journal of Systematics and Evolution. - : Wiley. - 1674-4918 .- 1759-6831. ; 54:6, s. 563-603 Tidskriftsartikel (refereegranskat)abstract Phylogeny has long informed pteridophyte classification. As our ability to infer evolutionary trees has improved, classifications aimed at recognizing natural groups have become increasingly predictive and stable. Here, we provide a modern, comprehensive classification for lycophytes and ferns, down to the genus level, utilizing a community-based approach. We use monophyly as the primary criterion for the recognition of taxa, but also aim to preserve existing taxa and circumscriptions that are both widely accepted and consistent with our understanding of pteridophyte phylogeny. In total, this classification treats an estimated 11 916 species in 337 genera, 51 families, 14 orders, and two classes. This classification is not intended as the final word on lycophyte and fern taxonomy, but rather a summary statement of current hypotheses, derived from the best available data and shaped by those most familiar with the plants in question. We hope that it will serve as a resource for those wanting references to the recent literature on pteridophyte phylogeny and classification, a framework for guiding future investigations, and a stimulus to further discourse.
4.	Meyer, Peter A., et al. (författare) Data publication with the structural biology data grid supports live analysis 2016 Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7 Tidskriftsartikel (refereegranskat)abstract Access to experimental X-ray diffraction image data is fundamental for validation and reproduction of macromolecular models and indispensable for development of structural biology processing methods. Here, we established a diffraction data publication and dissemination system, Structural Biology Data Grid (SBDG; data. sbgrid. org), to preserve primary experimental data sets that support scientific publications. Data sets are accessible to researchers through a community driven data grid, which facilitates global data access. Our analysis of a pilot collection of crystallographic data sets demonstrates that the information archived by SBDG is sufficient to reprocess data to statistics that meet or exceed the quality of the original published structures. SBDG has extended its services to the entire community and is used to develop support for other types of biomedical data sets. It is anticipated that access to the experimental data sets will enhance the paradigm shift in the community towards a much more dynamic body of continuously improving data analysis.
5.	Ekeberg, Tomas, et al. (författare) Three-dimensional reconstruction of the giant mimivirus particle with an X-ray free-electron laser 2015 Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 114:9, s. 098102:1-6 Tidskriftsartikel (refereegranskat)
6.	Kooij, J. J. S., et al. (författare) Updated European Consensus Statement on diagnosis and treatment of adult ADHD 2019 Ingår i: European psychiatry. - : Cambridge University Press (CUP). - 0924-9338 .- 1778-3585. ; 56, s. 14-34 Tidskriftsartikel (refereegranskat)abstract BackgroundAttention-deficit/hyperactivity disorder (ADHD) is among the most common psychiatric disorders of childhood that often persists into adulthood and old age. Yet ADHD is currently underdiagnosed and undertreated in many European countries, leading to chronicity of symptoms and impairment, due to lack of, or ineffective treatment, and higher costs of illness.MethodsThe European Network Adult ADHD and the Section for Neurodevelopmental Disorders Across the Lifespan (NDAL) of the European Psychiatric Association (EPA), aim to increase awareness and knowledge of adult ADHD in and outside Europe. This Updated European Consensus Statement aims to support clinicians with research evidence and clinical experience from 63 experts of European and other countries in which ADHD in adults is recognized and treated.ResultsBesides reviewing the latest research on prevalence, persistence, genetics and neurobiology of ADHD, three major questions are addressed: (1) What is the clinical picture of ADHD in adults? (2) How should ADHD be properly diagnosed in adults? (3) How should adult ADHDbe effectively treated?ConclusionsADHD often presents as a lifelong impairing condition. The stigma surrounding ADHD, mainly due to lack of knowledge, increases the suffering of patients. Education on the lifespan perspective, diagnostic assessment, and treatment of ADHD must increase for students of general and mental health, and for psychiatry professionals. Instruments for screening and diagnosis of ADHD in adults are available, as are effective evidence-based treatments for ADHD and its negative outcomes. More research is needed on gender differences, and in older adults with ADHD.
7.	Lopes de Abreu, Narjara, et al. (författare) The use of chloroplast genome sequences to solve phylogenetic incongruences in Polystachya Hook (Orchidaceae Juss) 2018 Ingår i: Peerj. - : PeerJ. - 2167-8359. ; 6 Tidskriftsartikel (refereegranskat)abstract Background: Current evidence suggests that for more robust estimates of species tree and divergence times, several unlinked genes are required. However, most phylogenetic trees for non-model organisms are based on single sequences or just a few regions, using traditional sequencing methods. Techniques for massive parallel sequencing or next generation sequencing (NGS) are an alternative to traditional methods that allow access to hundreds of DNA regions. Here we use this approach to resolve the phylogenetic incongruence found in Polystachya Hook. (Orchidaceae), a genus that stands out due to several interesting aspects, including cytological (polyploid and diploid species), evolutionary (reticulate evolution) and biogeographical (species widely distributed in the tropics and high endemism in Brazil). The genus has a notoriously complicated taxonomy, with several sections that are widely used but probably not monophyletic. Methods: We generated the complete plastid genome of 40 individuals from one clade within the genus. The method consisted in construction of genomic libraries, hybridization to RNA probes designed from available sequences of a related species, and subsequent sequencing of the product. We also tested how well a smaller sample of the plastid genome would perform in phylogenetic inference in two ways: by duplicating a fast region and analyzing multiple copies of this dataset, and by sampling without replacement from all non-coding regions in our alignment. We further examined the phylogenetic implications of non-coding sequences that appear to have undergone hairpin inversions (reverse complemented sequences associated with small loops). Results: We retrieved 131,214 bp, including coding and non-coding regions of the plastid genome. The phylogeny was able to fully resolve the relationships among all species in the targeted clade with high support values. The first divergent species are represented by African accessions and the most recent ones are among Neotropical species. Discussion: Our results indicate that using the entire plastid genome is a better option than screening highly variable markers, especially when the expected tree is likely to contain many short branches. The phylogeny inferred is consistent with the proposed origin of the genus, showing a probable origin in Africa, with later dispersal into the Neotropics, as evidenced by a clade containing all Neotropical individuals. The multiple positions of Polystachya concreta (Jacq.) Garay & Sweet in the phylogeny are explained by allotetraploidy. Polystachya estrellensis Rchb.f. can be considered a genetically distinct species from P. concreta and P. foliosa (Lindl.) Rchb.f., but the delimitation of P. concreta remains uncertain. Our study shows that NGS provides a powerful tool for inferring relationships at low taxonomic levels, even in taxonomically challenging groups with short branches and intricate morphology.
8.	Parkinson, Dilworth Y., et al. (författare) Real-Time Data-Intensive Computing 2016 Ingår i: Proceedings Of The 12Th International Conference On Synchrotron Radiation Instrumentation (SRI2015). - : Author(s). - 9780735413986 Konferensbidrag (refereegranskat)abstract Today users visit synchrotrons as sources of understanding and discovery-not as sources of just light, and not as sources of data. To achieve this, the synchrotron facilities frequently provide not just light but often the entire end station and increasingly, advanced computational facilities that can reduce terabytes of data into a form that can reveal a new key insight. The Advanced Light Source (ALS) has partnered with high performance computing, fast networking, and applied mathematics groups to create a "super-facility", giving users simultaneous access to the experimental, computational, and algorithmic resources to make this possible. This combination forms an efficient closed loop, where data-despite its high rate and volume-is transferred and processed immediately and automatically on appropriate computing resources, and results are extracted, visualized, and presented to users or to the experimental control system, both to provide immediate insight and to guide decisions about subsequent experiments during beamtime. We will describe our work at the ALS ptychography, scattering, micro-diffraction, and micro-tomography beamlines.
9.	Wiedorn, Max O., et al. (författare) Megahertz serial crystallography 2018 Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 9 Tidskriftsartikel (refereegranskat)abstract The new European X-ray Free-Electron Laser is the first X-ray free-electron laser capable of delivering X-ray pulses with a megahertz inter-pulse spacing, more than four orders of magnitude higher than previously possible. However, to date, it has been unclear whether it would indeed be possible to measure high-quality diffraction data at megahertz pulse repetition rates. Here, we show that high-quality structures can indeed be obtained using currently available operating conditions at the European XFEL. We present two complete data sets, one from the well-known model system lysozyme and the other from a so far unknown complex of a beta-lactamase from K. pneumoniae involved in antibiotic resistance. This result opens up megahertz serial femtosecond crystallography (SFX) as a tool for reliable structure determination, substrate screening and the efficient measurement of the evolution and dynamics of molecular structures using megahertz repetition rate pulses available at this new class of X-ray laser source.
10.	Bielecki, Johan, 1982, et al. (författare) Electrospray sample injection for single-particle imaging with x-ray lasers 2019 Ingår i: Science advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 5:5 Tidskriftsartikel (refereegranskat)abstract The possibility of imaging single proteins constitutes an exciting challenge for x-ray lasers. Despite encouraging results on large particles, imaging small particles has proven to be difficult for two reasons: not quite high enough pulse intensity from currently available x-ray lasers and, as we demonstrate here, contamination of the aerosolized molecules by nonvolatile contaminants in the solution. The amount of contamination on the sample depends on the initial droplet size during aerosolization. Here, we show that, with our electrospray injector, we can decrease the size of aerosol droplets and demonstrate virtually contaminant-free sample delivery of organelles, small virions, and proteins. The results presented here, together with the increased performance of next-generation x-ray lasers, constitute an important stepping stone toward the ultimate goal of protein structure determination from imaging at room temperature and high temporal resolution.
11.	Cima, Joana, et al. (författare) EQ-5D and Activity Inventory : Measures of Visual Health Outcome 2015 Ingår i: European Journal of Public Health. - : Oxford University Press (OUP). - 1101-1262 .- 1464-360X. ; 25:Suppl 3 Tidskriftsartikel (refereegranskat)abstract The aim of the study is to test if EQ-5D, a more generic instrument, and Activity Inventory, a more specific instrument to the visual condition, produce consistent results when considering the different levels of visual impairment. By assessing how these instruments reflect visual status in a sample of patients with visual impairment, we will help to understand how they can work in cultural context and population in which they were never tested before.Method is based on Multivariate Analysis of Variance, in which the levels of visual impairment (slightly, moderate, severe/blindness) are defined through the visual acuity values, and the utility values derived from EQ-5D and the Activity Inventory.Participants were recruited in 3 public hospitals as a part of an ongoing study of prevalence and costs of visual impairment in Portugal. Patients attending outpatient appointments in these hospitals with acuity in the better eye of 0,30logMAR or worse and/or visual field in the better eye <20 degrees were invited to take part in face-to-face interviews. Additional visual measures, as acuity was collected using standardize methods. Visual acuity was assessed using an internally illuminated ETDRS chart at 4 m with room lights extinguished.The results show that both instruments have a good explanatory power. However when considering different clinical conditions, the AI presents better results. The EQ-5D due its low sensitivity/adaptability does not capture differences in health status in patients with slightly and moderate visual impairment.Since EQ-5D is the instrument most used in the evaluation of public health programs performance, the results suggest that its use should be more cautious in a situation of different difficulty levels. The results indicate that in these cases the EQ-5D should be used with a complementary instrument more specific to the clinical condition.Key messagesThe results suggest that with different difficulty levels the EQ-5D should be used with a complementary instrument more specific to the clinical condition to be produced more reliable resultsThis study is supported by the Portuguese Foundation for Science and Technology (FCT) -POCTI & FSE GRANT: PTDC/DPT-EPI/0412/2012
12.	da Fonseca, Rute R., et al. (författare) The origin and evolution of maize in the Southwestern United States 2015 Ingår i: Nature Plants. - 2055-026X. ; 1:1 Tidskriftsartikel (refereegranskat)abstract The origin of maize (Zea mays mays) in the US Southwest remains contentious, with conflicting archaeological data supporting either coastal(1-4) or highland(5,6) routes of diffusion of maize into the United States. Furthermore, the genetics of adaptation to the new environmental and cultural context of the Southwest is largely uncharacterized(7). To address these issues, we compared nuclear DNA from 32 archaeological maize samples spanning 6,000 years of evolution to modern landraces. We found that the initial diffusion of maize into the Southwest about 4,000 years ago is likely to have occurred along a highland route, followed by gene flow from a lowland coastal maize beginning at least 2,000 years ago. Our population genetic analysis also enabled us to differentiate selection during domestication for adaptation to the climatic and cultural environment of the Southwest, identifying adaptation loci relevant to drought tolerance and sugar content.
13.	Daniel, Michael G., et al. (författare) Induction of human hemogenesis in adult fibroblasts by defined factors and hematopoietic coculture 2019 Ingår i: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 593:23, s. 3266-3287 Tidskriftsartikel (refereegranskat)abstract Transcription factor (TF)-based reprogramming of somatic tissues holds great promise for regenerative medicine. Previously, we demonstrated that the TFs GATA2, GFI1B, and FOS convert mouse and human fibroblasts to hemogenic endothelial-like precursors that generate hematopoietic stem progenitor (HSPC)-like cells over time. This conversion is lacking in robustness both in yield and biological function. Herein, we show that inclusion of GFI1 to the reprogramming cocktail significantly expands the HSPC-like population. AFT024 coculture imparts functional potential to these cells and allows quantification of stem cell frequency. Altogether, we demonstrate an improved human hemogenic induction protocol that could provide a valuable human in vitro model of hematopoiesis for disease modeling and a platform for cell-based therapeutics. Database: Gene expression data are available in the Gene Expression Omnibus (GEO) database under the accession number GSE130361.
14.	Daurer, Benedikt J., et al. (författare) Experimental strategies for imaging bioparticles with femtosecond hard X-ray pulses 2017 Ingår i: IUCrJ. - : INT UNION CRYSTALLOGRAPHY. - 2052-2525. ; 4, s. 251-262 Tidskriftsartikel (refereegranskat)abstract This study explores the capabilities of the Coherent X-ray Imaging Instrument at the Linac Coherent Light Source to image small biological samples. The weak signal from small samples puts a significant demand on the experiment. Aerosolized Omono River virus particles of similar to 40 nm in diameter were injected into the submicrometre X-ray focus at a reduced pressure. Diffraction patterns were recorded on two area detectors. The statistical nature of the measurements from many individual particles provided information about the intensity profile of the X-ray beam, phase variations in the wavefront and the size distribution of the injected particles. The results point to a wider than expected size distribution (from similar to 35 to similar to 300 nm in diameter). This is likely to be owing to nonvolatile contaminants from larger droplets during aerosolization and droplet evaporation. The results suggest that the concentration of nonvolatile contaminants and the ratio between the volumes of the initial droplet and the sample particles is critical in such studies. The maximum beam intensity in the focus was found to be 1.9 * 10(12) photons per mu m(2) per pulse. The full-width of the focus at half-maximum was estimated to be 500 nm (assuming 20% beamline transmission), and this width is larger than expected. Under these conditions, the diffraction signal from a sample-sized particle remained above the average background to a resolution of 4.25 nm. The results suggest that reducing the size of the initial droplets during aerosolization is necessary to bring small particles into the scope of detailed structural studies with X-ray lasers.
15.	Daurer, Benedikt J., et al. (författare) Hummingbird : monitoring and analyzing flash X-ray imaging experiments in real time 2016 Ingår i: Journal of applied crystallography. - 0021-8898 .- 1600-5767. ; 49, s. 1042-1047 Tidskriftsartikel (refereegranskat)
16.	Ekeberg, Tomas, et al. (författare) Single-shot diffraction data from the Mimivirus particle using an X-ray free-electron laser 2016 Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 3 Tidskriftsartikel (refereegranskat)abstract Free-electron lasers (FEL) hold the potential to revolutionize structural biology by producing X-ray pules short enough to outrun radiation damage, thus allowing imaging of biological samples without the limitation from radiation damage. Thus, a major part of the scientific case for the first FELs was three-dimensional (3D) reconstruction of non-crystalline biological objects. In a recent publication we demonstrated the first 3D reconstruction of a biological object from an X-ray FEL using this technique. The sample was the giant Mimivirus, which is one of the largest known viruses with a diameter of 450 nm. Here we present the dataset used for this successful reconstruction. Data-analysis methods for single-particle imaging at FELs are undergoing heavy development but data collection relies on very limited time available through a highly competitive proposal process. This dataset provides experimental data to the entire community and could boost algorithm development and provide a benchmark dataset for new algorithms.
17.	Farmand, Maryam, et al. (författare) Near-edge X-ray refraction fine structure microscopy 2017 Ingår i: Applied Physics Letters. - : AMER INST PHYSICS. - 0003-6951 .- 1077-3118. ; 110:6 Tidskriftsartikel (refereegranskat)abstract We demonstrate a method for obtaining increased spatial resolution and specificity in nanoscale chemical composition maps through the use of full refractive reference spectra in soft x-ray spectro- microscopy. Using soft x-ray ptychography, we measure both the absorption and refraction of x-rays through pristine reference materials as a function of photon energy and use these reference spectra as the basis for decomposing spatially resolved spectra from a heterogeneous sample, thereby quantifying the composition at high resolution. While conventional instruments are limited to absorption contrast, our novel refraction based method takes advantage of the strongly energy dependent scattering cross-section and can see nearly five-fold improved spatial resolution on resonance.
18.	Filipe Ramos, C., et al. (författare) Experimental and kinetic modelling investigation on NO, CO and NH3 emissions from NH3/CH4/air premixed flames 2019 Ingår i: Fuel. - : Elsevier BV. - 0016-2361. ; 254 Tidskriftsartikel (refereegranskat)abstract Ammonia (NH3) is regarded as one of the most viable alternatives to produce carbon-free energy. However, its low flammability and high NOx emissions associated with its combustion inhibit the implementation of pure NH3 as a fuel. Dual-fuel approaches with NH3 and more reactive fuels have been proposed; however, information on pollutant emissions is still scarce. The present work focuses on quantifying the gaseous pollutant emissions from the combustion of mixtures of NH3 and CH4 as a function of the equivalence ratio and amount of NH3 in the fuel mixture. A premixed laminar burner was fired with various mixtures of NH3/CH4 in air with equivalence ratios of 0.8, 0.9 and 1, and a fixed thermal input of 300 W. The NH3 molar fraction in the fuel mixture was varied from 0 (pure CH4) up to 0.7. Gas temperatures along the burner axis and emissions of NOx, CO and NH3 were measured for all conditions. The results were compared with kinetic simulations using recent chemical kinetic mechanism models. The experimental results showed that the NOx concentration initially increases as the fraction of NH3 in the fuel mixture rises up to 0.5, decreasing afterwards. Furthermore, NOx emissions decrease as the equivalence ratio is reduced towards fuel-lean conditions. CO and NH3 emissions are fairly low indicating complete combustion of CH4 and NH3. The chemical kinetic mechanisms considered showed fair agreement with the experimental trends, with the NOx and CO emissions being over-predicted for most conditions.
19.	Gomes, Andreia M., et al. (författare) Cooperative Transcription Factor Induction Mediates Hemogenic Reprogramming 2018 Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. Tidskriftsartikel (refereegranskat)abstract During development, hematopoietic stem and progenitor cells (HSPCs) arise from specialized endothelial cells by a process termed endothelial-to-hematopoietic transition (EHT). The genetic program driving human HSPC emergence remains largely unknown. We previously reported that the generation of hemogenic precursor cells from mouse fibroblasts recapitulates developmental hematopoiesis. Here, we demonstrate that human fibroblasts can be reprogrammed into hemogenic cells by the same transcription factors. Induced cells display dynamic EHT transcriptional programs, generate hematopoietic progeny, possess HSPC cell surface phenotype, and repopulate immunodeficient mice for 3 months. Mechanistically, GATA2 and GFI1B interact and co-occupy a cohort of targets. This cooperative binding is reflected by engagement of open enhancers and promoters, initiating silencing of fibroblast genes and activating the hemogenic program. However, GATA2 displays dominant and independent targeting activity during the early phases of reprogramming. These findings shed light on the processes controlling human HSC specification and support generation of reprogrammed HSCs for clinical applications. Gomes et al. show that specification of hemogenesis in human fibroblasts is mediated by cooperative transcription factor binding. GATA2 displays dominance, interacts with GFI1B, and recruits FOS to open chromatin, simultaneously silencing the fibroblast program and initiating an endothelial-to-hematopoietic transition to definitive hematopoiesis.
20.	Gorkhover, Tais, et al. (författare) Femtosecond X-ray Fourier holography imaging of free-flying nanoparticles 2018 Ingår i: Nature Photonics. - : Springer Science and Business Media LLC. - 1749-4885 .- 1749-4893. ; 12:3, s. 150-153 Tidskriftsartikel (refereegranskat)abstract Ultrafast X-ray imaging on individual fragile specimens such as aerosols 1 , metastable particles 2 , superfluid quantum systems 3 and live biospecimens 4 provides high-resolution information that is inaccessible with conventional imaging techniques. Coherent X-ray diffractive imaging, however, suffers from intrinsic loss of phase, and therefore structure recovery is often complicated and not always uniquely defined 4,5 . Here, we introduce the method of in-flight holography, where we use nanoclusters as reference X-ray scatterers to encode relative phase information into diffraction patterns of a virus. The resulting hologram contains an unambiguous three-dimensional map of a virus and two nanoclusters with the highest lateral resolution so far achieved via single shot X-ray holography. Our approach unlocks the benefits of holography for ultrafast X-ray imaging of nanoscale, non-periodic systems and paves the way to direct observation of complex electron dynamics down to the attosecond timescale.
21.	Hantke, Max F., et al. (författare) A data set from flash X-ray imaging of carboxysomes 2016 Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 3 Tidskriftsartikel (refereegranskat)abstract Ultra-intense femtosecond X-ray pulses from X-ray lasers permit structural studies on single particles and biomolecules without crystals. We present a large data set on inherently heterogeneous, polyhedral carboxysome particles. Carboxysomes are cell organelles that vary in size and facilitate up to 40% of Earth’s carbon fixation by cyanobacteria and certain proteobacteria. Variation in size hinders crystallization. Carboxysomes appear icosahedral in the electron microscope. A protein shell encapsulates a large number of Rubisco molecules in paracrystalline arrays inside the organelle. We used carboxysomes with a mean diameter of 115±26 nm from Halothiobacillus neapolitanus. A new aerosol sample-injector allowed us to record 70,000 low-noise diffraction patterns in 12 min. Every diffraction pattern is a unique structure measurement and high-throughput imaging allows sampling the space of structural variability. The different structures can be separated and phased directly from the diffraction data and open a way for accurate, high-throughput studies on structures and structural heterogeneity in biology and elsewhere.
22.	Hantke, Max Felix, 1984- (författare) Coherent Diffractive Imaging with X-ray Lasers 2016 Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract The newly emerging technology of X-ray free-electron lasers (XFELs) has the potential to revolutionise molecular imaging. XFELs generate very intense X-ray pulses and predictions suggest that they may be used for structure determination to atomic resolution even for single molecules. XFELs produce femtosecond pulses that outrun processes of radiation damage and permit the study of structures at room temperature and of structural dynamics.While the first demonstrations of flash X-ray diffractive imaging (FXI) on biological particles were encouraging, they also revealed technical challenges. In this work we demonstrated how some of these challenges can be overcome. We exemplified, with heterogeneous cell organelles, how tens of thousands of FXI diffraction patterns can be collected, sorted, and analysed in an automatic data processing pipeline. We improved image resolution and reduced problems with missing data. We validated, described, and deposited the experimental data in the Coherent X-ray Imaging Data Bank.We demonstrated that aerosol injection can be used to collect FXI data at high hit ratios and with low background. We reduced problems with non-volatile sample contaminants by decreasing aerosol droplet sizes from ~1000 nm to ~150 nm. We achieved this by adapting an electrospray aerosoliser to the Uppsala sample injector. Mie scattering imaging was used as a diagnostic tool to measure positions, sizes, and velocities of individual injected particles.XFEL experiments generate large amounts of data at high rates. Preparation, execution, and data analysis of these experiments benefits from specialised software. In this work we present new open-source software tools that facilitates prediction, online-monitoring, display, and pre-processing of XFEL diffraction data.We hope that this work is a valuable contribution in the quest of transitioning FXI from its first experimental demonstration into a technique that fulfills its potentials.
23.	Hantke, Max F., et al. (författare) Condor : a simulation tool for flash X-ray imaging 2016 Ingår i: Journal of applied crystallography. - 0021-8898 .- 1600-5767. ; 49, s. 1356-1362 Forskningsöversikt (refereegranskat)abstract Flash X-ray imaging has the potential to determine structures down to molecular resolution without the need for crystallization. The ability to accurately predict the diffraction signal and to identify the optimal experimental configuration within the limits of the instrument is important for successful data collection. This article introduces Condor, an open-source simulation tool to predict X-ray far-field scattering amplitudes of isolated particles for customized experimental designs and samples, which the user defines by an atomic or a refractive index model. The software enables researchers to test whether their envisaged imaging experiment is feasible, and to optimize critical parameters for reaching the best possible result. It also aims to support researchers who intend to create or advance reconstruction algorithms by simulating realistic test data. Condor is designed to be easy to use and can be either installed as a Python package or used from its web interface (http://lmb.icm.uu.se/condor). X-ray free-electron lasers have high running costs and beam time at these facilities is precious. Data quality can be substantially improved by using simulations to guide the experimental design and simplify data analysis.
24.	Hantke, Max Felix, et al. (författare) Rayleigh-scattering microscopy for tracking and sizing nanoparticles in focused aerosol beams 2018 Ingår i: IUCrJ. - 2052-2525. ; 5, s. 673-680 Tidskriftsartikel (refereegranskat)abstract Ultra-bright femtosecond X-ray pulses generated by X-ray free-electron lasers (XFELs) can be used to image high-resolution structures without the need for crystallization. For this approach, aerosol injection has been a successful method to deliver 70-2000 nm particles into the XFEL beam efficiently and at low noise. Improving the technique of aerosol sample delivery and extending it to single proteins necessitates quantitative aerosol diagnostics. Here a lab-based technique is introduced for Rayleigh-scattering microscopy allowing us to track and size aerosolized particles down to 40 nm in diameter as they exit the injector. This technique was used to characterize the 'Uppsala injector', which is a pioneering and frequently used aerosol sample injector for XFEL single-particle imaging. The particle-beam focus, particle velocities, particle density and injection yield were measured at different operating conditions. It is also shown how high particle densities and good injection yields can be reached for large particles (100-500 nm). It is found that with decreasing particle size, particle densities and injection yields deteriorate, indicating the need for different injection strategies to extend XFEL imaging to smaller targets, such as single proteins. This work demonstrates the power of Rayleigh-scattering microscopy for studying focused aerosol beams quantitatively. It lays the foundation for lab-based injector development and online injection diagnostics for XFEL research. In the future, the technique may also find application in other fields that employ focused aerosol beams, such as mass spectrometry, particle deposition, fuel injection and three-dimensional printing techniques.
25.	Johnson, Eileanoir B, et al. (författare) Neurofilament light protein in blood predicts regional atrophy in Huntington disease. 2018 Ingår i: Neurology. - 1526-632X. ; 90:8 Tidskriftsartikel (refereegranskat)abstract Neurofilament light (NfL) protein in blood plasma has been proposed as a prognostic biomarker of neurodegeneration in a number of conditions, including Huntington disease (HD). This study investigates the regional distribution of NfL-associated neural pathology in HD gene expansion carriers.We examined associations between NfL measured in plasma and regionally specific atrophy in cross-sectional (n = 198) and longitudinal (n = 177) data in HD gene expansion carriers from the international multisite TRACK-HD study. Using voxel-based morphometry, we measured associations between baseline NfL levels and both baseline gray matter and white matter volume; and longitudinal change in gray matter and white matter over the subsequent 3 years in HD gene expansion carriers.After controlling for demographics, associations between increased NfL levels and reduced brain volume were seen in cortical and subcortical gray matter and within the white matter. After also controlling for known predictors of disease progression (age and CAG repeat length), associations were limited to the caudate and putamen. Longitudinally, NfL predicted subsequent occipital gray matter atrophy and widespread white matter reduction, both before and after correction for other predictors of disease progression.These findings highlight the value of NfL as a dynamic marker of brain atrophy and, more generally, provide further evidence of the strong association between plasma NfL level, a candidate blood biomarker, and pathologic neuronal change.
26.	Kurta, Ruslan P., et al. (författare) Correlations in Scattered X-Ray Laser Pulses Reveal Nanoscale Structural Features of Viruses 2017 Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 119:15 Tidskriftsartikel (refereegranskat)abstract We use extremely bright and ultrashort pulses from an x-ray free-electron laser (XFEL) to measure correlations in x rays scattered from individual bioparticles. This allows us to go beyond the traditional crystallography and single-particle imaging approaches for structure investigations. We employ angular correlations to recover the three-dimensional (3D) structure of nanoscale viruses from x-ray diffraction data measured at the Linac Coherent Light Source. Correlations provide us with a comprehensive structural fingerprint of a 3D virus, which we use both for model-based and ab initio structure recovery. The analyses reveal a clear indication that the structure of the viruses deviates from the expected perfect icosahedral symmetry. Our results anticipate exciting opportunities for XFEL studies of the structure and dynamics of nanoscale objects by means of angular correlations.
27.	Lehtipalo, Katrianne, et al. (författare) The effect of acid-base clustering and ions on the growth of atmospheric nano-particles 2016 Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7 Tidskriftsartikel (refereegranskat)abstract The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial to understand how particles grow in the atmosphere. Insufficient experimental data has impeded a profound understanding of nano-particle growth under atmospheric conditions. Here we study nano-particle growth in the CLOUD (Cosmics Leaving OUtdoors Droplets) chamber, starting from the formation of molecular clusters. We present measured growth rates at sub-3 nm sizes with different atmospherically relevant concentrations of sulphuric acid, water, ammonia and dimethylamine. We find that atmospheric ions and small acid-base clusters, which are not generally accounted for in the measurement of sulphuric acid vapour, can participate in the growth process, leading to enhanced growth rates. The availability of compounds capable of stabilizing sulphuric acid clusters governs the magnitude of these effects and thus the exact growth mechanism. We bring these observations into a coherent framework and discuss their significance in the atmosphere.
28.	Lundholm, Ida V., et al. (författare) Considerations for three-dimensional image reconstruction from experimental data in coherent diffractive imaging 2018 Ingår i: IUCrJ. - : International Union of Crystallography. - 2052-2525. ; 5, s. 531-541 Tidskriftsartikel (refereegranskat)abstract Diffraction before destruction using X-ray free-electron lasers (XFELs) has the potential to determine radiation-damage-free structures without the need for crystallization. This article presents the three-dimensional reconstruction of the Melbournevirus from single-particle X-ray diffraction patterns collected at the LINAC Coherent Light Source (LCLS) as well as reconstructions from simulated data exploring the consequences of different kinds of experimental sources of noise. The reconstruction from experimental data suffers from a strong artifact in the center of the particle. This could be reproduced with simulated data by adding experimental background to the diffraction patterns. In those simulations, the relative density of the artifact increases linearly with background strength. This suggests that the artifact originates from the Fourier transform of the relatively flat background, concentrating all power in a central feature of limited extent. We support these findings by significantly reducing the artifact through background removal before the phase-retrieval step. Large amounts of blurring in the diffraction patterns were also found to introduce diffuse artifacts, which could easily be mistaken as biologically relevant features. Other sources of noise such as sample heterogeneity and variation of pulse energy did not significantly degrade the quality of the reconstructions. Larger data volumes, made possible by the recent inauguration of high repetition-rate XFELs, allow for increased signal-to-background ratio and provide a way to minimize these artifacts. The anticipated development of three-dimensional Fourier-volume-assembly algorithms which are background aware is an alternative and complementary solution, which maximizes the use of data.
29.	Maia, Filipe R. N. C., et al. (författare) CCP-FEL : a collection of computer programs for free-electron laser research 2016 Ingår i: Journal of applied crystallography. - 0021-8898 .- 1600-5767. ; 49, s. 1117-1120 Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract The latest virtual special issue of Journal of Applied Crystallography (http://journals.iucr.org/special_issues/2016/ccpfel) collects software for free-electron laser research and presents tools for a range of topics such as simulation of experiments, online monitoring of data collection, selection of hits, diagnostics of data quality, data management, data analysis and structure determination for both nanocrystallography and single-particle diffractive imaging. This article provides an introduction to the special issue.
30.	Maia, Filipe R. N. C., et al. (författare) The trickle before the torrent-diffraction data from X-ray lasers 2016 Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 3 Tidskriftsartikel (refereegranskat)abstract Today Scientific Data launched a collection of publications describing data from X-ray free-electron lasers under the theme 'Structural Biology Applications of X-ray Lasers'. The papers cover data on nanocrystals, single virus particles, isolated cell organelles, and living cells. All data are deposited with the Coherent X-ray Imaging Data Bank (CXIDB) and available to the scientific community to develop ideas, tools and procedures to meet challenges with the expected torrents of data from new X-ray lasers, capable of producing billion exposures per day.
31.	Majumdar, Suman, et al. (författare) Effects of the sources of reionization on 21-cm redshift-space distortions 2016 Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 456:2, s. 2080-2094 Tidskriftsartikel (refereegranskat)abstract The observed 21 cm signal from the epoch of reionization will be distorted along the line of sight by the peculiar velocities of matter particles. These redshift-space distortions will affect the contrast in the signal and will also make it anisotropic. This anisotropy contains information about the cross-correlation between the matter density field and the neutral hydrogen field, and could thus potentially be used to extract information about the sources of reionization. In this paper, we study a collection of simulated reionization scenarios assuming different models for the sources of reionization. We show that the 21 cm anisotropy is best measured by the quadrupole moment of the power spectrum. We find that, unless the properties of the reionization sources are extreme in some way, the quadrupole moment evolves very predictably as a function of global neutral fraction. This predictability implies that redshift-space distortions are not a very sensitive tool for distinguishing between reionization sources. However, the quadrupole moment can be used as a model-independent probe for constraining the reionization history. We show that such measurements can be done to some extent by first-generation instruments such as LOFAR, while the SKA should be able to measure the reionization history using the quadrupole moment of the power spectrum to great accuracy.
32.	Marchesini, Stefano, et al. (författare) SHARP : a distributed GPU-based ptychographic solver 2016 Ingår i: Journal of applied crystallography. - 0021-8898 .- 1600-5767. ; 49, s. 1245-1252 Tidskriftsartikel (refereegranskat)abstract Ever brighter light sources, fast parallel detectors and advances in phase retrieval methods have made ptychography a practical and popular imaging technique. Compared to previous techniques, ptychography provides superior robustness and resolution at the expense of more advanced and time-consuming data analysis. By taking advantage of massively parallel architectures, high-throughput processing can expedite this analysis and provide microscopists with immediate feedback. These advances allow real-time imaging at wavelength-limited resolution, coupled with a large field of view. This article describes a set of algorithmic and computational methodologies used at the Advanced Light Source and US Department of Energy light sources. These are packaged as a CUDA-based software environment named SHARP (http://camera.lbl.gov/sharp), aimed at providing state-of-the-art high-throughput ptychography reconstructions for the coming era of diffraction-limited light sources.
33.	Moorkens, E, et al. (författare) Policies for biosimilar uptake in Europe: An overview 2017 Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 12:12, s. e0190147- Tidskriftsartikel (refereegranskat)
34.	Munke, Anna, et al. (författare) Data Descriptor : Coherent diffraction of single Rice Dwarf virus particles using hard X-rays at the Linac Coherent Light Source 2016 Ingår i: Scientific Data. - : Nature Publishing Group. - 2052-4463. ; 3 Tidskriftsartikel (refereegranskat)abstract Single particle diffractive imaging data from Rice Dwarf Virus (RDV) were recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS). RDV was chosen as it is a wellcharacterized model system, useful for proof-of-principle experiments, system optimization and algorithm development. RDV, an icosahedral virus of about 70 nm in diameter, was aerosolized and injected into the approximately 0.1 mu m diameter focused hard X-ray beam at the CXI instrument of LCLS. Diffraction patterns from RDV with signal to 5.9 angstrom ngstrom were recorded. The diffraction data are available through the Coherent X-ray Imaging Data Bank (CXIDB) as a resource for algorithm development, the contents of which are described here.
35.	Nilsson, R. Henrik, 1976, et al. (författare) A comprehensive, automatically updated fungal ITS sequence dataset for reference-based chimera control in environmental sequencing efforts 2015 Ingår i: Microbes and Environments. - 1342-6311 .- 1347-4405. ; 30:2, s. 145-150 Tidskriftsartikel (refereegranskat)abstract The nuclear ribosomal internal transcribed spacer (ITS) region is the most commonly chosen genetic marker for the molecular identification of fungi in environmental sequencing and molecular ecology studies. Several analytical issues complicate such efforts, one of which is the formation of chimeric—artificially joined—DNA sequences during PCR amplification or sequence assembly. Several software tools are currently available for chimera detection, but rely to various degrees on the presence of a chimera-free reference dataset for optimal performance. However, no such dataset is available for use with the fungal ITS region. This study introduces a comprehensive, automatically updated reference dataset for fungal ITS sequences based on the UNITE database for the molecular identification of fungi. This dataset supports chimera detection throughout the fungal kingdom and for full-length ITS sequences as well as partial (ITS1 or ITS2 only) datasets. The performance of the dataset on a large set of artificial chimeras was above 99.5%, and we subsequently used the dataset to remove nearly 1,000 compromised fungal ITS sequences from public circulation. The dataset is available at http://unite.ut.ee/repository.php and is subject to web-based third-party curation.
36.	Okamoto, Kenta, et al. (författare) Cryo-EM structure of a Marseilleviridae virus particle reveals a large internal microassembly 2018 Ingår i: Virology. - : Elsevier BV. - 0042-6822 .- 1096-0341. ; 516, s. 239-245 Tidskriftsartikel (refereegranskat)abstract Nucleocytoplasmic large DNA viruses (NCLDVs) blur the line between viruses and cells. Melbournevirus (MelV, family Marseilleviridae) belongs to a new family of NCLDVs. Here we present an electron cryo-microscopy structure of the MelV particle, with the large triangulation number T = 309 constructed by 3080 pseudo-hexagonal capsomers. The most distinct feature of the particle is a large and dense body (LDB) consistently found inside all particles. Electron cryo-tomography of 147 particles shows that the LDB is preferentially located in proximity to the probable lipid bilayer. The LDB is 30 nm in size and its density matches that of a genome/protein complex. The observed LDB reinforces the structural complexity of MelV, setting it apart from other NCLDVs.
37.	Okamoto, Kenta, et al. (författare) The infectious particle of insect-borne totivirus-like Omono River virus has raised ridges and lacks fibre complexes 2016 Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6 Tidskriftsartikel (refereegranskat)abstract Omono River virus (OmRV) is a double-stranded RNA virus isolated from Culex mosquitos, and it belongs to a group of unassigned insect viruses that appear to be related to Totiviridae. This paper describes electron cryo-microscopy (cryoEM) structures for the intact OmRV virion to 8.9 angstrom resolution and the structure of the empty virus-like-particle, that lacks RNA, to 8.3 angstrom resolution. The icosahedral capsid contains 120-subunits and resembles another closely related arthropod-borne totivirus-like virus, the infectious myonecrosis virus (IMNV) from shrimps. Both viruses have an elevated plateau around their icosahedral 5-fold axes, surrounded by a deep canyon. Sequence and structural analysis suggests that this plateau region is mainly composed of the extended C-terminal region of the capsid proteins. In contrast to IMNV, the infectious form of OmRV lacks extensive fibre complexes at its 5-fold axes as directly confirmed by a contrast-enhancement technique, using Zernike phase-contrast cryo-EM. Instead, these fibre complexes are replaced by a short "plug" structure at the five-fold axes of OmRV. OmRV and IMNV have acquired an extracellular phase, and the structures at the five-fold axes may be significant in adaptation to cell-to-cell transmission in metazoan hosts.
38.	Pietrini, Alberto, et al. (författare) A statistical approach to detect protein complexes at X-ray free electron laser facilities 2018 Ingår i: Communications Physics. - : Springer Science and Business Media LLC. - 2399-3650. ; 1 Tidskriftsartikel (refereegranskat)abstract The Flash X-ray Imaging (FXI) technique, under development at X-ray free electron lasers (XFEL), aims to achieve structure determination based on diffraction from individual macromolecular complexes. We report an FXI study on the first protein complex-RNA polymerase II-ever injected at an XFEL. A successful 3D reconstruction requires a high number of observations of the sample in various orientations. The measured diffraction signal for many shots can be comparable to background. Here we present a robust and highly sensitive hit-identification method based on automated modeling of beamline background through photon statistics. It can operate at controlled false positive hit-rate of 3 x10(-5). We demonstrate its power in determining particle hits and validate our findings against an independent hit-identification approach based on ion time-of-flight spectra. We also validate the advantages of our method over simpler hit-identification schemes via tests on other samples and using computer simulations, showing a doubled hit-identification power.
39.	Reddy, Hemanth K. N., et al. (författare) Coherent soft X-ray diffraction imaging of coliphage PR772 at the Linac coherent light source 2017 Ingår i: Scientia Danica. Series H. Humanistica 4. - : Nature Publishing Group. - 1904-5506 .- 2052-4463. ; 4 Tidskriftsartikel (refereegranskat)abstract Single-particle diffraction from X-ray Free Electron Lasers offers the potential for molecular structure determination without the need for crystallization. In an effort to further develop the technique, we present a dataset of coherent soft X-ray diffraction images of Coliphage PR772 virus, collected at the Atomic Molecular Optics (AMO) beamline with pnCCD detectors in the LAMP instrument at the Linac Coherent Light Source. The diameter of PR772 ranges from 65-70 nm, which is considerably smaller than the previously reported similar to 600 nm diameter Mimivirus. This reflects continued progress in XFEL-based single-particle imaging towards the single molecular imaging regime. The data set contains significantly more single particle hits than collected in previous experiments, enabling the development of improved statistical analysis, reconstruction algorithms, and quantitative metrics to determine resolution and self-consistency.
40.	Rose, Max, et al. (författare) Single-particle imaging without symmetry constraints at an X-ray free-electron laser 2018 Ingår i: IUCrJ. - : INT UNION CRYSTALLOGRAPHY. - 2052-2525. ; 5, s. 727-736 Tidskriftsartikel (refereegranskat)abstract The analysis of a single-particle imaging (SPI) experiment performed at the AMO beamline at LCLS as part of the SPI initiative is presented here. A workflow for the three-dimensional virus reconstruction of the PR772 bacteriophage from measured single-particle data is developed. It consists of several well defined steps including single-hit diffraction data classification, refined filtering of the classified data, reconstruction of three-dimensional scattered intensity from the experimental diffraction patterns by orientation determination and a final three-dimensional reconstruction of the virus electron density without symmetry constraints. The analysis developed here revealed and quantified nanoscale features of the PR772 virus measured in this experiment, with the obtained resolution better than 10 nm, with a clear indication that the structure was compressed in one direction and, as such, deviates from ideal icosahedral symmetry.
41.	Sala, S., et al. (författare) Ptychographic imaging for the characterization of X-ray free-electron laser beams 2017 Ingår i: X-RAY MICROSCOPY CONFERENCE 2016 (XRM 2016). - : IOP Publishing. Konferensbidrag (refereegranskat)abstract We present some preliminary results from a study aimed at the characterization of the wavefront of X-ray free electron laser (XFEL) beams in the same operation conditions as for single particle imaging (or flash X-ray imaging) experiments. The varying illumination produced by wavefront fluctuations between several pulses leads to a partially coherent average beam which can be decomposed into several coherent modes using ptychographic reconstruction algorithms. Such a decomposition can give insight into pulse-to-pulse variations of the wavefront. We discuss data collected at the Linac Coherent Light Source (LCLS) and FERMI.
42.	van der Schot, Gijs, et al. (författare) Imaging single cells in a beam of live cyanobacteria with an X-ray laser 2015 Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 6 Tidskriftsartikel (refereegranskat)abstract There exists a conspicuous gap of knowledge about the organization of life at mesoscopic levels. Ultra-fast coherent diffractive imaging with X-ray free-electron lasers can probe structures at the relevant length scales and may reach sub-nanometer resolution on micron-sized living cells. Here we show that we can introduce a beam of aerosolised cyanobacteria into the focus of the Linac Coherent Light Source and record diffraction patterns from individual living cells at very low noise levels and at high hit ratios. We obtain two-dimensional projection images directly from the diffraction patterns, and present the results as synthetic X-ray Nomarski images calculated from the complex-valued reconstructions. We further demonstrate that it is possible to record diffraction data to nanometer resolution on live cells with X-ray lasers. Extension to sub-nanometer resolution is within reach, although improvements in pulse parameters and X-ray area detectors will be necessary to unlock this potential.
43.	van der Schot, Gijs, et al. (författare) Open data set of live cyanobacterial cells imaged using an X-ray laser 2016 Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 3 Tidskriftsartikel (refereegranskat)abstract Structural studies on living cells by conventional methods are limited to low resolution because radiation damage kills cells long before the necessary dose for high resolution can be delivered. X-ray free-electron lasers circumvent this problem by outrunning key damage processes with an ultra-short and extremely bright coherent X-ray pulse. Diffraction-before-destruction experiments provide high-resolution data from cells that are alive when the femtosecond X-ray pulse traverses the sample. This paper presents two data sets from micron-sized cyanobacteria obtained at the Linac Coherent Light Source, containing a total of 199,000 diffraction patterns. Utilizing this type of diffraction data will require the development of new analysis methods and algorithms for studying structure and structural variability in large populations of cells and to create abstract models. Such studies will allow us to understand living cells and populations of cells in new ways. New X-ray lasers, like the European XFEL, will produce billions of pulses per day, and could open new areas in structural sciences.
44.	Wright, Alison E., et al. (författare) Male-biased gene expression resolves sexual conflict through the evolution of sex-specific genetic architecture 2018 Ingår i: Evolution Letters. - : Oxford University Press (OUP). - 2056-3744. ; 2:2, s. 52-61 Tidskriftsartikel (refereegranskat)abstract Many genes are subject to contradictory selection pressures in males and females, and balancing selection resulting from sexual conflict has the potential to substantially increase standing genetic diversity in populations and thereby act as an important force in adaptation. However, the underlying causes of sexual conflict, and the potential for resolution, remains hotly debated. Using transcriptome-resequencing data from male and female guppies, we use a novel approach, combining patterns of genetic diversity and intersexual divergence in allele frequency, to distinguish the different scenarios that give rise to sexual conflict, and how this conflict may be resolved through regulatory evolution. We show that reproductive fitness is the main source of sexual conflict, and this is resolved via the evolution of male-biased expression. Furthermore, resolution of sexual conflict produces significant differences in genetic architecture between males and females, which in turn lead to specific alleles influencing sex-specific viability. Together, our findings suggest an important role for sexual conflict in shaping broad patterns of genome diversity, and show that regulatory evolution is a rapid and efficient route to the resolution of conflict.
45.	Yu, Young-Sang, et al. (författare) Three-dimensional localization of nanoscale battery reactions using soft X-ray tomography 2018 Ingår i: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 9 Tidskriftsartikel (refereegranskat)abstract Battery function is determined by the efficiency and reversibility of the electrochemical phase transformations at solid electrodes. The microscopic tools available to study the chemical states of matter with the required spatial resolution and chemical specificity are intrinsically limited when studying complex architectures by their reliance on two-dimensional projections of thick material. Here, we report the development of soft X-ray ptychographic tomography, which resolves chemical states in three dimensions at 11 nm spatial resolution. We study an ensemble of nano-plates of lithium iron phosphate extracted from a battery electrode at 50% state of charge. Using a set of nanoscale tomograms, we quantify the electrochemical state and resolve phase boundaries throughout the volume of individual nanoparticles. These observations reveal multiple reaction points, intra-particle heterogeneity, and size effects that highlight the importance of multi-dimensional analytical tools in providing novel insight to the design of the next generation of high-performance devices.

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