| 1. |
- Ekeberg, Tomas, et al.
(författare)
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Single-shot diffraction data from the Mimivirus particle using an X-ray free-electron laser
- 2016
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Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 3
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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.
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| 2. |
- Jönsson, Mattias, et al.
(författare)
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Modelling the external radiation exposure from the Chernobyl fallout using data from the Swedish municipality measurement system
- 2017
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Ingår i: Journal of Environmental Radioactivity. - : Elsevier BV. - 0265-931X .- 1879-1700. ; 178-179, s. 16-27
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Tidskriftsartikel (refereegranskat)abstract
- In connection with the Chernobyl fallout and the subsequent deposition of radionuclides in Sweden, Swedish municipalities launched a measurement program to monitor the external radiation exposure. This program encompasses measurements of the ambient dose equivalent rate 1 m above ground at selected locations, and repeats those measurements at the same locations at 7-month intervals. Measurement data compiled from the seven locations with the highest deposition were combined with data from aerial surveys since May 1986 of ground deposition of 137Cs, high-resolution gamma spectrometry performed at four locations in May 1986, and measurements from fixed continuous air gamma rate monitoring stations from 28 April to 15 May 1986. Based on these datasets, a model of the time pattern of the external dose rate in terms of ambient dose equivalent rate from the Chernobyl fallout was developed. The decrease in the ambient dose equivalent rate could, on average, be described by a four-component exponential decay function with effective half-times of 6.8 ± 0.3 d, 104 ± 26 d, 1.0 ± 0.02 y and 5.5 ± 0.09 y, respectively. The predominant contributions to the external dose rate in the first month were from short-lived fission products superseded by 134Cs and then 137Cs. Integrated over 70 y and using extrapolation of the curve fits, our model predicts that 137Cs contributes about 60% and 134Cs contributes about 30% of the external effective dose at these seven locations. The projected time-integrated 70 y external effective dose to an unshielded person from all nuclides per unit total activity deposition of 137Cs is estimated to be 0.29 ± 0.0.08 mSv/(kBq m-2). These results are in agreement with those found in Chernobyl contaminated Russian forest areas, and emphasize the usefulness of maintaining a long-term and regular measurement program in contaminated areas.
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| 3. |
- Abolfathi, Bela, et al.
(författare)
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The Fourteenth Data Release of the Sloan Digital Sky Survey : First Spectroscopic Data from the Extended Baryon Oscillation Spectroscopic Survey and from the Second Phase of the Apache Point Observatory Galactic Evolution Experiment
- 2018
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Ingår i: Astrophysical Journal Supplement Series. - : IOP Publishing Ltd. - 0067-0049 .- 1538-4365. ; 235:2
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Tidskriftsartikel (refereegranskat)abstract
- The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since 2014 July. This paper describes the second data release from this phase, and the 14th from SDSS overall (making this Data Release Fourteen or DR14). This release makes the data taken by SDSS-IV in its first two years of operation (2014-2016 July) public. Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey; the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data-driven machine-learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from the SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS web site (www.sdss.org) has been updated for this release and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020 and will be followed by SDSS-V.
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| 4. |
- Blanton, Michael R., et al.
(författare)
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Sloan Digital Sky Survey IV : Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
- 2017
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Ingår i: Astronomical Journal. - : IOP Publishing Ltd. - 0004-6256 .- 1538-3881. ; 154:1
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Tidskriftsartikel (refereegranskat)abstract
- We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and. high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z similar to 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z similar to 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs. and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the. Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July.
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| 5. |
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| 6. |
- Falkenjack, Johan, 1986-
(författare)
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Towards a Model of General Text Complexity for Swedish
- 2018
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In an increasingly networked world, where the amount of written information is growing at a rate never before seen, the ability to read and absorb written information is of utmost importance for anything but a superficial understanding of life's complexities. That is an example of a sentence which is not very easy to read. It can be said to have a relatively high degree of text complexity. Nevertheless, the sentence is also true. It is important to be able to read and understand written materials. While not everyone might have a job where they have to read a lot, access to written material is necessary in order to participate in modern society. Most information, from news reporting, to medical information, to governmental information, come primarily in a written form.But what makes the sentence at the start of this abstract so complex? We can probably all agree that the length is part of it. But then what? Researches in the field of readability and text complexity analysis have been studying this question for almost 100 years. That research has over time come to include many computational and data driven methods within the field of computational linguistics.This thesis cover some of my contributions to this field of research, though with a main focus on Swedish rather than English text. It aims to explore two primary questions (1) Which linguistic features are most important when assessing text complexity in Swedish? and (2) How can we deal with the problem of data sparsity with regards to complexity annotated texts in Swedish?The first issue is tackled by exploring the task of identifying easy-to-read ("lättläst") text using classification with Support Vector Machines. A large set of linguistic features is evaluated with regards to predictive performance and is shown to separate easy-to-read texts from regular texts with a very high accuracy. Meanwhile, using a genetic algorithm for variable selection, we find that almost the same accuracy can be reached with only 8 features. This implies that this classification problem is not very hard and that results might not generalize to comparing less easy-to-read texts.This, in turn, brings us to the second question. Except for easy-to-read labeled texts, the data with text complexity annotations is very sparse. It consist of multiple small corpora using different scales to label documents. To deal with this problem, we propose a novel statistical model. The model belongs to the larger family of Probit models and is implemented in a Bayesian fashion and estimated using a Gibbs sampler based on extending a well established Gibbs sampler for the Ordered Probit model. This model is evaluated using both simulated and real world readability data with very promising results.
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| 7. |
- Frisk, Andreas, et al.
(författare)
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Magnetic and structural characterization of CoFeZr thin films grown by combinatorial sputtering
- 2019
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Ingår i: Physical Review Materials. - 2475-9953. ; 3:7
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Tidskriftsartikel (refereegranskat)abstract
- We report on a detailed investigation of structural and magnetic properties of thin CoFeZr films, produced by combinatorial cosputtering, with compositions in the ranges 30-85 at.% Co, 12-63 at.% Fe, and 4-8 at.% Zr. Extended x-ray absorption fine structure and x-ray diffraction measurements reveal that alloys with a Zr content below 5 at.% are polycrystalline with a bcc structure, while an amorphous morphology is stabilized at Zr contents above 6 at.%. All samples display a growth-induced in-plane uniaxial anisotropy, which is closely related to the Zr concentration gradients across the wafers. A model for the angular dependence of the reduced remanence, including a Gaussian distribution of easy/hard anisotropy axes, is presented and successfully used to fit the data for all samples. The magnetic moments of the polycrystalline films approximately follow the Slater-Pauling curve, and the magnetic moments of the amorphous films follow a similar trend, but with about 20 % lower values. X-ray magnetic circular dichroism measurements show, for the amorphous films, that the Co moments are virtually constant at 1.7(2)μB/atom.
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| 8. |
- Jarnerud, Tova, 1976-
(författare)
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Utilization of recovered lime-containing materials from pulp and paper industries as slag formers in stainless steel production
- 2019
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In recent years, major efforts have been made to develop a more circular economy. The desire to reuse, remanufacture and recycle materials are important for the development towards a sustainable society. An extended lifespan of materials helps to reduce the amount of waste kept in landfills, as well as to reduce the extraction of natural resources. Pulp and paper and steel industries are two of the largest export industrial sectors in Sweden. It is well known that the pulp and paper industries also generates large amounts of organic and inorganic wastes, of which a significant part is kept in landfills. Year by year deposit of wastes in landfills is becoming more difficult to handle and expensive due to stronger regulations and requirements regarding the environment. During Electric Arc Furnace (EAF) and Argon Oxygen Decarburization (AOD) stainless steelmaking operations, burnt lime (primary lime) is charged together with other slag forming materials in the furnace or converter to attain a specific basicity of the slag and to achieve purification from unwanted elements by chemical reactions in the steel.However, a number of CaO-containing wastes from pulp/paper mills can be used as slag formers in steelmaking processes to replace the currently used burnt natural lime, since the use of this primary lime does not conform with the closing the loop idea that is being prioritized in modern society. This thesis presents results from preliminary experiments for examining the replacement of primary lime with secondary lime from pulp and paper production waste as slag formers in EAF and AOD converters. The obtained results showed a possibility of using up to 30% CaO from secondary lime as a replacement for primary lime in the EAF. Furthermore, the amount of ferrosilicon alloys additions can be decreased by up to 3kg/ton of steel. For the AOD process the use of secondary lime doesn´t have any negative effects on the decarburization process and reduction process. Furthermore, it has similar desulphurization functions as the primary lime. However, the phosphorus content in the metal was slightly increased. Thus, the replacement ratio of secondary lime will be limited by the acceptable phosphorus level in the final steel due to higher phosphorus content in wastes from pulp and paper mills compared to that in primary lime. Moreover, it was revealed during this study that slags from AOD converters can be used as binding agents for briquetting of these secondary lime materials. These results shows that waste/by products from two major industries can be used to make metallurgical briquettes, uniting two major industrial sectors in a circular symbiosis towards a more sustainable future.
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| 9. |
- Je, Byoung Il, et al.
(författare)
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Signaling from maize organ primordia via FASCIATED EAR3 regulates stem cell proliferation and yield traits
- 2016
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 48:7, s. 785-791
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Tidskriftsartikel (refereegranskat)abstract
- Shoot apical meristems are stem cell niches that balance proliferation with the incorporation of daughter cells into organ primordia. This balance is maintained by CLAVATA-WUSCHEL feedback signaling between the stem cells at the tip of the meristem and the underlying organizing center. Signals that provide feedback from organ primordia to control the stem cell niche in plants have also been hypothesized, but their identities are unknown. Here we report FASCIATED EAR3 (FEA3), a leucine-rich-repeat receptor that functions in stem cell control and responds to a CLAVATA3/ESR-related (CLE) peptide expressed in organ primordia. We modeled our results to propose a regulatory system that transmits signals from differentiating cells in organ primordia back to the stem cell niche and that appears to function broadly in the plant kingdom. Furthermore, we demonstrate an application of this new signaling feedback, by showing that weak alleles of fea3 enhance hybrid maize yield traits.
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| 10. |
- Johansson, Robert, et al.
(författare)
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Arbitrarily applicable relational responding as non-axiomatic logical reasoning
- 2018
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Ingår i: Proceedings of the 14th SweCog Conference. - Skövde : University of Skövde. - 9789198366730 ; , s. 7-9
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Konferensbidrag (refereegranskat)abstract
- In the research tradition called “contextual behavioral science” (Zettle, Hayes, & Barnes-Holmes, 2016) it is argued that a large part of cognitive phenomena are made possible due to a type of operant behavior known as “arbitrarily applicable relational responding”. Relational Frame Theory (RFT; Hayes, Barnes-Holmes, & Roche, 2001; Roche & Dymond, 2013) is a contextual behavioral account of language and cognition. RFT aims to develop a unified account of language and cognition and have been showed to account for as diverse topics as language development, the emergence of a self, human suffering, intelligence, problem solving, etc. The fundamental thesis of RFT is that language and cognition are all instances of arbitrarily applicable relational responding (AARR). According to this perspective, relating means responding to one event in terms of another. While both non-humans and humans are able to respond relationally, only humans seem to able to do this arbitrarily. For example, a human being can be presented with three similar coins and being told that “coin A is worth less than coin B, which in turn is worth less than coin C”. The fact that a human being in some context would immediately pick coin A, is to RFT an example of AARR in which stimuli are arbitrarily related along a comparative dimension of worth.NARS (Non-Axiomatic Reasoning System; Wang, 2006, 2013) is a project aiming to building a general purpose intelligent system. An assumption in NARS is that the essence of intelligence is the principle of adapting to the environment while working with insufficient knowledge and resources. Accordingly, an intelligent system should rely on finite processing capacity, work in real time, be open to unexpected tasks, and learn from experience. NARS is built as a reasoning system, using a formal specification “non-axiomatic logic” (NAL) to define its functionality. NAL is designed incrementally with multiple layers. At each layer, NAL and its internal language Narsese are extended to have a higher expressive power, a richer semantics, and a larger set of inference rules, so as to increase the intelligence of the system. The reasoning process in NARS uniformly carries out many cognitive functions that are traditionally studied as separate processes with different mechanisms, such as learning, perceiving, planning, predicting, remembering, problem solving, decision making, etc.The primary aim of this work is to investigate if NARS can do AARR with gradually increasing complexity, and under which conditions this is made possible. Potential applications are for example describing and exploring mental health phenomena within an artificial general intelligence framework.
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