| 1. |
- Aad, G, et al.
(författare)
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- 2015
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swepub:Mat__t
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| 2. |
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| 3. |
- Shimwell, T. W., et al.
(författare)
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The LOFAR Two-metre Sky Survey: II. First data release
- 2019
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 622
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Forskningsöversikt (refereegranskat)abstract
- The LOFAR Two-metre Sky Survey (LoTSS) is an ongoing sensitive, high-resolution 120-168 MHz survey of the entire northern sky for which observations are now 20% complete. We present our first full-quality public data release. For this data release 424 square degrees, or 2% of the eventual coverage, in the region of the HETDEX Spring Field (right ascension 10h45m00s to 15h30m00s and declination 45°00′00″ to 57°00′00″) were mapped using a fully automated direction-dependent calibration and imaging pipeline that we developed. A total of 325 694 sources are detected with a signal of at least five times the noise, and the source density is a factor of ∼10 higher than the most sensitive existing very wide-area radio-continuum surveys. The median sensitivity is S144 MHz = 71 μJy beam -1 and the point-source completeness is 90% at an integrated flux density of 0.45 mJy. The resolution of the images is 6″ and the positional accuracy is within 0.2″. This data release consists of a catalogue containing location, flux, and shape estimates together with 58 mosaic images that cover the catalogued area. In this paper we provide an overview of the data release with a focus on the processing of the LOFAR data and the characteristics of the resulting images. In two accompanying papers we provide the radio source associations and deblending and, where possible, the optical identifications of the radio sources together with the photometric redshifts and properties of the host galaxies. These data release papers are published together with a further ∼20 articles that highlight the scientific potential of LoTSS.
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| 4. |
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| 5. |
- Gottardo, A., et al.
(författare)
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New spectroscopic information on 211,213Tl : A changing structure beyond the N=126 shell closure
- 2019
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Ingår i: Physical Review C. - 2469-9985. ; 99:5
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Tidskriftsartikel (refereegranskat)abstract
- The neutron-rich isotopes 211,213Tl, beyond the N=126 shell closure, have been studied for the first time in isomer γ-ray decay, exploiting the fragmentation of a primary uranium beam at the Fragment Separator-Rare Isotopes Investigation at GSI setup. The observed isomeric states in 211,213Tl show a deviation from the seniority-like scheme of 209Tl. The possible interpretation of the data is discussed on the basis of energy-level systematics and shell-model calculations.
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| 6. |
- Shimwell, T. W., et al.
(författare)
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The LOFAR Two-metre Sky Survey: I. Survey description and preliminary data release
- 2017
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 598, s. Art no A104-
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Tidskriftsartikel (refereegranskat)abstract
- The LOFAR Two-metre Sky Survey (LoTSS) is a deep 120-168 MHz imaging survey that will eventually cover the entire northern sky. Each of the 3170 pointings will be observed for 8 h, which, at most declinations, is sufficient to produce ~5? resolution images with a sensitivity of ~100 ?Jy/beam and accomplish the main scientific aims of the survey, which are to explore the formation and evolution of massive black holes, galaxies, clusters of galaxies and large-scale structure. Owing to the compact core and long baselines of LOFAR, the images provide excellent sensitivity to both highly extended and compact emission. For legacy value, the data are archived at high spectral and time resolution to facilitate subarcsecond imaging and spectral line studies. In this paper we provide an overview of the LoTSS. We outline the survey strategy, the observational status, the current calibration techniques, a preliminary data release, and the anticipated scientific impact. The preliminary images that we have released were created using a fully automated but direction-independent calibration strategy and are significantly more sensitive than those produced by any existing large-Area low-frequency survey. In excess of 44 000 sources are detected in the images that have a resolution of 25?, typical noise levels of less than 0.5 mJy/beam, and cover an area of over 350 square degrees in the region of the HETDEX Spring Field (right ascension 10h45m00s to 15h30m00s and declination 45°00?00? to 57°00?00?).
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| 7. |
- Alexander, T., et al.
(författare)
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Isomeric Ratios in 206Hg
- 2015
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Ingår i: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 46:3, s. 601-605
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Tidskriftsartikel (refereegranskat)abstract
- Hg-206 was populated in the fragmentation of an E/A = 1 GeV Pb-208 beam at GSI. It was part of a campaign to study nuclei around Pb-208 via relativistic Coulomb excitation. The observation of the known isomeric states confirmed the identification of the fragmentation products. The isomeric decays were also used to prove that the correlations between beam identification detectors and the AGATA gamma-ray tracking array worked properly and that the tracking efficiency was independent of the time relative to the prompt flash.
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| 8. |
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| 9. |
- Paulsen, B. S., et al.
(författare)
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Ectopic expression of RAD52 and dn53BP1 improves homology-directed repair during CRISPR-Cas9 genome editing
- 2017
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Ingår i: Nature Biomedical Engineering. - : Springer Science and Business Media LLC. - 2157-846X. ; 1:11, s. 878-888
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Tidskriftsartikel (refereegranskat)abstract
- Gene disruption by clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) is highly efficient and relies on the error-prone non-homologous end-joining pathway. Conversely, precise gene editing requires homology-directed repair (HDR), which occurs at a lower frequency than non-homologous end-joining in mammalian cells. Here, by testing whether manipulation of DNA repair factors improves HDR efficacy, we show that transient ectopic co-expression of RAD52 and a dominant-negative form of tumour protein p53-binding protein 1 (dn53BP1) synergize to enable efficient HDR using a single-stranded oligonucleotide DNA donor template at multiple loci in human cells, including patient-derived induced pluripotent stem cells. Co-expression of RAD52 and dn53BP1 improves multiplexed HDR-mediated editing, whereas expression of RAD52 alone enhances HDR with Cas9 nickase. Our data show that the frequency of non-homologous end-joining-mediated double-strand break repair in the presence of these two factors is not suppressed and suggest that dn53BP1 competitively antagonizes 53BP1 to augment HDR in combination with RAD52. Importantly, co-expression of RAD52 and dn53BP1 does not alter Cas9 off-target activity. These findings support the use of RAD52 and dn53BP1 co-expression to overcome bottlenecks that limit HDR in precision genome editing. © 2017 The Author(s).
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| 10. |
- Yang, W., et al.
(författare)
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Immunogenic neoantigens derived from gene fusions stimulate T cell responses
- 2019
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Ingår i: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 25:5
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Tidskriftsartikel (refereegranskat)abstract
- Anti-tumor immunity is driven by self versus non-self discrimination. Many immunotherapeutic approaches to cancer have taken advantage of tumor neoantigens derived from somatic mutations. Here, we demonstrate that gene fusions are a source of immunogenic neoantigens that can mediate responses to immunotherapy. We identified an exceptional responder with metastatic head and neck cancer who experienced a complete response to immune checkpoint inhibitor therapy, despite a low mutational load and minimal pre-treatment immune infiltration in the tumor. Using whole-genome sequencing and RNA sequencing, we identified a novel gene fusion and demonstrated that it produces a neoantigen that can specifically elicit a host cytotoxic T cell response. In a cohort of head and neck tumors with low mutation burden, minimal immune infiltration and prevalent gene fusions, we also identified gene fusion-derived neoantigens that generate cytotoxic T cell responses. Finally, analyzing additional datasets of fusion-positive cancers, including checkpoint-inhibitor-treated tumors, we found evidence of immune surveillance resulting in negative selective pressure against gene fusion-derived neoantigens. These findings highlight an important class of tumor-specific antigens and have implications for targeting gene fusion events in cancers that would otherwise be less poised for response to immunotherapy, including cancers with low mutational load and minimal immune infiltration.
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| 11. |
- Biswas, A., et al.
(författare)
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Adolescent girls’ attitudes toward female genital mutilation : A study in seven African countries [version 1; referees: 2 approved]
- 2018
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Ingår i: F1000 Research. - : F1000 Research Ltd. - 2046-1402. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Background: The study’s aim is to examine adolescent girls’ attitudes toward the continuation or discontinuation of female genital mutilation (FGM) in association with their demographics in seven different countries in Africa. Methods: Data from the women’s survey of the Demographic and Health Surveys (DHS) conducted by the respective ministries (of Health and Family Welfare) in Egypt, Guinea, Kenya, Mali, Niger, Senegal and Sierra Leone were used. Adolescent girls (15-19 years) were included in the current analysis: Egypt (N=636), Guinea (N=1994), Kenya (N= 1767), Mali (N=2791), Niger (N=1835), Senegal (N=3604), Sierra Leone (N=1237). Results: Prevalence of supporting the continuation of FGM among adolescent girls was in Egypt 58%, Guinea 63%, Kenya 16%, Mali 72%, Niger 3%, Senegal 23%, and Sierra Leone 52%. Being Muslim and having low economic status were significantly associated with supporting the continuation of FGM in five of the participating countries. Girls having no education or only primary education in Guinea, Kenya, Mali and Sierra Leone exhibited a higher likelihood of supporting FGM than girls with secondary or higher education. In Egypt, Niger and Senegal there was no association between education and supporting FGM. The girls who stated that they had no exposure to media showed the higher likelihood of supporting FGM in Guinea, Kenya, and Senegal than those with exposure to media. Conclusions: The current study argues that increasing media coverage and education, and reducing poverty are of importance for shifting adolescent girls’ attitudes in favor of discontinuation of FGM. © 2018 Dalal K et al.
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| 12. |
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| 13. |
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| 14. |
- Nandi, A., et al.
(författare)
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Accretion flow dynamics during 1999 outburst of XTE J1859+226—modeling of broadband spectra and constraining the source mass
- 2018
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Ingår i: Astrophysics and Space Science. - : Springer Netherlands. - 0004-640X .- 1572-946X. ; 363:5
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Tidskriftsartikel (refereegranskat)abstract
- We examine the dynamical behavior of accretion flow around XTE J1859+226 during the 1999 outburst by analyzing the entire outburst data (∼166 days) from RXTE Satellite. Towards this, we study the hysteresis behavior in the hardness intensity diagram (HID) based on the broadband (3–150 keV) spectral modeling, spectral signature of jet ejection and the evolution of Quasi-periodic Oscillation (QPO) frequencies using the two-component advective flow model around a black hole. We compute the flow parameters, namely Keplerian accretion rate (m˙ d), sub-Keplerian accretion rate (m˙ h), shock location (rs) and black hole mass (Mbh) from the spectral modeling and study their evolution along the q-diagram. Subsequently, the kinetic jet power is computed as Ljetobs∼3–6×1037ergs−1 during one of the observed radio flares which indicates that jet power corresponds to 8–16% mass outflow rate from the disc. This estimate of mass outflow rate is in close agreement with the change in total accretion rate (∼14%) required for spectral modeling before and during the flare. Finally, we provide a mass estimate of the source XTE J1859+226 based on the spectral modeling that lies in the range of 5.2–7.9 M⊙ with 90% confidence.
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| 15. |
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| 16. |
- Fullagar, Wilfred K., et al.
(författare)
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Beating Darwin-Bragg losses in lab-based ultrafast X-ray experiments
- 2017
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Ingår i: Structural Dynamics. - : AIP Publishing. - 2329-7778. ; 4:4
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Tidskriftsartikel (refereegranskat)abstract
- The use of low temperature thermal detectors for avoiding Darwin-Bragg losses in lab-based ultrafast experiments has begun. An outline of the background of this new development is offered, showing the relevant history and initiative taken by this work.
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| 17. |
- Kumar, Mukesh, et al.
(författare)
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The impact of additional scalar bosons at the LHC
- 2017
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Ingår i: HIGH ENERGY PARTICLE PHYSICS WORKSHOP 2016. - : IOP PUBLISHING LTD.
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Konferensbidrag (refereegranskat)abstract
- In this study we consider an effective model by introducing two hypothetical real scalars, H and chi - a dark matter candidate, where the masses of these scalars are 2m(h) < m(H) < 2m(t) and m(chi) approximate to m(h)/2 with m(h) and m(t) being the Standard Model Higgs boson and top quark masses, respectively. A distortion in the transverse momentum distributions of h in the intermediate region of the spectrum through the processes pp -> H -> h(chi chi) could be observed in this model. An additional scalar, S, has been postulated to explain large H -> h(chi chi) branching ratios, assuming m(h) less than or similar to m(s) less than or similar to mH - m(h) and m(s) > 2m(chi). Furthermore, a scenario of a two Higgs doublet model (2HDM) is introduced and a detailed proposal at the present energies of the Large Hadron Collider to study the extra CP-even (h, H), CP-odd (A) and charged (H-+/-) scalars has been pursued. With possible phenomenological implications, production and decay modes for these scalars are discussed. Based on the mass spectrum of H, A and H-+/-, the production of multi-leptons and Z+jets+missing-energy events are predicted. A specific, Type-II 2HDM model is discussed in detail.
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| 18. |
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| 21. |
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| 22. |
- Parmar, Priya, et al.
(författare)
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The Stroke Riskometer (TM) App: Validation of a data collection tool and stroke risk predictor
- 2015
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Ingår i: International Journal of Stroke. - : SAGE Publications. - 1747-4949 .- 1747-4930. ; 10:2, s. 231-244
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe greatest potential to reduce the burden of stroke is by primary prevention of first-ever stroke, which constitutes three quarters of all stroke. In addition to population-wide prevention strategies (the mass' approach), the high risk' approach aims to identify individuals at risk of stroke and to modify their risk factors, and risk, accordingly. Current methods of assessing and modifying stroke risk are difficult to access and implement by the general population, amongst whom most future strokes will arise. To help reduce the burden of stroke on individuals and the population a new app, the Stroke Riskometer(TM), has been developed. We aim to explore the validity of the app for predicting the risk of stroke compared with current best methods. Methods752 stroke outcomes from a sample of 9501 individuals across three countries (New Zealand, Russia and the Netherlands) were utilized to investigate the performance of a novel stroke risk prediction tool algorithm (Stroke Riskometer(TM)) compared with two established stroke risk score prediction algorithms (Framingham Stroke Risk Score [FSRS] and QStroke). We calculated the receiver operating characteristics (ROC) curves and area under the ROC curve (AUROC) with 95% confidence intervals, Harrels C-statistic and D-statistics for measure of discrimination, R-2 statistics to indicate level of variability accounted for by each prediction algorithm, the Hosmer-Lemeshow statistic for calibration, and the sensitivity and specificity of each algorithm. ResultsThe Stroke Riskometer(TM) performed well against the FSRS five-year AUROC for both males (FSRS=750% (95% CI 723%-776%), Stroke Riskometer(TM)=740(95% CI 713%-767%) and females [FSRS=703% (95% CI 679%-728%, Stroke Riskometer(TM)=715% (95% CI 690%-739%)], and better than QStroke [males - 597% (95% CI 573%-620%) and comparable to females=711% (95% CI 690%-731%)]. Discriminative ability of all algorithms was low (C-statistic ranging from 051-056, D-statistic ranging from 001-012). Hosmer-Lemeshow illustrated that all of the predicted risk scores were not well calibrated with the observed event data (P<0006). ConclusionsThe Stroke Riskometer(TM) is comparable in performance for stroke prediction with FSRS and QStroke. All three algorithms performed equally poorly in predicting stroke events. The Stroke Riskometer(TM) will be continually developed and validated to address the need to improve the current stroke risk scoring systems to more accurately predict stroke, particularly by identifying robust ethnic/race ethnicity group and country specific risk factors.
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| 23. |
- Radhika, D., et al.
(författare)
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Broad-band spectral evolution and temporal variability of IGR J17091-3624 during its 2016 outburst : SWIFT and NuSTAR results
- 2018
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Ingår i: Astrophysics and Space Science. - : Springer. - 0004-640X .- 1572-946X. ; 363:9
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Tidskriftsartikel (refereegranskat)abstract
- We report on the 2016 outburst of the transient Galactic Black Hole candidate IGR J17091-3624 based on the observation campaign carried out with SWIFT and NuSTAR. The outburst profile, as observed with SWIFT-XRT, shows a typical 'q'-shape in the Hardness Intensity Diagram (HID). Based on the spectral and temporal evolution of the different parameters, we are able to identify all the spectral states in the q-profile of HID and the Hardness-RMS diagram (HRD). Both XRT and NuSTAR observations show an evolution of low frequency Quasi periodic oscillations (QPOs) during the low hard and hard intermediate states of the outburst rising phase. We also find mHz QPOs along-with distinct coherent class variabilities (heartbeat oscillations) with different timescales, similar to the -class (observed in GRS 1915+105). Phenomenological modelling of the broad-band XRT and NuSTAR spectra also reveals the evolution of high energy cut-off and presence of reflection from ionized material during the rising phase of the outburst. Further, we conduct the modelling of X-ray spectra of SWIFT and NuSTAR in 0.5-79 keV to understand the accretion flow dynamics based on two component flow model. From this modelling, we constrain the mass of the source to be in the range of with 90% confidence, which is consistent with earlier findings.
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| 24. |
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| 25. |
- Uhlig, Jens, et al.
(författare)
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High-resolution X-ray emission spectroscopy with transition-edge sensors: present performance and future potential.
- 2015
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Ingår i: Journal of Synchrotron Radiation. - 1600-5775. ; 22:Pt 3, s. 766-775
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Tidskriftsartikel (refereegranskat)abstract
- X-ray emission spectroscopy (XES) is a powerful element-selective tool to analyze the oxidation states of atoms in complex compounds, determine their electronic configuration, and identify unknown compounds in challenging environments. Until now the low efficiency of wavelength-dispersive X-ray spectrometer technology has limited the use of XES, especially in combination with weaker laboratory X-ray sources. More efficient energy-dispersive detectors have either insufficient energy resolution because of the statistical limits described by Fano or too low counting rates to be of practical use. This paper updates an approach to high-resolution X-ray emission spectroscopy that uses a microcalorimeter detector array of superconducting transition-edge sensors (TESs). TES arrays are discussed and compared with conventional methods, and shown under which circumstances they are superior. It is also shown that a TES array can be integrated into a table-top time-resolved X-ray source and a soft X-ray synchrotron beamline to perform emission spectroscopy with good chemical sensitivity over a very wide range of energies.
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