| 1. |
- Brennan, S. J., et al.
(author)
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Photometric and spectroscopic evolution of the interacting transient AT 2016jbu(Gaia16cfr)
- 2022
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In: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 513:4, s. 5642-5665
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Journal article (peer-reviewed)abstract
- We present the results from a high-cadence, multiwavelength observation campaign of AT 2016jbu (aka Gaia16cfr), an interacting transient. This data set complements the current literature by adding higher cadence as well as extended coverage of the light-curve evolution and late-time spectroscopic evolution. Photometric coverage reveals that AT 2016jbu underwent significant photometric variability followed by two luminous events, the latter of which reached an absolute magnitude of MV ∼ −18.5 mag. This is similar to the transient SN 2009ip whose nature is still debated. Spectra are dominated by narrow emission lines and show a blue continuum during the peak of the second event. AT 2016jbu shows signatures of a complex, non-homogeneous circumstellar material (CSM). We see slowly evolving asymmetric hydrogen line profiles, with velocities of 500 km s−1 seen in narrow emission features from a slow-moving CSM, and up to 10 000 km s−1 seen in broad absorption from some high-velocity material. Late-time spectra (∼+1 yr) show a lack of forbidden emission lines expected from a core-collapse supernova and are dominated by strong emission from H, He I, and Ca II. Strong asymmetric emission features, a bumpy light curve, and continually evolving spectra suggest an inhibit nebular phase. We compare the evolution of H α among SN 2009ip-like transients and find possible evidence for orientation angle effects. The light-curve evolution of AT 2016jbu suggests similar, but not identical, circumstellar environments to other SN 2009ip-like transients.
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| 3. |
- Halme, P., et al.
(author)
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Challenges of ecological restoration : Lessons from forests in northern Europe
- 2013
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In: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 167, s. 248-256
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Research review (peer-reviewed)abstract
- The alarming rate of ecosystem degradation has raised the need for ecological restoration throughout different biomes and continents. North European forests may appear as one of the least vulnerable ecosystems from a global perspective, since forest cover is not rapidly decreasing and many ecosystem services remain at high level. However, extensive areas of northern forests are heavily exploited and have lost a major part of their biodiversity value. There is a strong requirement to restore these areas towards a more natural condition in order to meet the targets of the Convention on Biological Diversity. Several northern countries are now taking up this challenge by restoring forest biodiversity with increasing intensity. The ecology and biodiversity of boreal forests are relatively well understood making them a good model for restoration activities in many other forest ecosystems. Here we introduce northern forests as an ecosystem, discuss the historical and recent human impact and provide a brief status report on the ecological restoration projects and research already conducted there. Based on this discussion, we argue that before any restoration actions commence, the ecology of the target ecosystem should be established with the need for restoration carefully assessed and the outcome properly monitored. Finally, we identify the most important challenges that need to be solved in order to carry out efficient restoration with powerful and long-term positive impacts on biodiversity: coping with unpredictability, maintaining connectivity in time and space, assessment of functionality, management of conflicting interests and social restrictions and ensuring adequate funding. © 2013 Elsevier Ltd.
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| 4. |
- Tartaglia, Leonardo, et al.
(author)
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The long-lived Type IIn SN 2015da : Infrared echoes and strong interaction within an extended massive shell star star star
- 2020
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 635
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Journal article (peer-reviewed)abstract
- In this paper we report the results of the first similar to four years of spectroscopic and photometric monitoring of the Type IIn supernova SN 2015da (also known as PSN J13522411+3941286, or iPTF16tu). The supernova exploded in the nearby spiral galaxy NGC 5337 in a relatively highly extinguished environment. The transient showed prominent narrow Balmer lines in emission at all times and a slow rise to maximum in all bands. In addition, early observations performed by amateur astronomers give a very well-constrained explosion epoch. The observables are consistent with continuous interaction between the supernova ejecta and a dense and extended H-rich circumstellar medium. The presence of such an extended and dense medium is difficult to reconcile with standard stellar evolution models, since the metallicity at the position of SN 2015da seems to be slightly subsolar. Interaction is likely the mechanism powering the light curve, as confirmed by the analysis of the pseudo bolometric light curve, which gives a total radiated energy greater than or similar to 10(51) erg. Modeling the light curve in the context of a supernova shock breakout through a dense circumstellar medium allowed us to infer the mass of the prexisting gas to be similar or equal to 8 M-circle dot, with an extreme mass-loss rate for the progenitor star similar or equal to 0.6 M-circle dot yr(-1), suggesting that most of the circumstellar gas was produced during multiple eruptive events. Near- and mid-infrared observations reveal a fluxexcess in these domains, similar to those observed in SN 2010jl and other interacting transients, likely due to preexisting radiatively heated dust surrounding the supernova. By modeling the infrared excess, we infer a mass greater than or similar to 0.4 x 10(-3) M-circle dot for the dust.
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| 6. |
- Madar Johansson, Miralda, et al.
(author)
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The binding mechanism of the virulence factor Streptococcus suis adhesin P subtype to globotetraosylceramide is associated with systemic disease
- 2020
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In: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 295:42, s. 14305-14324
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Journal article (peer-reviewed)abstract
- Streptococcus suis is part of the pig commensal microbiome but strains can also be pathogenic, causing pneumonia and meningitis in pigs as well as zoonotic meningitis. According to genomic analysis, S. suis is divided into asymptomatic carriage, respiratory and systemic strains with distinct genomic signatures. Because the strategies to target pathogenic S. suis are limited, new therapeutic approaches are needed. The virulence factor S. suis adhesin P (SadP) recognizes the galabiose Gal alpha 1-4Gal-oligosaccharide. Based on its oligosaccharide fine specificity, SadP can be divided into subtypes P-N and P-O. We show here that subtype P-N is distributed in the systemic strains causing meningitis, whereas type P-O is found in asymptomatic carriage and respiratory strains. Both types of SadP are shown to predominantly bind to pig lung globotriaosylceramide (Gb3). However, SadP adhesin from systemic subtype P-N strains also binds to globotetraosylceramide (Gb4). Mutagenesis studies of the galabiose-binding domain of type P-N SadP adhesin showed that the amino acid asparagine 285, which is replaced by an aspartate residue in type P-O SadP, was required for binding to Gb4 and, strikingly, was also required for interaction with the glycomimetic inhibitor phenylurea-galabiose. Molecular dynamics simulations provided insight into the role of Asn-285 for Gb4 and phenylurea-galabiose binding, suggesting additional hydrogen bonding to terminal GalNAc of Gb4 and the urea group. Thus, the Asn-285-mediated molecular mechanism of type P-N SadP binding to Gb4 could be used to selectively target S. suis in systemic disease without interfering with commensal strains, opening up new avenues for interventional strategies against this pathogen.
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| 8. |
- Plucinski, L, et al.
(author)
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Resonant shake-up satellites in photoemission at the Ga 3p photothreshold in GaN
- 2005
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In: Solid State Communications. - : Elsevier BV. - 1879-2766 .- 0038-1098. ; 136:4, s. 191-195
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Journal article (peer-reviewed)abstract
- Photoemission spectra recorded near the Ga 3p photothreshold from GaN have been found to contain satellites of the main Ga 3d emission line. The intensity of these satellites resonate at this threshold, and are associated with a 3d(8) state. The correlation energies and binding energies for the satellite multiplet have been measured for the satellite and related Auger transitions. The satellite multiplet contains additional constant binding energy features not observed in previous studies of other Ga compounds. The present results are compared with those for Gal? and GaAs.
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| 9. |
- Sahlstrom, T., et al.
(author)
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Workforce participation and activities in Parkinson's disease patients receiving device-aided therapy
- 2018
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In: Acta Neurologica Scandinavica. - : Hindawi Limited. - 0001-6314 .- 1600-0404. ; 138:1, s. 78-84
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Journal article (peer-reviewed)abstract
- Objectives: Many countries have an aging population, and it is thus likely that Parkinson's disease (PD) will become an increasing health problem. It is important to ensure this group can use their resources in the best way possible, including remaining in the work market. This study aimed to investigate workforce participation and daily activities among patients with PD receiving device-aided therapy to provide new knowledge that may be used to inform decisions about these therapy options.Materials and Methods:This was a retrospective, descriptive quantitative pilot study, including 67 patients with PD from 3 centers in Sweden and Denmark. Included patients were younger than 67years at the time of introduction of device-aided therapy. Eligible patients were identified by the Swedish national Parkinson patient registry or by the treating neurologist. Quantitative interviews were made by telephone.Results:A majority of the patients could perform the same, or more, amount of activities approximately 5years after the introduction of device-aided therapy. A small number of patients receiving deep brain stimulation (DBS) and levodopa-carbidopa intestinal gel (LCIG) were able to increase their work capacity within 1year of initiating device-aided therapy and a remarkably high share could still work at the end-point of this study, approximately 15years since the diagnosis of PD.Conclusions:Device-aided therapy may sustain or increase daily activities and workforce participation in patients with PD who have not yet reached retirement age. There is need for prospective studies, both quantitative and qualitative, to confirm these results.
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| 10. |
- Andersen, J. N., et al.
(author)
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Strong phonon replicas in Be 1s photoemission spectra
- 2001
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In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 86:19, s. 4398-4401
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Journal article (peer-reviewed)abstract
- Strong phonon replicas in Be 1s photoemission spectra were investigated. The fine structure caused by intrinsic excitation of a narrow band of optical phonons was discussed in the 1s photoemission proces. The excitations of the optical Be phonons in the photoemission process caused fine structures. It was found that the phonon replicas in Be metal were strong due to large size misfit between neutral and core-ionized Be.
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