| 1. |
- Henschen, Jonatan, 1989-
(författare)
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Bacterial adhesion to polyelectrolyte modified materials based on nanocellulose
- 2016
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Since the introduction of materials based on cellulose nanofibrils (CNFs), these materials have been studied extensively and are suggested to be suitable for use in, for example, hygiene and health care products. A property not very well studied but that could further increase the usability of CNF products is the possibility of controlling bacterial adhesion to the materials. Controlling and fine-tuning the bacterial adhesion makes it possible to produce contact-active antibacterial materials as well as anti-adhesive materials.The current thesis shows how the number of bacteria adhering to CNF-based materials can be altered through the adsorption of polyelectrolyte multilayers. Polyvinylamine (PVAm) and polyacrylic acid (PAA) were adsorbed in multilayers to achieve differently charged materials. The CNF substrates consisted of both crosslinked and non-crosslinked films with different surface charges and structures as well as porous aerogels.The results show the possibility of adsorbing PVAm/PAA to recharge the surfaces and construct multilayers. The polyelectrolyte adsorption was affected both by crosslinking and by changing the surface charge of the CNF films. Increasing the surface charge resulted in a decreased PVAm adsorption after the first polymer layer. Crosslinking the films resulted in a low initial PVAm adsorption, but as more layers were adsorbed, the PVAm adsorption increased similarly to the non-crosslinked films. The PVAm adsorption to the aerogels was lower than expected, taking into account their high surface area and surface charge, possibly due to crowding effects on the surface due to geometric limitations.Only the CNF films with the lowest surface charge and the aerogels adsorbed high numbers of bacteria from bacterial suspensions. The bacterial adsorption to the films was affected by the surface charge, the PAA adsorption and the PVAm adsorption, with a higher net surface charge leading to higher bacterial adsorption. The aerogels efficiently removed bacteria from the bacterial suspensions by adsorbing them onto their surface, with some samples removing over 99.9 % of the bacteria. The results presented in this thesis are believed to lead to a better understanding of both polyelectrolyte adsorption on CNF materials and bacterial adhesion to CNF materials and how polyelectrolyte multilayer adsorption can alter it.
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| 2. |
- Larsson, Josefin, et al.
(författare)
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Spectral components in the bright, long GRB 061007 : properties of the photosphere and the nature of the outflow
- 2011
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 414:3, s. 2642-2649
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Tidskriftsartikel (refereegranskat)abstract
- We present a time-resolved spectral analysis of the bright, long GRB 061007 (z = 1.261) using Swift and Suzaku data. We find that the prompt emission of the burst can be equally well explained by a photospheric component together with a power law as by a Band function, and we explore the implications of the former model. The photospheric component, which we model with a multicolour blackbody, dominates the spectra and has a very stable shape throughout the burst. This component provides a natural explanation for the hardness-intensity correlation seen within the burst and also allows us to estimate the bulk Lorentz factor and the radius of the photosphere. The power-law component dominates the fit at high energies and has a nearly constant slope of -1.5. We discuss the possibility that this component is of the same origin as the high-energy power laws recently observed in some Fermi bursts.
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| 3. |
- Preece, R., et al.
(författare)
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The First Pulse of the Extremely Bright GRB 130427A : A Test Lab for Synchrotron Shocks
- 2014
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 343:6166, s. 51-54
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Tidskriftsartikel (refereegranskat)abstract
- Gamma-ray burst (GRB) 130427A is one of the most energetic GRBs ever observed. The initial pulse up to 2.5 seconds is possibly the brightest well-isolated pulse observed to date. A fine time resolution spectral analysis shows power-law decays of the peak energy from the onset of the pulse, consistent with models of internal synchrotron shock pulses. However, a strongly correlated power-law behavior is observed between the luminosity and the spectral peak energy that is inconsistent with curvature effects arising in the relativistic outflow. It is difficult for any of the existing models to account for all of the observed spectral and temporal behaviors simultaneously.
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| 4. |
- Ryde, Felix, et al.
(författare)
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IDENTIFICATION AND PROPERTIES OF THE PHOTOSPHERIC EMISSION IN GRB090902B
- 2010
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Ingår i: The Astrophysical Journal Letters. - 2041-8205 .- 2041-8213. ; 709:2, s. l172-L177
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Tidskriftsartikel (refereegranskat)abstract
- The Fermi Gamma-ray Space Telescope observed the bright and long GRB090902B, lying at a redshift of z = 1.822. Together the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM) cover the spectral range from 8 keV to >300 GeV. Here we show that the prompt burst spectrum is consistent with emission from the jet photosphere combined with nonthermal emission described by a single power law with photon index -1.9. The photosphere gives rise to a strong quasi-blackbody spectrum which is somewhat broader than a single Planck function and has a characteristic temperature of similar to 290 keV. We model the photospheric emission with a multicolor blackbody, and its shape indicates that the photospheric radius increases at higher latitudes. We derive the averaged photospheric radius R-ph = (1.1 +/- 0.3) x 10(12) Y-1/4 cm and the bulk Lorentz factor of the flow, which is found to vary by a factor of 2 and has a maximal value of Gamma = 750 Y-1/4. Here, Y is the ratio between the total fireball energy and the energy emitted in the gamma rays. We find that during the first quarter of the prompt phase the photospheric emission dominates, which explains the delayed onset of the observed flux in the LAT compared to the GBM. We interpret the broadband emission as synchrotron emission at R similar to 4 x 10(15) cm. Our analysis emphasizes the importance of having high temporal resolution when performing spectral analysis on gamma-ray bursts, since there is strong spectral evolution.
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| 5. |
- Soffitta, Paolo, et al.
(författare)
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XIPE : the X-ray imaging polarimetry explorer
- 2013
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Ingår i: Experimental astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 36:3, s. 523-567
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Tidskriftsartikel (refereegranskat)abstract
- X-ray polarimetry, sometimes alone, and sometimes coupled to spectral and temporal variability measurements and to imaging, allows a wealth of physical phenomena in astrophysics to be studied. X-ray polarimetry investigates the acceleration process, for example, including those typical of magnetic reconnection in solar flares, but also emission in the strong magnetic fields of neutron stars and white dwarfs. It detects scattering in asymmetric structures such as accretion disks and columns, and in the so-called molecular torus and ionization cones. In addition, it allows fundamental physics in regimes of gravity and of magnetic field intensity not accessible to experiments on the Earth to be probed. Finally, models that describe fundamental interactions (e.g. quantum gravity and the extension of the Standard Model) can be tested. We describe in this paper the X-ray Imaging Polarimetry Explorer (XIPE), proposed in June 2012 to the first ESA call for a small mission with a launch in 2017. The proposal was, unfortunately, not selected. To be compliant with this schedule, we designed the payload mostly with existing items. The XIPE proposal takes advantage of the completed phase A of POLARIX for an ASI small mission program that was cancelled, but is different in many aspects: the detectors, the presence of a solar flare polarimeter and photometer and the use of a light platform derived by a mass production for a cluster of satellites. XIPE is composed of two out of the three existing JET-X telescopes with two Gas Pixel Detectors (GPD) filled with a He-DME mixture at their focus. Two additional GPDs filled with a 3-bar Ar-DME mixture always face the Sun to detect polarization from solar flares. The Minimum Detectable Polarization of a 1 mCrab source reaches 14 % in the 2-10 keV band in 10(5) s for pointed observations, and 0.6 % for an X10 class solar flare in the 15-35 keV energy band. The imaging capability is 24 arcsec Half Energy Width (HEW) in a Field of View of 14.7 arcmin x 14.7 arcmin. The spectral resolution is 20 % at 6 keV and the time resolution is 8 mu s. The imaging capabilities of the JET-X optics and of the GPD have been demonstrated by a recent calibration campaign at PANTER X-ray test facility of the Max-Planck-Institut fur extraterrestrische Physik (MPE, Germany). XIPE takes advantage of a low-earth equatorial orbit with Malindi as down-link station and of a Mission Operation Center (MOC) at INPE (Brazil). The data policy is organized with a Core Program that comprises three months of Science Verification Phase and 25 % of net observing time in the following 2 years. A competitive Guest Observer program covers the remaining 75 % of the net observing time.
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| 6. |
- Sundelöf, Andreas, et al.
(författare)
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Fisk- och skaldjursbestånd i hav och sötvatten 2021 : Resursöversikt
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I rapporten kan du ta del av bedömningen som görs av situationen för bestånd som regleras inom ramen för EU:s gemensamma fiskeripolitik (GFP). Bedömningarna baseras på det forskningssamarbete och den rådgivning som sker inom det Internationella Havsforskningsrådet (ICES). Sammantaget redovisas tillståndet för 107 bestånd av 48 fisk- och skaldjursarter.De bestånd som förvaltas nationellt baseras på de biologiska underlagen, och rådgivningen i huvudsak på den forskning och övervakning samt analys som bedrivs av Institutionen för akvatiska resurser vid Sveriges lantbruksuniversitet (SLU Aqua) samt yrkesfiskets rapportering.Rapporten är en beställning från Havs- och vattenmyndigheten (HaV) till Sveriges lantbruksuniversitet (SLU) och utgör ett viktigt kunskapsunderlag till myndighetens arbete. Den uppfyller de krav som finns inom EU:s gemensamma fiskeripolitik om att basera förvaltningen på bästa tillgängliga vetenskap. Denna rapport är också ett stöd till det arbete som beskrivs närmare i strategin för framtidens fiske och tillhörande handlingsplaner för vattenbruk, yrkes- och fritidsfiske som HaV och Jordbruksverket har tagit fram i dialog med fiskets och vattenbrukets intressenter.
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| 7. |
- Abellán, F. J., et al.
(författare)
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Very Deep inside the SN 1987A Core Ejecta : Molecular Structures Seen in 3D
- 2017
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Ingår i: Astrophysical Journal Letters. - : Institute of Physics Publishing. - 2041-8205 .- 2041-8213. ; 842:2
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Tidskriftsartikel (refereegranskat)abstract
- Most massive stars end their lives in core-collapse supernova explosions and enrich the interstellar medium with explosively nucleosynthesized elements. Following core collapse, the explosion is subject to instabilities as the shock propagates outward through the progenitor star. Observations of the composition and structure of the innermost regions of a core-collapse supernova provide a direct probe of the instabilities and nucleosynthetic products. SN 1987A in the Large Magellanic Cloud is one of very few supernovae for which the inner ejecta can be spatially resolved but are not yet strongly affected by interaction with the surroundings. Our observations of SN 1987A with the Atacama Large Millimeter/submillimeter Array are of the highest resolution to date and reveal the detailed morphology of cold molecular gas in the innermost regions of the remnant. The 3D distributions of carbon and silicon monoxide (CO and SiO) emission differ, but both have a central deficit, or torus-like distribution, possibly a result of radioactive heating during the first weeks ("nickel heating"). The size scales of the clumpy distribution are compared quantitatively to models, demonstrating how progenitor and explosion physics can be constrained.
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| 8. |
- Adriani, O., et al.
(författare)
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The gamma-400 space observatory : Status and perspectives
- 2014
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Ingår i: Proceedings of Science. - : Sissa Medialab Srl.
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Konferensbidrag (refereegranskat)abstract
- The present design of the new space observatory GAMMA-400 is presented in this paper. The instrument has been designed for the optimal detection of gamma rays in a broad energy range (from ∼100 MeV up to 3 TeV), with excellent angular and energy resolution. The observatory will also allow precise and high statistic studies of the electron component in the cosmic rays up to the multi TeV region, as well as protons and nuclei spectra up to the knee region. The GAMMA-400 observatory will allow to address a broad range of science topics, like search for signatures of dark matter, studies of Galactic and extragalactic gamma-ray sources, Galactic and extragalactic diffuse emission, gamma-ray bursts and charged cosmic rays acceleration and diffusion mechanism up to the knee.
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| 9. |
- Ahlgren, Björn, et al.
(författare)
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A Search for Lensed Gamma-Ray Bursts in 11 yr of Observations by Fermi GBM
- 2020
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 897:2
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Tidskriftsartikel (refereegranskat)abstract
- Macrolensing of gamma-ray bursts (GRBs) is expected to manifest as a GRB recurring with the same light curve and spectrum as a previous one, but with a different flux and a slightly offset position. Identifying such lensed GRBs may give important information about the lenses, the cosmology, and the GRBs themselves. Here we present a search for lensed GRBs among similar to 2700 GRBs observed by the Fermi Gamma-ray Burst Monitor during 11 yr of operations. To identify lensed GRBs, we perform initial cuts on position, time-averaged spectral properties, and relative duration. We then use the cross-correlation function to assess the similarity of light curves, and finally we analyze the time-resolved spectra of the most promising candidates. We find no convincing lens candidates. The most similar pairs are single-pulsed GRBs with relatively few time bins for the spectral analysis. This is best explained by similarities within the GRB population rather than lensing. However, the null result does not rule out the presence of macrolensed GRBs in the sample. In particular, we find that observational uncertainties and Poisson fluctuations can lead to significant differences within a pair of lensed GRBs.
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| 10. |
- Ahlgren, Björn, et al.
(författare)
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Confronting GRB prompt emission with a model for subphotospheric dissipation
- 2015
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Ingår i: Monthly Notices of the Royal Astronomical Society: Letters. - : Oxford University Press. - 1745-3925 .- 1745-3933. ; 454:1, s. L31-L35
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Tidskriftsartikel (refereegranskat)abstract
- The origin of the prompt emission in gamma-ray bursts (GRBs) is still an unsolved problem and several different mechanisms have been suggested. Here, we fit Fermi GRB data with a photospheric emission model which includes dissipation of the jet kinetic energy below the photosphere. The resulting spectra are dominated by Comptonization and contain no significant contribution from synchrotron radiation. In order to fit to the data, we span a physically motivated part of the model's parameter space and create DREAM (Dissipation with Radiative Emission as A table Model), a table model for XSPEC. We show that this model can describe different kinds of GRB spectra, including GRB 090618, representing a typical Band function spectrum, and GRB 100724B, illustrating a double peaked spectrum, previously fitted with a Band+blackbody model, suggesting they originate from a similar scenario. We suggest that the main difference between these two types of bursts is the optical depth at the dissipation site.
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| 11. |
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| 12. |
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| 13. |
- Ahlgren, Björn, et al.
(författare)
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Investigating Subphotospheric Dissipation in Gamma-Ray Bursts Using Joint Fermi-Swift Observations
- 2019
-
Ingår i: Astrophysical Journal. - : IOP PUBLISHING LTD. - 0004-637X .- 1538-4357. ; 880:2
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Tidskriftsartikel (refereegranskat)abstract
- The jet photosphere has been proposed as the origin for the gamma-ray burst (GRB) prompt emission. In many such models, characteristic features in the spectra appear below the energy range of the Fermi Gamma-ray Burst Monitor (GBM) detectors, so joint fits with X-ray data are important in order to assess the photospheric scenario. Here we consider a particular photospheric model which assumes localized subphotospheric dissipation by internal shocks in a non-magnetized outflow. We investigate it using Bayesian inference and a sample of eight GRBs with known redshifts which are observed simultaneously with Fermi GBM and the Swift X-ray Telescope (XRT). This provides us with an energy range of 0.3. keV-40. MeV and much tighter parameter constraints. We analyze 32 spectra and find that 16 are well described by the model. We also find that the estimates of the bulk Lorentz factor, Gamma, and the fireball luminosity, L-0,L-52, decrease while the fraction of dissipated energy, epsilon(d), increases in the joint fits compared to GBM-only fits. These changes are caused by a small excess of counts in the XRT data, relative to the model predictions from fits to GBM-only data. The fact that our limited implementation of the physical scenario yields 50% accepted spectra is promising, and we discuss possible model revisions in the light of the new data. Specifically, we argue that the inclusion of significant magnetization, as well as removing the assumption of internal shocks, will provide better fits at low energies.
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| 14. |
- Ahlgren, Björn, 1990-
(författare)
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Subphotospheric dissipation in gamma-ray bursts observed by the Fermi Gamma-ray Space Telescope
- 2016
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Gamma-ray bursts (GRBs) are the brightest events in the Universe, for a short time outshining the rest of the Universe combined, as they explode with isotropic equivalent luminosities up to $10^{54}$ erg s$^{-1}$. These events are believed to be connected to supernovae and to binary compact object mergers, such as binary neutron stars or neutron star -- black hole systems. The origin of the so-called prompt emission in GRBs remains an unsolved problem, although some progress is being made. Spectral analysis of prompt emission has traditionally been performed with the Band function, an empirical model with no physical interpretation, and it is just recently that physical models have started to be fitted to data. This thesis presents spectral analysis of GRB data from the Fermi Gamma-ray Space Telescope using a physical model for subphotospheric dissipation. The model is developed using a numerical code and implemented as a table model in {\scriptsize XSPEC}. Paper \rom{1} presents the model and provides a proof-of-concept of fitting GRB data with such a model. Specifically, two GRBs are fitted and compared with the corresponding Band function fits. In paper \rom{2}, a sample of 37 bursts are fitted with an extended version of the model and improved analysis tools. Overall, about a third of the fitted spectra can be described by the model. From these fits it is concluded that the scenario of subphotospheric dissipation can describe all spectral shapes present in the sample. The key characteristic of the spectra that are not fitted by the model is that they are very luminous. Within the context of the model, this suggests that the assumption of internal shocks as a dissipation mechanism cannot explain the full population of GRBs. Alternatively, additional emission components may required. The thesis concludes that subphotospheric dissipation is viable as a possible origin of GRB prompt emission. Furthermore, it shows the importance of using physically motivated models when analysing GRBs.
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| 15. |
- Ahlgren, Björn, et al.
(författare)
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Testing a model for subphotospheric dissipation in GRBs: fits to Fermi data constrain the dissipation scenario
- 2019
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 485, s. 474-497
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Tidskriftsartikel (refereegranskat)abstract
- It has been suggested that the prompt emission in gamma-ray bursts (GRBs) could be described by radiation from the photosphere in a hot fireball. Such models must be tested by directly fitting them to data. In this work we use data from the Fermi Gamma-ray Space Telescope and consider a specific photospheric model, in which the kinetic energy of a low-magnetization outflow is dissipated locally by internal shocks below the photosphere. We construct a table model with a physically motivated parameter space and fit it to time-resolved spectra of the 36 brightest Fermi GRBs with a known redshift. We find that about two-thirds of the examined spectra cannot be described by the model, as it typically underpredicts the observed flux. However, since the sample is strongly biased towards bright GRBs, we argue that this fraction will be significantly lowered when considering the full population. From the successful fits we find that the model can reproduce the full range of spectral slopes present in the sample. For these cases we also find that the dissipation consistently occurs at a radius of ∼1012 cm and that only a few per cent efficiency is required. Furthermore, we find a positive correlation between the fireball luminosity and the Lorentz factor. Such a correlation has been previously reported by independent methods. We conclude that if GRB spectra are due to photospheric emission, the dissipation cannot only be the specific scenario we consider here.
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| 16. |
- Al-Adhami, Maissa, 1972-, et al.
(författare)
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Can an extended civic orientation course improve newly settled migrants’ health literacy and social capital? : A quasi-experimental study
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Structural and contextual factors such as limited work opportunities, restrictive integration policies and discrimination negatively affect the health and well-being of newly settled refugee migrants in receiving high-income countries. Health promotion initiatives aiming to facilitate access to work and integration by enhancing individual-level health resources have been tried out within the Swedish Civic Orientation. However, longitudinal evaluations of these interventions are rare. The aim of the current study was to compare the effectiveness of a regular and an extended civic orientation course with added health communication and examine whether the latter would improve self-rated health and psychological well-being, health literacy, and social capital among newly settled refugee migrants in Sweden. Pre-and post-assessment questionnaires were collected from the intervention group receiving the extended course (n=143) and a control group receiving the regular course (n=173). Linear mixed models and Chi-square analyses showed a significant increase with a small effect size (0.21) in health literacy in the intervention group. However, there were no significant changes in emotional and practical support, general self-rated health, or psychological well-being. The findings indicate that added health communication provided within the Swedish civic orientation can increase health literacy. However, further longitudinal studies are needed to confirm the sustainability of the observed effect and examine whether these short-term improvements in health literacy translate to long-term benefits in other outcomes such as health and integration of newly settled refugee migrants.
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| 17. |
- Al Adhami, Maissa, Doctoral candidate, 1972-, et al.
(författare)
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Can extended health communication improve newly settled refugees’ health literacy? A quasi-experimental study from Sweden
- 2024
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Ingår i: Health Promotion International. - : Oxford University Press. - 0957-4824 .- 1460-2245. ; 39:2
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Tidskriftsartikel (refereegranskat)abstract
- Structural and contextual factors such as limited work and housing opportunities negatively affect the health and well-being of newly settled refugee migrants in receiving high-income countries. Health promotion initiatives aiming at strengthening health and integration have been tried out within the Swedish Introduction program for refugee migrants. However, longitudinal evaluations of these interventions are rare. The aim of the current study was to compare the effectiveness of a regular and an extended civic orientation course with added health communication and examine whether the latter would improve self-rated health and psychological well-being, health literacy and social capital among newly settled refugee migrants in Sweden. Pre- and post-assessment questionnaires were collected from the intervention group receiving the extended course (n = 143) and a control group receiving the regular course (n = 173). Linear mixed models and chi-square analyses showed a significant increase with a small effect size (0.21) in health literacy in the intervention group. However, there were no significant changes in emotional and practical support, general self-rated health or psychological well-being. The findings indicate that added health communication provided embedded in the civic orientation course can increase health literacy. However, further longitudinal studies are needed to confirm the sustainability of the observed effect and examine whether these short-term improvements in health literacy translate to long-term advances in health and integration.
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| 18. |
- Al Adhami, Maissa, Doctoral candidate, 1972-, et al.
(författare)
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Can extended health communication improve newly settled refugees' health literacy? A quasi-experimental study from Sweden
- 2024
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Ingår i: Health Promotion International. - : Oxford University Press. - 0957-4824 .- 1460-2245. ; 39:2
-
Tidskriftsartikel (refereegranskat)abstract
- Structural and contextual factors such as limited work and housing opportunities negatively affect the health and well-being of newly settled refugee migrants in receiving high-income countries. Health promotion initiatives aiming at strengthening health and integration have been tried out within the Swedish Introduction program for refugee migrants. However, longitudinal evaluations of these interventions are rare. The aim of the current study was to compare the effectiveness of a regular and an extended civic orientation course with added health communication and examine whether the latter would improve self-rated health and psychological well-being, health literacy and social capital among newly settled refugee migrants in Sweden. Pre- and post-assessment questionnaires were collected from the intervention group receiving the extended course (n = 143) and a control group receiving the regular course (n = 173). Linear mixed models and chi-square analyses showed a significant increase with a small effect size (0.21) in health literacy in the intervention group. However, there were no significant changes in emotional and practical support, general self-rated health or psychological well-being. The findings indicate that added health communication provided embedded in the civic orientation course can increase health literacy. However, further longitudinal studies are needed to confirm the sustainability of the observed effect and examine whether these short-term improvements in health literacy translate to long-term advances in health and integration.
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| 19. |
- Al Adhami, Maissa, 1972-, et al.
(författare)
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"This course is like a compass to us" : a qualitative study on newly settled migrants' perceptions of civic and health orientation in Sweden
- 2021
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Ingår i: BMC Public Health. - : BioMed Central (BMC). - 1471-2458. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Migrants face structural, socio-political barriers in their resettlement processes that negatively affect their health. Migration also adversely impacts resources such as social capital and health literacy that are of importance for health and integration into society. Hence, there is a need for health promotion in the early post-migration phase. In Sweden, newly settled refugee migrants who have received a residence permit are offered an Introduction programme including a civic orientation course. The program is intended to facilitate access to the labour market and promote integration. The aim of the study was to explore participants' perceptions and experiences of a civic orientation course with added health communication. Methods We performed six focus group discussions: two in Arabic, two in Farsi and two in Somali. The discussions were facilitated by native speaking moderators. Participants were 32 men and women recruited from civic orientation classes in the county of Stockholm. We used an interview guide with semi-structured questions. The data were analysed using a method for content analysis for focus group discussions. Results Three main categories were identified: (1) 'The course gives valuable information but needs adjustments', which includes that the civic and health orientation is needed earlier, during the asylum phase, and that planning and course content need adjustments. (2) 'The health communication inspired participants to focus on their health', which includes that the health communication was useful and inspired uptake of healthier habits. (3) 'Participation in the course promoted independence and self-confidence', which includes that the course gave insights into society and values in Sweden, and promoted independence and new social contacts. Conclusion This study adds knowledge about the users' perspectives on the potential of civic orientation to promote the health and integration of newly settled migrants, describing ways in which civic orientation with added health communication promoted health and empowerment. However, the content and delivery of the course need adjustment to better fit the migrants' life situations and varying pre-existing knowledge.
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| 20. |
- Almung, Magnus, et al.
(författare)
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I solitärens skugga : Nyttobyggnadens kreativa restaurering
- 2015
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Rapport (populärvet., debatt m.m.)abstract
- Ekonomibyggnader har alltid behövts för de huvudbyggnader som finns inom våra bevarade kulturmiljöer. Några nyttobyggnader uppskattas och används fortfarande, andra betraktas som problematiska överloppsbyggnader, många rivs. Alltför få har dokumenterats eller fått sin historia klarlagd vilket undanhållit viktig kunskap om samhällets framväxt. Vi vill synliggöra och betona vikten av att bevara och utveckla hela bebyggelsemiljöer, ofta med ett antal hus utöver huvudbyggnaden och tillhörande yttre miljö i staden eller på landet. Denna rapport visar kursdeltagarnas projektarbeten om nyttobyggnader. De har dokumenterat med traditionella och nya arbetsmetoder, inventerat och intervjuat, läst och besökt arkiv, värderat, analyserat och därefter föreslagit hur man ska ta hand om och utveckla nyttobyggnaderna i sina kulturmiljöer.
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| 21. |
- Alp, Dennis, MSc, 1992-
(författare)
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An X-Ray View of Core-collapse Supernovae
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A core-collapse supernova (CCSN) is an astronomical explosion that indicates the death of a massive star. From observations, it is clear that a large fraction of all massive stars undergoes supernova (SN) explosions, but describing how SNe explode has remained a challenge for many decades. A key piece of the puzzle is the properties of the progenitor star.The attached papers focus on comparing theoretical predictions with observations, primarily observations of SN 1987A. It is the closest observed SN in more than four centuries, allowing for more detailed studies than for any other SN. The papers investigate different aspects of the SN phenomenon. These individual studies are observationally diverse, but all attempt to answer different questions that are important for our understanding of the SN process.The properties of the progenitor star set the stage for the SN. Paper III compares SN models based on different progenitor stars with early X-ray and gamma-ray observations of SN 1987A. The results help constrain the evolution of the progenitor. In Paper IV, we searched for SN shock breakouts (SBOs), which are the first electromagnetic signals from CCSNe. The discovered candidates convey information about the progenitors, test the SBO theory, and indicate the presence of other types of X-ray transients.The SN explosion mechanism itself is also integral to the analysis in Paper III. The explosion models used in Paper III rely on some of the most recent three-dimensional neutrino-driven SN models. The results lend further support to the hypothesis that delayed neutrino heating is sufficient to explode the vast majority of all CCSNe.Much can also be learned about SNe by studying their remnants. The remains of the core, the compact remnant, in SN 1987A has not yet been detected. We have investigated how a compact object can remain hidden in the ejecta in Paper I, using an absorption model from Paper II. We favor a scenario where the compact object is a neutron star that is quiescent, dust-obscured, and only emitting thermal emission. Paper V is another study of SN 1987A, but focuses on the X-ray emission from the ongoing interactions between the ejecta and circumstellar medium (CSM). The X-ray emission is primarily generated by thermal processes in shocks produced by collisions between the ejecta and the CSM. We found no evidence for any contribution from relativistic particles or a neutron star.Our description of CCSNe continues to improve but many questions remain unanswered. Future observations will further our knowledge and the models we have studied can be used for continued analyses. The next generation of X-ray missions is very promising and a Galactic SN, which would greatly accelerate the entire research field, could occur at any time.
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| 22. |
- Alp, Dennis, MSc, 1992-, et al.
(författare)
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Blasts from the Past : Supernova Shock Breakouts among X-Ray Transients in the XMM-Newton Archive
- 2020
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 896:1
-
Tidskriftsartikel (refereegranskat)abstract
- The first electromagnetic signal from a supernova (SN) is released when the shock crosses the progenitor surface. This shock breakout (SBO) emission provides constraints on progenitor and explosion properties. Observationally, SBOs appear as minute- to hour-long extragalactic X-ray transients. They are challenging to detect and only one SBO has been observed to date. Here, we search the XMM-Newton archive and find 12 new SN SBO candidates. We identify host galaxies to nine of these at estimated redshifts of 0.1-1. The SBO candidates have energies of similar to 10(46)erg, timescales of 30-3000 s, and temperatures of 0.1-1 keV. They are all consistent with being SN SBOs, but some may be misidentified Galactic foreground sources or other extragalactic objects. SBOs from blue supergiants agree well with most of the candidates. However, a few could be SBOs from Wolf-Rayet stars surrounded by dense circumstellar media, whereas two are more naturally explained as SBOs from red supergiants. The observations tentatively support non-spherical SBOs and are in agreement with asymmetries predicted by recent three-dimensional SN explosion simulations. eROSITA may detect similar to 2 SBOs per year, which could be detected in live analyses and promptly followed up.
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| 23. |
- Alp, Dennis, MSc, 1992-
(författare)
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Core-collapse Supernovae : Theory vs. Observations
- 2019
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A core-collapse supernova (CCSN) is an astronomical explosion that indicates the death of a massive star. The iron core of the star collapses into either a neutron star or a black hole while the rest of the material is expelled at high velocities. Supernovae (SNe) are important for the chemical evolution of the Universe because a large fraction of the heavier elements such as oxygen, silicon, and iron are liberated by CCSN explosions. Another important role of SNe is that the ejected material seed the next generation of stars and planets. From observations, it is clear that a large fraction of all massive stars undergoes SN explosions, but describing how SNe explode has remained a challenge for many decades.The attached papers focus on comparing theoretical predictions with observations, primarily observations of SN 1987A. The compact remnant in SN 1987A has not yet been detected and we have investigated how a compact object can remain hidden in the ejecta (Paper I and II). Because of the high opacity of the metal-rich ejecta, the direct X-ray observations are not very constraining even for potentially favorable viewing angles. However, the combined observations still strongly constrain fallback accretion and put a limit on possible pulsar wind activity. The thermal surface emission from a neutron star is consistent with the observations if our line of sight is dust-obscured, and only marginally consistent otherwise. Future observations provide promising opportunities for detecting the compact object.We have also compared the most recent three-dimensional neutrino-driven SN models that are based on explosion simulations with early X-ray and gamma-ray observations of SN 1987A (Paper III). The models that are designed to match SN 1987A fit the data well, but not all tensions can be explained by choosing a suitable viewing angle. More generally, the asymmetries do not affect the early emission qualitatively and different progenitors of the same class result in similar early emission. We also find that the progenitor metallicity is important for the low-energy X-ray cuto↵. Current instruments should be able to detect this emission from SNe at distances of 3–10 Mpc, which correspond to distances slightly beyond the Local Group.
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| 24. |
- Alp, Dennis, et al.
(författare)
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The 30 Year Search for the Compact Object in SN 1987A
- 2018
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Ingår i: Astrophysical Journal. - : Institute of Physics Publishing (IOPP). - 0004-637X .- 1538-4357. ; 864:2
-
Tidskriftsartikel (refereegranskat)abstract
- Despite more than 30 years of searching, the compact object in Supernova (SN) 1987A has not yet been detected. We present new limits on the compact object in SN 1987A using millimeter, near-infrared, optical, ultraviolet, and X-ray observations from ALMA, VLT, HST, and Chandra. The limits are approximately 0.1 mJy (0.1 x 10(-26) erg s(-1) cm(-2) Hz(-1)) at 213 GHz, 1 L-circle dot (6 x 10(-29) erg s(-1) cm(-2) Hz(-1)) in the optical if our line of sight is free of ejecta dust, and 10(36) erg s(-1) (2 x 10(-30) erg s(-1) cm(-2) Hz(-1) ) in 2-10 keV X-rays. Our X-ray limits are an order of magnitude less constraining than previous limits because we use a more realistic ejecta absorption model based on three-dimensional neutrino-driven SN explosion models. The allowed bolometric luminosity of the compact object is 22 L-circle dot if our line of sight is free of ejecta dust, or 138L(circle dot) if dust-obscured. Depending on assumptions, these values limit the effective temperature of a neutron star (NS) to <4-8 MK and do not exclude models, which typically are in the range 3-4 MK. For the simplest accretion model, the accretion rate for an efficiency 77 is limited to <10(-11) eta(-1) M-circle dot yr(-1), which excludes most predictions. For pulsar activity modeled by a rotating magnetic dipole in vacuum, the limit on the magnetic field strength (B) for a given spin period (P) is B less than or similar to 10(14) P-2 G s(-2), which firmly excludes pulsars comparable to the Crab. By combining information about radiation reprocessing and geometry, we infer that the compact object is a dust-obscured thermally emitting NS, which may appear as a region of higher-temperature ejecta dust emission.
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| 25. |
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| 26. |
- Alp, Dennis, PhD, 1992-, et al.
(författare)
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Thermal Emission and Radioactive Lines, but No Pulsar, in the Broadband X-Ray Spectrum of Supernova 1987A
- 2021
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 916:2
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Tidskriftsartikel (refereegranskat)abstract
- Supernova 1987A offers a unique opportunity to study an evolving supernova in unprecedented detail over several decades. The X-ray emission is dominated by interactions between the ejecta and the circumstellar medium, primarily the equatorial ring (ER). We analyze 3.3.Ms of NuSTAR data obtained between 2012 and 2020, and two decades of XMM-Newton data. Since similar to 2013, the flux below 2.keV has declined, the 3-8.keV flux has increased but has started to flatten, and the emission above 10.keV has remained nearly constant. The spectra are well described by a model with three thermal shock components. Two components at 0.3 and 0.9.keV are associated with dense clumps in the ER, and a 4.keV component may be a combination of emission from diffuse gas in the ER and the surrounding low-density H II region. We disfavor models that involve nonthermal X-ray emission and place constraints on nonthermal components, but cannot firmly exclude an underlying power law. Radioactive lines show a Ti-44 redshift of 670(+520) (-380) km s(-1), Ti-44 mass of ' 1.73(-0.29)(+0.27) 10(-4) M-circle dot, and Fe-55Y mass of <4.2 10(-4) M-circle dot. The 35-65.keV luminosity limit on the compact object is 2 ' 1034.erg.s-1, and < 15% of the 10-20.keV flux is pulsed. Considering previous limits, we conclude that there are currently no indications of a compact object, aside from a possible hint of dust heated by a neutron star in recent ALMA images.
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| 27. |
- Alp, Dennis, et al.
(författare)
-
X-Ray Absorption in Young Core-collapse Supernova Remnants
- 2018
-
Ingår i: Astrophysical Journal. - : Institute of Physics Publishing (IOPP). - 0004-637X .- 1538-4357. ; 864:2
-
Tidskriftsartikel (refereegranskat)abstract
- The material expelled by core-collapse supernova (SN) explosions absorbs X-rays from the central regions. We use SN models based on three-dimensional neutrino-driven explosions to estimate optical depths to the center of the explosion, compare different progenitor models, and investigate the effects of explosion asymmetries. The optical depths below 2 keV for progenitors with a remaining hydrogen envelope are expected to be high during the first century after the explosion due to photoabsorption. A typical optical depth is 100 t(4)(-2 )E(-2), where t(4) is the time since the explosion in units of 10,000 days (similar to 27 years) and E is the energy in units of keV. Compton scattering dominates above 50 keV, but the scattering depth is lower and reaches unity at similar to 1000 days at 1 MeV. The optical depths are approximately an order of magnitude lower for hydrogen-stripped progenitors. The metallicity of the SN ejecta is much higher than that in the interstellar medium, which enhances photoabsorption and makes absorption edges stronger. These results are applicable to young SN remnants in general, but we explore the effects on observations of SN 1987A and the compact object in Cas A in detail. For SN 1987A, the absorption is high and the X-ray upper limits of similar to 100 L-circle dot on a compact object are approximately an order of magnitude less constraining than previous estimates using other absorption models. The details are presented in an accompanying paper. For the central compact object in Cas A, we find no significant effects of our more detailed absorption model on the inferred surface temperature.
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| 28. |
- Alp, Dennis, MSc, 1992-, et al.
(författare)
-
X-Ray and Gamma-Ray Emission from Core-collapse Supernovae : Comparison of Three-dimensional Neutrino-driven Explosions with SN 1987A
- 2019
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 882:1
-
Tidskriftsartikel (refereegranskat)abstract
- During the first few hundred days after the explosion, core-collapse supernovae (SNe) emit down-scattered X-rays and gamma-rays originating from radioactive line emissions, primarily from the Ni-56 -> Co-56 -> Fe-56 chain. We use supernova (SN) models based on three-dimensional neutrino-driven explosion simulations of single stars and mergers to compute this emission and compare the predictions with observations of SN 1987A. A number of models are clearly excluded, showing that high-energy emission is a powerful way of discriminating between models. The best models are almost consistent with the observations, but differences that cannot be matched by a suitable choice of viewing angle are evident. Therefore, our self-consistent models suggest that neutrino-driven explosions are able to produce, in principle, sufficient mixing, although remaining discrepancies may require small changes to the progenitor structures. The soft X-ray cutoff is primarily determined by the metallicity of the progenitor envelope. The main effect of asymmetries is to vary the flux level by a factor of similar to 3. For the more asymmetric models, the shapes of the light curves also change. In addition to the models of SN 1987A, we investigate two models of SNe II-P and one model of a stripped-envelope SN IIb. The Type II-P models have observables similar to those of the models of SN 1987A, but the stripped-envelope SN model is significantly more luminous and evolves faster. Finally, we make simple predictions for future observations of nearby SNe.
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| 29. |
- Arendt, Richard G., et al.
(författare)
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JWST NIRCam Observations of SN 1987A : Spitzer Comparison and Spectral Decomposition
- 2023
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 959:2
-
Tidskriftsartikel (refereegranskat)abstract
- JWST Near Infrared Camera (NIRCam) observations at 1.5–4.5 μm have provided broadband and narrowband imaging of the evolving remnant of SN 1987A with unparalleled sensitivity and spatial resolution. Comparing with previous marginally spatially resolved Spitzer Infrared Array Camera (IRAC) observations from 2004 to 2019 confirms that the emission arises from the circumstellar equatorial ring (ER), and the current brightness at 3.6 and 4.5 μm was accurately predicted by extrapolation of the declining brightness tracked by IRAC. Despite the regular light curve, the NIRCam observations clearly reveal that much of this emission is from a newly developing outer portion of the ER. Spots in the outer ER tend to lie at position angles in between the well-known ER hotspots. We show that the bulk of the emission in the field can be represented by five standard spectral energy distributions, each with a distinct origin and spatial distribution. This spectral decomposition provides a powerful technique for distinguishing overlapping emission from the circumstellar medium and the supernova ejecta, excited by the forward and reverse shocks, respectively.
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| 30. |
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| 31. |
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| 32. |
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| 33. |
- Bodén, Robert, 1973-, et al.
(författare)
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Suppressing visual hallucinations in an adolescent by occipital transcranial magnetic stimulation: A single-case experimental research design.
- 2021
-
Ingår i: Neuropsychological rehabilitation. - : Informa UK Limited. - 1464-0694 .- 0960-2011. ; 33:2, s. 346-55
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Tidskriftsartikel (refereegranskat)abstract
- Visual hallucinations after central or peripheral impairment, commonly called Charles Bonnet syndrome, are often highly distressing and with few available treatment options. Here we report a case where an adolescent developed severely distressing visual hallucinations after hypoxic damage to the occipital cortex following a suicide attempt. The patient received active and sham occipital continuous theta-burst stimulation (cTBS) in a single-case experimental research design and a subsequent open phase, to evaluate cTBS as a Charles Bonnet treatment. The visual hallucinations seemed to decrease more during active than sham cTBS in the blind phase, and in the following week of repeated five daily treatments they almost disappeared. A normalization of increased activity in the lateral visual network after cTBS was observed on a functional magnetic resonance imaging resting-state analysis compared with 42 healthy controls. Visual evoked potentials stayed largely unchanged both in the sham-controlled blind phase and the subsequent open phase. During the two weeks after the open phase with repeated cTBS sessions, the visual hallucinations gradually reappeared and almost returned to the baseline level. Our findings suggest that active cTBS over the primary visual cortex can reduce visual hallucinations through modulation of downstream visual regions, though the effect is temporally limited.
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| 34. |
- Brooks, Samantha J, et al.
(författare)
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Obsessive-compulsivity and working memory are associated with differential prefrontal cortex and insula activation in adolescents with a recent diagnosis of an eating disorder
- 2014
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Ingår i: Psychiatry Research. - : Elsevier BV. - 0165-1781 .- 1872-7123 .- 0925-4927. ; 224:3, s. 246-253
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Tidskriftsartikel (refereegranskat)abstract
- The role of rumination at the beginning of eating disorder (ED) is not well understood. We hypothesised that impulsivity, rumination and restriction could be associated with neural activity in response to food stimuli in young individuals with eating disorders (ED). We measured neural responses with functional magnetic resonance imaging (fMRI), tested working memory (WM) and administered the eating disorders examination questionnaire (EDE-Q), Barratt impulsivity scale (BIS-11) and obsessive-compulsive inventory (OCI-R) in 15 adolescent females with eating disorder not otherwise specified (EDNOS) (mean age 15 years) and 20 age-matched healthy control females. We found that EDNOS subjects had significantly higher scores on the BIS 11, EDE-Q and OCI-R scales. Significantly increased neural responses to food images in the EDNOS group were observed in the prefrontal circuitry. OCI-R scores in the EDNOS group also significantly correlated with activity in the prefrontal circuitry and the cerebellum. Significantly slower WM responses negatively correlated with bilateral superior frontal gyrus activity in the EDNOS group. We conclude that ruminations, linked to WM, are present in adolescent females newly diagnosed with EDNOS. These may be risk factors for the development of an eating disorder and may be detectable before disease onset.
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| 35. |
- Bryhn, Andreas, et al.
(författare)
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Fisk- och skaldjursbestånd i hav och sötvatten 2019 : Resursöversikt
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Fisken i havet är en resurs som rör sig fritt över nationella gränser. EU har därför en gemensam fiskeripolitik (GFP). Många arter som är viktiga för Sverige regleras inte i GFP och förvaltas därför nationellt.Denna rapport syftar till att:beskriva utvecklingen av fiskeripolitikenförklara den nuvarande politikens mål och regelverk och dess relation till mål och regler på miljöområdetförklara politikens nationella genomförande och det nationella handlingsutrymmetexemplifiera hur Havs- och vattenmyndigheten arbetat med att reglera fisket.
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| 36. |
- Cigan, Phil, et al.
(författare)
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High Angular Resolution ALMA Images of Dust and Molecules in the SN 1987A Ejecta
- 2019
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 886:1
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Tidskriftsartikel (refereegranskat)abstract
- We present high angular resolution (similar to 80 mas) ALMA continuum images of the SN.1987A system, together with CO J = 2 -> 1, J = 6 -> 5, and SiO J = 5 -> 4 to J = 7 -> 6 images, which clearly resolve the ejecta (dust continuum and molecules) and ring (synchrotron continuum) components. Dust in the ejecta is asymmetric and clumpy, and overall the dust fills the spatial void seen in H alpha images, filling that region with material from heavier elements. The dust clumps generally fill the space where CO J = 6 -> 5 is fainter, tentatively indicating that these dust clumps and CO are locationally and chemically linked. In these regions, carbonaceous dust grains might have formed after dissociation of CO. The dust grains would have cooled by radiation, and subsequent collisions of grains with gas would also cool the gas, suppressing the CO J = 6 -> 5 intensity. The data show a dust peak spatially coincident with the molecular hole seen in previous ALMA CO J = 2 -> 1 and SiO J = 5 -> 4 images. That dust peak, combined with CO and SiO line spectra, suggests that the dust and gas could be at higher temperatures than the surrounding material, though higher density cannot be totally excluded. One of the possibilities is that a compact source provides additional heat at that location. Fits to the far-infrared-millimeter spectral energy distribution give ejecta dust temperatures of 18-23 K. We revise the ejecta dust mass to M-dust = 0.2-0.4 M-circle dot for carbon or silicate grains, or a maximum of <0.7 M-circle dot for a mixture of grain species, using the predicted nucleosynthesis yields as an upper limit.
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| 37. |
- Daka, Bledar, 1976, et al.
(författare)
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Circulating concentrations of endothelin-1 predict coronary heart disease in women but not in men: A longitudinal observational study in the Vara-Skövde Cohort
- 2015
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Ingår i: BMC Cardiovascular Disorders. - : Springer Science and Business Media LLC. - 1471-2261. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- © 2015 Daka et al.Background: The vasoconstricting peptide endothelin-1 has been proposed to be a marker of cardiovascular disease. Our aim was to investigate whether circulating endothelin-1 levels predict coronary heart disease (CHD) in Sweden. Methods: In 2002-2005, 2816 adult participants (30-74 years) were randomly selected from two municipalities in south-western Sweden. Cardiovascular risk factors and endothelin-1 levels were assessed at baseline, and incident CHD was followed-up in all participants through 2011. After exclusion of 50 participants due to known CHD at baseline and 21 participants because of unsuccessful analysis of endothelin-1, 2745 participants were included in the study. In total, 72 CHD events (52 in men and 20 in women) were registered during the follow-up time. Results: We showed that baseline circulating endothelin-1 levels were higher in women with incident CHD than in women without CHD (3.2 pg/ml, SE: 0.36 vs 2.4 pg/ml, SE: 0.03, p = 0.003) whereas this difference was not observed in men (2.3 pg/ml, SE: 0.16 vs 2.3 pg/ml, SE: 0.04, p = 0.828). An age-adjusted Cox proportional regression analysis showed an enhanced risk of CHD with increasing baseline endothelin-1 levels in women (hazard ratio (HR) = 1.51, 95 % CI = 1.1-2.1, p = 0.015) but not in men (HR = 0.98, 95 % CI = 0.8-1.2, p = 0.854). Furthermore, the predictive value of endothelin-1 for incident CHD in women was still significant after adjustments for age, HOMA-IR, apolipoprotein (apo)B/apoA1 and smoking (HR = 1.53, CI = 1.1-1.2, p = 0.024). Conclusion: Circulating endothelin-1 levels may predict CHD in women.
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| 38. |
- D'Ammando, Filippo, et al.
(författare)
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A Panchromatic View of Relativistic Jets in Narrow-Line Seyfert 1 Galaxies
- 2016
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Ingår i: Galaxies. - : MDPI AG. - 2075-4434. ; 4:3
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Tidskriftsartikel (refereegranskat)abstract
- The discovery by the Large Area Telescope on board Fermi of variable -ray emission from radio-loud narrow-line Seyfert 1 (NLSy1) galaxies revealed the presence of a possible third class of Active Galactic Nuclei (AGN) with relativistic jets in addition to blazars and radio galaxies. Considering that NLSy1 are usually hosted in spiral galaxies, this finding poses intriguing questions about the nature of these objects and the formation of relativistic jets. We report on a systematic investigation of the -ray properties of a sample of radio-loud NLSy1, including the detection of new objects, using 7 years of Fermi-LAT data with the new Pass 8 event-level analysis. In addition we discuss the radio-to-very-high-energy properties of the -ray emitting NLSy1, their host galaxy, and black hole mass in the context of the blazar scenario and the unification of relativistic jets at different scales.
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| 39. |
- D’Ammando, F., et al.
(författare)
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Gamma-ray emitting narrow-line Seyfert 1 galaxies. New discoveries and open questions
- 2014
-
Ingår i: Proceedings of the International Astronomical Union. - 1743-9213 .- 1743-9221. ; 9:S304, s. 140-143
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Tidskriftsartikel (refereegranskat)abstract
- The discovery of γ-ray emission from 5 radio-loud narrow-line Seyfert 1 galaxies revealed the presence of a possible emerging third class of AGNs with relativistic jets, in addition to blazars and radio galaxies. The existence of relativistic jets also in this subclass of Seyfert galaxies opened an unexplored research space for our knowledge of the radio-loud AGNs. Here, we discuss the radio-to-γ-rays properties of the γ-ray emitting narrow-line Seyfert 1 galaxies, also in comparison with the blazar scenario.
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| 40. |
- D'Ammando, F., et al.
(författare)
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Multiwavelength observations of the gamma-ray-emitting narrow-line Seyfert 1 PMN J0948+0022 in 2011
- 2014
-
Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 438:4, s. 3521-3534
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Tidskriftsartikel (refereegranskat)abstract
- We report on radio-to-gamma-ray observations during 2011 May-September of PMN J0948+0022, the first narrow-line Seyfert 1 (NLSy1) galaxy detected in gamma-rays by Fermi-Large Area Telescope. Strong variability was observed in gamma-rays, with two flaring periods peaking on 2011 June 20 and July 28. The variability observed in optical and near-infrared seems to have no counterpart in gamma-rays. This different behaviour could be related to a bending and inhomogeneous jet or a turbulent extreme multicell scenario. The radio spectra showed a variability pattern typical of relativistic jets. The XMM spectrum shows that the emission from the jet dominates above similar to 2 keV, while a soft X-ray excess is evident in the low-energy part of the X-ray spectrum. Models where the soft emission is partly produced by blurred reflection or Comptonization of the thermal disc emission provide good fits to the data. The X-ray spectral slope is similar to that found in radio-quiet NLSy1, suggesting that a standard accretion disc is present, as expected from the high accretion rate. Except for the soft X-ray excess, unusual in jet-dominated active galactic nuclei, PMN J0948+0022, shows all characteristics of the blazar class.
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| 41. |
- D'Ammando, F., et al.
(författare)
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Relativistic jets in narrow-line Seyfert 1 galaxies. New discoveries and open questions
- 2013
-
Ingår i: EPJ Web of Conferences. - : EDP Sciences. - 2100-014X. ; , s. 05006-
-
Konferensbidrag (refereegranskat)abstract
- Before the launch of the Fermi satellite only two classes of AGNs were known to produce relativistic jets and thus emit up to the γ-ray energy range: blazars and radio galaxies, both hosted in giant elliptical galaxies. The first four years of observations by the Large Area Telescope on board Fermi confirmed that these two are the most numerous classes of identified sources in the extragalactic γ-ray sky, but the discovery of γ-ray emission from 5 radio-loud narrow-line Seyfert 1 galaxies revealed the presence of a possible emerging third class of AGNs with relativistic jets. Considering that narrow-line Seyfert 1 galaxies seem to be typically hosted in spiral galaxy, this finding poses intriguing questions about the nature of these objects, the onset of production of relativistic jets, and the cosmological evolution of radio-loud AGN. Here, we discuss the radio-to-γ-rays properties of the γ-ray emitting narrow-line Seyfert 1 galaxies, also in comparison with the blazar scenario.
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| 42. |
- D'Ammando, F., et al.
(författare)
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The first gamma-ray detection of the narrow-line Seyfert 1 FBQS J1644+2619
- 2015
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 452:1, s. 520-524
-
Tidskriftsartikel (refereegranskat)abstract
- We report the discovery of gamma-ray emission from the narrow-line Seyfert 1 (NLSy1) galaxy FBQS J1644+2619 by the Large Area Telescope on board the Fermi satellite. The Third Fermi LAT Source catalogue reports an unidentified gamma-ray source, detected over the first four years of Fermi operation, 0 degrees.23 from the radio position of the NLSy1. Analysing 76 months of gamma-ray data (2008 August 4-2014 December 31) we are able to better constrain the localization of the gamma-ray source. The new position of the gamma-ray source is 0 degrees.05 from FBQS J1644+2619, suggesting a spatial association with the NLSy1. This is the sixth NLSy1 detected at high significance by Fermi-LAT so far. Notably, a significant increase of activity was observed in gamma-rays from FBQS J1644+2619 during 2012 July-October, and an increase of activity in the V band was detected by the Catalina Real-Time Sky Survey in the same period.
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| 43. |
- D’Ammando, F., et al.
(författare)
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The most powerful flaring activity from the NLSy1 PMN J0948+0022
- 2015
-
Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press. - 0035-8711 .- 1365-2966. ; 446:3, s. 2456-2467
-
Tidskriftsartikel (refereegranskat)abstract
- We report on multifrequency observations performed during 2012 December–2013 August of the first narrow-line Seyfert 1 galaxy detected in γ-rays, PMN J0948+0022 (z = 0.5846). A γ-ray flare was observed by the Large Area Telescope on board Fermi during 2012 December–2013 January, reaching a daily peak flux in the 0.1–100 GeV energy range of (155 ± 31) × 10−8 ph cm−2 s−1 on 2013 January 1, corresponding to an apparent isotropic luminosity of ∼1.5 × 1048 erg s−1. The γ-ray flaring period triggered Swift and Very Energetic Radiation Imaging Telescope Array System (VERITAS) observations in addition to radio and optical monitoring by Owens Valley Radio Observatory, Monitoring Of Jets in Active galactic nuclei with VLBA Experiments, and Catalina Real-time Transient Survey. A strong flare was observed in optical, UV, and X-rays on 2012 December 30, quasi-simultaneously to the γ-ray flare, reaching a record flux for this source from optical to γ-rays. VERITAS observations at very high energy (E > 100 GeV) during 2013 January 6–17 resulted in an upper limit of F>0.2 TeV < 4.0 × 10−12 ph cm−2 s−1. We compared the spectral energy distribution (SED) of the flaring state in 2013 January with that of an intermediate state observed in 2011. The two SEDs, modelled as synchrotron emission and an external Compton scattering of seed photons from a dust torus, can be modelled by changing both the electron distribution parameters and the magnetic field.
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| 44. |
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| 45. |
- Eidhagen, Josefin, et al.
(författare)
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Synchrotron XPS and Electrochemical Study of Aging Effect on Passive Film of Ni Alloys
- 2023
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 170:2, s. 021506-
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Tidskriftsartikel (refereegranskat)abstract
- To investigate aging effect on the passive film of Ni23Cr15Mo and Ni22Cr9Mo3Nb, synchrotron-based X-ray photoelectron spectroscopy (XPS) was used to analyze the structure and composition of the air-formed passive film on the alloys. The corrosion resistance of the two Ni alloys in 1 M NaCl solution was evaluated with electrochemical cyclic polarization measurement. The synchrotron XPS measurement provided detailed information about chemical states of alloying elements in the passive film, showing that the passive film consists of an inner oxide layer and an outer hydroxide layer. The XPS data allowed precise determination of the chemical composition and the thickness of the outer hydroxide layer, the inner oxide layer, and the underlying subsurface alloy layer. The Cr-oxide in the inner layer grows thicker with aging time, leading to Cr-depletion in the subsurface region. Mo and Nb in the alloy form mixed oxides and hydroxides, and aging in air leads to transformation of the lower valence oxides into higher valence oxides. The freshly formed oxide film exhibits similar barrier properties as the aged oxide film. The stability of the passive film formed on Ni22Cr9Mo3Nb seems to be better than that on Ni23Cr15Mo.
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| 46. |
- Eklund, Rakel, 1986-, et al.
(författare)
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Surviving COVID-19 : patients' experiences of care and path to recovery
- 2024
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Ingår i: International Journal of Qualitative Studies on Health and Well-being. - : Taylor & Francis. - 1748-2623 .- 1748-2631. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To examine patients' experiences of receiving care on an ICU for COVID-19 and the subsequent rehabilitation process.Methods: An explorative and inductive design was used. Participants were recruited from two university hospitals in Sweden. Patients admitted to the ICU due to COVID-19 from March 2020 to April 2021, who enrolled in the ICU follow-up, and understood and spoke Swedish were invited to participate. In total, 20 participants completed a semi-structured interview, of whom 18 were included in the thematic analysis.Results: The analysis resulted in two themes: "An isolated world with silver linings" and "Recovery in the wake of the pandemic". Findings show that patients cared for on an ICU for COVID-19 during the pandemic felt safe but experienced a sense of vulnerability. After discharge, physical rehabilitation was a slow process with frustrating day-to-day fluctuations. Mentally, participants felt isolated, fatigued, and emotionally sensitive. Patients reported that love and support from family and friends were crucial for the recovery process.Conclusions: This study highlights the challenges of recovering from COVID-19, emphasizing the importance of continued support from health care, public services, family and friends. It provides important insights into patients' experiences and can inform future healthcare strategies and policies.
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| 47. |
- Ekström, Magnus, et al.
(författare)
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A nationwide structure for valid Long-Term oxygen therapy : 29-Year prospective data in Sweden
- 2017
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Ingår i: International Journal of COPD. - 1176-9106. ; 12, s. 3159-3169
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Tidskriftsartikel (refereegranskat)abstract
- Background: Long-term oxygen therapy (LTOT) improves prognosis in COPD with severe hypoxemia. However, adherence to criteria for eligibility and quality of LTOT is often insufficient and varies between countries. The aim of this study was to evaluate a national structure for prescription and management of LTOT over three decades in Sweden. Methods: The study was a prospective, population-based study of 23,909 patients on LTOT from 1987 to 2015 in the Swedish National Register of Respiratory Failure (Swedevox). We assessed the prevalence, incidence, and structure of LTOT; completeness of registration in Swedevox; and validity of prescription and management of LTOT in Sweden according to seven published quality indicators. Results: LTOT was prescribed by 48 respiratory or medicine units and managed mainly by specialized oxygen nurses. Swedevox had a stable completeness of 85% of patients starting LTOT since 1987. The national incidence of LTOT increased from 3.9 to 14.7/100,000 inhabitants over the time period. In 2015, 2,596 patients had ongoing therapeutic LTOT in the registry, a national prevalence of 31.6/100,000. Adherence to prescription recommendations and fulfillment of quality criteria was stable or improved over time. Of patients starting LTOT in 2015, 88% had severe hypoxemia (partial pressure of arterial oxygen [PaO2] < 7.4 kPa) and 97% had any degree of hypoxemia (PaO2 < 8.0 kPa); 98% were prescribed oxygen ≥15 hours/day or more; 76% had both stationary and mobile oxygen equipment; 75% had a mean PaO2> 8.0 kPa breathing oxygen; and 98% were non-smokers. Conclusion: We present a structure for prescription, management, and follow-up of LTOT. The national registry effectively monitored adherence to prescription recommendations and most likely contributed to improved quality of care.
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| 48. |
- Ekström, Magnus, et al.
(författare)
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Patient reported outcome measures in chronic obstructive pulmonary disease : Which to use?
- 2016
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Ingår i: Expert Review of Respiratory Medicine. - Oxfordshire, United Kingdom : Taylor & Francis. - 1747-6348 .- 1747-6356. ; 10:3, s. 351-362
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Forskningsöversikt (refereegranskat)abstract
- Patient-reported outcomes (PROs), such as symptoms and perceived health status, are essential in chronic obstructive pulmonary disease (COPD) for determining disease severity, impact on daily life, effect of treatment and recovery from exacerbations. This field has evolved rapidly and there are a plethora of instruments assessing different PROs. The aim of this review is to provide an understanding of the concept of PROs in COPD. The PROs reflect important aspects of COPD which have a direct impact on daily life. Common symptoms such as dyspnea, cough, phlegm, anxiety, fatigue, and pain and as well as physical function and the risk for and occurrence of acute exacerbations should be assessed both in the clinic and in research. Besides impact on daily life, some of the PROs are related to disease progress and mortality. Construction of composite variables including different disease specific and generic PROs provide a general estimation of health status.
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| 49. |
- Eliasson, Gabriella, et al.
(författare)
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Comorbid conditions as predictors of mortality in severe COPD - an eight-year follow-up cohort study
- 2023
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Ingår i: European Clinical Respiratory Journal. - : Taylor & Francis. - 2001-8525. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Co-morbidities are common in chronic obstructive pulmonary disease (COPD) and are associated with increased morbidity and mortality. The aim of the present study was to explore the prevalence of several comorbid conditions in severe COPD, and to investigate and compare their associations with long-term mortality.Methods: In May 2011 to March 2012, 241 patients with COPD stage 3 or 4 were included in the study. Information was collected on sex, age, smoking history, weight and height, current pharmacological treatment, number of exacerbations the recent year and comorbid conditions. At December 31st, 2019, mortality data (all-cause and cause specific) were collected from the National Cause of Death Register. Data were analyzed using Cox-regression analysis with gender, age, previously established predictors of mortality and comorbid conditions as independent variables, and all-cause mortality and cardiac and respiratory mortality, respectively, as dependent variables.Results: Out of 241 patients, 155 (64%) were deceased at the end of the study period; 103 patients (66%) died of respiratory disease and 25 (16%) of cardiovascular disease. Impaired kidney function was the only comorbid condition independently associated with increased all-cause mortality (HR (95% CI) 3.41 (1.47-7.93) p=0.004) and respiratory mortality (HR (95%CI) 4.63 (1.61 to 13.4), p = 0.005). In addition, age >= 70, BMI <22 and lower FEV1 expressed as %predicted were significantly associated with increased all-cause and respiratory mortality.Conclusion: In addition to the risk factors high age, low BMI and poor lung function; impaired kidney function appears to be an important risk factor for mortality in the long term, which should be taken into account in the medical care of patients with severe COPD.
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| 50. |
- Fahlman, Andreas, et al.
(författare)
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Resting metabolic rate and lung function in fasted and fed rough-toothed dolphins, Steno bredanensis
- 2024
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Ingår i: Marine mammal science. - : WILEY. - 0824-0469 .- 1748-7692. ; 40:1, s. 210-221
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Tidskriftsartikel (refereegranskat)abstract
- We measured resting metabolic rate (RMR), tidal volume (V-T), breathing frequency (f(R)), respiratory flow, and endexpired gases in rough-toothed dolphins (Steno bredanensis) housed in managed care after an overnight fast and 1-2 hr following a meal. The measured average (+/- standard deviation) V-T (4.0 +/- 1.3 L) and f(R) (1.9 +/- 1.0 breaths/min) were higher and lower, respectively, as compared with estimated values from both terrestrial and aquatic mammals, and the average V-T was 43% of the estimated total lung capacity. The end-expired gas levels suggested that this species keep alveolar O-2 (10.6% or 80 mmHg) and CO2 (7.6% or 57 mmHg), and likely arterial gas tensions, low and high, respectively, to maximize efficiency of gas exchange. We show that following an overnight fast, the RMR (566 +/- 158 ml O-2/min) was 1.8 times the estimated value predicted by Kleiber for terrestrial mammals of the same size. We also show that between 1 and 2 hr after ingestion of a meal, the metabolic rate increases an average of 29% (709 +/- 126 ml O-2/min). Both body mass (M-b) and f(R) significantly altered the measured RMR and we propose that both these variables should be measured when estimating energy use in cetaceans.
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