| 1. |
- Hillier, Ladeana W, et al.
(författare)
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Sequence and comparative analysis of the chicken genome provide unique perspectives on vertebrate evolution
- 2004
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Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 432:7018, s. 695-716
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Tidskriftsartikel (refereegranskat)abstract
- We present here a draft genome sequence of the red jungle fowl, Gallus gallus. Because the chicken is a modern descendant of the dinosaurs and the first non-mammalian amniote to have its genome sequenced, the draft sequence of its genome--composed of approximately one billion base pairs of sequence and an estimated 20,000-23,000 genes--provides a new perspective on vertebrate genome evolution, while also improving the annotation of mammalian genomes. For example, the evolutionary distance between chicken and human provides high specificity in detecting functional elements, both non-coding and coding. Notably, many conserved non-coding sequences are far from genes and cannot be assigned to defined functional classes. In coding regions the evolutionary dynamics of protein domains and orthologous groups illustrate processes that distinguish the lineages leading to birds and mammals. The distinctive properties of avian microchromosomes, together with the inferred patterns of conserved synteny, provide additional insights into vertebrate chromosome architecture.
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| 2. |
- Hibar, Derrek P., et al.
(författare)
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Novel genetic loci associated with hippocampal volume
- 2017
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (r(g) = -0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness.
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| 3. |
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| 4. |
- Abe, O, et al.
(författare)
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Effects of chemotherapy and hormonal therapy for early breast cancer on recurrence and 15-year survival: an overview of the randomised trials
- 2005
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Ingår i: The Lancet. - 1474-547X. ; 365:9472, s. 1687-1717
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Tidskriftsartikel (refereegranskat)abstract
- Background Quinquennial overviews (1985-2000) of the randomised trials in early breast cancer have assessed the 5-year and 10-year effects of various systemic adjuvant therapies on breast cancer recurrence and survival. Here, we report the 10-year and 15-year effects. Methods Collaborative meta-analyses were undertaken of 194 unconfounded randomised trials of adjuvant chemotherapy or hormonal therapy that began by 1995. Many trials involved CMF (cyclophosphamide, methotrexate, fluorouracil), anthracycline-based combinations such as FAC (fluorouracil, doxombicin, cyclophosphamide) or FEC (fluorouracil, epirubicin, cyclophosphamide), tamoxifen, or ovarian suppression: none involved taxanes, trastuzumab, raloxifene, or modem aromatase inhibitors. Findings Allocation to about 6 months of anthracycline-based polychemotherapy (eg, with FAC or FEC) reduces the annual breast cancer death rate by about 38% (SE 5) for women younger than 50 years of age when diagnosed and by about 20% (SE 4) for those of age 50-69 years when diagnosed, largely irrespective of the use of tamoxifen and of oestrogen receptor (ER) status, nodal status, or other tumour characteristics. Such regimens are significantly (2p=0 . 0001 for recurrence, 2p<0 . 00001 for breast cancer mortality) more effective than CMF chemotherapy. Few women of age 70 years or older entered these chemotherapy trials. For ER-positive disease only, allocation to about 5 years of adjuvant tamoxifen reduces the annual breast cancer death rate by 31% (SE 3), largely irrespective of the use of chemotherapy and of age (<50, 50-69, &GE; 70 years), progesterone receptor status, or other tumour characteristics. 5 years is significantly (2p<0 . 00001 for recurrence, 2p=0 . 01 for breast cancer mortality) more effective than just 1-2 years of tamoxifen. For ER-positive tumours, the annual breast cancer mortality rates are similar during years 0-4 and 5-14, as are the proportional reductions in them by 5 years of tamoxifen, so the cumulative reduction in mortality is more than twice as big at 15 years as at 5 years after diagnosis. These results combine six meta-analyses: anthracycline-based versus no chemotherapy (8000 women); CMF-based versus no chemotherapy (14 000); anthracycline-based versus CMF-based chemotherapy (14 000); about 5 years of tamoxifen versus none (15 000); about 1-2 years of tamoxifen versus none (33 000); and about 5 years versus 1-2 years of tamoxifen (18 000). Finally, allocation to ovarian ablation or suppression (8000 women) also significantly reduces breast cancer mortality, but appears to do so only in the absence of other systemic treatments. For middle-aged women with ER-positive disease (the commonest type of breast cancer), the breast cancer mortality rate throughout the next 15 years would be approximately halved by 6 months of anthracycline-based chemotherapy (with a combination such as FAC or FEC) followed by 5 years of adjuvant tamoxifen. For, if mortality reductions of 38% (age <50 years) and 20% (age 50-69 years) from such chemotherapy were followed by a further reduction of 31% from tamoxifen in the risks that remain, the final mortality reductions would be 57% and 45%, respectively (and, the trial results could well have been somewhat stronger if there had been full compliance with the allocated treatments). Overall survival would be comparably improved, since these treatments have relatively small effects on mortality from the aggregate of all other causes. Interpretation Some of the widely practicable adjuvant drug treatments that were being tested in the 1980s, which substantially reduced 5-year recurrence rates (but had somewhat less effect on 5-year mortality rates), also substantially reduce 15-year mortality rates. Further improvements in long-term survival could well be available from newer drugs, or better use of older drugs.
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| 5. |
- Aharonian, Felix, et al.
(författare)
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Atmospheric gas dynamics in the Perseus cluster observed with Hitomi
- 2018
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Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press (OUP). - 0004-6264 .- 2053-051X. ; 70:2
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Tidskriftsartikel (refereegranskat)abstract
- Extending the earlier measurements reported in Hitomi collaboration (2016, Nature, 535, 117), we examine the atmospheric gas motions within the central 100 kpc of the Perseus cluster using observations obtained with the Hitomi satellite. After correcting for the point spread function of the telescope and using optically thin emission lines, we find that the line-of-sight velocity dispersion of the hot gas is remarkably low and mostly uniform. The velocity dispersion reaches a maxima of approximately 200 km s(-1) toward the central active galactic nucleus (AGN) and toward the AGN inflated northwestern ghost bubble. Elsewhere within the observed region, the velocity dispersion appears constant around 100 km s(-1). We also detect a velocity gradient with a 100 km s(-1) amplitude across the cluster core, consistent with large-scale sloshing of the core gas. If the observed gas motions are isotropic, the kinetic pressure support is less than 10% of the thermal pressure support in the cluster core. The well-resolved, optically thin emission lines have Gaussian shapes, indicating that the turbulent driving scale is likely below 100 kpc, which is consistent with the size of the AGN jet inflated bubbles. We also report the first measurement of the ion temperature in the intracluster medium, which we find to be consistent with the electron temperature. In addition, we present a new measurement of the redshift of the brightest cluster galaxy NGC 1275.
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| 6. |
- Aharonian, Felix, et al.
(författare)
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Atomic data and spectral modeling constraints from high-resolution X-ray observations of the Perseus cluster with Hitomi
- 2018
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Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press (OUP). - 0004-6264 .- 2053-051X. ; 70:2
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Tidskriftsartikel (refereegranskat)abstract
- The Hitomi Soft X-ray Spectrometer spectrum of the Perseus cluster, with similar to 5 eV resolution in the 2-9 keV band, offers an unprecedented benchmark of the atomic modeling and database for hot collisional plasmas. It reveals both successes and challenges of the current atomic data and models. The latest versions of AtomDB/APEC (3.0.8), SPEX (3.03.00), and CHIANTI (8.0) all provide reasonable fits to the broad-band spectrum, and are in close agreement on best-fit temperature, emission measure, and abundances of a few elements such as Ni. For the Fe abundance, the APEC and SPEX measurements differ by 16%, which is 17 times higher than the statistical uncertainty. This is mostly attributed to the differences in adopted collisional excitation and dielectronic recombination rates of the strongest emission lines. We further investigate and compare the sensitivity of the derived physical parameters to the astrophysical source modeling and instrumental effects. The Hitomi results show that accurate atomic data and models are as important as the astrophysical modeling and instrumental calibration aspects. Substantial updates of atomic databases and targeted laboratory measurements are needed to get the current data and models ready for the data from the next Hitomi-level mission.
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| 7. |
- Aharonian, Felix, et al.
(författare)
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Detection of polarized gamma-ray emission from the Crab nebula with the Hitomi Soft Gamma-ray Detector
- 2018
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Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press (OUP). - 0004-6264 .- 2053-051X. ; 70:6
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Tidskriftsartikel (refereegranskat)abstract
- We present the results from the Hitomi Soft Gamma-ray Detector (SGD) observation of the Crab nebula. The main part of SGD is a Compton camera, which in addition to being a spectrometer, is capable of measuring polarization of gamma-ray photons. The Crab nebula is one of the brightest X-ray / gamma-ray sources on the sky, and, the only source from which polarized X-ray photons have been detected. SGD observed the Crab nebula during the initial test observation phase of Hitomi. We performed the data analysis of the SGD observation, the SGD background estimation and the SGD Monte Carlo simulations, and, successfully detected polarized gamma-ray emission from the Crab nebula with only about 5 ks exposure time. The obtained polarization fraction of the phase-integrated Crab emission (sum of pulsar and nebula emissions) is (22.1% +/- 10.6%), and, the polarization angle is 110.degrees 7 + 13.degrees 2 /-13.degrees 0 in the energy range of 60-160 keV (The errors correspond to the 1 sigma deviation). The confidence level of the polarization detection was 99.3%. The polarization angle measured by SGD is about one sigma deviation with the projected spin axis of the pulsar, 124.degrees 0 +/- 0.degrees 1.
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| 8. |
- Aharonian, Felix, et al.
(författare)
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Glimpse of the highly obscured HMXB IGR J16318-4848 with Hitomi
- 2018
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Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press (OUP). - 0004-6264 .- 2053-051X. ; 70:2
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Tidskriftsartikel (refereegranskat)abstract
- We report on a Hitomi observation of IGR J16318-4848, a high-mass X-ray binary system with an extremely strong absorption of N-H similar to 10(24) cm(-2). Previous X-ray studies revealed that its spectrum is dominated by strong fluorescence lines of Fe as well as continuum emission lines. For physical and geometrical insight into the nature of the reprocessing material, we utilized the high spectroscopic resolving power of the X-ray microcalorimeter (the soft X-ray spectrometer: SXS) and the wide-band sensitivity by the soft and hard X-ray imagers (SXI and HXI) aboard Hitomi. Even though the photon counts are limited due to unintended off-axis pointing, the SXS spectrum resolves Fe K alpha(1) and K alpha(2) lines and puts strong constraints on the line centroid and line width. The line width corresponds to a velocity of 160(-70)(+300) km s(-1). This represents the most accurate, and smallest, width measurement of this line made so far from the any X-ray binary, much less than the Doppler broadening and Doppler shift expected from speeds that are characteristic of similar systems. Combined with the K-shell edge energy measured by the SXI and HXI spectra, the ionization state of Fe is estimated to be in the range of Fe I-IV. Considering the estimated ionization parameter and the distance between the X-ray source and the absorber, the density and thickness of the materials are estimated. The extraordinarily strong absorption and the absence of a Compton shoulder component have been confirmed. These characteristics suggest reprocessing materials that are distributed in a narrow solid angle or scattering, primarily by warm free electrons or neutral hydrogen. This measurement was achieved using the SXS detection of 19 photons. It provides strong motivation for follow-up observations of this and other X-ray binaries using the X-ray Astrophysics Recovery Mission and other comparable future instruments.
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| 9. |
- Aharonian, Felix, et al.
(författare)
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Hitomi observation of radio galaxy NGC 1275 : The first X-ray microcalorimeter spectroscopy of Fe-K alpha line emission from an active galactic nucleus
- 2018
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Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press (OUP). - 0004-6264 .- 2053-051X. ; 70:2
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Tidskriftsartikel (refereegranskat)abstract
- The origin of the narrow Fe-K alpha fluorescence line at 6.4 keV from active galactic nuclei has long been under debate; some of the possible sites are the outer accretion disk, the broad line region, a molecular torus, or interstellar/intracluster media. In 2016 February-March, we performed the first X-ray microcalorimeter spectroscopy with the Soft X-ray Spectrometer (SXS) on board the Hitomi satellite of the Fanaroff-Riley type I radio galaxy NGC 1275 at the center of the Perseus cluster of galaxies. With the high-energy resolution of similar to 5 eV at 6 keV achieved by Hitomi/SXS, we detected the Fe-K alpha line with similar to 5.4 sigma significance. The velocity width is constrained to be 500-1600 km s(-1) (FWHM for Gaussian models) at 90% confidence. The SXS also constrains the continuum level from the NGC 1275 nucleus up to similar to 20 keV, giving an equivalent width of similar to 20 eV for the 6.4 keV line. Because the velocity width is narrower than that of the broad H alpha line of similar to 2750 km s(-1), we can exclude a large contribution to the line flux from the accretion disk and the broad line region. Furthermore, we performed pixel map analyses on the Hitomi/SXS data and image analyses on the Chandra archival data, and revealed that the Fe-K alpha line comes from a region within similar to 1.6 kpc of the NGC 1275 core, where an active galactic nucleus emission dominates, rather than that from intracluster media. Therefore, we suggest that the source of the Fe-K alpha line from NGC 1275 is likely a low-covering-fraction molecular torus or a rotating molecular disk which probably extends from a parsec to hundreds of parsecs scale in the active galactic nucleus system.
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| 10. |
- Aharonian, Felix, et al.
(författare)
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Hitomi observations of the LMC SNR N 132 D : Highly redshifted X-ray emission from iron ejecta
- 2018
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Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press (OUP). - 0004-6264 .- 2053-051X. ; 70:2
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Tidskriftsartikel (refereegranskat)abstract
- We present Hitomi observations of N 132 D, a young, X-ray bright, O-rich core-collapse supernova remnant in the Large Magellanic Cloud (LMC). Despite a very short observation of only 3.7 ks, the Soft X-ray Spectrometer (SXS) easily detects the line complexes of highly ionized S K and Fe K with 16-17 counts in each. The Fe feature is measured for the first time at high spectral resolution. Based on the plausible assumption that the Fe K emission is dominated by He-like ions, we find that the material responsible for this Fe emission is highly redshifted at similar to 800 km s(-1) compared to the local LMC interstellar medium (ISM), with a 90% credible interval of 50-1500 km s(-1) if a weakly informative prior is placed on possible line broadening. This indicates (1) that the Fe emission arises from the supernova ejecta, and (2) that these ejecta are highly asymmetric, since no blueshifted component is found. The S K velocity is consistent with the local LMC ISM, and is likely from swept-up ISM material. These results are consistent with spatial mapping that shows the He-like Fe concentrated in the interior of the remnant and the S tracing the outer shell. The results also show that even with a very small number of counts, direct velocity measurements from Doppler-shifted lines detected in extended objects like supernova remnants are now possible. Thanks to the very low SXS background of similar to 1 event per spectral resolution element per 100 ks, such results are obtainable during short pointed or slew observations with similar instruments. This highlights the power of high-spectral-resolution imaging observations, and demonstrates the new window that has been opened with Hitomi and will be greatly widened with future missions such as the X-ray Astronomy Recovery Mission (XARM) and Athena.
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| 11. |
- Aharonian, Felix, et al.
(författare)
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Hitomi X-ray observation of the pulsar wind nebula G21.5-0.9
- 2018
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Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press (OUP). - 0004-6264 .- 2053-051X. ; 70:3
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Tidskriftsartikel (refereegranskat)abstract
- We present results from the Hitomi X-ray observation of a young composite-type supernova remnant (SNR) G21.5-0.9, whose emission is dominated by the pulsar wind nebula (PWN) contribution. The X-ray spectra in the 0.8-80 keV range obtained with the Soft X-ray Spectrometer (SXS), Soft X-ray Imager, and Hard X-ray Imager (HXI) show a significant break in the continuum as previously found with the NuSTAR observation. After taking into account all known emissions from the SNR other than the PWN itself, we find that the Hitomi spectra can be fitted with a broken power law with photon indices of Gamma(1) = 1.74 +/- 0.02 and Gamma(2) = 2.14 +/- 0.01 below and above the break at 7.1 +/- 0.3 keV, which is significantly lower than the NuSTAR result (similar to 9.0 keV). The spectral break cannot be reproduced by time-dependent particle injection one-zone spectral energy distribution models, which strongly indicates that a more complex emission model is needed, as suggested by recent theoretical models. We also search for narrow emission or absorption lines with the SXS, and perform a timing analysis of PSR J1833-1034 with the HXI and the Soft Gamma-ray Detector. No significant pulsation is found from the pulsar. However, unexpectedly, narrow absorption line features are detected in the SXS data at 4.2345 keV and 9.296 keV with a significance of 3.65 sigma. While the origin of these features is not understood, their mere detection opens up a new field of research and was only possible with the high resolution, sensitivity, and ability to measure extended sources provided by an X-ray microcalorimeter.
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| 12. |
- Aharonian, Felix, et al.
(författare)
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Hitomi X-ray studies of giant radio pulses from the Crab pulsar
- 2018
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Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press (OUP). - 0004-6264 .- 2053-051X. ; 70:2
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Tidskriftsartikel (refereegranskat)abstract
- To search for giant X-ray pulses correlated with the giant radio pulses (GRPs) from the Crab pulsar, we performed a simultaneous observation of the Crab pulsar with the X-ray satellite Hitomi in the 2-300 keV band and the Kashima NICT radio telescope in the 1.4-1.7 GHz band with a net exposure of about 2 ks on 2016 March 25, just before the loss of the Hitomi mission. The timing performance of the Hitomi instruments was confirmed to meet the timing requirement and about 1000 and 100 GRPs were simultaneously observed at the main pulse and inter-pulse phases, respectively, and we found no apparent correlation between the giant radio pulses and the X-ray emission in either the main pulse or inter-pulse phase. All variations are within the 2 sigma fluctuations of the X-ray fluxes at the pulse peaks, and the 3 sigma upper limits of variations of main pulse or inter-pulse GRPs are 22% or 80% of the peak flux in a 0.20 phase width, respectively, in the 2-300 keV band. The values for main pulse or inter-pulse GRPs become 25% or 110%, respectively, when the phase width is restricted to the 0.03 phase. Among the upper limits from the Hitomi satellite, those in the 4.5-10 keV and 70-300 keV bands are obtained for the first time, and those in other bands are consistent with previous reports. Numerically, the upper limits of the main pulse and inter-pulse GRPs in the 0.20 phase width are about (2.4 and 9.3) x 10(-11) erg cm(-2), respectively. No significant variability in pulse profiles implies that the GRPs originated from a local place within the magneto-sphere. Although the number of photon-emitting particles should temporarily increase to account for the brightening of the radio emission, the results do not statistically rule out variations correlated with the GRPs, because the possible X-ray enhancement may appear due to a > 0.02% brightening of the pulse-peak flux under such conditions.
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| 13. |
- Aharonian, Felix, et al.
(författare)
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Measurements of resonant scattering in the Perseus Cluster core with Hitomi SXS
- 2018
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Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press (OUP). - 0004-6264 .- 2053-051X. ; 70:2
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Tidskriftsartikel (refereegranskat)abstract
- Thanks to its high spectral resolution (similar to 5 eV at 6 keV), the Soft X-ray Spectrometer (SXS) on board Hitomi enables us to measure the detailed structure of spatially resolved emission lines from highly ionized ions in galaxy clusters for the first time. In this series of papers, using the SXS we have measured the velocities of gas motions, metallicities and the multi-temperature structure of the gas in the core of the Perseus Cluster. Here, we show that when inferring physical properties from line emissivities in systems like Perseus, the resonant scattering effect should be taken into account. In the Hitomi waveband, resonant scattering mostly affects the Fe XXV He alpha line (w)-the strongest line in the spectrum. The flux measured by Hitomi in this line is suppressed by a factor of similar to 1.3 in the inner similar to 30 kpc, compared to predictions for an optically thin plasma; the suppression decreases with the distance from the center. The w line also appears slightly broader than other lines from the same ion. The observed distortions of the w line flux, shape, and distance dependence are all consistent with the expected effect of the resonant scattering in the Perseus core. By measuring the ratio of fluxes in optically thick (w) and thin (Fe XXV forbidden, He beta, Ly alpha) lines, and comparing these ratios with predictions from Monte Carlo radiative transfer simulations, the velocities of gas motions have been obtained. The results are consistent with the direct measurements of gas velocities from line broadening described elsewhere in this series, although the systematic and statistical uncertainties remain significant. Further improvements in the predictions of line emissivities in plasma models, and deeper observations with future X-ray missions offering similar or better capabilities to the Hitomi SXS, will enable resonant scattering measurements to provide powerful constraints on the amplitude and anisotropy of cluster gas motions.
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| 14. |
- Aharonian, Felix, et al.
(författare)
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Search for thermal X-ray features from the Crab nebula with the Hitomi soft X-ray spectrometer
- 2018
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Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press (OUP). - 0004-6264 .- 2053-051X. ; 70:2
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Tidskriftsartikel (refereegranskat)abstract
- The Crab nebula originated from a core-collapse supernova (SN) explosion observed in 1054 AD. When viewed as a supernova remnant (SNR), it has an anomalously low observed ejecta mass and kinetic energy for an Fe-core-collapse SN. Intensive searches have been made for a massive shell that solves this discrepancy, but none has been detected. An alternative idea is that SN 1054 is an electron-capture (EC) explosion with a lower explosion energy by an order of magnitude than Fe-core-collapse SNe. X-ray imaging searches were performed for the plasma emission from the shell in the Crab outskirts to set a stringent upper limit on the X-ray emitting mass. However, the extreme brightness of the source hampers access to its vicinity. We thus employed spectroscopic technique using the X-ray micro-calorimeter on board the Hitomi satellite. By exploiting its superb energy resolution, we set an upper limit for emission or absorption features from as yet undetected thermal plasma in the 2-12 keV range. We also re-evaluated the existing Chandra and XMM-Newton data. By assembling these results, a new upper limit was obtained for the X-ray plasma mass of less than or similar to 1 M-circle dot for a wide range of assumed shell radius, size, and plasma temperature values both in and out of collisional equilibrium. To compare with the observation, we further performed hydrodynamic simulations of the Crab SNR for two SN models (Fe-core versus EC) under two SN environments (uniform interstellar medium versus progenitor wind). We found that the observed mass limit can be compatible with both SN models if the SN environment has a low density of less than or similar to 0.03 cm(-3) (Fe core) or less than or similar to 0.1 cm(-3) (EC) for the uniform density, or a progenitor wind density somewhat less than that provided by amass loss rate of 10(-5) M-circle dot yr(-1) at 20 km s(-1) for the wind environment.
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| 15. |
- Aharonian, Felix, et al.
(författare)
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Solar abundance ratios of the iron-peak elements in the Perseus cluster
- 2017
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 551:7681, s. 478-
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Tidskriftsartikel (refereegranskat)abstract
- The metal abundance of the hot plasma that permeates galaxy clusters represents the accumulation of heavy elements produced by billions of supernovae(1). Therefore, X-ray spectroscopy of the intracluster medium provides an opportunity to investigate the nature of supernova explosions integrated over cosmic time. In particular, the abundance of the iron-peak elements (chromium, manganese, iron and nickel) is key to understanding how the progenitors of typical type Ia supernovae evolve and explode(2-6). Recent X-ray studies of the intracluster medium found that the abundance ratios of these elements differ substantially from those seen in the Sun(7-11), suggesting differences between the nature of type Ia supernovae in the clusters and in the Milky Way. However, because the K-shell transition lines of chromium and manganese are weak and those of iron and nickel are very close in photon energy, highresolution spectroscopy is required for an accurate determination of the abundances of these elements. Here we report observations of the Perseus cluster, with statistically significant detections of the resonance emission from chromium, manganese and nickel. Our measurements, combined with the latest atomic models, reveal that these elements have near-solar abundance ratios with respect to iron, in contrast to previous claims. Comparison between our results and modern nucleosynthesis calculations(12-14) disfavours the hypothesis that type Ia supernova progenitors are exclusively white dwarfs with masses well below the Chandrasekhar limit (about 1.4 times the mass of the Sun). The observed abundance pattern of the iron-peak elements can be explained by taking into account a combination of near-and sub-Chandrasekhar-mass type Ia supernova systems, adding to the mounting evidence that both progenitor types make a substantial contribution to cosmic chemical enrichment(5,15,16).
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| 16. |
- Aharonian, Felix, et al.
(författare)
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Temperature structure in the Perseus cluster core observed with Hitomi
- 2018
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Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press (OUP). - 0004-6264 .- 2053-051X. ; 70:2
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Tidskriftsartikel (refereegranskat)abstract
- The present paper explains the temperature structure of X-ray emitting plasma in the core of the Perseus cluster based on 1.8-20.0 keV data obtained with the Soft X-ray Spectrometer (SXS) on board the Hitomi Observatory. A series of four observations was carried out, with a total effective exposure time of 338 ks that covered a central region of similar to 7' in diameter. SXS was operated with an energy resolution of similar to 5 eV (full width at half maximum) at 5.9 keV. Not only fine structures of K-shell lines in He-like ions, but also transitions from higher principal quantum numbers were clearly resolved from Si through Fe. That enabled us to perform temperature diagnostics using the line ratios of Si, S, Ar, Ca, and Fe, and to provide the first direct measurement of the excitation temperature and ionization temperature in the Perseus cluster. The observed spectrum is roughly reproduced by a single-temperature thermal plasma model in collisional ionization equilibrium, but detailed line-ratio diagnostics reveal slight deviations from this approximation. In particular, the data exhibit an apparent trend of increasing ionization temperature with the atomic mass, as well as small differences between the ionization and excitation temperatures for Fe, the only element for which both temperatures could be measured. The best-fit two-temperature models suggest a combination of 3 and 5 keV gas, which is consistent with the idea that the observed small deviations from a single-temperature approximation are due to the effects of projecting the known radial temperature gradient in the cluster core along the line of sight. A comparison with the Chandra/ACIS and the XMM-Newton/RGS results, on the other hand, suggests that additional lower-temperature components are present in the intracluster medium (ICM), but not detectable with Hitomi/SXS giving its 1.8-20 keV energy band.
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| 17. |
- Andersson, Kjell, et al.
(författare)
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Connecting Municipal and Regional Level Planning: Analysis and Visualization of Sustainability Indicators in Bergslagen, Sweden
- 2013
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Ingår i: European Planning Studies. - : Informa UK Limited. - 0965-4313 .- 1469-5944. ; 21, s. 1210-1234
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Tidskriftsartikel (refereegranskat)abstract
- Sustainable development as a process towards sustainability requires collaboration among societal actors and stakeholders at multiple levels. A key issue is to provide them with that they have comprehensive and transparent knowledge base representing the state and trends of different dimensions of sustainability. This study addresses the need to analyse and present data of sustainability as a foundation for the sustainable development process within municipalities, and among them. As a case study, we focus on 18 municipalities in the crisis-struck Bergslagen region in Sweden and compare them with 101 surrounding municipalities. Data from 2001 and 2006 on 15 indicators representing ecological, economic and social sustainability criteria were transformed to a common scale through normalization around the median, and summarized. Bergslagen region municipalities performed poorer than the surrounding ones for all dimensions in 2006. The change from 2001 to 2006 was positive for economic and social criteria, while the ecological dimension developed negatively in all municipalities. We stress the need for municipalities to collaborate with each other and other actors both at municipal and regional levels, and to use sustainability indicators as a base for informed planning processes. We propose visualization of indicators using maps to support decision-making and social learning.
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| 18. |
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| 19. |
- Andersson, Kjell, et al.
(författare)
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Green infrastructures and intensive forestry: Need and opportunity for spatial planning in a Swedish rural-urban gradient
- 2013
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 28, s. 143-165
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Tidskriftsartikel (refereegranskat)abstract
- There is a current industrial and societal interest in Europe to further intensify the yield of wood for the forest industry and biomass. At the same time, green infrastructures for ecological and sociocultural values in forest landscapes should be functional. Municipalities have exclusive responsibility for comprehensive planning in Sweden. We modelled the spatial distribution of green infrastructures in terms of three forest types with high ecological values, and three sociotopes with high sociocultural values in 119 municipalities in a ruralurban gradient in Sweden. Forest land without such values should be available for intensive forestry with lower conflict risk. We also estimated the municipalities' potential for physical planning in terms of financial and social capital, and ownership category structure. The area of functional green infrastructures varied considerably among municipalities. Municipalities with a high proportion of functional green infrastructure, thus less available for intensive forestry, were characterised by a stronger tax base, higher population density and lower demographic dependency ratio, and lower proportions of industrial and state forest ownership. We discuss the need for and opportunities of introducing collaborative physical planning to accommodate multiple demands on forest landscapes. We conclude that to accommodate both functional green infrastructures and intensive forestry, a landscape approach including knowledge-based collaboration is needed at multiple-levels of governance and management.
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| 20. |
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| 21. |
- Andersson, Kjell, 1956-2014, et al.
(författare)
-
Limited GIS skills hamper spatial planning for green infrastructures in Sweden
- 2022
-
Ingår i: Geografiska Notiser. - : Geografilärarnas Riksförening. - 0016-724X. ; 80:1, s. 16-35
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The term green infrastructure captures the need to conserve biodiversity and to sustain landscapes’ different ecosystem services. Maintaining green infrastructures through protected areas, management and landscape restoration requires knowledge in geography, spatial data about biophysical, anthropogenic and immaterial values, spatial comprehensive planning, and thus geographical information systems (GIS). To understand land use planning practices and planning education regarding GIS in Sweden we interviewed 43 planners and reviewed 20 planning education programmes. All planners used GIS to look at data but did not carry out spatial analyses of land covers. BSc programmes included more GIS than MSc programmes but very few taught analyses for spatial planning. As key spatial planning actors, municipalities’ barriers and bridges for improved GIS use for collaborative learning about green infrastructures are discussed. A concluding section presents examples of how GIS can support spatial planning for green infrastructures.
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| 22. |
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| 23. |
- Angelstam, Per, et al.
(författare)
-
Evidence-Based Knowledge Versus Negotiated Indicators for Assessment of Ecological Sustainability : The Swedish Forest Stewardship Council Standard as a Case Study
- 2013
-
Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 42:2, s. 229-240
-
Tidskriftsartikel (refereegranskat)abstract
- Assessing ecological sustainability involves monitoring of indicators and comparison of their states with performance targets that are deemed sustainable. First, a normative model was developed centered on evidence-based knowledge about (a) forest composition, structure, and function at multiple scales, and (b) performance targets derived by quantifying the habitat amount in naturally dynamic forests, and as required for presence of populations of specialized focal species. Second, we compared the Forest Stewardship Council (FSC) certification standards' ecological indicators from 1998 and 2010 in Sweden to the normative model using a Specific, Measurable, Accurate, Realistic, and Timebound (SMART) indicator approach. Indicator variables and targets for riparian and aquatic ecosystems were clearly under-represented compared to terrestrial ones. FSC's ecological indicators expanded over time from composition and structure towards function, and from finer to coarser spatial scales. However, SMART indicators were few. Moreover, they poorly reflected quantitative evidence-based knowledge, a consequence of the fact that forest certification mirrors the outcome of a complex social negotiation process.
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| 24. |
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| 25. |
- Angelstam, Per, et al.
(författare)
-
Knowledge production and learning for sustainable forest management on the ground: Pan-European landscapes as a time machine
- 2011
-
Ingår i: Forestry. - : Oxford University Press (OUP). - 0015-752X .- 1464-3626. ; 84, s. 581-596
-
Tidskriftsartikel (refereegranskat)abstract
- While sustainable forest management (SFM) policy processes are well developed, implementation on the ground remains a challenge. Given the diversity of biophysical conditions, economic histories and governance systems on the European continent, regionally and temporally adapted and adaptive solutions are needed for both social and ecological systems. To illustrate this, we apply (1) a biographic forest and woodland history approach to central Sweden's Bergslagen region, where boreal sustained yield forestry was widely applied first and (2) a comparative case study approach using five European landscapes that represent different forest history phases in Scotland, Germany, Ukraine and Russia. Additionally, we illustrate the need to learn from reference landscapes for natural forest and cultural woodland systems such as in economically remote regions in Romania, Russia and on the Iberian Peninsula. We conclude that there is great opportunity for innovative knowledge production about both governance and management for different SFM dimensions based on comparisons among concrete landscapes. In addition, there is a need to develop local place-based social learning processes that are characterized by a focus on a geographical area, commitment to SFM policy visions and collaborative approaches to development that include both ecological and social systems.
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| 26. |
- Angelstam, Per, et al.
(författare)
-
Knowledge Production and Learning for Sustainable Landscapes: Forewords by the Researchers and Stakeholders
- 2013
-
Ingår i: AMBIO: A Journal of the Human Environment. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 42, s. 111-115
-
Tidskriftsartikel (refereegranskat)abstract
- This special issue of AMBIO presents a new approach to sustainability science that goes beyond interdisciplinary research. Using coupled natural and human systems, or landscapes, as multiple case studies in Europe's East and West knowledge production and learning toward transdisciplinary research was applied in Sweden, countries in Central and Eastern Europe, and Russia. First, the research group Forest-Landscape-Society summarizes the research program (2005-2012) behind this special issue of AMBIO and its development to participate in transdisciplinary research. Second, stakeholders at multiple levels provide their views on the new approach presented and reported.
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| 27. |
- Angelstam, Per, et al.
(författare)
-
Knowledge Production and Learning for Sustainable Landscapes: Seven Steps Using Social-Ecological Systems as Laboratories
- 2013
-
Ingår i: AMBIO: A Journal of the Human Environment. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 42, s. 116-128
-
Tidskriftsartikel (refereegranskat)abstract
- There are multiple challenges regarding use and governance of landscapes' goods, functions and intangible values for ecosystem health and human well-being. One group of challenges is to measure and assess principal sustainability dimensions through performance targets, so stakeholders have transparent information about states and trends. Another group is to develop adaptive governance at multiple levels, and management of larger geographical areas across scales. Addressing these challenges, we present a framework for transdisciplinary research using multiple landscapes as place-based case studies that integrates multiple research disciplines and non-academic actors: (1) identify a suite of landscapes, and for each (2) review landscape history, (3) map stakeholders, use and non-use values, products and land use, (4) analyze institutions, policies and the system of governance, (5) measure ecological, economic, social and cultural sustainability, (6) assess sustainability dimensions and governance, and finally (7) make comparisons and synthesize. Collaboration, communication and dissemination are additional core features. We discuss barriers bridges and bridges for applying this approach.
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| 28. |
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| 29. |
- Angelstam, Per, et al.
(författare)
-
Learning about the history of landscape use for the future : consequences for ecological and social systems in Swedish Bergslagen
- 2013
-
Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 42:2, s. 146-159
-
Tidskriftsartikel (refereegranskat)abstract
- Barriers and bridges to implement policies about sustainable development and sustainability commonly depend on the past development of social-ecological systems. Production of metals required integration of use of ore, streams for energy, and wood for bioenergy and construction, as well as of multiple societal actors. Focusing on the Swedish Bergslagen region as a case study we (1) describe the phases of natural resource use triggered by metallurgy, (2) the location and spatial extent of 22 definitions of Bergslagen divided into four zones as a proxy of cumulative pressure on landscapes, and (3) analyze the consequences for natural capital and society. We found clear gradients in industrial activity, stream alteration, and amount of natural forest from the core to the periphery of Bergslagen. Additionally, the legacy of top-down governance is linked to today's poorly diversified business sector and thus municipal vulnerability. Comparing the Bergslagen case study with other similar regions in Russia and Germany, we discuss the usefulness of multiple case studies.
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| 30. |
- Angelstam, Per, et al.
(författare)
-
Measurement, Collaborative Learning and Research for Sustainable Use of Ecosystem Services: Landscape Concepts and Europe as Laboratory
- 2013
-
Ingår i: AMBIO: A Journal of the Human Environment. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 42, s. 129-145
-
Tidskriftsartikel (refereegranskat)abstract
- Policies at multiple levels pronounce the need to encompass both social and ecological systems in governance and management of natural capital in terms of resources and ecosystems. One approach to knowledge production and learning about landscapes as social-ecological systems is to compare multiple case studies consisting of large spaces and places. We first review the landscape concepts' biophysical, anthropogenic, and intangible dimensions. Second, we exemplify how the different landscape concepts can be used to derive measurable variables for different sustainability indicators. Third, we review gradients in the three dimensions of the term landscape on the European continent, and propose to use them for the stratification of multiple case studies of social-ecological systems. We stress the benefits of the landscape concepts to measure sustainability, and how this can improve collaborative learning about development toward sustainability in social-ecological systems. Finally, analyses of multiple landscapes improve the understanding of context for governance and management.
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| 31. |
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| 32. |
- Angelstam, Per, et al.
(författare)
-
Protecting forest areas for biodiversity in Sweden 1991–2010: the policy implementation process and outcomes on the ground
- 2011
-
Ingår i: Silva Fennica. - : Finnish Society of Forest Science. - 0037-5330 .- 2242-4075. ; 45, s. 1111-1133
-
Tidskriftsartikel (refereegranskat)abstract
- Swedish forest and environmental policies imply that forests should be managed so that all naturally occurring species are maintained in viable populations. This requires maintenance of functional networks of representative natural forest and cultural woodland habitats. We first review the policy implementation process regarding protected areas in Sweden 1991-2010, how ecological knowledge was used to formulate interim short-term and strategic long-term biodiversity conservation goals, and the development of a hierarchical spatial planning approach. Second, we present data about the amount of formally protected and voluntarily set aside forest stands, and evaluate how much remains in terms of additional forest protection, conservation management and habitat restoration to achieve forest and environmental policy objectives in the long-term. Third, a case study in central Sweden was made to estimate the functionality of old Scots pine, Norway spruce and deciduous forest habitats, as well as cultural woodland, in different forest regions. Finally, we assess operational biodiversity conservation planning processes. We conclude that Swedish policy pronouncements capture the contemporary knowledge about biodiversity and conservation planning well. However, the existing area of protected and set-aside forests is presently too small and with too poor connectivity. To bridge this gap, spatial planning, management and restoration of habitat, as well as collaboration among forest and conservation planners need to be improved.
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| 33. |
- Angelstam, Per, et al.
(författare)
-
Solving Problems in Social-Ecological Systems : Definition, Practice and Barriers of Transdisciplinary Research
- 2013
-
Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 42:2, s. 254-265
-
Tidskriftsartikel (refereegranskat)abstract
- Translating policies about sustainable development as a social process and sustainability outcomes into the real world of social-ecological systems involves several challenges. Hence, research policies advocate improved innovative problem-solving capacity. One approach is transdisciplinary research that integrates research disciplines, as well as researchers and practitioners. Drawing upon 14 experiences of problem-solving, we used group modeling to map perceived barriers and bridges for researchers' and practitioners' joint knowledge production and learning towards transdisciplinary research. The analysis indicated that the transdisciplinary research process is influenced by (1) the amount of traditional disciplinary formal and informal control, (2) adaptation of project applications to fill the transdisciplinary research agenda, (3) stakeholder participation, and (4) functional team building/development based on self-reflection and experienced leadership. Focusing on implementation of green infrastructure policy as a common denominator for the delivery of ecosystem services and human well-being, we discuss how to diagnose social-ecological systems, and use knowledge production and collaborative learning as treatments.
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| 34. |
- Angelstam, Per, et al.
(författare)
-
Sustainable Bergslagen : a landscape approach initiative in Sweden
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Bergslagen in south-central Sweden is an informal region with a long history of intensive land use. The legacies of than 2000 years of integrated use of ore, forests and water major national and international economic importance now involve several challenges for the maintenance of landscapes. This includes sustainability of rural and urban communities, of green infrastructures for natural capital and human well-being as well as of forests, river basins and mining. In response to this cross-sectoral integration necessary at multiple levels of public, private and civil as well as academia and schools. Landscapes need thus to be viewed as integrated socio-ecological systems. Collaboration and continuous learning among actors and stakeholders are needed for sustainable use and management of landscapes’ goods, services and values. To support this requires (1) data, monitoring and assessment of different aspects of sustainability, (2) continuous knowledge production about material and immaterial landscape values relevant for the management of ecological, economic, social and cultural dimensions, (3) information and communication using both traditional media, as well as (4) through art and culture. the vision to contribute to satisfying these requirements Sustainable Bergslagen initiative emerged gradually since 2004 as a multi-level partnership for sustainable landscapes (www.bergslagen.org). By joining the International Model Forest Network (IMFN), and the network for Long Term Socio-Economic and Ecological Research (LTSER), actors and stakeholders can learn from other regions’ sustainable development processes, and make Bergslagen more visible internationally.
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| 35. |
- Angelstam, Per, et al.
(författare)
-
The Euroscapes network : learning for sustainable landscapes
- 2014
-
Ingår i: Euroscapes Communication. - 2001-5801.
-
Annan publikation (populärvet., debatt m.m.)abstract
- -Sustainable landscapes require evidence-based knowledge about multiple goods, services and values, as well as integrated place-based collaboration among actors and stakeholders at multiple levels. -EUROSCAPES is an international network of researchers, journalists and practitioners that supports sharing of knowledge about how to maintain and develop sustainable landscapes. --Euro... is about the diversity of places in the European continent’s East and West - from the Ural Mountains and Caucasus to the Atlantic Ocean. --...scapes links to the word landscape, which has biophysical, anthropogenic and perceived dimensions. -EUROSCAPES gathers and communicates knowledge using three series of publications: --EUROSCAPES News with short texts and illustrations that can be used by journalists. --EUROSCAPES Communication with popular summaries of peer-reviewed publications and reports. --EUROSCAPES Report with longer peer-reviewed comprehensive text. -EUROSCAPES uses the web site www.euroscapes.org to disseminate these publication series using five themes: People, Places, Practices, Projects, and Publications.
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| 36. |
- Axelsson, Boman, et al.
(författare)
-
Laser-induced incandescence for soot particle size and volume fraction measurements using on-line extinction calibration
- 2001
-
Ingår i: Applied Physics B. - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 72:3, s. 367-372
-
Tidskriftsartikel (refereegranskat)abstract
- A novel technique for two-dimensional measurements of soot volume fraction and particle size has been developed. It is based on a combined measurement of extinction and laser-induced incandescence using Nd:YAG laser wavelengths of 532 nm and 1064 nm. A low-energy laser pulse at 532 nm was used for extinction measurements and was followed by a more intense pulse at 1064 nm, delayed by 15 ns, for LII measurements. The 532-nm beam was split into a signal beam passing the flame and a reference beam, both of which were directed to a dye cell. The resulting fluorescence signals, from which the extinction was deduced, together with the LII signal, were registered on a single CCD detector. Thus the two-dimensional LII image could be converted to a soot volume fraction map through a calibration procedure during the same laser shot. The soot particle sizes were evaluated from the ratio of the temporal LII signals at two gate time positions. The uncertainty in the particle sizing arose mainly from the low signal for small particles at long gate times and the uncertainty in the flame temperature. The technique was applied to a well-characterized premixed flat flame, the soot properties of which had been previously thoroughly investigated.
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| 37. |
- Axelsson, Boman, et al.
(författare)
-
Laser-Induced Incandescence for Soot Particle Size Measurements in Premixed Flat Flames
- 2000
-
Ingår i: Applied Optics. - 2155-3165. ; 39:21, s. 3683-3690
-
Tidskriftsartikel (refereegranskat)abstract
- Measurements of soot properties by means of laser-induced incandescence (LII) and combined scattering–extinction were performed in well-characterized premixed ethylene–air flames. In particular, the possibility of using LII as a tool for quantitative particle sizing was investigated. Particle sizes were evaluated from the temporal decay of the LII signal combined with heat balance modeling of laser-heated particles, and these sizes were compared with the particle sizes deduced from scattering–extinction measurements based on isotropic sphere theory. The correspondence was good early in the soot-formation process but less good at later stages, possibly because aggregation to clusters began to occur. A critical analysis has been made of how uncertainties in different parameters, both experimental and in the model, affect the evaluated particle sizes for LII. A sensitivity analysis of the LII model identified the ambient-flame temperature as a major source of uncertainty in the evaluated particle size, a conclusion that was supported by an analysis based on temporal LII profiles.
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| 38. |
- Axelsson, Erland, et al.
(författare)
-
Psychological treatments for irritable bowel syndrome : a comprehensive systematic review and meta-analysis
- 2023
-
Ingår i: Cognitive Behaviour Therapy. - : Routledge. - 1650-6073 .- 1651-2316. ; 52:6, s. 565-584
-
Forskningsöversikt (refereegranskat)abstract
- A wide range of psychological treatments have been found to reduce the symptoms of irritable bowel syndrome (IBS) but their relative effects are unclear. In this systematic review and meta-analysis, we determined the effects of psychological treatments for IBS, including subtypes of cognitive behavior therapy, versus attention controls. We searched 11 databases (March 2022) for studies of psychological treatments for IBS, reported in journal articles, books, dissertations, and conference abstracts. The resulting database comprised 9 outcome domains from 118 studies published in 1983–2022. Using data from 62 studies and 6496 participants, we estimated the effect of treatment type on improvement in composite IBS severity using random-effects meta-regression. In comparison with the attention controls, there was a significant added effect of exposure therapy (g = 0.52, 95% CI = 0.17–0.88) and hypnotherapy (g = 0.36, 95% CI = 0.06–0.67) when controlling for the pre- to post-assessment duration. When additional potential confounders were included, exposure therapy but not hypnotherapy retained a significant added effect. Effects were also larger with a longer duration, individual treatment, questionnaire (non-diary) outcomes, and recruitment outside of routine care. Heterogeneity was substantial. Tentatively, exposure therapy appears to be a particularly promising treatment for IBS. More direct comparisons in randomized controlled trials are needed. OSF.io identifier: 5yh9a.
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| 39. |
- Axelsson, Eva, et al.
(författare)
-
Recessiveness and Dominance in Barley Mutants Deficient in Mg-Chelatase Subunit D, an AAA Protein Involved in Chlorophyll Biosynthesis.
- 2006
-
Ingår i: Plant Cell. - : Oxford University Press (OUP). - 1040-4651 .- 1532-298X. ; 18:12, s. 3606-3616
-
Tidskriftsartikel (refereegranskat)abstract
- Mg-chelatase catalyzes the insertion of Mg2+ into protoporphyrin IX at the first committed step of the chlorophyll biosynthetic pathway. It consists of three subunits: I, D, and H. The I subunit belongs to the AAA protein superfamily ( ATPases associated with various cellular activities) that is known to form hexameric ring structures in an ATP-dependant fashion. Dominant mutations in the I subunit revealed that it functions in a cooperative manner. We demonstrated that the D subunit forms ATP-independent oligomeric structures and should also be classified as an AAA protein. Furthermore, we addressed the question of cooperativity of the D subunit with barley (Hordeum vulgare) mutant analyses. The recessive behavior in vivo was explained by the absence of mutant proteins in the barley cell. Analogous mutations in Rhodobacter capsulatus and the resulting D proteins were studied in vitro. Mixtures of wild-type and mutant R. capsulatus D subunits showed a lower activity compared with wild-type subunits alone. Thus, the mutant D subunits displayed dominant behavior in vitro, revealing cooperativity between the D subunits in the oligomeric state. We propose a model where the D oligomer forms a platform for the stepwise assembly of the I subunits. The cooperative behavior suggests that the D oligomer takes an active part in the conformational dynamics between the subunits of the enzyme.
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| 40. |
- Axelsson, Jimmy, et al.
(författare)
-
Ejection fraction in left bundle branch block is disproportionately reduced in relation to amount of myocardial scar
- 2018
-
Ingår i: Journal of Electrocardiology. - : Elsevier BV. - 0022-0736 .- 1532-8430. ; 51:6, s. 1071-1076
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: The relationship between left ventricular (LV) ejection fraction (EF) and LV myocardial scar can identify potentially reversible causes of LV dysfunction. Left bundle branch block (LBBB) alters the electrical and mechanical activation of the LV. We hypothesized that the relationship between LVEF and scar extent is different in LBBB compared to controls. Methods: We compared the relationship between LVEF and scar burden between patients with LBBB and scar (n = 83), and patients with chronic ischemic heart disease and scar but no electrocardiographic conduction abnormality (controls, n = 90), who had undergone cardiovascular magnetic resonance (CMR) imaging at one of three centers. LVEF (%) was measured in CMR cine images. Scar burden was quantified by CMR late gadolinium enhancement (LGE) and expressed as % of LV mass (%LVM). Maximum possible LVEF (LVEFmax) was defined as the function describing the hypotenuse in the LVEF versus myocardial scar extent scatter plot. Dysfunction index was defined as LVEFmax derived from the control cohort minus the measured LVEF. Results: Compared to controls with scar, LBBB with scar had a lower LVEF (median [interquartile range] 27 [19–38] vs 36 [25–50] %, p < 0.001), smaller scar (4 [1–9] vs 11 [6–20] %LVM, p < 0.001), and greater dysfunction index (39 [30–52] vs 21 [12–35] % points, p < 0.001). Conclusions: Among LBBB patients referred for CMR, LVEF is disproportionately reduced in relation to the amount of scar. Dyssynchrony in LBBB may thus impair compensation for loss of contractile myocardium.
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| 41. |
- Axelsson, Magnus A. B., et al.
(författare)
-
Retrospective identification of new psychoactive substances in patient samples submitted for clinical drug analysis
- 2022
-
Ingår i: Basic & Clinical Pharmacology & Toxicology. - : Wiley. - 1742-7835 .- 1742-7843. ; 131:5, s. 420-434
-
Tidskriftsartikel (refereegranskat)abstract
- New psychoactive substances (NPS) are life threatening through unpredictable toxicity and limited analytical options for clinicians. We present the retrospective identification of NPS in raw data from a liquid chromatography-high resolution mass spectrometry (LC-HRMS)-based multidrug panel analysis on 14 367 clinical oral fluid samples requested during 2019 mainly by psychiatric and addiction care clinics. Retrospectively analysed NPS included 48 notified originally in 2019 by the European Union Early Warning System (EU EWS) and 28 frequently reported in Sweden. Of 88 included NPS, 34 (mitragynine, flualprazolam, 3F/4F-α-P(i)HP, etizolam, 4F-MDMB-BINACA, cyproheptadine, 5F-MDMB-PICA, isotonitazene, isohexedrone, MDPEP, N-ethylpentedrone, tianeptine, flubromazolam, 4′-methylhexedrone, α-P(i)HP, eutylone, mephedrone, N-ethylhexedrone, 5F-MDMB-PINACA, ADB-BUTINACA, 3-methoxy PCP, 4F-furanylfentanyl, 4F-isobuturylfentanyl, acrylfentanyl, furanylfentanyl, clonazolam, norfludiazepam, 3F-phenmetrazine, 3-MMC, 4-methylpentedrone, BMDP, ethylphenidate, methylone and α-PVP) were identified as 219 findings in 84 patients. Eight NPS notified in 2019 were identified, five before EWS release. NPS occurred in 1.20% of all samples and 1.53% of samples containing traditional drugs, and in 1.87% of all patients and 2.88% of patients using traditional drugs. NPS use was more common in men and polydrug users. Legal (not scheduled) NPS were more used than comparable illegal ones. Retrospective identification could be useful when prioritizing NPS for clinical routine analysis and when studying NPS epidemiology. © 2022 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society). Published by John Wiley & Sons Ltd.
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| 42. |
- Axelsson, Robert, et al.
(författare)
-
Evaluation of Multi-level Social Learning for Sustainable Landscapes : Perspective of a Development Initiative in Bergslagen, Sweden
- 2013
-
Ingår i: Ambio. - : Springer Netherlands. - 0044-7447 .- 1654-7209. ; 42:2, s. 241-253
-
Tidskriftsartikel (refereegranskat)abstract
- To implement policies about sustainable landscapes and rural development necessitates social learning about states and trends of sustainability indicators, norms that define sustainability, and adaptive multi-level governance. We evaluate the extent to which social learning at multiple governance levels for sustainable landscapes occur in 18 local development initiatives in the network of Sustainable Bergslagen in Sweden. We mapped activities over time, and interviewed key actors in the network about social learning. While activities resulted in exchange of experiences and some local solutions, a major challenge was to secure systematic social learning and make new knowledge explicit at multiple levels. None of the development initiatives used a systematic approach to secure social learning, and sustainability assessments were not made systematically. We discuss how social learning can be improved, and how a learning network of development initiatives could be realized.
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| 43. |
- Axelsson, Robert
(författare)
-
Integrative Research and Transdisciplinary Knowledge Production: A Review of Barriers and Bridges
- 2010
-
Ingår i: Journal of Landscape Ecology. - : Walter de Gruyter GmbH. - 1803-2427 .- 1805-4196. ; 3, s. 14-40
-
Tidskriftsartikel (refereegranskat)abstract
- Contemporary policies about use of natural resources clearly pronounce sustainable development towards the goal sustainability as a focal objective. A key challenge for research is to support improvements and management by evaluation of sustainability policy implementation, i.e. outcomes on the ground and the social process in actual landscapes. However, while a landscape consists of integrated social and ecological subsystems and should thus be treated as a holistic unit or system, most research and postgraduate training is disciplinary. This means that very few researchers are equipped to solve problems or contribute to solutions in the non-academic world. There is thus a need for universities to learn integrative (interdisciplinary and transdisciplinary) research and knowledge production that meets complex challenges related to sustainable development and sustainability issues as for example management and governance of natural resources. In this paper I review the background, concepts and the barriers and bridges to integrative research and knowledge production. As a base for evaluation and development of integrative research projects I propose a normative model for integrative knowledge production processes. This was done through a literature review and a study of an integrative research project. I discuss how transdisciplinary research about landscapes and to solve complex sustainability issues can be designed, viz. (1) there is a need for a common understanding of different types of integrative research, (2) an outspoken aim to develop socially robust knowledge, (3) a model for transdisciplinary collaborative learning processes, and (4) a funding scheme that include academic and non-academic participants and matches the long process of partnership building during the full knowledge production process, from problem identification/definition to an improvement or a management solution.
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| 44. |
|
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| 45. |
- Axelsson, Robert, et al.
(författare)
-
Social and Cultural Sustainability: Criteria, Indicators, Verifier Variables for Measurement and Maps for Visualization to Support Planning
- 2013
-
Ingår i: AMBIO: A Journal of the Human Environment. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 42, s. 215-228
-
Tidskriftsartikel (refereegranskat)abstract
- Policies on economic use of natural resources require considerations to social and cultural values. In order to make those concrete in a planning context, this paper aims to interpret social and cultural criteria, identify indicators, match these with verifier variables and visualize them on maps. Indicators were selected from a review of scholarly work and natural resource policies, and then matched with verifier variables available for Sweden's 290 municipalities. Maps of the spatial distribution of four social and four cultural verifier variables were then produced. Consideration of social and cultural values in the studied natural resource use sectors was limited. The spatial distribution of the verifier variables exhibited a general divide between northwest and south Sweden, and regional rural and urban areas. We conclude that it is possible to identify indicators and match them with verifier variables to support inclusion of social and cultural values in planning.
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| 46. |
- Axelsson, Robert, et al.
(författare)
-
Sustainable Development and Sustainability: Landscape Approach as a Practical Interpretation of Principles and Implementation Concepts
- 2011
-
Ingår i: Journal of Landscape Ecology. - : Walter de Gruyter GmbH. - 1803-2427 .- 1805-4196. ; 4, s. 5-30
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Tidskriftsartikel (refereegranskat)abstract
- The situation for governors and managers of natural resources has increased in complexity. Previously it was enough to sustain the yields of wood, food and energy. Today, maintenance of ecosystem services, conservation of biodiversity, rural development and human wellbeing are new additional objectives. At the same time there are new risks and uncertainties linked to climate change, economic globalisation, energy security and water supply. Consequently, adaptive and holistic research, governance and management are needed. Landscape is a concept and framework that can be used as an approach to enhance implementation of policies about sustainable development as a societal process and sustainability as outcomes on the ground. For our analysis to define the landscape approach we used a hierarchical framework consisting of principles, concepts and initiatives; and included three principles defining SD and sustainability and five international concepts to analyze its implementation for our analysis to define landscape approach. We propose a practical operationalization that consists of five core attributes, (1) a sufficiently large area that matches management requirements and challenges to deliver desired goods, services and values, (2) multi-level and multi-sector stakeholder collaboration that promotes sustainable development as a social process, (3) commitment to and understanding of sustainability as an aim among stakeholders, (4) integrative knowledge production, and (5) sharing of experience, results and information, to develop local or tacit to general or explicit knowledge. Finally, we discuss the need for integrative research to study landscape approach concepts and what local initiatives using different concepts deliver on the ground.
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| 47. |
- Axelsson, Robert, et al.
(författare)
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The Challenge of Transdisciplinary Research : A Case Study of Learning by Evaluation for Sustainable Transport Infrastructures
- 2020
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 12:17, s. 1-24
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Tidskriftsartikel (refereegranskat)abstract
- While transdisciplinary (TD) research is desired in order to solve real world sustainability issues, this may be challenging for both academic and non-academic participants. Supporting learning through evaluation, we analyzed a project aiming at sustainable transport infrastructures. After developing a TD research framework as a benchmark, two external independent evaluators interviewed all project researchers, representatives for end-users, and donors. The evaluators compared results with the framework, and evaluators and participants critically reflected on the results together. There were three inconsistencies relative to the framework: (1) limited understanding of TD research among project management, end-users, and most of the researchers; (2) no structured learning process among end-users; instead, they expressed very diverse opinions about what they expected from the project; (3) project leaders had limited understanding of the special challenges of TD research, did not fully understand the status of the project's social system, and thus did not act as facilitators of the required collaborative learning process. Non-academic participants saw themselves as customers and not as partners in the knowledge production process. We conclude that TD problem-solving research requires much time and needs facilitation and training. A preparatory phase with a lower level of funding would be helpful in preparing for TD processes.
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| 48. |
- Axelsson, Robert, et al.
(författare)
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Uneven-aged forest management in boreal Sweden: local forestry stakeholders' perceptions of different sustainability dimensions
- 2011
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Ingår i: Forestry. - : Oxford University Press (OUP). - 0015-752X .- 1464-3626. ; 84, s. 567-579
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Tidskriftsartikel (refereegranskat)abstract
- To implement policies on sustainable forest management (SFM), there is a need to satisfy economical, ecological and socio-cultural sustainability objectives. Due to a long history of sustained yield wood production to satisfy the needs of the forest industry, clearfelling management systems are used in similar to 96 per cent of managed forests in Sweden. To satisfy the intentions of contemporary forest and land use policies, uneven-aged forest management systems as a complement are currently debated. We interviewed local forestry stakeholders in the Swedish boreal forest region's north and south about their views on and attitudes towards different forest management systems' contribution to SFM. Most stakeholders were generally negative to the use of uneven-aged system for sustained yield wood production but saw advantages for ecological and socio-cultural dimensions of SFM. To encourage the use of even-aged cohort and uneven-aged systems to satisfy all dimensions of SFM, there is a need for improved communication, education and public awareness. This could ultimately lead to a more constructive and less heated debate. In addition, there is a need of more empirically based knowledge about uneven-aged and cohort forest management systems' pros and cons when it comes to satisfying economical, ecological and socio-cultural objectives.
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| 49. |
- Axelsson, Stefan, et al.
(författare)
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Detecting Defects with an Interactive Code Review Tool Based on Visualisation and Machine Learning
- 2009
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Konferensbidrag (refereegranskat)abstract
- Code review is often suggested as a means of improving code quality. Since humans are poor at repetitive tasks, some form of tool support is valuable. To that end we developed a prototype tool to illustrate the novel idea of applying machine learning (based on Normalised Compression Distance) to the problem of static analysis of source code. Since this tool learns by example, it is rivially programmer adaptable. As machine learning algorithms are notoriously difficult to understand operationally (they are opaque) we applied information visualisation to the results of the learner. In order to validate the approach we applied the prototype to source code from the open-source project Samba and from an industrial, telecom software system. Our results showed that the tool did indeed correctly find and classify problematic sections of code based on training examples.
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| 50. |
- Blicharska, Malgorzata, 1979-, et al.
(författare)
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Road, forestry and regional planners’ work for biodiversity conservation and public participation : a case study in Poland’s hotspots regions
- 2011
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Ingår i: Journal of Environmental Planning and Management. - : Informa UK Limited. - 0964-0568 .- 1360-0559. ; 54:10, s. 1373-1395
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Tidskriftsartikel (refereegranskat)abstract
- We studied how regional, road and forestry planning sectors work to implement policies about biodiversity conservation and public participation. Evaluations were based on a normative model for planning derived from the existing international policies and relevant literature. Key planning actors were then interviewed with regard to their understanding of biodiversity and participation policies as well as ability to act and willingness to implement them. The results indicate several gaps in planning processes, for example, insufficient knowledge about biodiversity conservation and participation, limited resources and tools for planning of functional habitat networks and collaboration, poor connections between local and regional planning, and weakly developed public participation. The main problem for effective policy implementation seems to be related to planners' ability to act, which indicates that relatively low priority was given to provide resources for biodiversity conservation and public participation by the relevant units. We discuss our findings in relation to the implementation of environmental policies in the new EU countries of Eastern and Central Europe.
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