| 1. |
- Arvizu, Dan, et al.
(författare)
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Technical Summary
- 2011
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Ingår i: IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation.
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Bokkapitel (refereegranskat)
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| 2. |
- del Río, Miren, et al.
(författare)
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Emerging stability of forest productivity by mixing two species buffers temperature destabilizing effect
- 2022
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Ingår i: Journal of Applied Ecology. - : John Wiley & Sons. - 0021-8901 .- 1365-2664. ; 59:11, s. 2730-2741
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Tidskriftsartikel (refereegranskat)abstract
- The increasing disturbances in monocultures around the world are testimony to their instability under global change. Many studies have claimed that temporal stability of productivity increases with species richness, although the ecological fundamentals have mainly been investigated through diversity experiments. To adequately manage forest ecosystems, it is necessary to have a comprehensive understanding of the effect of mixing species on the temporal stability of productivity and the way in which it is influenced by climate conditions across large geographical areas. Here, we used a unique dataset of 261 stands combining pure and two-species mixtures of four relevant tree species over a wide range of climate conditions in Europe to examine the effect of species mixing on the level and temporal stability of productivity. Structural equation modelling was employed to further explore the direct and indirect influence of climate, overyielding, species asynchrony and additive effect (i.e. temporal stability expected from the species growth in monospecific stands) on temporal stability in mixed forests. We showed that by adding only one tree species to monocultures, the level (overyielding: +6%) and stability (temporal stability: +12%) of stand growth increased significantly. We identified the key effect of temperature on destabilizing stand growth, which may be mitigated by mixing species. We further confirmed asynchrony as the main driver of temporal stability in mixed stands, through both the additive effect and species interactions, which modify between-species asynchrony in mixtures in comparison to monocultures. Synthesis and applications. This study highlights the emergent properties associated with mixing two species, which result in resource efficient and temporally stable production systems. We reveal the negative impact of mean temperature on temporal stability of forest productivity and how the stabilizing effect of mixing two species can counterbalance this impact. The overyielding and temporal stability of growth addressed in this paper are essential for ecosystem services closely linked with the level and rhythm of forest growth. Our results underline that mixing two species can be a realistic and effective nature-based climate solution, which could contribute towards meeting EU climate target policies.
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| 3. |
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| 4. |
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| 5. |
- Lilja, Mirjam, 1981-, et al.
(författare)
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Drug loading and release of Tobramycin from Hydroxyapatite coated fixation pins
- 2013
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Ingår i: Journal of materials science. Materials in medicine. - : Springer Science and Business Media LLC. - 0957-4530 .- 1573-4838. ; 24:9, s. 2265-2274
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Tidskriftsartikel (refereegranskat)abstract
- This paper evaluates the loading and release properties of Tobramycin incorporated by adsorptive loading from a solution into plasma sprayed and biomimetically coated Hydroxyapatite (HA) fixation pins. The aim of this study is to contribute towards designing a functional implant surface offering local release of the antibiotic agent to prevent post-surgical infections. Cathodic arc deposition is used to coat stainless steel fixation pins with a bioactive, anatase phase dominated, TiO2 coating onto which a HA layer is grown biomimetically. The loading and release properties are evaluated by studying the subsequent release of Tobramycin using high performance liquid chromatography and correlated to the differences in HA coating microstructure and the physical conditions under loading. The results from these studies show that a dual loading strategy consisting of a solution temperature of 90 °C and a pressure of 6 bar during a loading time of 5 min release a sufficient amount of Tobramycin to guarantee the inhibition of Staphylococcus aureus up to 2 days for plasma sprayed HA coatings and for 8 days for biomimetic coatings. The present study emphasizes the advantages of the nanoporous structure of biomimetically deposited HA over the more dense structure of plasma sprayed HA coatings in terms of antibiotic incorporation and subsequent sustained release and provides a valuable outline for the design of implant surfaces aiming for a fast-loading and controlled, local drug administration.
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| 6. |
- Lilja, Mirjam, 1981-, et al.
(författare)
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Impact of Biomechanical Forces on Antibiotics Release Kinetics from Hydroxyapatite Coated Surgical Fixation Pins
- 2013
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Ingår i: Journal of Biomaterials and Nanobiotechnology. - : Scientific Research Publishing, Inc.. - 2158-7027 .- 2158-7043. ; 4:4, s. 343-350
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Tidskriftsartikel (refereegranskat)abstract
- This work investigates the impact of biomechanical wear and abrasion on the antibiotic release profiles of hydroxyapa-tite (HA) coated fixation pins during their insertion into synthetic bone. Stainless steel fixation pins are coated with crystalline TiO2 by cathodic arc evaporation forming the bioactive layer for biomimetic deposition of Tobramycin con-taining HA. Tobramycin is either introduced by co-precipitation during HA formation or by adsorption-loading after HA deposition. The samples containing antibiotics are inserted into bone mimicking polyethylene foam after which the drug release is monitored using high performance liquid chromatography. This analysis shows that HA coating wear and delamination significantly decrease the amount of drug released during initial burst, but only marginally influence the sustained release period. Spalled coating fragments are found to remain within the synthetic bone material structure. The presence of HA within this structure supports the assumption that the local release of Tobramycin is not only ex-pected to eliminate bacteria growth directly at the pin interface but as well at some distance from the implant. Further-more, no negative effect of gamma sterilization could be observed on the drug release profile. Overall, the observed results demonstrate the feasibility of a multifunctional implant coating that is simultaneously able to locally deliver clinically relevant doses of antibiotics and an HA coating capable of promoting osteoconduction. This is a potentially promising step toward orthopaedic devices that combine good fixation with the ability to treat and prevent post-surgical infections.
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| 7. |
- Pretzsch, Hans, et al.
(författare)
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With increasing site quality asymmetric competition and mortality reduces Scots pine (Pinus sylvestris L.) stand structuring across Europe
- 2022
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Ingår i: Forest Ecology and Management. - : Elsevier. - 0378-1127 .- 1872-7042. ; 520
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Tidskriftsartikel (refereegranskat)abstract
- Heterogeneity of structure can increase mechanical stability, stress resistance and resilience, biodiversity and many other functions and services of forest stands. That is why many silvicultural measures aim at enhancing structural diversity. However, the effectiveness and potential of structuring may depend on the site conditions. Here, we revealed how the stand structure is determined by site quality and results from site-dependent partitioning of growth and mortality among the trees. We based our study on 90 mature, even-aged, fully stocked monocultures of Scots pine (Pinus sylvestris L.) sampled in 21 countries along a productivity gradient across Europe. A mini-simulation study further analyzed the site-dependency of the interplay between growth and mortality and the resulting stand structure. The overarching hypothesis was that the stand structure changes with site quality and results from the site-dependent asymmetry of competition and mortality.First, we show that Scots pine stands structure across Europe become more homogeneous with increasing site quality. The coefficient of variation and Gini coefficient of stem diameter and tree height continuously decreased, whereas Stand Density Index and stand basal area increased with site index.Second, we reveal a site-dependency of the growth distribution among the trees and the mortality. With increasing site index, the asymmetry of both competition and growth distribution increased and suggested, at first glance, an increase in stand heterogeneity. However, with increasing site index, mortality eliminates mainly small instead of all-sized trees, cancels the size variation and reduces the structural heterogeneity.Third, we modelled the site-dependent interplay between growth partitioning and mortality. By scenario runs for different site conditions, we can show how the site-dependent structure at the stand level emerges from the asymmetric competition and mortality at the tree level and how the interplay changes with increasing site quality across Europe.Our most interesting finding was that the growth partitioning became more asymmetric and structuring with increasing site quality, but that the mortality eliminated predominantly small trees, reduced their size variation and thus reversed the impact of site quality on the structure. Finally, the reverse effects of mode of growth partitioning and mortality on the stand structure resulted in the highest size variation on poor sites and decreased structural heterogeneity with increasing site quality. Since our results indicate where heterogeneous structures need silviculture interventions and where they emerge naturally, we conclude that these findings may improve system understanding and modelling and guide forest management aiming at structurally rich forests.
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| 8. |
- Sterner, Thomas, 1952, et al.
(författare)
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Funding Inclusive Green Transition through Greenhouse Gas Pricing : Carbon Pricing
- 2020
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Ingår i: ifo DICE Report. - 2511-7815. ; 18:1, s. 3-8
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Tidskriftsartikel (refereegranskat)abstract
- 2015 was a special year. During a few months the political stars aligned and made it possible for the international community to agree on the Agenda 2030 for Sustainable Development and the Paris Agreement to limit global warming. Now the signatories need to find ways to implement these agreements, which not only imply a deep decarbonization of the economy but must also meet the Sustainable Development Goals. In this article we discuss the importance of pricing greenhouse gas (GHG) emissions2 to make this happen. Climate abatement is a truly global public good and so we actually have to have a functioning policy in all countries. Our interest is thus on pricing in all countries but in particular the developing countries that are bigger and most crucial to the struggle for a green transition.
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| 9. |
- Sörensen, Jan Henrik, et al.
(författare)
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Biomechanical and Antibacterial Properties of Tobramycin Loaded Hydroxyapatite Coated Fixation Pins
- 2014
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Ingår i: Journal of Biomedical Materials Research. Part B - Applied biomaterials. - : Wiley. - 1552-4973 .- 1552-4981. ; 102:7, s. 1381-1392
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Tidskriftsartikel (refereegranskat)abstract
- The present study investigates the use of nanoporous, biomimetic hydroxyapatite (HA) coatings deposited on TiO2 coated fixation pins as functional implant surfaces for the local release of Tobramycin in order to prevent bacterial colonization. The impact of HA-coating thickness, coating morphology and biomechanical forces during insertion into synthetic bone on the drug loading and release properties are analyzed. The coatings are shown to exhibit bactericidal effects against Staphylococcus aureus in agar medium for a duration of 6 days after loading by adsorption with Tobramycin for only 5 min at elevated temperature and pressure. Furthermore, high performance liquid chromatography analysis shows a drug release in phosphate buffered saline for 8 days with antibiotic concentration remaining above the minimal inhibitory concentration for S. aureus during the entire release period. Biomechanical insertion tests into synthetic bone and conventional scratch testing demonstrate adhesive strength at the HA/TiO2 interface. Biocompatibility is verified by cell viability tests. Outgrowth endothelial cells, as well as primary osteoblasts, are viable and firmly attached to both HA and TiO2 surfaces. The results presented are encouraging and support the concept of functional HA coatings as local drug delivery vehicles for biomedical applications to treat as well as to prevent post-surgical infections.
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| 10. |
- Sörensen, Jan Henrik, et al.
(författare)
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Biomimetic Hydroxyapatite Coated Titanium Screws Demonstrate Rapid Implant Stabilization and Safe Removal In-Vivo
- 2015
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Ingår i: Journal of Biomaterials and Nanobiotechnology. - : Scientific Research Publishing, Inc.. - 2158-7027 .- 2158-7043. ; 6, s. 20-35
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Tidskriftsartikel (refereegranskat)abstract
- The early fixation of bone screws after surgical implantation still remains a challenge in the fieldof traumatology. Whilst hydroxyapatite (HA) coatings are known to enhance the fixation of implants;their removal at a later time-point may be problematic. An HA coating has been developedto demonstrate that both implant fixation and safe removal are feasible in the same design. Accordinglythe aim of this study was to compare the in-vivo performance of thin biomimetic HA coatedtitanium screws to uncoated counterparts used as control after bilateral implantation in the femoralcondyle of 36 New Zealand White Rabbits. The screws were analysed macroscopically, byhistology, micro-CT and biomechanically at both two and six weeks post-implantation. The HAcoated screws demonstrated excellent biocompatibility. At two weeks the HA coated screws demonstrateda significant increase in removal torque values as well as a strong trend towards higherpull-out forces. In addition histology confirmed a higher degree of osseointegration and directbone to implant contact. At six weeks no difference in pull-out force and removal torque could bedetected. SEM images confirmed the absence of any residual HA coating indicating a fast coatingdegradation in-vivo. The low level of removal torque after full osseointegration at 6 weeks supportsthe feasibility of safe and easy removal of the implant. The HA coating under study appearsto offer a unique characteristic of enhanced fixation with a minimal increase in removal torqueafter full osseointegration. This may be of value in clinical applications where it is necessary toassure both screw fixation and later removal.
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