| 1. |
- Lewin, Harris A., et al.
(författare)
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The Earth BioGenome Project 2020 : Starting the clock
- 2022
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences (PNAS). - 0027-8424 .- 1091-6490. ; 119:4
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Jahnke, T., et al.
(författare)
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Inner-Shell-Ionization-Induced Femtosecond Structural Dynamics of Water Molecules Imaged at an X-Ray Free-Electron Laser
- 2021
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Ingår i: Physical Review X. - : American Physical Society. - 2160-3308. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- The ultrafast structural dynamics of water following inner-shell ionization is a crucial issue in high-energy radiation chemistry. We have exposed isolated water molecules to a short x-ray pulse from a free-electron laser and detected momenta of all produced ions in coincidence. By combining experimental results and theoretical modeling, we can image dissociation dynamics of individual molecules in unprecedented detail. We reveal significant molecular structural dynamics in H2O2+, such as asymmetric deformation and bond-angle opening, leading to two-body or three-body fragmentation on a timescale of a few femtoseconds. We thus reconstruct several snapshots of structural dynamics at different time intervals, which highlight dynamical patterns that are relevant as initiating steps of subsequent radiation-damage processes.
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| 3. |
- Kitchener, A.C., et al.
(författare)
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Systematics, evolution and genetics of bears
- 2020
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Ingår i: <em>Bears of the World: Ecology, Conservation, and Management</em>. - Cambridge, UK : Cambridge University Press. ; , s. 3-20
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Bokkapitel (refereegranskat)
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| 4. |
- Remme, Roy P., et al.
(författare)
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Aligning nature-based solutions with ecosystem services in the urban century
- 2024
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Ingår i: Ecosystem Services. - 2212-0416. ; 66
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Tidskriftsartikel (refereegranskat)abstract
- In an increasingly urbanized world, the concepts of ecosystem services and nature-based solutions can help tackle grand challenges. However, ambiguity in their definitions and in the relationship between the two concepts complicates comprehensive research efforts as well as their effective application in policy and planning in urban systems. This paper presents a framework to clarify and explicitly relate the two concepts, enhancing their applicability in the management of urban challenges. Within the framework, addressing urban challenges serves as the starting point for the development and implementation of nature-based solutions. Nature-based solutions alter the flows of ecosystem services that are produced by an ecosystem by altering the performance of the ecosystem or by changing how people engage with the ecosystem. This results both in changes in the target ecosystem services, as well as non-targeted ecosystem services, leading to benefits. Using two illustrative case studies, we show how the framework can be applied to two urban challenges that are expected to increase in intensity in cities across the world: stormwater management and urban heat stress. Moreover, we highlight key research topics that will benefit from more integrated use of nature-based solutions and ecosystem services. The framework helps emphasize co-benefits, and can be used to help make co-benefits and multifunctionality explicit in urban decision-making and planning processes.
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| 5. |
- Hailer, Frank, et al.
(författare)
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Nuclear Genomic Sequences Reveal that Polar Bears Are an Old and Distinct Bear Lineage
- 2012
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 336:6079, s. 344-347
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies have shown that the polar bear matriline (mitochondrial DNA) evolved from a brown bear lineage since the late Pleistocene, potentially indicating rapid speciation and adaption to arctic conditions. Here, we present a high-resolution data set from multiple independent loci across the nuclear genomes of a broad sample of polar, brown, and black bears. Bayesian coalescent analyses place polar bears outside the brown bear clade and date the divergence much earlier, in the middle Pleistocene, about 600 (338 to 934) thousand years ago. This provides more time for polar bear evolution and confirms previous suggestions that polar bears carry introgressed brown bear mitochondrial DNA due to past hybridization. Our results highlight that multilocus genomic analyses are crucial for an accurate understanding of evolutionary history.
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| 6. |
- Hailer, F., et al.
(författare)
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Response to comment on "Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage"
- 2013
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 340:6127, s. 1522-b
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Tidskriftsartikel (refereegranskat)abstract
- Nakagome et al. reanalyzed some of our data and assert that we cannot refute the mitochondrial DNA-based scenario for polar bear evolution. Their single-locus test statistic is strongly affected by introgression and incomplete lineage sorting, whereas our multilocus approaches are better suited to recover the true species relationships. Indeed, our sister-lineage model receives high support in a Bayesian model comparison.
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| 7. |
- Holgerson, Meredith A., et al.
(författare)
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Classifying Mixing Regimes in Ponds and Shallow Lakes
- 2022
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Ingår i: Water resources research. - : John Wiley & Sons. - 0043-1397 .- 1944-7973. ; 58:7
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Tidskriftsartikel (refereegranskat)abstract
- Lakes are classified by thermal mixing regimes, with shallow waterbodies historically categorized as continuously mixing systems. Yet, recent studies demonstrate extended summertime stratification in ponds, underscoring the need to reassess thermal classifications for shallow waterbodies. In this study, we examined the summertime thermal dynamics of 34 ponds and shallow lakes across temperate North America and Europe to categorize and identify the drivers of different mixing regimes. We identified three mixing regimes: rarely (n = 18), intermittently (n = 10), and often (n = 6) mixed, where waterbodies mixed an average of 2%, 26%, and 75% of the study period, respectively. Waterbodies in the often mixed category were larger (≥4.17 ha) and stratification weakened with increased wind shear stress, characteristic of “shallow lakes.” In contrast, smaller waterbodies, or “ponds,” mixed less frequently, and stratification strengthened with increased shortwave radiation. Shallow ponds (<0.74 m) mixed intermittently, with daytime stratification often breaking down overnight due to convective cooling. Ponds ≥0.74 m deep were rarely or never mixed, likely due to limited wind energy relative to the larger density gradients associated with slightly deeper water columns. Precipitation events weakened stratification, even causing short-term mixing (hours to days) in some sites. By examining a broad set of shallow waterbodies, we show that mixing regimes are highly sensitive to very small differences in size and depth, with potential implications for ecological and biogeochemical processes. Ultimately, we propose a new framework to characterize the variable mixing regimes of ponds and shallow lakes.
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| 8. |
- Janke, H. P., et al.
(författare)
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Bioinspired coupled helical coils for soft tissue engineering of tubular structures : Improved mechanical behavior of tubular collagen type I templates
- 2017
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Ingår i: Acta Biomaterialia. - : ELSEVIER SCI LTD. - 1742-7061 .- 1878-7568. ; 59, s. 234-242
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Tidskriftsartikel (refereegranskat)abstract
- The design of constructs for tubular tissue engineering is challenging. Most biomaterials need to be reinforced with supporting structures such as knittings, meshes or electrospun material to comply with the mechanical demands of native tissues. In this study, coupled helical coils (CHCs) were manufactured to mimic collagen fiber orientation as found in nature. Monofilaments of different commercially available biodegradable polymers were wound and subsequently fused, resulting in right-handed and left-handed polymer helices fused together in joints where the filaments cross. CHCs of different polymer composition were tested to determine the tensile strength, strain recovery, hysteresis, compressive strength and degradation of CHCs of different composition. Subsequently, seamless and stable hybrid constructs consisting of PDSII (R) USP 2-0 CHCs embedded in porous collagen type I were produced. Compared to collagen alone, this hybrid showed superior strain recovery (93.5 +/- 0.9% vs 71.1 +/- 12.6% in longitudinal direction; 87.1 +/- 6.6% vs 57.2 +/- 4.6% in circumferential direction) and hysteresis (18.9 +/- 2.7% vs 51.1 +/- 12.0% in longitudinal direction; 11.5 +/- 4.6% vs 46.3 +/- 6.3% in circumferential direction). Furthermore, this hybrid construct showed an improved Young's modulus in both longitudinal (0.5 +/- 0.1 MPa vs 0.2 +/- 0.1 MPa; 2.5-fold) and circumferential (1.65 +/- 0.07 MPa vs (2.9 +/- 0.3) x 10(-2) MPa; 57-fold) direction, respectively, compared to templates created from collagen alone. Moreover, hybrid template characteristics could be modified by changing the CHC composition and CHCs were produced showing a mechanical behavior similar to the native ureter. CHC-enforced templates, which are easily tunable to meet different demands may be promising for tubular tissue engineering. Statement of Significance Most tubular constructs lack sufficient strength and tunability to comply with the mechanical demands of native tissues. Therefore, we embedded coupled helical coils (CHCs) produced from biodegradable polymers - to mimic collagen fiber orientation as found in nature - in collagen type I sponges. We show that the mechanical behavior of CHCs is very similar to native tissue and strengths structurally weak tubular constructs. The production procedure is relatively easy, reproducible and mechanical features can be controlled to meet different mechanical demands. This is promising in template manufacture, hence offering new opportunities in tissue engineering of tubular organs and preventing graft failure.
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| 9. |
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| 10. |
- Kehoe, Laura, et al.
(författare)
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Make EU trade with Brazil sustainable
- 2019
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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