| 1. |
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| 2. |
- Aleni, Afshin H., et al.
(författare)
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3D printing of dense and porous TiO2 structures
- 2020
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Ingår i: Ceramics International. - : Elsevier. - 0272-8842 .- 1873-3956. ; 46:10, s. 16725-16732
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Tidskriftsartikel (refereegranskat)abstract
- Direct foam writing allows the fabrication of highly porous and hierarchical ceramic structures with high specific mechanical properties. This manufacturing technique, however, has mainly used stabilized Al2O3 foam inks. In this work, we pressent a novel foam ink based on TiO2. This ink uses polyvinyl alcohol (PVA) as a binder and a small amount of zinc as a frothing agent. We used this ink to produce cylindrical foam samples via direct foam writing. The foams had a porosity of up to 65% and a mean pore size of 180 μm, which is significantly larger than previously reported for direct foam writing with Al2O3. The foams were tested in compression and were found to have an elastic modulus of 0.5 GPa and a compressive strength of 12–18 MPa. These mechanical properties are similar to those of porous ceramics produced by conventional manufacturing routes. Therefore, this work represents a step forward by broadening the direct foam writing process to a wider range of porous ceramics.
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| 3. |
- Alfjorden, Anders, et al.
(författare)
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Identification of a new gregarine parasite [Apicomplexa, Alveolata] in mass mortality events of freshwater pearl mussels (Margaritifera margaritifera)
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The freshwater pearl mussel (FPM) Margaritifera margaritifera is a Holarctic species with key roles in river ecosystems. Although of highly ecological importance the species is globally threatened and reaching nearing extinction in Europe. FPM is particularly vulnerable to fluctuations of environmental conditions, being entirely dependent of highly oxygenated streams with clear running water. Therefore anthropogenic activities resulting in habitat loss or affecting water quality such as sedimentation, eutrophication, or acidification of streams have been viewed as important causes of the mass mortality events in FPM. However, in many of these investigations, possible infections from protist parasites were never considered. Here report on a novel parasite associated with several population losses in Swedish rivers. Phylogenetic analysis of the first molecular data for this parasite (18S rDNA gene) revealed that it is related to a terrestrial group of gregarines (Apicomplexa), specifically to parasites of tadpoles belonging to the genus Nematopsis. Further investigations of environmental data revealed the presence of this parasite in Canadian peat bogs and Swedish lakes. We describe the parasite using histology, in-situ hybridization, and transmission electron microscopy and propose a tentative life cycle within the FPM host. Together, our results identify for the first time a pathogenic agent that maybe responsible for the steady decline of a critical animal species in freshwater ecosystems worldwide.
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| 4. |
- Andersson, Niklas, 1970, et al.
(författare)
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A variant near the interleukin-6 gene is associated with fat mass in Caucasian men
- 2010
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 34:6, s. 1011-9
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Regulation of fat mass appears to be associated with immune functions. Studies of knockout mice show that endogenous interleukin (IL)-6 can suppress mature-onset obesity. OBJECTIVE: To systematically investigate associations of single nucleotide polymorphisms (SNPs) near the IL-6 (IL6) and IL-6 receptor (IL6R) genes with body fat mass, in support for our hypothesis that variants of these genes can be associated with obesity. DESIGN AND STUDY SUBJECTS: The Gothenburg Osteoporosis and Obesity Determinants (GOOD) study is a population-based cross-sectional study of 18- to 20-year-old men (n=1049), from the Gothenburg area (Sweden). Major findings were confirmed in two additional cohorts consisting of elderly men from the Osteoporotic Fractures in Men (MrOS) Sweden (n=2851) and MrOS US (n=5611) multicenter population-based studies. MAIN OUTCOME: The genotype distributions and their association with fat mass in different compartments, measured with dual-energy X-ray absorptiometry. RESULTS: Out of 18 evaluated tag SNPs near the IL6 and IL6R genes, a recently identified SNP rs10242595 G/A (minor allele frequency=29%) 3' of the IL6 gene was negatively associated with the primary outcome total body fat mass (effect size -0.11 standard deviation (s.d.) units per A allele, P=0.02). This negative association with fat mass was also confirmed in the combined MrOS Sweden and MrOS US cohorts (effect size -0.05 s.d. units per A allele, P=0.002). When all three cohorts were combined (n=8927, Caucasian subjects), rs10242595(*)A showed a negative association with total body fat mass (effect size -0.05 s.d. units per A allele, P<0.0002). Furthermore, the rs10242595(*)A was associated with low body mass index (effect size -0.03, P<0.001) and smaller regional fat masses. None of the other SNPs investigated in the GOOD study were reproducibly associated with body fat. CONCLUSIONS: The IL6 gene polymorphism rs10242595(*)A is associated with decreased fat mass in three combined cohorts of 8927 Caucasian men.
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| 5. |
- Andersson, Niklas, 1970, et al.
(författare)
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Variants of the interleukin-1 receptor antagonist gene are associated with fat mass in men
- 2009
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 33:5, s. 525-533
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Tidskriftsartikel (refereegranskat)abstract
- Context: Immune functions seem to have connections to variations in body fat mass. Studies of knockout mice indicate that endogenous interleukin (IL)-1 can suppress mature-onset obesity. Objective: To systematically investigate our hypotheses that single- nucleotide polymorphisms (SNPs) and/or haplotypes variants in the IL-1 gene system are associated with fat mass. Subjects: The Gothenburg osteoporosis and obesity determinants (GOOD) study is a population-based cross-sectional study of 18-20 year-old men (n = 1068), from Gothenburg, Sweden. Major findings were confirmed in elderly men (n = 3014) from the Swedish part of the osteoporotic fractures in men (MrOS) multicenter population-based study. Main Outcome Measure: The genotype distributions and their association with body fat mass in different compartments, measured with dual-energy X-ray absorptiometry (DXA). Results: Out of 15 investigated SNPs in the IL-1 receptor antagonist (IL1RN) gene, a recently identified 30 untranslated region C4T (rs4252041, minor allele frequency 4%) SNP was associated with the primary outcome total fat mass (P = 0.003) and regional fat masses, but not with lean body mass or serum IL-1 receptor 1 (IL1RN) levels. This SNP was also associated with body fat when correcting the earlier reported IL1RN_2018 T4C (rs419598) SNP (in linkage disequilibrium with a well-studied variable number tandem repeat of 86 bp). The association between rs4252041 SNP and body fat was confirmed in the older MrOS population (P = 0.03). The rs4252041 SNP was part of three haplotypes consisting of five adjacent SNPs that were identified by a sliding window approach. These haplotypes had a highly significant global association with total body fat (P < 0.001). None of the other investigated members of the IL-1 gene family displayed any SNPs that have not been described previously to be significantly associated with body fat. Conclusions: The IL1RN gene, shown to enhance obesity by suppressing IL-1 effects in experimental animals, have no previously described gene polymorphisms and haplotypes that are associated with fat, but not lean mass in two populations of men. International Journal of Obesity (2009) 33, 525-533; doi: 10.1038/ijo.2009.47; published online 17 March 2009
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| 6. |
- Angelstam, Per, et al.
(författare)
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Maintaining natural and traditional cultural green infrastructures across Europe: learning from historic and current landscape transformations
- 2021
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Ingår i: Landscape Ecology. - : Springer Publishing Company. - 0921-2973 .- 1572-9761. ; 36:2, s. 637-663
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Tidskriftsartikel (refereegranskat)abstract
- Context Maintaining functional green infrastructures (GIs) require evidence-based knowledge about historic and current states and trends of representative land cover types. Objectives We address: (1) the long-term loss and transformation of potential natural forest vegetation; (2) the effects of site productivity on permanent forest loss and emergence of traditional cultural landscapes; (3) the current management intensity; and (4) the social-ecological contexts conducive to GI maintenance . Methods We selected 16 case study regions, each with a local hotspot landscape, ranging from intact forest landscapes, via contiguous and fragmented forest covers, to severe forest loss. Quantitative open access data were used to estimate (i) the historic change and (ii) transformation of land covers, and (iii) compare the forest canopy loss from 2000 to 2018. Qualitative narratives about each hotspot landscape were analysed for similarities (iv). Results While the potential natural forest vegetation cover in the 16 case study regions had a mean of 86%, historically it has been reduced to 34%. Higher site productivity coincided with transformation to non-forest land covers. The mean annual forest canopy loss for 2000-2018 ranged from 0.01 to 1.08%. The 16 case studies represented five distinct social-ecological contexts (1) radical transformation of landscapes, (2) abuse of protected area concepts, (3) ancient cultural landscapes (4) multi-functional forests, and (5) intensive even-aged forest management, of which 1 and 4 was most common. Conclusions GIs encompass both forest naturalness and traditional cultural landscapes. Our review of Pan-European regions and landscapes revealed similarities in seemingly different contexts, which can support knowledge production and learning about how to sustain GIs.
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| 7. |
- Angelstam, Per, et al.
(författare)
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Meeting places and social capital supporting rural landscape stewardship : A Pan-European horizon scanning
- 2021
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Ingår i: Ecology and Society. - : Resilience Alliance. - 1708-3087. ; 26:1
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Tidskriftsartikel (refereegranskat)abstract
- Achieving sustainable development as an inclusive societal process in rural landscapes, and sustainability in terms of functional green infrastructures for biodiversity conservation and ecosystem services, are wicked challenges. Competing claims from various sectors call for evidence-based adaptive collaborative governance. Leveraging such approaches requires maintenance of several forms of social interactions and capitals. Focusing on Pan-European regions with different environmental histories and cultures, we estimate the state and trends of two groups of factors underpinning rural landscape stewardship, namely, (1) traditional rural landscape and novel face-to-face as well as virtual fora for social interaction, and (2) bonding, bridging, and linking forms of social capital. We applied horizon scanning to 16 local landscapes located in 18 countries, representing Pan-European social-ecological and cultural gradients. The resulting narratives, and rapid appraisal knowledge, were used to estimate portfolios of different fora for social interactions and forms of social capital supporting landscape stewardship. The portfolios of fora for social interactions were linked to societal cultures across the European continent: "self-expression and secular-rational values" in the northwest, "Catholic" in the south, and "survival and traditional authority values" in the East. This was explained by the role of traditional secular and religious local meeting places. Virtual internet-based fora were most widespread. Bonding social capitals were the strongest across the case study landscapes, and linking social capitals were the weakest. This applied to all three groups of fora. Pan-European social-ecological contexts can be divided into distinct clusters with respect to the portfolios of different fora supporting landscape stewardship, which draw mostly on bonding and bridging forms of social capital. This emphasizes the need for regionally and culturally adapted approaches to landscape stewardship, which are underpinned by evidence-based knowledge about how to sustain green infrastructures based on both forest naturalness and cultural landscape values. Sharing knowledge from comparative studies can strengthen linking social capital.
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| 8. |
- Antonsson, Kjell, et al.
(författare)
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Occurrence of the hermit beetle (Osmoderma eremita), in Sweden.
- 2003
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Ingår i: Entomologisk tidskrift. - 0013-886X. ; 124:4, s. 225-240
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Tidskriftsartikel (refereegranskat)abstract
- We have compiled data on the occurrence of a threatened beetle, Osmoderma eremita, in Sweden. The species inhabits tree hollows with wood mould. The data were compiled from field surveys conducted in 1993-2003, using pitfall traps at 401 localities and using wood mould sampling at 104 localities. We have also gone through published data and all larger Swedish museums and registered old records. O. eremita was recorded at about 30% of the field surveys. In Sweden, oak is by far the most important host tree species, but the beetle has also been found in other deciduous trees, such as beech, alder, ash and lime. Currently, 270 localities with Osmoderma eremita, defined as records of living adults, larvae, fragments of adult body parts, or excrements situated at least 1 km from each other, are known in Sweden. 129 of these localities are records of live beetles or larvae made after 1990. The species is found in the southern third of Sweden only, and there are more localities in the eastern part compared to the western. The great majority of the localities have been discovered during the last ten years. At some of the localities only excrements or fragments have been recorded, and the species might actually be extinct at some of these localities. Due to low search intensity historically, it is impossible to use these data to discover any changes in the distribution or occurrence over time. Because old, hollow oaks were much more frequent 200 years ago, we suggest that the species has decreased severely in Sweden since that time. Today, old oaks are rarely cut down but instead lack of grazing cattle is a threat because many sites regrow with dense tree stands which outcompete the old hollow trees. Many local extinctions could also be expected during the next few decades, because many of the localities have too few hollow trees and are too isolated. At many localities, lack of younger trees which can take over the role as host trees when the present trees die will also be a problem in the future.
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| 9. |
- Arslangundogdu, Zeynel, et al.
(författare)
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The Importance of Urban Green Spaces for Resident and Migrant Birds - A Case Study from Tepeören Cemetery in Istanbul-Türkiye
- 2023
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Ingår i: KASTAMONU UNIVERSITY JOURNAL OF FORESTRY FACULTY. - : KASTAMONU UNIV. - 1303-2399. ; 23:2, s. 131-143
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Tidskriftsartikel (refereegranskat)abstract
- Aim of study: This study was carried out to determine the effects and importance of urban cemeteries on bird species diversity. Area of study: The Tepeoren cemetery is one of the oldest and most historically important cemeteries in the Istanbul region. Material and methods: Field studies of birds were carried out between April-September 2018/2019. During the study period of 12 months, the cemetery was visited twice a month. The species list of the area was created by registering all feeding, lodging, roosting and nesting birds observed in the area. Main results: It was determined that 36 bird species occured in the cemetery, out of which ten species were identified as breeding in the area. The main bird species that used the cemetery as breeding ground, was Corvus monedula (Western jackdaw) that utilizes the cavities of old oaks for nesting. The average number of eggs per nest was found to be 4.3 based on the examination of 49 active nests in 2018-2019. The number of fledged birds per nest was determined as 1.1. Higlights: In the current study, the importance of the city cemeteries in terms of bird diversity has been revealed. The presence of plant species that provide suitable nesting conditions for the reproduction of birds in these cemeteries supports the survival of the birds in the city.
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| 10. |
- Audusseau, Hélène, et al.
(författare)
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Rewiring of interactions in a changing environment : nettle-feeding butterflies and their parasitoids
- 2021
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Ingår i: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 130:4, s. 624-636
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Tidskriftsartikel (refereegranskat)abstract
- Climate and land use change can alter the incidence and strength of biotic interactions, with important effects on the distribution, abundance and function of species. To assess the importance of these effects and their dynamics, studies quantifying how biotic interactions change in space and time are needed. We studied interactions between nettle-feeding butterflies and their shared natural enemies (parasitoids) locally and across 500 km latitudinal gradient in Sweden. We also examined the potential impact of the range-expansion of the butterfly Araschnia levana on resident butterflies via shared parasitoids, by studying how parasitism in resident butterflies covaries with the presence or absence of the newly-established species. We collected 6777 larvae of four nettle-feeding butterfly species (Aglais urticae, Aglais io, Ar. levana and Vanessa atalanta), over two years, at 19 sites distributed along the gradient. We documented the parasitoid complex for each butterfly species and measured their overlap, and analysed how parasitism rates were affected by butterfly species assemblage, variations in abundance, time, and the arrival of Ar. levana. Parasitoids caused high mortality, with substantial overlap in the complex of parasitoids associated with the four host butterflies. Levels of parasitism differed significantly among butterflies and were influenced by the local butterfly species assemblage. Our results also suggest that parasitism in resident butterflies is elevated at sites where Ar. levana has been established for a longer period. In our study system, variations in butterfly species assemblages were associated in a predictable way with substantial variations in rates of parasitism. This relationship is likely to affect the dynamics of the butterfly host species, and potentially cascade to the larger number of species with which they interact. These results highlight the importance of indirect interactions and their potential to reorganise ecological communities, especially in the context of shifts in species distributions in a warmer world.
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