| 1. |
- Callaghan, Terry V., et al.
(författare)
-
Improving dialogue among researchers, local and indigenous peoples and decision-makers to address issues of climate change in the North
- 2020
-
Ingår i: Ambio: a Journal of the Human Environment. - : Springer Science and Business Media LLC. - 0044-7447. ; 49:6, s. 1161-1178
-
Tidskriftsartikel (refereegranskat)abstract
- The Circumpolar North has been changing rapidly within the last decades, and the socioeconomic systems of the Eurasian Arctic and Siberia in particular have displayed the most dramatic changes. Here, anthropogenic drivers of environmental change such as migration and industrialization are added to climate-induced changes in the natural environment such as permafrost thawing and increased frequency of extreme events. Understanding and adapting to both types of changes are important to local and indigenous peoples in the Arctic and for the wider global community due to transboundary connectivity. As local and indigenous peoples, decision-makers and scientists perceive changes and impacts differently and often fail to communicate efficiently to respond to changes adequately, we convened a meeting of the three groups in Salekhard in 2017. The outcomes of the meeting include perceptions of how the three groups each perceive the main issues affecting health and well-being and recommendations for working together better.
|
|
| 2. |
- Andoralov, Victor, et al.
(författare)
-
Octaheme nitrite reductase : The mechanism of intramolecular electron transfer and kinetics of nitrite bioelectroreduction.
- 2021
-
Ingår i: Bioelectrochemistry. - : Elsevier. - 1567-5394 .- 1878-562X. ; 138
-
Tidskriftsartikel (refereegranskat)abstract
- Detailed impedance and voltammetric studies of hexameric octaheme nitrite reductase immobilized on carbon-based nanomaterials, specifically nanotubes and nanoparticles, were performed. Well-pronounced bioelectrocatalytic reduction of nitrite on enzyme-modified electrodes was obtained. Analysis of the impedance data indicated the absence of long-lived intermediates involved in the nitrite reduction. Cyclic voltammograms of biomodified electrodes had a bi-sigmoidal shape, which pointed to the presence of two enzyme orientations on carbon supports. The maximum (limiting) catalytic currents were determined and, by applying the correction by the mixed kinetics equation, the Tafel dependences were plotted for each catalytic wave/each enzyme orientation. Finally, two schemes for the rate-limiting processes during bioelectrocatalysis were proposed, viz. for low- and high-potential orientations.
|
|
| 3. |
- Gauld, Jethro G., et al.
(författare)
-
Hotspots in the grid : Avian sensitivity and vulnerability to collision risk from energy infrastructure interactions in Europe and North Africa
- 2022
-
Ingår i: Journal of Applied Ecology. - : John Wiley & Sons. - 0021-8901 .- 1365-2664. ; 59:6, s. 1496-1512
-
Tidskriftsartikel (refereegranskat)abstract
- Wind turbines and power lines can cause bird mortality due to collision or electrocution. The biodiversity impacts of energy infrastructure (EI) can be minimised through effective landscape-scale planning and mitigation. The identification of high-vulnerability areas is urgently needed to assess potential cumulative impacts of EI while supporting the transition to zero carbon energy. We collected GPS location data from 1,454 birds from 27 species susceptible to collision within Europe and North Africa and identified areas where tracked birds are most at risk of colliding with existing EI. Sensitivity to EI development was estimated for wind turbines and power lines by calculating the proportion of GPS flight locations at heights where birds were at risk of collision and accounting for species' specific susceptibility to collision. We mapped the maximum collision sensitivity value obtained across all species, in each 5 x 5 km grid cell, across Europe and North Africa. Vulnerability to collision was obtained by overlaying the sensitivity surfaces with density of wind turbines and transmission power lines. Results: Exposure to risk varied across the 27 species, with some species flying consistently at heights where they risk collision. For areas with sufficient tracking data within Europe and North Africa, 13.6% of the area was classified as high sensitivity to wind turbines and 9.4% was classified as high sensitivity to transmission power lines. Sensitive areas were concentrated within important migratory corridors and along coastlines. Hotspots of vulnerability to collision with wind turbines and transmission power lines (2018 data) were scattered across the study region with highest concentrations occurring in central Europe, near the strait of Gibraltar and the Bosporus in Turkey. Synthesis and applications. We identify the areas of Europe and North Africa that are most sensitive for the specific populations of birds for which sufficient GPS tracking data at high spatial resolution were available. We also map vulnerability hotspots where mitigation at existing EI should be prioritised to reduce collision risks. As tracking data availability improves our method could be applied to more species and areas to help reduce bird-EI conflicts.
|
|
| 4. |
- Ktitorov, Pavel, et al.
(författare)
-
Shrub-dwelling species are joining the Arctic passerine bird community in the Chaun Delta (Western Chukotka, Russia)
- 2021
-
Ingår i: Polar Biology. - : Springer Science and Business Media LLC. - 0722-4060 .- 1432-2056. ; 44:9, s. 1847-1857
-
Tidskriftsartikel (refereegranskat)abstract
- Avian communities play a pivotal role in Arctic ecosystems and birds have become the key model taxa for climate change research. Due to funding priorities, Arctic passerines have been studied less intensively than waterfowl and shorebirds. In our study, we aim to partly fill this gap and look at the change in passerine community species composition in the Chaun River Delta in Northeast Siberia (68.81° N, 170.62° E) between 1970–1980 and 2002–2019. We restricted our comparison to 16 tundra-dwelling species associated with grass and shrub tundra habitats. During the first period, 12 passerine species were reported and by the end of the last period, 14 species. Our observations show that four species of shrub-dwelling passerines, the Dusky Warbler (Phylloscopus fuscatus), two species of Turdus thrushes, and the Siberian Rubythroat (Calliope calliope), have joined the local community. Additionally, one Turdus thrush species increased in numbers. The only passerine species that used to be common in the 70’s and rare in the 2000s is the Lapland Bunting (Calcarius lapponicus). Yellow-breasted Bunting (Emberiza aureola, vagrant in 70’s) and Siberian Chiffchaff (Phylloscopus tristis, rare breeder in 70’s) have not been recorded during the most recent period. At the same time, there was no observed change in abundance for eight species of songbirds. The results of supervised satellite image classification did not detect any local-scale increase of shrub cover in our study site. However, a broad-scale assessment of vegetation change using NDVI suggests substantial greening or ‘shrubification’ across the region. We speculate that it promotes region-wide increases and range expansion of some shrub-dwelling species, recorded in our study.
|
|
| 5. |
- Nguyen, Tran Nguyen, et al.
(författare)
-
Binding ability of first and second generation/carbazolylphenyl dendrimers with Zn(II) tetraphenylporphyrin core towards small heterocyclic substrates
- 2014
-
Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 4:38, s. 19703-19709
-
Tidskriftsartikel (refereegranskat)abstract
- A study of complex formation of Zn(II) tetraarylporphyrin dendrimers with carbazolylphenyl branches towards 1,4-diazabicyclo-[2.2.2]octane, pyridine, imidazole, N-methylimidazole and 1,2,3-triazole was carried out by spectrophotometric and H-1 NMR titration methods. It has been shown that the binding ability of the porphyrin receptors towards mono and bidentate N-containing substrates depends on the nature, number and generation of the branches. Bulky substituents are able either to significantly reduce the binding ability of the tetrapyrrolic cores due to the shielding of the porphyrin reaction centres, or to significantly increase it by forming intramolecular cavities for complementary binding of substrates. It has been determined that due to a good geometric match of the ligand's size with the size of the intramolecular cavities of the porphyrin receptors, and by the existence of additional hydrogen bonding and/or pi-pi interactions between the ligand and the triazole fragments of the porphyrin the Zn-tetraarylporphyrins with eight 4-carbazolylphenyl-1,2,3-triazole end groups of the first and the second generations could be used as effective receptors for imidazole, N-methylimidazole and 1,2,3-triazole. Taking into account the fact that binding is accompanied by a clear and easily identifiable response in the UV-Vis spectra of the reaction mixture, these metalloporphyrins could be considered as molecular optical sensing devices for small heterocyclic substrates.
|
|
| 6. |
- Shen, Defeng, et al.
(författare)
-
A Homeotic Mutation Changes Legume Nodule Ontogeny into Actinorhizal-Type Ontogeny
- 2020
-
Ingår i: The Plant Cell. - : Oxford University Press (OUP). - 1040-4651 .- 1532-298X. ; 32:6, s. 1868-1885
-
Tidskriftsartikel (refereegranskat)abstract
- A homeotic mutation in Medicago truncatula NODULE ROOT1 converts legume-type nodules into actinorhizal-type nodules, suggesting that the two nodule types have a shared evolutionary origin. Some plants fix atmospheric nitrogen by hosting symbiotic diazotrophic rhizobia or Frankia bacteria in root organs known as nodules. Such nodule symbiosis occurs in 10 plant lineages in four taxonomic orders: Fabales, Fagales, Cucurbitales, and Rosales, which are collectively known as the nitrogen-fixing clade. Nodules are divided into two types based on differences in ontogeny and histology: legume-type and actinorhizal-type nodules. The evolutionary relationship between these nodule types has been a long-standing enigma for molecular and evolutionary biologists. Recent phylogenomic studies on nodulating and nonnodulating species in the nitrogen-fixing clade indicated that the nodulation trait has a shared evolutionary origin in all 10 lineages. However, this hypothesis faces a conundrum in that legume-type and actinorhizal-type nodules have been regarded as fundamentally different. Here, we analyzed the actinorhizal-type nodules formed by Parasponia andersonii (Rosales) and Alnus glutinosa (Fagales) and found that their ontogeny is more similar to that of legume-type nodules (Fabales) than generally assumed. We also show that in Medicago truncatula, a homeotic mutation in the co-transcriptional regulator gene NODULE ROOT1 (MtNOOT1) converts legume-type nodules into actinorhizal-type nodules. These experimental findings suggest that the two nodule types have a shared evolutionary origin.
|
|
| 7. |
- Shen, Defeng, et al.
(författare)
-
The BOP-type co-transcriptional regulator NODULE ROOT1 promotes stem secondary growth of the tropical Cannabaceae tree Parasponia andersonii
- 2021
-
Ingår i: The Plant Journal. - : John Wiley & Sons. - 0960-7412 .- 1365-313X. ; 106:5, s. 1366-1386
-
Tidskriftsartikel (refereegranskat)abstract
- Tree stems undergo a massive secondary growth in which secondary xylem and phloem tissues arise from the vascular cambium. Vascular cambium activity is driven by endogenous developmental signalling cues and environmental stimuli. Current knowledge regarding the genetic regulation of cambium activity and secondary growth is still far from complete. The tropical Cannabaceae tree Parasponia andersonii is a non-legume research model of nitrogen-fixing root nodulation. Parasponia andersonii can be transformed efficiently, making it amenable for CRISPR-Cas9-mediated reverse genetics. We considered whether P. andersonii also could be used as a complementary research system to investigate tree-related traits, including secondary growth. We established a developmental map of stem secondary growth in P. andersonii plantlets. Subsequently, we showed that the expression of the co-transcriptional regulator PanNODULE ROOT1 (PanNOOT1) is essential for controlling this process. PanNOOT1 is orthologous to Arabidopsis thaliana BLADE-ON-PETIOLE1 (AtBOP1) and AtBOP2, which are involved in the meristem-to-organ-boundary maintenance. Moreover, in species forming nitrogen-fixing root nodules, NOOT1 is known to function as a key nodule identity gene. Parasponia andersonii CRISPR-Cas9 loss-of-function Pannoot1 mutants are altered in the development of the xylem and phloem tissues without apparent disturbance of the cambium organization and size. Transcriptomic analysis showed that the expression of key secondary growth-related genes is significantly down-regulated in Pannoot1 mutants. This allows us to conclude that PanNOOT1 positively contributes to the regulation of stem secondary growth. Our work also demonstrates that P. andersonii can serve as a tree research system.
|
|
| 8. |
- Tian, Yuxi, et al.
(författare)
-
Improving photo-stability of conjugated polymer MEH-PPV embedded in solid matrices by purification of the matrix polymer
- 2014
-
Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 599, s. 142-145
-
Tidskriftsartikel (refereegranskat)abstract
- For single molecule spectroscopy (SMS), molecules under study are usually immobilized in a polymer matrix e. g. poly(methyl methacrylate). We show a very significant improvement of the conjugated polymer MEH-PPV photo-stability and decrease of the luminescence impurities concentration when the matrix is purified. We identify benzoyl peroxide (a common radical initiator) as a possible oxidizing agent which residuals in the polymer matrix destroy MEH-PPV. These results show that purification and selection of a matrix obtained by radical-free synthetic technique are of great importance for SMS as well as other technologies using polymer matrices as hosts for light-emitting materials. (C) 2014 Elsevier B. V. All rights reserved.
|
|
