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| 3. |
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| 4. |
- Appeltans, W., et al.
(författare)
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The Magnitude of Global Marine Species Diversity
- 2012
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822 .- 1879-0445. ; 22:23, s. 2189-2202
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Tidskriftsartikel (refereegranskat)abstract
- Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. Results: There are similar to 226,000 eukaryotic marine species described. More species were described in the past decade (similar to 20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are similar to 170,000 synonyms, that 58,000-72,000 species are collected but not yet described, and that 482,000-741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7-1.0 million marine species. Past rates of description of new species indicate there may be 0.5 +/- 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century.
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| 5. |
- Daniau, A. -L, et al.
(författare)
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predictability of biomass burning in response to climate changes
- 2012
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Ingår i: Global Biogeochemical Cycles. - 0886-6236 .- 1944-9224. ; 26, s. GB4007-
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Tidskriftsartikel (refereegranskat)abstract
- Climate is an important control on biomass burning, but the sensitivity of fire to changes in temperature and moisture balance has not been quantified. We analyze sedimentary charcoal records to show that the changes in fire regime over the past 21,000 yrs are predictable from changes in regional climates. Analyses of paleo-fire data show that fire increases monotonically with changes in temperature and peaks at intermediate moisture levels, and that temperature is quantitatively the most important driver of changes in biomass burning over the past 21,000 yrs. Given that a similar relationship between climate drivers and fire emerges from analyses of the interannual variability in biomass burning shown by remote-sensing observations of month-by-month burnt area between 1996 and 2008, our results signal a serious cause for concern in the face of continuing global warming.
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| 6. |
- Sim, Thomas G., et al.
(författare)
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Regional variability in peatland burning at mid-to high-latitudes during the Holocene
- 2023
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Ingår i: Quaternary Science Reviews. - : Elsevier. - 0277-3791 .- 1873-457X. ; 305
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Tidskriftsartikel (refereegranskat)abstract
- Northern peatlands store globally-important amounts of carbon in the form of partly decomposed plant detritus. Drying associated with climate and land-use change may lead to increased fire frequency and severity in peatlands and the rapid loss of carbon to the atmosphere. However, our understanding of the patterns and drivers of peatland burning on an appropriate decadal to millennial timescale relies heavily on individual site-based reconstructions. For the first time, we synthesise peatland macrocharcoal re-cords from across North America, Europe, and Patagonia to reveal regional variation in peatland burning during the Holocene. We used an existing database of proximal sedimentary charcoal to represent regional burning trends in the wider landscape for each region. Long-term trends in peatland burning appear to be largely climate driven, with human activities likely having an increasing influence in the late Holocene. Warmer conditions during the Holocene Thermal Maximum (similar to 9e6 cal. ka BP) were associated with greater peatland burning in North America's Atlantic coast, southern Scandinavia and the Baltics, and Patagonia. Since the Little Ice Age, peatland burning has declined across North America and in some areas of Europe. This decline is mirrored by a decrease in wider landscape burning in some, but not all sub-regions, linked to fire-suppression policies, and landscape fragmentation caused by agricultural expansion. Peatlands demonstrate lower susceptibility to burning than the wider landscape in several instances, probably because of autogenic processes that maintain high levels of near-surface wetness even during drought. Nonetheless, widespread drying and degradation of peatlands, particularly in Europe, has likely increased their vulnerability to burning in recent centuries. Consequently, peatland restoration efforts are important to mitigate the risk of peatland fire under a changing climate. Finally, we make recommendations for future research to improve our understanding of the controls on peatland fires.(c) 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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| 9. |
- Marcaide, J. M., et al.
(författare)
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Discovery of shell-like radio-structure in SN1993J
- 1995
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Ingår i: Nature. - London : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 373:6509, s. 44-45
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Tidskriftsartikel (refereegranskat)abstract
- SUPERNOVA explosions are poorly understood, partly because of difficulties in modelling them theoretically(1), and partly because there have been no supernovae observed in our Galaxy since the invention of the telescope. But the recent discovery(2) of supernova SN1993J in the nearby galaxy M81 offers an opportunity to investigate the evolution of the remnant, and its interaction with the surrounding interstellar medium, at high resolution. Here we present radio observations of SN1993J, made using very-long-baseline interferometry, which show the development of a shell structure. This 8-month-old radio shell is the youngest ever discovered in a supernova. The data suggest that the supernova explosion and the expanding shell of the remnant have nearly spherical symmetry, with small deviations where some parts of the shell are brighter than others. If these deviations arise because of variations in the density of the shell, this may reconcile earlier reports of symmetric radio emission(3) with the observed optical asymmetry(4,5), as the density variations could easily cause the latter. We infer that the radio emission is generated at the interface(6-9), where the surrounding gas is shocked by the ejecta.
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| 10. |
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| 11. |
- Lopez-Vicario, C, et al.
(författare)
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Association of a variant in the gene encoding for ERV1/ChemR23 with reduced inflammation in visceral adipose tissue from morbidly obese individuals
- 2017
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1, s. 15724-
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Tidskriftsartikel (refereegranskat)abstract
- Obesity comorbidities are closely associated with chronic low-grade adipose tissue inflammation. A number of SNPs associated with inflammation has been identified, underscoring the impact of genetic determinants on this process. Here, we screened SNPs in genes with pro-inflammatory (IL-1β, IL-6, STAT3 and JAK2), anti-inflammatory (IL-10 and SOCS3) and pro-resolving (ERV1/ChemR23) properties in 101 obese and 99 non-obese individuals. Among the SNPs analyzed, we identified that individuals carrying a C allele in the rs1878022 polymorphism of the ERV1/ChemR23 gene, which encodes for the receptor of the pro-resolving mediator RvE1, had increased ERV1/ChemR23 protein expression and reduced levels of the inflammatory cytokine IL-6 in adipose tissue. Moreover, patients carrying the C allele in homozygosity had lower plasma levels of IL-6, IFN-α2, IL-15, IL-1ra, IL-10, GM-CSF, G-CSF and VEGF and enhanced leukocyte responsiveness to RvE1. C-carriers also exhibited decreased TAG to HDL ratio, a surrogate marker of insulin resistance and a predictor of incident fatty liver. Finally, we confirmed in vivo that the ERV1/ChemR23 receptor regulates systemic and tissue inflammation since mice lacking ERV1/ChemR23 expression showed increased IL-6 levels in adipose tissue and peritoneal macrophages. Together, our study identified an ERV1/ChemR23 variant that protects patients with obesity from excessive inflammatory burden.
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| 12. |
- Lundgren, Edvin, et al.
(författare)
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Geometry of the valence transition induced surface reconstruction of Sm(0001).
- 2002
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Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 88:13, s. 136102-136102
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Tidskriftsartikel (refereegranskat)abstract
- We present a structural determination of the surface reconstruction of the Sm(0001) surface using surface x-ray diffraction, scanning tunneling microscopy, and ab initio calculations. The reconstruction is associated with a large (22%) expansion of the atomic radius for the top monolayer surface Sm atoms. The mechanism driving the surface reconstruction in Sm is unique among all elements and is connected to the strong correlations of the 4f electrons in Sm and the intermediate valence observed in certain Sm compounds. The atoms constituting the top monolayer of Sm(0001) have vastly different chemical properties compared to the layer underneath and behave as if they were an adsorbate of a different chemical species.
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| 13. |
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| 14. |
- Rius, J., et al.
(författare)
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Selective fragmentation of valence- and core-electron-excited CD4 and SF6 molecules
- 2002
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Ingår i: Surface review and letters. - 0218-625X. ; 9:1, s. 117-123
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Tidskriftsartikel (refereegranskat)abstract
- Electron-ion coincidence measurements with energy-resolved electrons are a powerful tool in studies of molecular fragmentation processes, since fragmentation from a specific doorway state can be monitored while the remaining reactions are discriminated. Presently, we have applied this technique in measurements of coincidence spectra of the CD4 and SF6 molecules after valence and core electron excitation. The newly constructed energy-resolved electron-ion coincidence station developed for this project has been used. Our results on CD4 are the first demonstration of a correlation between vibrations and molecular dissociation observed in this molecule. The SF6 spectra reveal strong selectivity in dissociation following distinct electronic states of the molecule. This selectivity reflects the bonding properties of the potential surfaces involved in the studied processes. The obtained results exemplify the potential of the new multicoincidence station used in this work.
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| 15. |
- Van Haute, L., et al.
(författare)
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TEFM variants impair mitochondrial transcription causing childhood-onset neurological disease
- 2023
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Mutations in the mitochondrial or nuclear genomes are associated with a diverse group of human disorders characterized by impaired mitochondrial respiration. Within this group, an increasing number of mutations have been identified in nuclear genes involved in mitochondrial RNA biology. The TEFM gene encodes the mitochondrial transcription elongation factor responsible for enhancing the processivity of mitochondrial RNA polymerase, POLRMT. We report for the first time that TEFM variants are associated with mitochondrial respiratory chain deficiency and a wide range of clinical presentations including mitochondrial myopathy with a treatable neuromuscular transmission defect. Mechanistically, we show muscle and primary fibroblasts from the affected individuals have reduced levels of promoter distal mitochondrial RNA transcripts. Finally, tefm knockdown in zebrafish embryos resulted in neuromuscular junction abnormalities and abnormal mitochondrial function, strengthening the genotype-phenotype correlation. Our study highlights that TEFM regulates mitochondrial transcription elongation and its defect results in variable, tissue-specific neurological and neuromuscular symptoms.
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| 17. |
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| 18. |
- Blackwell, Simon E., et al.
(författare)
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Optimism and mental imagery : A possible cognitive marker to promote well-being?
- 2013
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Ingår i: Psychiatry Research. - : ELSEVIER IRELAND LTD. - 0165-1781 .- 1872-7123. ; 206:1, s. 56-61
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Tidskriftsartikel (refereegranskat)abstract
- Optimism is associated with a range of benefits not only for general well-being, but also for mental and physical health. The development of psychological interventions to boost optimism derived from cognitive science would have the potential to provide significant public health benefits, yet cognitive markers of optimism are little understood. The current study aimed to take a first step in this direction by identifying a cognitive marker for optimism that could provide a modifiable target for innovative interventions. In particular we predicted that the ability to generate vivid positive mental imagery of the future would be associated with dispositional optimism. A community sample of 237 participants completed a survey comprising measures of mental imagery and optimism, and socio-demographic information. Vividness of positive future imagery was significantly associated with optimism, even when adjusting for socio-demographic factors and everyday imagery use. The ability to generate vivid mental imagery of positive future events may provide a modifiable cognitive marker of optimism. Boosting positive future imagery could provide a cognitive target for treatment innovations to promote optimism, with implications for mental health and even physical well-being. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
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| 19. |
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| 20. |
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| 21. |
- Guillén, Yolanda, et al.
(författare)
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Genomics of ecological adaptation in cactophilic Drosophila.
- 2014
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Ingår i: Genome Biology and Evolution. - : Oxford University Press (OUP). - 1759-6653. ; 7:1, s. 349-66
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Tidskriftsartikel (refereegranskat)abstract
- Cactophilic Drosophila species provide a valuable model to study gene-environment interactions and ecological adaptation. Drosophila buzzatii and Drosophila mojavensis are two cactophilic species that belong to the repleta group, but have very different geographical distributions and primary host plants. To investigate the genomic basis of ecological adaptation, we sequenced the genome and developmental transcriptome of D. buzzatii and compared its gene content with that of D. mojavensis and two other noncactophilic Drosophila species in the same subgenus. The newly sequenced D. buzzatii genome (161.5 Mb) comprises 826 scaffolds (>3 kb) and contains 13,657 annotated protein-coding genes. Using RNA sequencing data of five life-stages we found expression of 15,026 genes, 80% protein-coding genes, and 20% noncoding RNA genes. In total, we detected 1,294 genes putatively under positive selection. Interestingly, among genes under positive selection in the D. mojavensis lineage, there is an excess of genes involved in metabolism of heterocyclic compounds that are abundant in Stenocereus cacti and toxic to nonresident Drosophila species. We found 117 orphan genes in the shared D. buzzatii-D. mojavensis lineage. In addition, gene duplication analysis identified lineage-specific expanded families with functional annotations associated with proteolysis, zinc ion binding, chitin binding, sensory perception, ethanol tolerance, immunity, physiology, and reproduction. In summary, we identified genetic signatures of adaptation in the shared D. buzzatii-D. mojavensis lineage, and in the two separate D. buzzatii and D. mojavensis lineages. Many of the novel lineage-specific genomic features are promising candidates for explaining the adaptation of these species to their distinct ecological niches.
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| 22. |
- Guinovart, Tomas, et al.
(författare)
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A reference electrode based on polyvinyl butyral (PVB) polymer for decentralized chemical measurements
- 2014
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Ingår i: Analytica Chimica Acta. - : Elsevier. - 0003-2670 .- 1873-4324. ; 821, s. 72-80
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Tidskriftsartikel (refereegranskat)abstract
- A new solid-state reference electrode using a polymeric membrane of polyvinyl butyral (PVB), Ag/AgCl and NaCl to be used in decentralized chemical measurements is presented. The electrode is made by drop-casting the membrane cocktail onto a glassy carbon (GC) substrate. A stable potential (less than 1 mV dec−1) over a wide range of concentrations for the several chemical species tested is obtained. No significant influence to changes in redox potential, light and pH are observed. The response of this novel electrode shows good correlation when compared with a conventional double-junction reference electrode. Also good long-term stability (90 ± 33 μV/h) and a lifetime of approximately 4 months are obtained. Aspects related to the working mechanisms are discussed. Atomic Force Microscopy (AFM) studies reveal the presence of nanopores and channels on the surface, and electrochemical impedance spectroscopy (EIS) of optimized electrodes show low bulk resistances, usually in the kΩ range, suggesting that a nanoporous polymeric structure is formed in the interface with the solution. Future applications of this electrode as a disposable device for decentralized measurements are discussed. Examples of the utilization on wearable substrates (tattoos, fabrics, etc) are provided.
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| 23. |
- Guinovart, Tomas, et al.
(författare)
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Potentiometric sensors using cotton yarns, carbon nanotubes and polymeric membranes
- 2013
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Ingår i: The Analyst. - : Royal Society of Chemistry. - 0003-2654 .- 1364-5528. ; 138:18, s. 5208-5215
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Tidskriftsartikel (refereegranskat)abstract
- A simple and generalized approach to build electrochemical sensors for wearable devices is presented. Commercial cotton yarns are first turned into electrical conductors through a simple dyeing process using a carbon nanotube ink. These conductive yarns are then partially coated with a suitable polymeric membrane to build ion-selective electrodes. Potentiometric measurements using these yarn-potentiometric sensors are demonstrated. Examples of yarns that can sense pH, K+ and NH4+ are presented. In all cases, these sensing yarns show limits of detection and linear ranges that are similar to those obtained with lab-made solid-state ion-selective electrodes. Through the immobilization of these sensors in a band-aid, it is shown that this approach could be easily implemented in a wearable device. Factors affecting the performance of the sensors and future potential applications are discussed.
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| 24. |
- Hudson, J., et al.
(författare)
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Secondary contacts and genetic admixture shape colonization by an amphiatlantic epibenthic invertebrate
- 2020
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Ingår i: Evolutionary Applications. - : Wiley. - 1752-4571. ; 13:3, s. 600-612
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Tidskriftsartikel (refereegranskat)abstract
- Research on the genetics of invasive species often focuses on patterns of genetic diversity and population structure within the introduced range. However, a growing body of literature is demonstrating the need to study how native genotypes affect both ecological and evolutionary mechanisms within the introduced range. Here, we used genotyping-by-sequencing to study both native and introduced ranges [based on 1,653 single nucleotide polymorphisms (SNPs)] of the amphiatlantic marine invertebrate Ciona intestinalis. A previous study using microsatellites analysed samples collected along the Swedish west coast and showed the presence of genetically distinct lineages in deep and shallow waters. Using 1,653 single nucleotide polymorphisms (SNPs) from newly collected samples (285 individuals), we first confirmed the presence of this depth-defined genomic divergence along the Swedish coast. We then used approximate Bayesian computation to infer the historical relationship among sites from the North Sea, the English Channel and the northwest Atlantic and found evidence of ancestral divergence between individuals from deep waters off Sweden and individuals from the English Channel. This divergence was followed by a secondary contact that led to a genetic admixture between the ancestral populations (i.e., deep Sweden and English Channel), which originated the genotypes found in shallow Sweden. We then revealed that the colonization of C. intestinalis in the northwest Atlantic was as a result of an admixture between shallow Sweden and the English Channel genotypes across the introduced range. Our results showed the presence of both past and recent genetic admixture events that together may have promoted the successful colonizations of C. intestinalis. Our study suggests that secondary contacts potentially reshape the evolutionary trajectories of invasive species through the promotion of intraspecific hybridization and by altering both colonization patterns and their ecological effects in the introduced range.
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| 25. |
- Kerric, Gaelle, et al.
(författare)
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Nanostructured assemblies for ion-sensors : functionalization of multi-wall carbon nanotubes with benzo-18-crown-6 for Pb2+ determination
- 2012
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Ingår i: Journal of Materials Chemistry. - : Royal Society of Chemistry. - 0959-9428 .- 1364-5501. ; 22:32, s. 16611-16617
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis and full characterization of new hybrid materials, i.e. benzo-18-crown-6 covalently linked to multi-wall carbon nanotubes – incorporating first and second generation dendrimer approaches – are reported here. Furthermore, the benefit of using these new nanostructured assemblies is demonstrated for solid-contact ion-selective sensor configuration. Both selective recognition and ion-to-electron transduction events take place at the same hybrid nanostructured material. Functionalization of multi-wall carbon nanotubes (MWCNTs) plays a key role in the development of such devices not only allowing an improvement of the analytical parameters such as selectivity and stability but also providing simplicity in the manufacturing stages.
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| 28. |
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| 29. |
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| 30. |
- Mattos, Caio R. C., et al.
(författare)
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Rainfall and topographic position determine tree embolism resistance in AmazÃŽnia and Cerrado sites
- 2023
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Ingår i: Environmental Research Letters. - : Institute of Physics Publishing (IOPP). - 1748-9326. ; 18:11
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Tidskriftsartikel (refereegranskat)abstract
- Droughts are predicted to increase in both frequency and intensity by the end of the 21st century, but ecosystem response is not expected to be uniform across landscapes. Here we assess the importance of the hill-to-valley hydrologic gradient in shaping vegetation embolism resistance under different rainfall regimes using hydraulic functional traits. We demonstrate that rainfall and hydrology modulate together the embolism resistance of tree species in different sites and topographic positions. Although buffered by stable access to groundwater, valley plants are intrinsically more vulnerable to drought-induced embolism than those on hills. In all study sites, the variability in resistance to embolism is higher on hills than on valleys, suggesting that the diversity of strategies to cope with drought is more important for tree communities on hills. When comparing our results with previously published data across the tropics, we show greater variability at the local scale than previously reported. Our results reinforce the urgent need to extend sampling efforts across rainfall regimes and topographic positions to improve the characterization of ecosystem resistance to drought at finer spatial scales.
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| 31. |
- Novell, Marta, et al.
(författare)
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Paper-Based Ion-Selective Potentiometric Sensors
- 2012
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 84:11, s. 4695-4702
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Tidskriftsartikel (refereegranskat)abstract
- A new approach to develop ultra low-cost, robust, rugged, and disposable potentiometric sensors is presented. A suspension of carbon nanotubes in a water-surfactant mixture (carbon nanotubes ink) is applied on conventional filter papers to turn them into conductive papers, which are then used as a substrate to build ion-selective electrodes. The electrodes are made by drop casting a membrane on a small circular area of the conductive paper. In this way, the carbon nanotubes act as both electric conductors and ion-to-electron transducers of the potentiometric signal. Electrodes for sensing K +, NH 4 +, and pH were built and tested using this approach, and the results were compared with classical solid-state ion selective electrodes using carbon nanotubes as transducers and glassy carbon as a substrate. In all cases, the analytical performance (sensitivity, linear ranges, limits of detection, selectivity, etc.) of these disposable paper electrodes was similar to that obtained for the more conventional type of ion-selective-electrodes. This opens new avenues for very low-cost platforms for generation of chemical information.
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| 35. |
- Stankiewicz, M., et al.
(författare)
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Relaxation dynamics of SF6 studied by energy-resolved electron ion coincidence technique
- 2004
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Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 137-40, s. 369-375
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Tidskriftsartikel (refereegranskat)abstract
- The mass spectra from the SF6 molecule acquired by energy-resolved electron ion coincidence (EREICO) technique using (1t(1g) + [5t(1u),1t(2u)]), (3e(g) + 1t(2g)), 4t(1u), and 5a(1g) electrons after both valence and S 2p(-1) 6a(1g) core excitation reveal a strong selectivity in the dissociation from these states. From the comparison of the obtained spectra, the influence of the core-excited state in the relaxation pathway of the molecule is studied. The S 2p --> 6a(1g) core excitation does not affect the relaxation dynamics after participator Auger decay to the (1t(1g) + [5t(1u),1t(2u)])(-1) and (4t(1u))(-l) states, but it alters the relaxation dynamics after participator Auger decay to the (3e(g) + 1t(2g))(-1) and (5a(1g))(-1) states with respect to the decay processes after direct excitation of the same orbitals. These observations point to core excitation induced dissociation in the SF6 molecule.
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| 36. |
- Volski, V., et al.
(författare)
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Overview of the software integration activities within ACE
- 2006
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Ingår i: First European Conference on Antennas and Propagation (EuCAP), 2006, Nice, France, 6 - 10 November 2006. - : IEEE. - 0379-6566. - 9789290929376 ; 626 SP
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Konferensbidrag (refereegranskat)abstract
- The ACE project initiated the start of several integration activities between European institutions involved in electromagnetic modeling of antennas with planar or conformal topologies. The goal of the integration activities was / is not to create a global software package that integrates the software of all partners, but to initiate a long term process for antenna software integration activities within the European antenna community. During the first two years of ACE the integration activities were performed in several groups with a rather small number of partners in each group. The groups were formed by partners who wanted to integrate a specific approach developed by one partner into the software code of another partner. This allows increasing the capability and efficiency of a software code. In this paper a short overview of all integration activities is given.
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