| 1. |
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| 2. |
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| 3. |
- Buntgen, U., et al.
(author)
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Tree rings reveal globally coherent signature of cosmogenic radiocarbon events in 774 and 993 CE
- 2018
-
In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9
-
Journal article (peer-reviewed)abstract
- Though tree-ring chronologies are annually resolved, their dating has never been independently validated at the global scale. Moreover, it is unknown if atmospheric radiocarbon enrichment events of cosmogenic origin leave spatiotemporally consistent fingerprints. Here we measure the 14C content in 484 individual tree rings formed in the periods 770–780 and 990–1000 CE. Distinct 14C excursions starting in the boreal summer of 774 and the boreal spring of 993 ensure the precise dating of 44 tree-ring records from five continents. We also identify a meridional decline of 11-year mean atmospheric radiocarbon concentrations across both hemispheres. Corroborated by historical eye-witness accounts of red auroras, our results suggest a global exposure to strong solar proton radiation. To improve understanding of the return frequency and intensity of past cosmic events, which is particularly important for assessing the potential threat of space weather on our society, further annually resolved 14C measurements are needed.
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| 4. |
- Emile-Geay, J., et al.
(author)
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Data Descriptor: A global multiproxy database for temperature reconstructions of the Common Era
- 2017
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In: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 4
-
Journal article (peer-reviewed)abstract
- Reproducible climate reconstructions of the Common Era (1 CE to present) are key to placing industrial-era warming into the context of natural climatic variability. Here we present a community-sourced database of temperature-sensitive proxy records from the PAGES2k initiative. The database gathers 692 records from 648 locations, including all continental regions and major ocean basins. The records are from trees, ice, sediment, corals, speleothems, documentary evidence, and other archives. They range in length from 50 to 2000 years, with a median of 547 years, while temporal resolution ranges from biweekly to centennial. Nearly half of the proxy time series are significantly correlated with HadCRUT4.2 surface temperature over the period 1850-2014. Global temperature composites show a remarkable degree of coherence between high-and low-resolution archives, with broadly similar patterns across archive types, terrestrial versus marine locations, and screening criteria. The database is suited to investigations of global and regional temperature variability over the Common Era, and is shared in the Linked Paleo Data (LiPD) format, including serializations in Matlab, R and Python. Since the pioneering work of D'Arrigo and Jacoby1-3, as well as Mann et al. 4,5, temperature reconstructions of the Common Era have become a key component of climate assessments6-9. Such reconstructions depend strongly on the composition of the underlying network of climate proxies10, and it is therefore critical for the climate community to have access to a community-vetted, quality-controlled database of temperature-sensitive records stored in a self-describing format. The Past Global Changes (PAGES) 2k consortium, a self-organized, international group of experts, recently assembled such a database, and used it to reconstruct surface temperature over continental-scale regions11 (hereafter, ` PAGES2k-2013'). This data descriptor presents version 2.0.0 of the PAGES2k proxy temperature database (Data Citation 1). It augments the PAGES2k-2013 collection of terrestrial records with marine records assembled by the Ocean2k working group at centennial12 and annual13 time scales. In addition to these previously published data compilations, this version includes substantially more records, extensive new metadata, and validation. Furthermore, the selection criteria for records included in this version are applied more uniformly and transparently across regions, resulting in a more cohesive data product. This data descriptor describes the contents of the database, the criteria for inclusion, and quantifies the relation of each record with instrumental temperature. In addition, the paleotemperature time series are summarized as composites to highlight the most salient decadal-to centennial-scale behaviour of the dataset and check mutual consistency between paleoclimate archives. We provide extensive Matlab code to probe the database-processing, filtering and aggregating it in various ways to investigate temperature variability over the Common Era. The unique approach to data stewardship and code-sharing employed here is designed to enable an unprecedented scale of investigation of the temperature history of the Common Era, by the scientific community and citizen-scientists alike.
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| 5. |
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| 6. |
- Zammit, A. R., et al.
(author)
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A Coordinated Multi-study Analysis of the Longitudinal Association Between Handgrip Strength and Cognitive Function in Older Adults
- 2021
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In: The journals of gerontology. Series B, Psychological sciences and social sciences. - : Oxford University Press (OUP). - 1758-5368 .- 1079-5014. ; 76:2, s. 229-241
-
Journal article (peer-reviewed)abstract
- OBJECTIVE: Handgrip strength, an indicator of overall muscle strength, has been found to be associated with slower rate of cognitive decline and decreased risk for cognitive impairment and dementia. However, evaluating the replicability of associations between aging-related changes in physical and cognitive functioning is challenging due to differences in study designs and analytical models. A multiple-study coordinated analysis approach was used to generate new longitudinal results based on comparable construct-level measurements and identical statistical models and to facilitate replication and research synthesis. METHODS: We performed coordinated analysis on 9 cohort studies affiliated with the Integrative Analysis of Longitudinal Studies of Aging and Dementia (IALSA) research network. Bivariate linear mixed models were used to examine associations among individual differences in baseline level, rate of change, and occasion-specific variation across grip strength and indicators of cognitive function, including mental status, processing speed, attention and working memory, perceptual reasoning, verbal ability, and learning and memory. Results were summarized using meta-analysis. RESULTS: After adjustment for covariates, we found an overall moderate association between change in grip strength and change in each cognitive domain for both males and females: Average correlation coefficient was 0.55 (95% CI = 0.44-0.56). We also found a high level of heterogeneity in this association across studies. DISCUSSION: Meta-analytic results from nine longitudinal studies showed consistently positive associations between linear rates of change in grip strength and changes in cognitive functioning. Future work will benefit from the examination of individual patterns of change to understand the heterogeneity in rates of aging and health-related changes across physical and cognitive biomarkers. Published by Oxford University Press on behalf of The Gerontological Society of America 2019.
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| 7. |
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| 8. |
- Jackson, Victoria E, et al.
(author)
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Meta-analysis of exome array data identifies six novel genetic loci for lung function.
- 2018
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In: Wellcome open research. - : F1000 Research Ltd. - 2398-502X. ; 3
-
Journal article (peer-reviewed)abstract
- Background: Over 90 regions of the genome have been associated with lung function to date, many of which have also been implicated in chronic obstructive pulmonary disease. Methods: We carried out meta-analyses of exome array data and three lung function measures: forced expiratory volume in one second (FEV 1), forced vital capacity (FVC) and the ratio of FEV 1 to FVC (FEV 1/FVC). These analyses by the SpiroMeta and CHARGE consortia included 60,749 individuals of European ancestry from 23 studies, and 7,721 individuals of African Ancestry from 5 studies in the discovery stage, with follow-up in up to 111,556 independent individuals. Results: We identified significant (P<2·8x10 -7) associations with six SNPs: a nonsynonymous variant in RPAP1, which is predicted to be damaging, three intronic SNPs ( SEC24C, CASC17 and UQCC1) and two intergenic SNPs near to LY86 and FGF10. Expression quantitative trait loci analyses found evidence for regulation of gene expression at three signals and implicated several genes, including TYRO3 and PLAU. Conclusions: Further interrogation of these loci could provide greater understanding of the determinants of lung function and pulmonary disease.
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| 9. |
- Neikter, Magnus, 1988-, et al.
(author)
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Texture of electron beam melted Ti-6Al-4V measured with neutron diffraction
- 2020
-
Conference paper (peer-reviewed)abstract
- Texture in materials is important as it contributes to anisotropy in the bulk mechanical properties. Ti-6Al-4V built with the additive manufacturing process (AM) electron beam melting (EBM) has been found to have anisotropic mechanical properties. Therefore, this work has been performed to investigate the texture variations of EBM built Ti-6Al-4V with neutron time of flight (TOF). For the work, samples were produced with different build geometries off-set by 90 degrees. A cast sample was additionally analyzed to investigate the bulk texture of conventionally manufactured material. Microstructural characterization was performed and the cast material was found to have a coarse colony α microstructure, whereas the EBM built material had a finer basket weave microstructure. Overall, the texture of the EBM built material was found to be weak having an multiple of random distribution (MRD) index of ~1 for the α phase, whilst the cast material possessed more than twice the amount of preferred orientation i.e. MRD 2.51 for the α phase.
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| 10. |
- Andersson, K., et al.
(author)
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Failure Investigation of an Airline Engine Failure During Take Off
- 2013
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In: Praktische Metallographie/Practical Metallography. - : Walter de Gruyter GmbH. - 0032-678X. ; 50:12, s. 821-830
-
Journal article (peer-reviewed)abstract
- An Iran Airlines CF6-8002A2F engine had a turbine failure during takeoff from the Arlanda airport in Sweden, in January 2010. Failure investigation of the engine was performed by Lufthansa Technik AG (LHT). The Swedish Accident Investigation Board (SHK) requested a second opinion of the available High Pressure Turbine (HPT) Diffuser Aft Seal hardware, received from LHT, and because of GKN Aerospace Sweden's extensive experience as Original Equipment Manufacturer (OEM) of Swedish fighter engines this second failure analysis work was performed by GKN. The failure investigation of the Diffuser Aft Seal pieces and fragments received from LHT revealed no fractures or fatigue cracks which are believed to be evidences of the primary cause to the failure. However, a secondary fatigue crack was found in an aft tooth fragment from the Diffuser Aft Seal. This tooth fragment has also a machining step on the forward surface, between a repair weld and the original tooth, with a geometry which gives a stress concentration factor of about 2.5 for radial and bending stresses in this area. This machining step may have contributed to initiate a fatigue crack in the seal tooth.
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| 11. |
- D'Orangeville, Loic, et al.
(author)
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Drought timing and local climate determine the sensitivity of eastern temperate forests to drought
- 2018
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In: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 24:6, s. 2339-2351
-
Journal article (peer-reviewed)abstract
- Projected changes in temperature and drought regime are likely to reduce carbon (C) storage in forests, thereby amplifying rates of climate change. While such reductions are often presumed to be greatest in semi-arid forests that experience widespread tree mortality, the consequences of drought may also be important in temperate mesic forests of Eastern North America (ENA) if tree growth is significantly curtailed by drought. Investigations of the environmental conditions that determine drought sensitivity are critically needed to accurately predict ecosystem feedbacks to climate change. We matched site factors with the growth responses to drought of 10,753 trees across mesic forests of ENA, representing 24 species and 346 stands, to determine the broad-scale drivers of drought sensitivity for the dominant trees in ENA. Here we show that two factors-the timing of drought, and the atmospheric demand for water (i.e., local potential evapotranspiration; PET)-are stronger drivers of drought sensitivity than soil and stand characteristics. Droughtinduced reductions in tree growth were greatest when the droughts occurred during early-season peaks in radial growth, especially for trees growing in the warmest, driest regions (i.e., highest PET). Further, mean species trait values (rooting depth and psi(50)) were poor predictors of drought sensitivity, as intraspecific variation in sensitivity was equal to or greater than interspecific variation in 17 of 24 species. From a general circulation model ensemble, we find that future increases in earlyseason PET may exacerbate these effects, and potentially offset gains in C uptake and storage in ENA owing to other global change factors.
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| 12. |
- Johnson, Alexander I., et al.
(author)
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A multiferroic molecular magnetic qubit
- 2019
-
In: Journal of Chemical Physics. - : American Institute of Physics (AIP). - 0021-9606 .- 1089-7690. ; 151:17, s. 1-7
-
Journal article (peer-reviewed)abstract
- The chiral Fe3O(NC5H5)3(O2CC6H5)6 molecular cation, with C-3 symmetry, is composed of three six-fold coordinated spin-carrying Fe3+ cations that form a perfect equilateral triangle. Experimental reports demonstrating the spin-electric effect in this system also identify the presence of a magnetic uniaxis and suggest that this molecule may be a good candidate for an externally controllable molecular qubit. Here, we demonstrate, using standard density-functional methods, that the spin-electric behavior of this molecule could be even more interesting as there are energetically competitive reference states associated with both high and low local spins (S = 5/2 vs S = 1/2) on the Fe3+ ions. Each of these structures allow for spin-electric ground states. We find that qualitative differences in the broadening of the Fe(2s) and O(1s) core levels, shifts in the core-level energies, and the magnetic signatures of the single-spin anisotropy Hamiltonian may be used to confirm whether a transition between a high-spin manifold and a low spin manifold occurs.
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| 13. |
- Leland, Caroline, et al.
(author)
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Missing Rings, Synchronous Growth, and Ecological Disturbance in a 36-Year Pitch Pine (Pinus rigida) Provenance Study
- 2016
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:5
-
Journal article (peer-reviewed)abstract
- Provenance studies are an increasingly important analog for understanding how trees adapted to particular climatic conditions might respond to climate change. Dendrochronological analysis can illuminate differences among trees from different seed sources in terms of absolute annual growth and sensitivity to external growth factors. We analyzed annual radial growth of 567 36-year-old pitch pine (Pinus rigida Mill.) trees from 27 seed sources to evaluate their performance in a New Jersey Pine Barrens provenance experiment. Unexpectedly, missing rings were prevalent in most trees, and some years-1992, 1999, and 2006-had a particularly high frequency of missing rings across the plantation. Trees from local seed sources (<55 km away from the plantation) had a significantly smaller percentage of missing rings from 1980-2009 (mean: 5.0%), relative to northernmost and southernmost sources (mean: 9.3% and 7.9%, respectively). Some years with a high frequency of missing rings coincide with outbreaks of defoliating insects or dry growing season conditions. The propensity for missing rings synchronized annual variations in growth across all trees and might have complicated the detection of potential differences in interannual variability among seed sources. Average ring width was significantly larger in seed sources from both the southernmost and warmest origins compared to the northernmost and coldest seed sources in most years. Local seed sources had the highest average radial growth. Adaptation to local environmental conditions and disturbances might have influenced the higher growth rate found in local seed sources. These findings underscore the need to understand the integrative impact of multiple environmental drivers, such as disturbance agents and climate change, on tree growth, forest dynamics, and the carbon cycle.
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| 14. |
- Liang, E. Y., et al.
(author)
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Strong link between large tropical volcanic eruptions and severe droughts prior to monsoon in the central Himalayas revealed by tree-ring records
- 2019
-
In: Science Bulletin. - : Elsevier BV. - 2095-9273. ; 64:14, s. 1018-1023
-
Journal article (peer-reviewed)abstract
- Large tropical volcanic eruptions can cause short-term global cooling. However, little is known whether large tropical volcanic eruptions, like the one in Tambora/Indonesia in 1815, cause regional hydroclimatic anomalies. Using a tree-ring network of precisely dated Himalayan birch in the central Himalayas, we reconstructed variations in the regional pre-monsoon precipitation back to 1650 CE. A superposed epoch analysis indicates that the pre-monsoon regional droughts are associated with large tropical volcanic eruptions, appearing to have a strong influence on hydroclimatic conditions in the central Himalayas. In fact, the most severe drought since 1650 CE occurred after the Tambora eruption. These results suggest that dry conditions prior to monsoon in the central Himalayas were associated with explosive tropical volcanism. Prolonged La Nina events also correspond with persistent pre-monsoon droughts in the central Himalayas. Our results provide evidence that large tropical volcanic eruptions most likely induced severe droughts prior to monsoon in the central Himalayas. (C) 2019 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.
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| 15. |
- Linde, Anna-Malin, et al.
(author)
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Early evolution of the land plant circadian clock
- 2017
-
In: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 216:2, s. 576-590
-
Journal article (peer-reviewed)abstract
- While angiosperm clocks can be described as an intricate network of interlocked transcriptional feedback loops, clocks of green algae have been modelled as a loop of only two genes. To investigate the transition from a simple clock in algae to a complex one in angiosperms, we performed an inventory of circadian clock genes in bryophytes and charophytes. Additionally, we performed functional characterization of putative core clock genes in the liverwort Marchantia polymorpha and the hornwort Anthoceros agrestis. Phylogenetic construction was combined with studies of spatiotemporal expression patterns and analysis of M. polymorpha clock gene mutants. Homologues to core clock genes identified in Arabidopsis were found not only in bryophytes but also in charophytes, albeit in fewer copies. Circadian rhythms were detected for most identified genes in M. polymorpha and A. agrestis, and mutant analysis supports a role for putative clock genes in M. polymorpha. Our data are in line with a recent hypothesis that adaptation to terrestrial life occurred earlier than previously expected in the evolutionary history of charophyte algae. Both gene duplication and acquisition of new genes was important in the evolution of the plant circadian clock, but gene loss has also contributed to shaping the clock of bryophytes.
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| 16. |
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| 17. |
- Michalak, Lukasz, et al.
(author)
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Theory of tunneling spectroscopy in a Mn12 single-electron transistor by DFT methods
- 2010
-
In: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 104:1, s. 017202-017205
-
Journal article (peer-reviewed)abstract
- We consider tunneling transport through a Mn12 molecular magnet using spin density functional theory. A tractable methodology for constructing many-body wave functions from Kohn-Sham orbitals allows for the determination of spin-dependent matrix elements for use in transport calculations. The tunneling conductance at finite bias is characterized by peaks representing transitions between spin multiplets, separated by an energy on the order of the magnetic anisotropy. The energy splitting of the spin multiplets and the spatial part of their many-body wave functions, describing the orbital degrees of freedom of the excess charge, strongly affect the electronic transport, and can lead to negative differential conductance.
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| 18. |
- Neikter, Magnus, 1988-, et al.
(author)
-
Alpha texture variations in additive manufactured Ti-6Al-4V investigated with neutron diffraction
- 2018
-
In: Additive Manufacturing. - : Elsevier. - 2214-8604 .- 2214-7810. ; 23, s. 225-234
-
Journal article (peer-reviewed)abstract
- Variation of texture in Ti-6Al-4V samples produced by three different additive manufacturing (AM) processes has been studied by neutron time-of-flight (TOF) diffraction. The investigated AM processes were electron beam melting (EBM), selective laser melting (SLM) and laser metal wire deposition (LMwD). Additionally, for the LMwD material separate measurements were done on samples from the top and bottom pieces in order to detect potential texture variations between areas close to and distant from the supporting substrate in the manufacturing process. Electron backscattered diffraction (EBSD) was also performed on material parallel and perpendicular to the build direction to characterize the microstructure. Understanding the context of texture for AM processes is of significant relevance as texture can be linked to anisotropic mechanical behavior. It was found that LMwD had the strongest texture while the two powder bed fusion (PBF) processes EBM and SLM displayed comparatively weaker texture. The texture of EBM and SLM was of the same order of magnitude. These results correlate well with previous microstructural studies. Additionally, texture variations were found in the LMwD sample, where the part closest to the substrate featured stronger texture than the corresponding top part. The crystal direction of the α phase with the strongest texture component was [112¯3]. © 2018 Elsevier B.V.
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| 19. |
- Nossa, Javier, et al.
(author)
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Electric control of a {Fe4} single-molecule magnet in a single-electron transistor
- 2013
-
In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 88:22, s. Article ID: 224423-
-
Journal article (peer-reviewed)abstract
- Using first-principles methods, we study theoretically the properties of an individual {Fe-4} single-molecule magnet (SMM) attached to metallic leads in a single-electron transistor geometry. We show that the conductive leads do not affect the spin ordering and magnetic anisotropy of the neutral SMM. On the other hand, the leads have a strong effect on the anisotropy of the charged states of the molecule, which are probed in Coulomb blockade transport. Furthermore, we demonstrate that an external electric potential, modeling a gate electrode, can be used to manipulate the magnetic properties of the system. For a charged molecule, by localizing the extra charge with the gate voltage closer to the magnetic core, the anisotropy magnitude and spin ordering converges to the values found for the isolated {Fe-4} SMM. We compare these findings with the results of recent quantum transport experiments in three-terminal devices.
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| 20. |
- Nossa, Javier, 1979-, et al.
(author)
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Electric control of spin states in frustrated triangular molecular magnets
- 2023
-
In: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 107:24
-
Journal article (peer-reviewed)abstract
- Frustrated triangular molecular magnets are a very important class of magnetic molecules since the absence of inversion symmetry allows an external electric field to couple directly with the spin chirality that characterizes their ground state. The spin-electric coupling in these molecular magnets leads to an efficient and fast method of manipulating spin states, making them an exciting candidate for quantum information processing. The efficiency of the spin-electric coupling depends on the spin-induced electric-dipole moment of the frustrated spin configurations contributing to the chiral ground state. In this paper, we report on first-principles calculations of spin-electric coupling in a {V3} triangular magnetic molecule. We have explicitly calculated the spin-induced charge redistribution within the magnetic centers that is responsible for the spin-electric coupling. Furthermore, we have generalized the method of calculating the strength of the spin-electric coupling to calculate any triangular spin-1/2 molecule with C3 symmetry and have applied it to calculate the coupling strength in {V15} molecular magnets.
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| 21. |
- Pederson, Eric R. A., et al.
(author)
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Genome Sequencing of Pleurozium schreberi : The Assembled and Annotated Draft Genome of a Pleurocarpous Feather Moss
- 2019
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In: G3. - : Oxford University Press (OUP). - 2160-1836. ; 9:9, s. 2791-2797
-
Journal article (peer-reviewed)abstract
- The pleurocarpous feather moss Pleurozium schreberi is a ubiquitous moss species which plays a fundamental role in many terrestrial ecosystems, for instance within the boreal forest, the Earth's largest terrestrial biome, this species plays a significant role in driving ecosystem nitrogen and carbon inputs and fluxes. By hosting dinitrogen (N-2)-fixing cyanobacteria, the moss-cyanobacteria symbiosis constitutes the main nitrogen input into the ecosystem and by the high productivity and the low decomposability of the moss litter, P. schreberi contributes significantly to build-up soil organic matter, and therefore long-term C sequestration. Knowledge on P. schreberi genome will facilitate the development of 'omics' and system's biology approaches to gain a more complete understanding of the physiology and ecological adaptation of the moss and the mechanisms underpinning the establishment of the symbiosis. Here we present the de novo assembly and annotation of P. schreberi genome that will help investigating these questions. The sequencing was performed using the HiSeq X platform with Illumina paired-end and mate-pair libraries prepared with CTAB extracted DNA. In total, the assembled genome was approximately 318 Mb, while repetitive elements account for 28.42% of the genome and 15,992 protein-coding genes were predicted from the genome, of which 84.23% have been functionally annotated. We anticipate that the genomic data generated will constitute a significant resource to study ecological and evolutionary genomics of P. schreberi, and will be valuable for evo-devo investigations as well as our understanding of the evolution of land plants by providing the genome of a pleurocarpous moss.
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| 22. |
- Pederson, Robert, et al.
(author)
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Microstructure and mechanical properties of friction- and electron-beam welded Ti-6Al-4V and Ti-6Al-2Sn-4Zr-6Mo
- 2012
-
In: Materials Science & Engineering. - : Elsevier. - 0921-5093 .- 1873-4936. ; 552, s. 555-565
-
Journal article (peer-reviewed)abstract
- This work presents mechanical data and microstructural characterization of friction welded (FRW) and electron beam welded (EBW) post weld heat treated (PWHT) specimens of Ti-6Al-2Sn-4Zr-6Mo and Ti-6Al-4V. PWHT Ti6246/Ti6246 welds and Ti64/Ti6246 welds were evaluated with tensile-, creep-. Charpy-V, and microhardness tests. The PWHT treatments were 593 degrees C/2 h, 640 degrees C/2 h and 704 degrees C/2 h, respectively. The microstructure of the different weld types and alloy combinations where examined and characterized using optical microscope and SEM. Tensile strength and yield strength were within specification for both material combinations. The elongation for Ti6246 welded to Ti6246 is below specification. Only small variations in tensile properties were found for the different PWHTs. Fracture occurred in base material of the Ti64 alloy for the combination of Ti64 welded to Ti6246. Charpy-V tests shows that the welds are more brittle compared with the base material. The largest difference was found in Ti6246 welded to Ti6246. No significant variation in creep properties for the different PWHTs has been found. Ti64 welded to Ti6246 shows poor creep properties due to the high testing temperature for the Ti64 alloy. Ti6246 welded to Ti6246 shows good creep properties compared to the base material. The general trend for the weld microhardness was a decreasing hardness with increasing PWHT temperature. One exception though was the FRW Ti64/Ti6246 combination, were the hardness of the Ti6246 side of the HAZ, close to the interface between the two alloys, was highest after a PWHT temperature of 593 degrees C, then decreasing in hardness for 640 degrees C, not PWHT and being least hard for the PWHT temperature of 704 degrees C. The hardness of the Ti64 base material showed no decrease after the PWHTs, but the hardness of the Ti6246 bulk material decreased after PWHT at 704 degrees C. (c) 2012 Elsevier B.V. All rights reserved.
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| 23. |
- Pertsova, Anna, 1985-, et al.
(author)
-
Chapter Three : Electronic Transport as a Driver for Self-Interaction-Corrected Methods
- 2015
-
In: Advances In Atomic, Molecular, and Optical Physics. - : Academic Press. - 9780128021279 ; , s. 29-86
-
Book chapter (peer-reviewed)abstract
- While spintronics often investigates striking collective spin e ects in large systems, a very important research direction deals with spin-dependent phenomena in nanostructures, reaching the extreme of a single spin conned in a quantum dot, in a molecule, or localized on an impurity or dopant. The issue considered in this chapter involves taking this extreme to the nanoscale and the quest to use rst-principles methods to predict and control the behavior of a few \spins" (down to 1 spin) when they are placed in an interesting environment. Particular interest is on environments for which addressing these systems with external elds and/or electric or spin currents is possible. The realization of such systems, including those that consist of a core of a few transition-metal (TM) atoms carrying a spin, connected and exchanged-coupled through bridging oxo-ligands has been due to work by many experimental researchers at the interface of atomic, molecular and condensed matter physics. This chapter addresses computational problems associated with understanding the behaviors of nanoand molecular-scale spin systems and reports on how the computational complexity increases when such systems are used for elements of electron transport devices. Especially for cases where these elements are attached to substrates with electronegativities that are very di erent than the molecule, or for coulomb blockade systems, or for cases where the spin-ordering within the molecules is weakly antiferromagnetic, the delocalization error in DFT is particularly problematic and one which requires solutions, such as self-interaction corrections, to move forward. We highlight the intersecting elds of spin-ordered nanoscale molecular magnets, electron transport, and coulomb blockade and highlight cases where self-interaction corrected methodologies can improve our predictive power in this emerging field.
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| 24. |
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| 25. |
- Stuart, Rhona K., et al.
(author)
-
Bidirectional C and N transfer and a potential role for sulfur in an epiphytic diazotrophic mutualism
- 2020
-
In: The ISME Journal. - : Springer Science and Business Media LLC. - 1751-7362 .- 1751-7370. ; 14:12, s. 3068-3078
-
Journal article (peer-reviewed)abstract
- In nitrogen-limited boreal forests, associations between feathermoss and diazotrophic cyanobacteria control nitrogen inputs and thus carbon cycling, but little is known about the molecular regulators required for initiation and maintenance of these associations. Specifically, a benefit to the cyanobacteria is not known, challenging whether the association is a nutritional mutualism. Targeted mutagenesis of the cyanobacterial alkane sulfonate monooxygenase results in an inability to colonize feathermosses by the cyanobacteriumNostoc punctiforme, suggesting a role for organic sulfur in communication or nutrition. Isotope probing paired with high-resolution imaging mass spectrometry (NanoSIMS) demonstrated bidirectional elemental transfer between partners, with carbon and sulfur both being transferred to the cyanobacteria, and nitrogen transferred to the moss. These results support the hypothesis that moss and cyanobacteria enter a mutualistic exosymbiosis with substantial bidirectional material exchange of carbon and nitrogen and potential signaling through sulfur compounds.
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| 26. |
- Tengvall, Katarina, 1980-, et al.
(author)
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Bayesian model and selection signature analyses reveal risk factors for canine atopic dermatitis
- 2022
-
In: Communications Biology. - : Springer Nature. - 2399-3642. ; 5:1
-
Journal article (peer-reviewed)abstract
- Canine atopic dermatitis is an inflammatory skin disease with clinical similarities to human atopic dermatitis. Several dog breeds are at increased risk for developing this disease but previous genetic associations are poorly defined. To identify additional genetic risk factors for canine atopic dermatitis, we here apply a Bayesian mixture model adapted for mapping complex traits and a cross-population extended haplotype test to search for disease-associated loci and selective sweeps in four dog breeds at risk for atopic dermatitis. We define 15 associated loci and eight candidate regions under selection by comparing cases with controls. One associated locus is syntenic to the major genetic risk locus (Filaggrin locus) in human atopic dermatitis. One selection signal in common type Labrador retriever cases positions across the TBC1D1 gene (body weight) and one signal of selection in working type German shepherd controls overlaps the LRP1B gene (brain), near the KYNU gene (psoriasis). In conclusion, we identify candidate genes, including genes belonging to the same biological pathways across multiple loci, with potential relevance to the pathogenesis of canine atopic dermatitis. The results show genetic similarities between dog and human atopic dermatitis, and future across-species genetic comparisons are hereby further motivated.
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| 27. |
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| 28. |
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