| 1. |
- Palmer, Nicholette D, et al.
(author)
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A genome-wide association search for type 2 diabetes genes in African Americans.
- 2012
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In: PloS one. - San Francisco : Public Library of Science (PLoS). - 1932-6203. ; 7:1, s. e29202-
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Journal article (peer-reviewed)abstract
- African Americans are disproportionately affected by type 2 diabetes (T2DM) yet few studies have examined T2DM using genome-wide association approaches in this ethnicity. The aim of this study was to identify genes associated with T2DM in the African American population. We performed a Genome Wide Association Study (GWAS) using the Affymetrix 6.0 array in 965 African-American cases with T2DM and end-stage renal disease (T2DM-ESRD) and 1029 population-based controls. The most significant SNPs (n = 550 independent loci) were genotyped in a replication cohort and 122 SNPs (n = 98 independent loci) were further tested through genotyping three additional validation cohorts followed by meta-analysis in all five cohorts totaling 3,132 cases and 3,317 controls. Twelve SNPs had evidence of association in the GWAS (P<0.0071), were directionally consistent in the Replication cohort and were associated with T2DM in subjects without nephropathy (P<0.05). Meta-analysis in all cases and controls revealed a single SNP reaching genome-wide significance (P<2.5×10(-8)). SNP rs7560163 (P = 7.0×10(-9), OR (95% CI) = 0.75 (0.67-0.84)) is located intergenically between RND3 and RBM43. Four additional loci (rs7542900, rs4659485, rs2722769 and rs7107217) were associated with T2DM (P<0.05) and reached more nominal levels of significance (P<2.5×10(-5)) in the overall analysis and may represent novel loci that contribute to T2DM. We have identified novel T2DM-susceptibility variants in the African-American population. Notably, T2DM risk was associated with the major allele and implies an interesting genetic architecture in this population. These results suggest that multiple loci underlie T2DM susceptibility in the African-American population and that these loci are distinct from those identified in other ethnic populations.
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| 2. |
- Boström, Per, 1982-
(author)
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”Det här är ju dött tåg liksom…” : en studie av metaforer för ROMANTISK KÄRLEK i talad svenska
- 2018
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Doctoral thesis (other academic/artistic)abstract
- The purpose of this study is to investigate the metaphorization of ROMANTIC LOVE in spoken Swedish. The study is based on 4 semi-structured focus group conversations with participants in two age groups; 24–33 and 50–54. A Swedish short film and questions related to the film were used as stimuli for the conversations. Research questions asked are 1) How is the concept of ROMANTIC LOVE metaphorized in the recorded group conversations? 2) How does the metaphorization vary between the conversations? and 3) What cultural model for ROMANTIC LOVE in the conversations can be reconstructed based on identified metaphorizations? The study is situated within Cognitive Linguistics and the framework of Conceptual Metaphor Theory and a Discourse Dynamics Approach to Metaphor. Consequently, metaphor is seen as a cognitive, linguistic, socio-cultural and discursive phenomenon, where metaphorization is a dynamic process that develops, adapts and flows within the conversations and between the participants. Accordingly, the identified metaphorizations are considered to be influenced by the speakers and their embodied experiences, their embodied cognition, the discourse event, and socio-cultural aspects of metaphorization. The focus of the present study, ROMANTIC LOVE, is considered as a dynamic concept based on philosophical, feminist, psychological and metaphorical research. Metaphors are identified through a discourse dynamic version of MIP and MIPVU.From the analyses, 6 systematic metaphors are proposed, where ROMANTIC LOVE is metaphorized as a PHYSICAL OBJECT (incl. as a POSSESSION and as a LIVING ORGANISM), as a CONTAINER (incl. CONSTRUCTION and BODY as a CONTAINER), as TRAVELLING together (with primary focus on TRAVELLING together rather than SOURCE or TARGET), as a UNITY (with focus on how a UNITY is ESTABLISHED, MAINTAINED and DISSOLVED, ideally by two COMPATIBLE partners), as a PHYSICAL and NATURAL FORCE and as a DISEASE (where LOVE can affect a person’s perception and sanity). In addition, ROMANTIC LOVE is, in a small number of expressions, metaphorized as a CRIME, as a PHYSICAL CONFLICT and as a GAME. The variation in metaphorization is small between the conversations. Some metaphorizations seem to be related to the age of the participants. ROMANTIC LOVE ismoreover something people usually have influence over and in some ways can control. In total, 780 metaphorical expressions and 9 source domains are identified. Departing from the interplay betweenmetaphorization and culture, a cultural model for ROMANTIC LOVE is reconstructed, where a multifaceted, embodied and experiential concept of ROMANTIC LOVE emerges.
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| 3. |
- Boström, M., et al.
(author)
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Dispersion Forces Stabilize Ice Coatings at Certain Gas Hydrate Interfaces That Prevent Water Wetting
- 2019
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In: ACS Earth and Space Chemistry. - : American Chemical Society. - 2472-3452. ; 3:6, s. 1014-1022
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Journal article (peer-reviewed)abstract
- Gas hydrates formed in oceans and permafrost occur in vast quantities on Earth representing both a massive potential fuel source and a large threat in climate forecasts. They have been predicted to be important on other bodies in our solar systems such as Enceladus, a moon of Saturn. CO 2 -hydrates likely drive the massive gas-rich water plumes seen and sampled by the spacecraft Cassini, and the source of these hydrates is thought to be due to buoyant gas hydrate particles. Dispersion forces can in some cases cause gas hydrates at thermal equilibrium to be coated in a 3-4 nm thick film of ice, or to contact water directly, depending on which gas they contain. As an example, the results are valid at a quadruple point of the water-CO 2 gas hydrate system, where a film is formed not only for the model with pure ice but also in the presence of impurities in water or in the ice layer. These films are shown to significantly alter the properties of the gas hydrate clusters, for example, whether they float or sink. It is also expected to influence gas hydrate growth and gas leakage.
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| 4. |
- Boström, M., et al.
(author)
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Tuning the Casimir-Lifshitz force with gapped metals
- 2023
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In: Physical Review B. - : American Physical Society (APS). - 2469-9950 .- 2469-9969. ; 108:16
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Journal article (peer-reviewed)abstract
- The Casimir-Lifshitz interaction, a long-range force that arises between solids and molecules due to quantum fluctuations in electromagnetic fields, has been widely studied in solid-state physics. The degree of polarization in this interaction is influenced by the dielectric properties of the materials involved, which in turn are determined by factors such as band-to-band transitions, free carrier contributions, phonon contributions, and exciton contributions. Gapped metals, a new class of materials with unique electronic structures, offer the potential to manipulate dielectric properties and, consequently, the Casimir-Lifshitz interaction. In this study, we theoretically investigate the finite temperature Casimir-Lifshitz interaction in La3Te4-based gapped metal systems with varying off-stoichiometry levels. We demonstrate that off-stoichiometric effects in gapped metals can be used to control the magnitude and, in some cases, even the sign of Casimir-Lifshitz interactions. We predict measurable corrections due to stoichiometry on the predicted Casimir force between a La3Te4 surface and a gold sphere, attached to an atomic force microscopy tip.
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| 5. |
- Boström, M., et al.
(author)
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Understanding ice and water film formation on soil particles by combining density functional theory and Casimir-Lifshitz forces
- 2023
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In: Physical Review B. - : American Physical Society (APS). - 2469-9950 .- 2469-9969. ; 108:12
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Journal article (peer-reviewed)abstract
- Thin films of ice and water on soil particles play crucial roles in environmental and technological processes. Understanding the fundamental physical mechanisms underlying their formation is essential for advancing scientific knowledge and engineering practices. Herein, we focus on the role of the Casimir-Lifshitz force, also referred to as dispersion force, in the formation and behavior of thin films of ice and water on soil particles at 273.16 K, arising from quantum fluctuations of the electromagnetic field and depending on the dielectric properties of interacting materials. We employ the first-principles density functional theory (DFT) to compute the dielectric functions for two model materials, CaCO3 and Al2O3, essential constituents in various soils. These dielectric functions are used with the Kramers-Kronig relationship and different extrapolations to calculate the frequency-dependent quantities required for determining forces and free energies. Moreover, we assess the accuracy of the optical data based on the DFT to model dispersion forces effectively, such as those between soil particles. Our findings reveal that moisture can accumulate into almost micron-sized water layers on the surface of calcite (soil) particles, significantly impacting the average dielectric properties of soil particles. This research highlights the relevance of DFT-based data for understanding thin film formation in soil particles and offers valuable insights for environmental and engineering applications.
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| 6. |
- Boström, M., et al.
(author)
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van der Waals induced ice growth on partially melted ice nuclei in mist and fog
- 2023
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In: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 25:47, s. 32709-32714
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Journal article (peer-reviewed)abstract
- Ice nucleation and formation play pivotal roles across various domains, from environmental science to food engineering. However, the exact ice formation mechanisms remain incompletely understood. This study introduces a novel ice formation process, which can be either heterogeneous or homogeneous, depending on the initial conditions. The process initiates ice crystal growth from a nucleus composed of a micron-sized partially melted ice particle. We explore the role of van der Waals (Lifshitz)-free energy and its resulting stress in the accumulation of ice at the interface with water vapor. Our analysis suggests that this process could lead to thicknesses ranging from nanometers to micrometers, depending on the size and degree of initial melting of the ice nucleus. We provide evidence for the growth of thin ice layers instead of liquid water films on a partially melted ice-vapor interface, offering some insights into mist and fog formation. We also link it to potential atmospheric and astrogeophysical applications.
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| 7. |
- Luo, Y. -W, et al.
(author)
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Database of diazotrophs in global ocean : abundance, biomass and nitrogen fixation rates
- 2012
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In: Earth System Science Data. - : Copernicus GmbH. - 1866-3508 .- 1866-3516. ; 4:1, s. 47-73
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Journal article (peer-reviewed)abstract
- Marine N-2 fixing microorganisms, termed di-azotrophs, are a key functional group in marine pelagic ecosystems. The biological fixation of dinitrogen ( N-2) to bioavailable nitrogen provides an important new source of nitrogen for pelagic marine ecosystems and influences primary productivity and organic matter export to the deep ocean. As one of a series of efforts to collect biomass and rates specific to different phytoplankton functional groups, we have constructed a database on diazotrophic organisms in the global pelagic upper ocean by compiling about 12 000 direct field measurements of cyanobacterial diazotroph abundances (based on microscopic cell counts or qPCR assays targeting the nifH genes) and N-2 fixation rates. Biomass conversion factors are estimated based on cell sizes to convert abundance data to diazotrophic biomass. The database is limited spatially, lacking large regions of the ocean especially in the Indian Ocean. The data are approximately log-normal distributed, and large variances exist in most sub-databases with non-zero values differing 5 to 8 orders of magnitude. Reporting the geometric mean and the range of one geometric standard error below and above the geometric mean, the pelagic N-2 fixation rate in the global ocean is estimated to be 62 (52-73) Tg Nyr(-1) and the pelagic diazotrophic biomass in the global ocean is estimated to be 2.1 (1.4-3.1) Tg C from cell counts and to 89 (43-150) Tg C from nifH- based abundances. Reporting the arithmetic mean and one standard error instead, these three global estimates are 140 +/- 9.2 Tg Nyr(-1), 18 +/- 1.8 Tg C and 590 +/- 70 Tg C, respectively. Uncertainties related to biomass conversion factors can change the estimate of geometric mean pelagic diazotrophic biomass in the global ocean by about +/- 70 %. It was recently established that the most commonly applied method used to measure N-2 fixation has underestimated the true rates. As a result, one can expect that future rate measurements will shift the mean N-2 fixation rate upward and may result in significantly higher estimates for the global N-2 fixation. The evolving database can nevertheless be used to study spatial and temporal distributions and variations of marine N-2 fixation, to validate geochemical estimates and to parameterize and validate biogeochemical models, keeping in mind that future rate measurements may rise in the future.
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| 8. |
- Pittman, S. J., et al.
(author)
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Seascape ecology : identifying research priorities for an emerging ocean sustainability science
- 2021
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In: Marine Ecology Progress Series. - : INTER-RESEARCH. - 0171-8630 .- 1616-1599. ; 663, s. 1-29
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Journal article (peer-reviewed)abstract
- Seascape ecology, the marine-centric counterpart to landscape ecology, is rapidly emerging as an interdisciplinary and spatially explicit ecological science with relevance to marine management, bio-diversity conservation, and restoration. While important progress in this field has been made in the past decade, there has been no coherent prioritisation of key research questions to help set the future research agenda for seascape ecology. We used a 2-stage modified Delphi method to solicit applied research questions from academic experts in seascape ecology and then asked respondents to identify priority questions across 9 interrelated research themes using 2 rounds of selection. We also invited senior management/conservation practitioners to prioritise the same research questions. Analyses highlighted congruence and discrepancies in perceived priorities for applied research. Themes related to both ecological concepts and management practice, and those identified as priorities include seascape change, seascape connectivity, spatial and temporal scale, ecosystem-based management, and emerging technologies and metrics. Highest-priority questions (upper tercile) received 50% agreement between respondent groups, and lowest priorities (lower tercile) received 58% agreement. Across all 3 priority tiers, 36 of the 55 questions were within a +/- 10% band of agreement. We present the most important applied research questions as determined by the proportion of votes received. For each theme, we provide a synthesis of the research challenges and the potential role of seascape ecology. These priority questions and themes serve as a roadmap for advancing applied seascape ecology during, and beyond, the UN Decade of Ocean Science for Sustainable Development (2021-2030).
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