| 1. |
- Margaryan, Ashot, et al.
(author)
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Population genomics of the Viking world
- 2020
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In: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 585:7825, s. 390-396
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Journal article (peer-reviewed)abstract
- The maritime expansion of Scandinavian populations during the Viking Age (about ad750–1050) was a far-flung transformation in world history1,2. Here we sequenced the genomes of 442humans from archaeological sites across Europe and Greenland (to a median depth of about 1×) to understand the global influence of this expansion. We find the Viking period involved gene flow into Scandinavia from the south and east. We observe genetic structure within Scandinavia, with diversity hotspots in the south and restricted gene flow within Scandinavia. We find evidence for a major influx of Danish ancestry into England; a Swedish influx into the Baltic; and Norwegian influx into Ireland, Iceland and Greenland. Additionally, we see substantial ancestry from elsewhere in Europe entering Scandinavia during the Viking Age. Our ancient DNA analysis also revealed that a Viking expedition included close family members. By comparing with modern populations, we find that pigmentation-associated loci have undergone strong population differentiation during the past millennium, and trace positively selected loci—including the lactase-persistence allele of LCT and alleles of ANKA that are associated with the immune response—in detail. We conclude that the Viking diaspora was characterized by substantial transregional engagement: distinct populations influenced the genomic makeup of different regions of Europe, and Scandinavia experienced increased contact with the rest of the continent.
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| 2. |
- Dai, Yao, et al.
(author)
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TMEFF1 is a neuron-specific restriction factor for herpes simplex virus
- 2024
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In: NATURE. - 0028-0836 .- 1476-4687. ; 632, s. 383-389
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Journal article (peer-reviewed)abstract
- The brain is highly sensitive to damage caused by infection and inflammation1,2. Herpes simplex virus 1 (HSV-1) is a neurotropic virus and the cause of herpes simplex encephalitis3. It is unknown whether neuron-specific antiviral factors control virus replication to prevent infection and excessive inflammatory responses, hence protecting the brain. Here we identify TMEFF1 as an HSV-1 restriction factor using genome-wide CRISPR screening. TMEFF1 is expressed specifically in neurons of the central nervous system and is not regulated by type I interferon, the best-known innate antiviral system controlling virus infections. Depletion of TMEFF1 in stem-cell-derived human neurons led to elevated viral replication and neuronal death following HSV-1 infection. TMEFF1 blocked the HSV-1 replication cycle at the level of viral entry through interactions with nectin-1 and non-muscle myosin heavy chains IIA and IIB, which are core proteins in virus-cell binding and virus-cell fusion, respectively4-6. Notably, Tmeff1-/- mice exhibited increased susceptibility to HSV-1 infection in the brain but not in the periphery. Within the brain, elevated viral load was observed specifically in neurons. Our study identifies TMEFF1 as a neuron-specific restriction factor essential for prevention of HSV-1 replication in the central nervous system. A study identifies TMEFF1 as a neuron-specific restriction factor essential for prevention of replication of herpes simplex virus type 1 in the central nervous system.
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| 3. |
- Li, Linjie, et al.
(author)
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Gas-to-Particle Partitioning of Products from Ozonolysis of Δ3-Carene and the Effect of Temperature and Relative Humidity
- 2024
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In: Journal of Physical Chemistry A. - Malmö : IVL Svenska Miljöinstitutet. - 1089-5639 .- 1520-5215. ; 128:5, s. 918-928
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Journal article (peer-reviewed)abstract
- Formation of oxidized products from Δ3-carene (C10H16) ozonolysis and their gas-to-particle partitioning at three temperatures (0, 10, and 20 °C) under dry conditions (<2% RH) and also at 10 °C under humid (78% RH) conditions were studied using a time-of-flight chemical ionization mass spectrometer (ToF-CIMS) combined with a filter inlet for gases and aerosols (FIGAERO). The Δ3-carene ozonolysis products detected by the FIGAERO-ToF-CIMS were dominated by semivolatile organic compounds (SVOCs). The main effect of increasing temperature or RH on the product distribution was an increase in fragmentation of monomer compounds (from C10 to C7 compounds), potentially via alkoxy scission losing a C3 group.The equilibrium partitioning coefficient estimated according to equilibrium partitioning theory shows that the measured SVOC products distribute more into the SOA phase as the temperature decreases from 20 to 10 and 0 °C and for most products as the RH increases from <2 to 78%. The temperature dependency of the saturation vapor pressure (above an assumed liquid state), derived from the partitioning method, also allows for a direct way to obtain enthalpy of vaporization for the detected species without accessibility of authentic standards of the pure substances. This method can provide physical properties, beneficial for, e.g., atmospheric modeling, of complex multifunctional oxidation products.
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| 4. |
- Luo, Yuanyuan, et al.
(author)
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Formation and temperature dependence of highly oxygenated organic molecules (HOMs) from Δ3-carene ozonolysis
- 2024
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In: ATMOSPHERIC CHEMISTRY AND PHYSICS. - 1680-7316 .- 1680-7324. ; 24:16, s. 9459-9473
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Journal article (peer-reviewed)abstract
- Delta(3)-carene is a prominent monoterpene in the atmosphere, contributing significantly to secondary organic aerosol (SOA) formation. However, knowledge about Delta(3)-carene oxidation pathways, particularly regarding their ability to form highly oxygenated organic molecules (HOMs), is still limited. In this study, we present HOM measurements during Delta(3)-carene ozonolysis under various conditions in two simulation chambers. We identified numerous HOMs (monomers: C7-10H10-18O6-14; dimers: C17-20H24-34O6-18) using a chemical ionization mass spectrometer (CIMS). Delta(3)-carene ozonolysis yielded higher HOM concentrations than alpha-pinene, with a distinct distribution, indicating differences in formation pathways. All HOM signals decreased considerably at lower temperatures, reducing the estimated molar HOM yield from similar to 3 % at 20 degrees C to similar to 0.5 % at 0 degrees C. Interestingly, the temperature change altered the HOM distribution, increasing the observed dimer-to-monomer ratios from roughly 0.8 at 20 degrees C to 1.5 at 0 degrees C. HOM monomers with six or seven O atoms condensed more efficiently onto particles at colder temperatures, while monomers with nine or more O atoms and all dimers condensed irreversibly even at 20 degrees C. Using the gas- and particle-phase chemistry kinetic multilayer model ADCHAM, we were also able to reproduce the experimentally observed HOM composition, yields, and temperature dependence.
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| 5. |
- Thomsen, Ditte, et al.
(author)
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The effect of temperature and relative humidity on secondary organic aerosol formation from ozonolysis of Δ3-carene
- 2024
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In: Environmental Science. - Malmö : IVL Svenska Miljöinstitutet. - 2634-3606. ; 4:1, s. 88-103
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Journal article (peer-reviewed)abstract
- This study investigates the effects of temperature and relative humidity (RH) on the formation of secondary organic aerosol (SOA) from D3-carene, a prevalent monoterpene in boreal forests. Dark ozonolysis experiments of 10 ppb D3-carene were conducted in the Aarhus University Research on Aerosol (AURA) atmospheric simulation chamber at temperatures of 0, 10, and 20 °C. Under dry conditions (RH < 2%), the SOA formation in terms of both particle number and mass concentration shows minimal temperature dependence. This is in contrast to previous findings at higher initial concentrations and suggests an effect of VOC loading for D3-carene. Interestingly, the mass fraction of key oxidation products (cis-3-caric acid, cis-3-caronic acid) exhibit a temperature dependence suggesting continuous condensation at lower temperatures, while evaporation and further reactions over time become more favourable at higher temperatures.The oxygen-to-carbon ratios in the particle phase and the occurrence of highly oxygenated organic molecules (HOM) in the gas phase show modest increases with higher temperatures. Predictions from the Aerosol Dynamics and Gas- and Particle-Phase Chemistry Kinetic Multilayer Model (ADCHAM) agrees with the experimental results regarding both physical particle properties and aerosol composition considering theexperimental uncertainties. At high RH (∼80%, 10 °C), a considerable increase in the particle nucleation rate and particle number concentration is observed compared to experiments under dry conditions. This is likely due to enhanced particle nucleation resulting from more stable cluster formation of water and inorganics at increased RH. However, RH does not affect the particle mass concentration.
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