Sub-local differences in Late Holocene land use at Orstad, Jæren in SW-Norway, revealed by soil pollen stratigraphy

Made available with permission from Maney Publishing / Environmental Archaeology. www.maneypublishing.com/journals/env and www.ingentaconnect.com/content/maney/env.Four soil profiles along an 84 m transect through a clearance cairn field on podsol soils at Orstad, Jæren, SW Norway, were investigated. By relating pollen-analytical results to soil stratigraphical and morphological features, it was possible to reconstruct the landuse history of the site, and to reveal differences along the transect, although pollen preservation was poor. Human activity at Orstad began about 4500 uncalibrated 14C years BP. The reason for an intermediate abandonment of the site between about 4000 and 3600 uncalibrated 14C years BP was presumably a higher ground-water level, caused by local deforestation and/or by a climatic change. After that period, people seem to have grown cereals (Triticum and Hordeum) on at least two different field patches on the site. This land use was presumably occasional, and related to extraordinary needs. Fire-clearance seems to have been practised to prepare the fields for cultivation after long fallow periods. Between 2900 and 3200 uncalibrated 14C years BP, Orstad was possibly permanently inhabited. The agricultural fields were moved to higher levels, as the initial fields had become nutrient-depleted and too moist. Thin black layers in the profile may be remains of manure

The genome sequence of Atlantic cod reveals a unique immune system

Atlantic cod (Gadus morhua) is a large, cold-adapted teleost that sustains long-standing commercial fisheries and incipient aquaculture. Here we present the genome sequence of Atlantic cod, showing evidence for complex thermal adaptations in its haemoglobin gene cluster and an unusual immune architecture compared to other sequenced vertebrates. The genome assembly was obtained exclusively by 454 sequencing of shotgun and paired-end libraries, and automated annotation identified 22,154 genes. The major histocompatibility complex (MHC)?II is a conserved feature of the adaptive immune system of jawed vertebrates, but we show that Atlantic cod has lost the genes for MHC?II, CD4 and invariant chain (Ii) that are essential for the function of this pathway. Nevertheless, Atlantic cod is not exceptionally susceptible to disease under natural conditions. We find a highly expanded number of MHC?I genes and a unique composition of its Toll-like receptor (TLR) families. This indicates how the Atlantic cod immune system has evolved compensatory mechanisms in both adaptive and innate immunity in the absence of MHC?II. These observations affect fundamental assumptions about the evolution of the adaptive immune system and its components in vertebrates