Shore Displacement in Western Uusimaa 500 BC-AD 1500

Numerous shore displacement studies have been completed in Finland, but the shore displacement history regarding the last four millennia is still poorly investigated. In this study, the shore displacement history of the coastal area of Western Uusimaa, in southern Finland, is reconstructed especially for the period 500 BC-AD1500. The isolation of 17 basins located in five areas (Kirkkonummi/Espoo, Orslandet (Ingå), Älgö (Ekenäs in Raseborg), Tenala (Raseborg) and Prästkulla (Ekenäs, Raseborg)) is determined. The methods include lithostratigraphic interpretation, diatom analyses and radiocarbon dating. The shore displacement history varies within the Western Uusimaa area. The highest ancient shoreline representing sea-level at 500 BC is about 8.5 m above present sea-level (a.s.l.) in Prästkulla, and 6.5 m a.s.l. in Kirkkonummi. In other areas, the shoreline representing this time falls between these elevations. The shoreline representing sea-level at AD 500 is 1-1.5 m a.s.l. in Western Uusimaa. These differences in shore level elevations are due to differences in isostatic uplift rates, which are slower in the east. The main trend in relative shore displacement along the southern coast of Finland is characterised by a generally decreasing uplift rate during the last 3500 years. I is not possible to detect any clear sea-level transgressions during this investigated period. The available data suggests possible local land uplift anomalies in the study area, but more investigations are needed to verify these results.

Holocene sea-level changes and glacio-isostasy in the Gulf of Finland, Baltic Sea

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The biogeography and ecology of common diatom species in the northern North Atlantic, and their implications for paleoceanographic reconstructions

Sound knowledge of present-day diatom species and their environments is crucial when attempting to reconstruct past climate and environmental changes based on fossil assemblages. For the North Atlantic region, the biogeography and ecology of many diatom taxa that are used as indicator-species in paleoceanographic studies are still not well known. Using information contained in large diatom-environment calibration datasets can greatly increase our knowledge on diatom taxa and improve the accuracy of paleoenvironmental reconstructions. A diatom calibration dataset including 183 surface sediment samples from the northern North Atlantic was used to explore the distribution and ecology of 21 common Northern Hemisphere diatom taxa. We define the ecological responses of these species to April sea ice concentrations and August sea surface temperatures (aSSTs) using Huisman-Olff-Fresco (HOF)-response curves, provide distribution maps, temperature optima and ranges, and high-quality light microscope images. Based on the results, we find species clearly associated with cold, warm and temperate waters. All species have a statistically significant relationship with aSST, and 15 species with sea ice. Of these, Actinocyclus curvatulus, Fragilariopsis oceanica and Porosira glacialis are most abundant at high sea ice concentrations, whereas Coscinodiscus radiants, Shionodiscus oestrupii, Thalassionema nitzschioides, Thalassiosira angulata, Thalassiosira nordenskioeldii and Thalassiosira pacifica are associated with low sea ice concentrations/ice-free conditions. Interestingly, some species frequently used as sea ice indicators, such as Fragilariopsis cylindrus, show similar abundances at high and low sea ice concentrations with no statistically significant relationship to sea ice.Peer reviewe

Environmental changes in Krossfjorden, Svalbard, since 1950 : Benthic foraminiferal and stable isotope evidence

Environmental changes for the past ca. 50 years were studied in a short sediment core from inner Krossfjorden, Svalbard, investigating benthic foraminifera and stable isotopes (delta O-18, delta C-13). A depth-age model based on anthropogenic Cs-137 time markers indicates that record covers the period from 1955 to 2007 and has sediment accumulation rates of ca. 0.3 to 1 cm/year. The benthic foraminifera are arctic and/or common in glaciomarine environments. Six fauna assemblages were identified using stratigraphically constrained cluster analysis. Benthic foraminiferal fauna assemblages are mainly dominated by Cassidulina reniforme. Elphidium clavatum is dominant from 1973 to 1986 and 2002 to 2007, likely due to greater turbidity in the water column. We interpret the increased percentages of Spiroplectammina biformis over the same intervals to reflect a slightly lower salinity probably caused by meltwater. During a short time period, 1970 to 1973, Stainforthia concava dominates the benthic foraminiferal fauna interpreted to reflect increased productivity within a marginal ice zone. Other species as Islandiella norcrossi, Nonionellina labradorica, Islandiella helenae, and Melonis barleanus also indicate more nutrient-rich waters are present but not very abundant throughout the record probably due to the glacier proximal position of the study site. The stable isotope record (delta O-18) shows lighter values from 2001 to 2007, which seem to correlate well with oceanographic monitoring data showing increasing core temperatures of West Spitsbergen Current.Peer reviewe

Host poly(ADP-ribose) polymerases (PARPs) in acute and chronic bacterial infections

AbstractProtein ADP-ribosylation is a reversible post-translational modification, which alters protein activity, localization, interactome or stability, leading to perturbation of cell signaling. This review summarizes the emerging data indicating that host cell ADP-ribosylating enzymes, poly(ADP-ribose) polymerases (PARPs), influence the course of a bacterial infection, in parallel to ADP-ribosylating bacterial toxins. Host cell PARP targeting could be an efficient therapeutic approach to treat certain bacterial infections, possibly by repurposing the approved or clinical trial PARP inhibitors developed for cancer therapy.</div

Improving the paleoceanographic proxy tool kit – On the biogeography and ecology of the sea ice-associated species Fragilariopsis oceanica, Fragilariopsis reginae-jahniae and Fossula arctica in the northern North Atlantic

A long-term perspective is essential for understanding environmental change. To be able to access the past, environmental archives such as marine and lake sediments that store information in the form of diverse proxy records are used. Whilst many analytical techniques exist to extract the information stored in these proxy records, the critical assessment and refinement of current methods in addition to developing new methods is crucial to improving our understanding. This study aims to improve our knowledge on diatom species used for reconstructing ocean surface conditions, especially temperature and sea ice variability over time. We define the distribution and the relationship to sea surface temperature (SST) and sea ice concentrations (SIC) of the species Fragilariopsis oceanica, Fragilariopsis reginae-jahniae and Fossula arctica using diatom training sets from the northern North Atlantic. We further assess the effect of separating these species compared to grouping them under F. oceanica, as has been done in the past. Our results suggest that while these three species share similarities such as the preference for stratified waters induced by sea ice or glacier meltwater, they also exhibit heterogeneous distributions across the northern North Atlantic, with individual optima for SST and SIC. This also affects quantitative reconstructions based on our data, resulting in lower SST and higher SIC estimates when the species are separated in the surface sediment and down-core diatom assemblages.Peer reviewe

The palaeoenvironment of the 'Antrea Net Find'

The 'Antrea Net Find', found in 1914 in Korpilahti in the Karelian Isthmus , is one of the most important archaeological discoveries in Finland. For a long time, it was the oldest dated net find in Europe. New sediment samples were taken from the assumed find spot in 1998. The original net material and the new sediment sequence around the find spot were re-investigated using modern physical and palaeoecological techniques, They included AMS radiocarbon dates from the net material and the sediment above the find, as well as lithostratigraphical and isotope analyses from the surrounding sediment sequence. Also the material of the net cord was investigated. The palaeoenvironment of the Korpilahti area around the time of the event was reconstructed using modern biostratigraphical diatom and pollen methods. The 'Antrea Net Find' was recovered from the uppermost part of silty clay gyttja. The AMS radiocarbon date of the net yielded an age of 9 140±135 BP. The net cord has been made of willow bast. The dates from the silty gyttja sediment above the find level yielded the ages 9095±90 and 8965±85 BP. Stable isotope data indicate a rapid change in the sediment c. 9000 BP (8250 calBC). The radiocarbon dates with the diatom stratigraphy typical for the Ancylus Lake stage from Korpilahti suggest that the artefacts sank at the time of the maximum of the Ancylus transgression between 9200 and 9100 BP (8400 and 8300 calBC). At this time, the environment was characterized by forests dominated by pine, which had been present for hundreds of years, and thus the bark of old trees was readily available for the bark floats

Effects of site preparation and reindeer grazing on the early-stage success of Scots pine regeneration from seeds in northern Finland and Sweden

The importance of sufficient soil scarification to ensure the regeneration of Scots pine on sub-dry and more fertile sites has been emphasized in many studies. Here we aimed to study, how site preparation intensity affects the early success of natural regeneration and sowing (bare seeds and seed pellets) of Scots pine with or without the reindeer grazing. The study area was located in northern Finland and Sweden where five site preparation methods were compared: unprepared control, logging machine tracks, Huminmix (mixing the mineral soil and organic layer), disc trenching and intensive disc trenching. In each of these we used direct seeding, seed pellets and natural regeneration. Results revealed that even the lightest site preparation methods can provide sufficient regeneration results while the reindeer grazing limits the optimal regeneration result. Huminmix and even the track of the logging machine could provide satisfactory regeneration results both in direct seeding and natural regeneration. This could facilitate the coexistence of forest management, reindeer herding and other land use forms in the same stands and area. The use of seed pellets needs further research, but it may have potential due to lower consumption of seeds and less need for site preparation

The northernmost discovery of a Miocene proboscidean bone in Europe

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