Circadian rhythms regulate living organisms over a 24h period. From daily activity to cellular function. The polar regions are subject to different photoperiods across the year, which impact the environmental conditions on a seasonal and daily basis. Evidence of crosstalk between circadian core clock genes and hypoxia with genes involved the mitochondrial dynamics, as well as oxygen sensing, provide ...

Processing of detritus is an important ecosystem function in freshwaters. In rivers and streams, the activity of shredding invertebrates play an important role in processing of coarse-particulate organic matter such as leaf litter. In stream food webs, fish may act as top predators and control activity of consumers such as shredders top down. This top-down effect may be of a directly consumptive nature, ...

Actuarial senescence is the irreversible decline of survival with increasing age. This phenomenon varies widely between taxa and species along the slow-fast continuum. However, inter-populational senescence differences have been less investigated, especially in the avian order. Here, I compared senescence rate between three contrasting populations of the Atlantic puffin (Fratercula arctica), and ...

Hooded seal pups are highly adapted to their proximate environment from the moment they are born. They are born with a substantial blubber layer, and they gain 20+ kg of body mass during their short nursing-period (2-4 days). With the body mass gained during nursing mainly being a result of fat deposition, it made them an excellent model to use when studying the fat metabolism and its contribution ...

Boreogadus saida (Polar cod) is a critical ecological linkage between planktonic primary production and megafaunal top consumers in the Arctic. Despite its critical ecology, the population structure, especially the relationship between fjord and oceanic groups inhabiting environments with different physical characteristics, is poorly described. Though the subject of several genetic studies, an ...

The Svalbard ptarmigan exhibits profound seasonal variations in body mass. The deposition of fat in the fall is an adaptation that allows the ptarmigan to survive periods of food shortages during the Arctic winter. In this study, previously unexplored molecular aspects of this well- established body mass cycle were investigated. Captive Svalbard ptarmigan fed ad libitum and kept under short photoperiod ...

The seasonal development of sea ice algae and bacteria was investigated in Ramfjorden, Norway, from February to April 2019 and compared to data from two Arctic fjords, Van Mijenfjorden and Billefjorden, sampled in April 2019. The sea ice in Ramfjorden was heavily freshwater influenced with bulk salinities ranging from 0.0 to 2.8, similar to those found in freshwater influenced Baltic Sea ice. The ...

Global warming has especially detrimental effects on Arctic regions. One major issue is permafrost thaw and sub-permafrost methane escape via surface seeps. While the mitigation potential of methane-consuming bacteria on marine pingo-like methane seeps is well described, terrestrial methane seeps are still understudied. Recently, open system pingos have gained attention as terrestrial methane seeps. ...

Introductions and invasions of species outside their natural range can have devastating effects on the native species and be a major driver of biodiversity change. When the zooplanktivorous vendace invaded the Pasvik watercourse in the 1990s, it quickly took over the ecological role of the native DR whitefish. In the upper part of the watercourse, DR whitefish was displaced from the pelagic habitat ...

Oral squamous cell carcinoma (OSCC) is an aggressive cancer associated with high mortality rates. The objective of this master project was to test the following hypotheses: (1) transforming growth factor β1 (TGFβ1) activates fibroblasts in vitro and basic fibroblast growth factor (bFGF) deactivates them while both increase fibroblast proliferation in cancer associated fibroblasts (CAFs); (2) the ...