Abstract (
)
Download PDF (
)
Knowledge map
Save
This paper reviews the major contributions made by Norwegian scientists to Arctic environmental sciences since the 1880s. The review begins with the first International Polar Year (IPY) in 1882-83. It then considers the 1890s to 1920s with the scientific expeditions focusing on ocean and sea ice conditions of Nansen, Amundsen and H. Sverdrup, and the mapping of the Queen Elizabeth Islands by Otto Sverdrup and colleagues. The period from 1911 to the mid-1920s also witnessed annual expeditions to Svalbard led by Adolf Hoel. The 1930s to 1945 period encompassed the Second International Polar Year when Arctic weather stations were established or maintained. The time interval post-World War II to 2000 witnessed major advances made possible by technical and organizational innovations. The establishment of the Norwegian Polar Institute in 1948 led to extensive research on the glaciers and snow cover in the Svalbard archipelago and to oceanographic and sea ice research in the Barents Sea and Arctic Ocean. Remote sensing methods began to be widely used from the 1980s. The new millennium saw the undertaking of the third IPY and a shift to multinational projects. New fields such as ocean-ice-atmosphere variability became active and there was much attention to high-latitude climate change in the context of global warming.
Abstract (
)
Download PDF (
)
Knowledge map
Save
Glutamate dehydrogenase (GDH) catalyzes the oxidative deamination of glutamate to
Abstract (
)
Download PDF (
)
Knowledge map
Save
Heat shock proteins (Hsps), produced by organisms under high temperature stimulation, play important roles in protein folding, translocation, and refolding/degradation. In this study, we investigated the expression level of the GrpE Hsp geneHsp845of Psychrobacter sp. G under different temperature and salinity stresses by quantitative real-time PCR and western blotting, respectively. At both transcriptional and translational levels,Hsp845gene expression was induced by high temperature (30℃) and inhibited by low temperatures (0℃ and 10℃).Hsp845expression was also induced both by the absence of salt (0‰) and high salinity (90‰ and 120‰) at the transcriptional level, but was only induced by high salinity (90‰ and 120‰) at the translational level. In a combined stress treatment,Hsp845was more sensitive to high temperature than to salinity at both transcriptional and translational levels. The increase in the translational-level expression ofHsp845lagged behind that at the transcriptional level, andHsp845maximum expression was also higher at the transcriptional than at the translational level. In the absence of salt, transcriptional- and translational-level expressions exhibited opposite patterns, suggesting that the underlying mechanism requires further study.
Abstract (
)
Download PDF (
)
Knowledge map
Save
Methane (CH4) is one of important greenhouse gases with chemical activity. The determination of isotopic compositions for CH4 emitted from the soils helps us to understand its production mechanisms. CH4 isotope measurements have been conducted for different types of global terrestrial ecosystems. However, no isotopic data of CH4 have been reported from Antarctic tundra soils. In this paper, ornithogenic soil profiles were collected from four penguin colonies, and potential CH4 production rates and its 13C ratio (δ13C) were investigated based upon laboratory incubation experiments. The mean CH4 production rates are highly variable in these soil profiles, ranging from 0.7 to 20.3μg CH4-C kg-1•h-1. These ornithogenic soils had high potential production rates of CH4 under ambient air incubation or under N2 incubation, indicating the importance of potential CH4 emissions from penguin colonies. Most of the soil samples had higherδ13C-CH4 under N2 incubation (-39.28%~-43.53%) than under the ambient air incubation (-42.81%~-57.19%). Highly anaerobic conditions were conducive to the production of CH4 enriched in 13C, and acetic acid reduction under N2 incubation might be a predominant source for soil CH4 production. Overall theδ13C-CH4 showed a significant negative correlation with CH4 production rates in ornithogenic tundra soils under N2 incubation (R2=0.41,p＜0.01) or under the ambient air incubation (R2=0.50,p＜0.01). Potential CH4 production from ornithogenic soils showed a significant positive correlation with total phosphorus (TP) and NH4+-N contents, pH and soil moisture (Mc), but theδ13C-CH4 showed a significant negative correlation with TP and NH4+-N contents, pH and Mc, indicating that the deposition amount of penguin guano increased potential CH4 production rates from tundra soils, but decreased theδ13C-CH4. The CH4 emissions from the ornithogenic soils affect carbon isotopic compositions of atmospheric CH4 in coastal Antarctica.
Abstract (
)
Download PDF (
)
Knowledge map
Save
Polar science outreach is strongly needed, because besides promoting the utility of polar studies for society as a whole, it can generate public demand for new projects and expeditions. The dissemination of polar discoveries should be reinforced in countries without polar territories and for which polar science might not be a priority. In this pilot study (N=182 participants) we have contrasted the opinions of polar scientists (French, Belgian, British, Canadian, Australian, German, Italian and Spanish researchers) with those of a potentially interested public (graduate students of pedagogy and biology), in order to assess if the communication channels employed by polar researchers to make their results public align with those used by non-polar experts for learning about polar discoveries. The results revealed that scientific publications and presentations were considered a priority by the researchers, and these scientific communication channels were preferentially employed. Only a minority of researchers thought that non-scientific publications might be a good communication resource. In contrast, both groups of students, which considered polar research important but not a top priority, employed the Internet as their main channel for information about polar discoveries. Students assessed the use of polar discoveries as positive for educational purposes at both Primary and Secondary levels. The information presently received by students was perceived as being too generalist and the main suggestions to improve outreach in this field, in addition to the use of Internet, were more rapid dissemination of new discoveries.
Abstract (
)
Download PDF (
)
Knowledge map
Save
Abstract (
)
Download PDF (
)
Knowledge map
Save
Abstract (
)
Download PDF (
)
Knowledge map
Save
沪公网安备 31011502017260号