Spatio-temporal Diptera visitation to Silene acaulis flowers studied with time-lapse cameras in Svalbard and Greenland

Flower visitation by flying arthropods has mainly been studied by direct human observation, which usually neglects seasonal development of flower abundance even though this is known to be important for visitor dynamics and match between trophic levels. In the present study, the arthropod visitor community focusing on Diptera was investigated on the cushion plant Silene acaulis (L.) Jacq. in relation to the available flower area. This was done using time-lapse cameras at one sub-Arctic, one low Arctic, and two high Arctic sites at Svalbard and Greenland. The S. acaulis flower visitor match at the Svalbard site was in addition characterized by using independent invertebrate traps located next to the camera site. Image annotation of cushion’s visitors ensured a high temporal resolution of data throughout the flowering season and showed a highly increased visitation frequency when more flowers were open. Individuals from several trophic levels visited S. acaulis, supporting the claim of S. acaulis as nursing plant and community hotspot. True flies (Diptera) were by far the most abundant visitors of the visitors identified. The Diptera visitor abundance per unit flower area showed large variations and varied over seasonal development, years, and between sites. Image-annotated visitors were observed both on open flowers and the remaining image. In average 40 % of Diptera visitors were observed on flowers. This percentage followed the increase in image area with open flowers and peaked the same time as flowering peak, thought the number was also site and year specific. For the largest camera site in Svalbard, this percentage of visitors on flowers strongly decreased during the three-year study period. The decrease may have been enhanced by delays in flowering onset that led to increased competition with other flower species, making S. acaulis flowers less attractive to visitors

Light and freshwater discharge drive the biogeochemistry and microbial ecology in a sub-Arctic fjord over the Polar night

The polar night has recently received increased attention as a surprisingly active biological season. Yet, polar night microbial ecology is a vastly understudied field. To identify the physical and biogeochemical parameters driving microbial activity over the dark season, we studied a sub-Arctic fjord system in northern Norway from autumn to early spring with detailed monthly sampling. We focused on the impact of mixing, terrestrial organic matter input and light on microbial ecosystem dynamics. Our study highlights strong differences in the key drivers between spring, autumn, and winter. The spring bloom started in March in a fully mixed water column, opposing the traditional critical depth hypothesis. Incident solar radiation was the key driver maximum Chlorophyll was reached in April. The onset of the autumn phytoplankton bloom was controlled by vertical mixing, causing nutrient upwelling and dilution of zooplankton grazers, which had their highest biomass during this time. According to the dilution-recoupling hypothesis grazer dilution reduced grazing stress and allowed the fall bloom formation. Mixing at that time was initiated by strong winds and reduced stratification as a consequence of freezing temperatures and lower freshwater runoff. During the light-limited polar night, the primary production was extremely low but bacteria continued growing on decaying algae, their exudates and also allochthonous organic matter. A melting event in January could have increased input of organic matter from land, supporting a mid-winter bacterial bloom. In conclusion, polar night biogeochemistry and microbial ecology was not only driven by light availability, but strongly affected by variability in reshwater discharge and allochthonous carbon input. With climate change freshwater discharge will increase in the Arctic, which will likely increase importance of the dynamics described in this study

Light and freshwater discharge drive the biogeochemistry and microbial ecology in a sub-Arctic fjord over the Polar night

The polar night has recently received increased attention as a surprisingly active biological season. Yet, polar night microbial ecology is a vastly understudied field. To identify the physical and biogeochemical parameters driving microbial activity over the dark season, we studied a sub-Arctic fjord system in northern Norway from autumn to early spring with detailed monthly sampling. We focused on the impact of mixing, terrestrial organic matter input and light on microbial ecosystem dynamics. Our study highlights strong differences in the key drivers between spring, autumn, and winter. The spring bloom started in March in a fully mixed water column, opposing the traditional critical depth hypothesis. Incident solar radiation was the key driver maximum Chlorophyll was reached in April. The onset of the autumn phytoplankton bloom was controlled by vertical mixing, causing nutrient upwelling and dilution of zooplankton grazers, which had their highest biomass during this time. According to the dilution-recoupling hypothesis grazer dilution reduced grazing stress and allowed the fall bloom formation. Mixing at that time was initiated by strong winds and reduced stratification as a consequence of freezing temperatures and lower freshwater runoff. During the light-limited polar night, the primary production was extremely low but bacteria continued growing on decaying algae, their exudates and also allochthonous organic matter. A melting event in January could have increased input of organic matter from land, supporting a mid-winter bacterial bloom. In conclusion, polar night biogeochemistry and microbial ecology was not only driven by light availability, but strongly affected by variability in reshwater discharge and allochthonous carbon input. With climate change freshwater discharge will increase in the Arctic, which will likely increase importance of the dynamics described in this study

Danish translation and adaptation of the Context Assessment Index (CAI) with implications for evidence-based practice

Background: Healthcare contexts are rapidly changing with growing demand for health services to accommodate an ageing population and financial pressures. Assessment of context in healthcare set-tings has been the subject of increasing debate. The Context Assessment Index (CAI) examines three interconnected contextual elements derived from the PARIHS-Framework with the purpose of providing practitioners with an understanding of the context in which they work. Aims: 1: To describe the translation of the CAI into Danish and adapt the instrument for use in Danish hospitals. 2: To evaluate the psychometric properties of the Danish version of the CAI. Methods: Translation and adaption included an expert panel and a translation/back-translation pro-cess. The CAI was then sent to 4416 nurses in the Region Zealand, Denmark. There are two alternative measurement models to explain the factor structure of the CAI, the five-factor model and the three-factor model. In order to provide the best explanation for the data both measurement models were examined using confirmatory factor analysis. Results: The CAI was translated and modified based on expert review and usability testing. 2261 nurses completed the CAI. For both models, factor loadings and fit statistics were acceptable, appropriate and statistically significant, and the measurement models were confirmed (5-factor model RMSEA 0.07, CFI=0.923; 3-factor model RMSEA 0.07, CFI=0.924). Cronbach alpha scores showed the models to have broadly acceptable scores (5-factor 0.64 – 0.89; 3-factor model 0.72 – 0.89). Linking Evidence to Action: The three-factor model can advantageously be used when the PARIHS framework is part of the project. In a translation process, differences in cultural specificity, language, and working environment have to be considered. By understanding the context of practice, nurses may enable person-centered care and improve patient outcomes.https://doi.org/10.1111/wvn.1234716pubpub

Tectonostratigraphic development of the Upper Triassic to Middle Jurassic in the Hoop Area, Barents Sea: Implications for understanding ultra-condensed reservoir units

The most prolific reservoir intervals in the Barents Sea are found in the Upper Triassic to Middle Jurassic Realgrunnen Subgroup, deposited during a major change in the structural evolution of the basin which greatly influenced its development and distribution. The effects are evident in one of the petroleum provinces in the SW Barents Sea, the Hoop Area. Due to the condensed nature of the succession, the tectonostratigraphic evolution has been enigmatic. We use a range of different methods and dataset, including high-resolution P-Cable seismic to determine the tectono-stratigraphic evolution of the succession. Results are important for exploration and production in the Hoop Area and beyond, but also for a broader understanding of how ultra-condensed successions might evolve during long periods of non-deposition and short bursts of deposition. Seven major phases of deposition and non-deposition/erosion are defined. Stage 1 represents fluvio-deltaic deposition in the Fruholmen Formation (Norian), followed by Stage 2 with significant truncation and non-deposition, lasting up to 35 million years. Deposition resumed with the shallow marine to fluvial Nordmela and Stø formations (Pliensbachian to Bajocian), which both encapsule long periods of erosion and non-deposition (stage 3–6). Stage 7 is represented by transgression and shelf deposition in the Fuglen Formation (Bathonian). The change from a high-accommodation setting with continuous and relatively high rate of accumulation in the Triassic, to a low-accommodation setting with episodic deposition and extensive sediment cannibalization in the Jurassic, resulted in cleaner sandstones with better reservoir properties. The low-accommodation setting also enabled coarse-graded detritus from hinterlands in Fennoscandia to prograde into distal part of the basin and more amalgamation of the sands during the Jurassic. Adversely, the low accommodation setting also caused a fragmented pattern of deposition and preservation that needs to be carefully considered in subsurface datasets, often with limited resolution.publishedVersio

Integrin β₁, osmosensing, and chemoresistance in mouse ehrlich carcinoma cells

Background/Aims: Altered expression of the integrin family of cell adhesion receptors has been associated with initiation, progression, and metastasis of solid tumors as well as in the development of chemoresistance. Here, we investigated the role of integrins, in particular integrin β1, in cell volume regulation and drug-induced apoptosis in adherent and non-adherent Ehrlich ascites cell lines. Methods: Adhesion phenotypes were verified by colorimetric cell-adhesion-assay. Quantitative real-time PCR and western blot were used to compare expression levels of integrin subunits. Small interfering RNA was used to silence integrin β1 expression. Regulatory volume decrease (RVD) after cell swelling was studied with calcein-fluorescence-self-quenching and Coulter counter analysis. Taurine efflux was estimated with tracer technique. Caspase assay was used to determine apoptosis. Results: We show that adherent cells have stronger fibronectin binding and a significantly increased expression of integrin α5, αv, and β1 at mRNA and protein level, compared to non-adherent cells. Knockdown of integrin β1 reduced RVD of the adherent but not of the non-adherent cells. Efflux of taurine was unaffected. In contrast to non-adherent, adherent cells exhibited chemoresistance to chemotherapeutic drugs (cisplatin and gemcitabine). However, knockdown of integrin β1 promoted cisplatin-induced caspase activity in adherent cells. Conclusion: Our data identifies integrin β1 as a part of the osmosensing machinery and regulator of cisplatin resistance in adherent Ehrlich cells

Spatio-temporal Diptera visitation to Silene acaulis flowers studied with time-lapse cameras in Svalbard and Greenland

Flower visitation by flying arthropods has mainly been studied by direct human observation, which usually neglects seasonal development of flower abundance even though this is known to be important for visitor dynamics and match between trophic levels. In the present study, the arthropod visitor community focusing on Diptera was investigated on the cushion plant Silene acaulis (L.) Jacq. in relation to the available flower area. This was done using time-lapse cameras at one sub-Arctic, one low Arctic, and two high Arctic sites at Svalbard and Greenland. The S. acaulis flower visitor match at the Svalbard site was in addition characterized by using independent invertebrate traps located next to the camera site. Image annotation of cushion’s visitors ensured a high temporal resolution of data throughout the flowering season and showed a highly increased visitation frequency when more flowers were open. Individuals from several trophic levels visited S. acaulis, supporting the claim of S. acaulis as nursing plant and community hotspot. True flies (Diptera) were by far the most abundant visitors of the visitors identified. The Diptera visitor abundance per unit flower area showed large variations and varied over seasonal development, years, and between sites. Image-annotated visitors were observed both on open flowers and the remaining image. In average 40 % of Diptera visitors were observed on flowers. This percentage followed the increase in image area with open flowers and peaked the same time as flowering peak, thought the number was also site and year specific. For the largest camera site in Svalbard, this percentage of visitors on flowers strongly decreased during the three-year study period. The decrease may have been enhanced by delays in flowering onset that led to increased competition with other flower species, making S. acaulis flowers less attractive to visitors