141 research outputs found
Tracking resource and policy impact : Incorporating millennium development goals & indicators and poverty reduction strategy paper monitoring across sectors
Ledet til lederutvikling. Nasjonal rektorutdanning i grunn- og videregående skole; forskjeller og likheter mellom de seks programtilbudene. Delrapport 2 fra Evaluering av den nasjonale rektorutdanningen
Den foreliggende delrapporten er den andre av fire rapporter fra følgeevalueringen av den nasjonale rektorutdanningen – et initiativ iverksatt av Utdanningsdirektoratet for rektorer og skoleledere i grunn- og videregående opplæring
Ledet til lederutvikling. Nasjonal rektorutdanning i grunn- og videregående skole; forskjeller og likheter mellom de seks programtilbyderne
-Norway recently launched a national program for school leader development, organized through the Directorate for Education (see Lysø et al 2011). NIFU and NTNU Samfunnsforskning were asked to evaluate the program, and this is the second of four reports from the on-going evaluation. In the current report, the program offers from six higher education institutions in Norway are analyzed with the aim of exploring the following research questions in more detail:
•What characterizes the program providers’ intentions regarding their study programs, and what ideas and practices are seen as central in the development of their program offers?
•How do participants in the programs assess their studies with respect to quality and relevance, and what are the expectations of the participants regarding their participation?
The main conclusion from the evaluation of these six programs is that they are very different. The programs have been designed with various intentions in mind, and their pedagogical design reflects this despite the fact that the programs offers also contain a number of similar elements. The participants experience the programs as both relevant and of high quality – regardless of which program they attended
Origin of marine invertebrate larvae on an Arctic inflow shelf
Many benthic invertebrate taxa possess planktonic early life stages which drift with water currents and contribute to dispersal of the species, sometimes reaching areas beyond the current ranges of the adults. Until recently, it had been difficult to identify planktonic larvae to species level due to lack of distinguishing features, preventing detection of expatriate species. Here, we used DNA metabarcoding of the COI gene to obtain species-level identification of early life stages of benthic invertebrates in zooplankton samples from the Barents Sea and around Svalbard, where, regionally, large volumes of warm Atlantic Water enter the Arctic from the south. We compared the larval community in the water column to the adult community on the seafloor to identify mismatches. In addition, we implemented particle tracking analysis to identify the possible areas of origin of larvae. Our results show that 30-45% of larval taxa—largely polychaetes and nudibranchs—were not local to the sampling area, though most were found nearby in the Barents Sea. In the particle tracking analysis, some larvae originating along the Norwegian coast were capable of reaching the northwest coast of Svalbard within 3 mo, but larvae found east of Svalbard had a more constrained possible area of origin which did not extend to the Norwegian coast. This study highlights largely regional-scale larval connectivity in the Barents Sea but demonstrates the potential for some long-lived larval taxa to travel to Svalbard and the Barents Sea from further south
Origin of marine invertebrate larvae on an Arctic inflow shelf
Many benthic invertebrate taxa possess planktonic early life stages which drift with water currents and contribute to dispersal of the species, sometimes reaching areas beyond the current ranges of the adults. Until recently, it had been difficult to identify planktonic larvae to species level due to lack of distinguishing features, preventing detection of expatriate species. Here, we used DNA metabarcoding of the COI gene to obtain species-level identification of early life stages of benthic invertebrates in zooplankton samples from the Barents Sea and around Svalbard, where, regionally, large volumes of warm Atlantic Water enter the Arctic from the south. We compared the larval community in the water column to the adult community on the seafloor to identify mismatches. In addition, we implemented particle tracking analysis to identify the possible areas of origin of larvae. Our results show that 30-45% of larval taxa—largely polychaetes and nudibranchs—were not local to the sampling area, though most were found nearby in the Barents Sea. In the particle tracking analysis, some larvae originating along the Norwegian coast were capable of reaching the northwest coast of Svalbard within 3 mo, but larvae found east of Svalbard had a more constrained possible area of origin which did not extend to the Norwegian coast. This study highlights largely regional-scale larval connectivity in the Barents Sea but demonstrates the potential for some long-lived larval taxa to travel to Svalbard and the Barents Sea from further south.publishedVersio
Stimulation of exosome release by extracellular DNA is conserved across multiple cell types
This is the submitted manuscript version of the following article Iliev, D., Strandskog, G., Nepal, A., Aspar, A., Olsen, R., Jørgensen, J., ... Mironova, R. (2018). Stimulation of exosome release by extracellular DNA is conserved across multiple cell types. The FEBS Journal, 285(16), 3114-3133. https://doi.org/10.1111/febs.14601. Published version available at https://doi.org/10.1111/febs.14601.Exosomes are distinguished from other types of extracellular vesicles by their small and relatively uniform size (30-100 nm) and their composition which reflects their endo-lysosomal origin. Involvement of these extracellular organelles in intercellular communication and their implication in pathological conditions has fuelled intensive research on mammalian exosomes; however, currently, very little is known about exosomes in lower vertebrates. Here we show that, in primary cultures of head kidney leukocytes from Atlantic salmon (Salmo salar), phosphorothioate CpG oligodeoxynucleotides induce secretion of vesicles with characteristics very similar to these of mammalian exosomes. Further experiments revealed that the oligonucleotide-induced exosome secretion did not depend on the CpG motifs but it relied on the phosphorothioate modification of the internucleotide linkage. Exosome secretion was also induced by genomic bacterial and eukaryotic DNA in toll-like receptor 9-negative piscine and human cell lines demonstrating that this is a phylogenetically conserved phenomenon which does not depend on activation of immune signaling pathways. In addition to exosomes, stimulation with phosphorothioate oligonucleotides and genomic DNA induced secretion of LC3B-II, an autophagosome marker, which was associated with vesicles of diverse size and morphology, possibly derived from autophagosome-related intracellular compartments. Overall, this work reveals a previously unrecognized biological activity of phosphorothioate ODNs and genomic DNA – their capacity to induce secretion of exosomes and other types of extracellular vesicles. This finding might help shed light on the side effects of therapeutic phosphorothioate oligodeoxynucleotides and the biological activity of extracellular genomic DNA which is often upregulated in pathological conditions
Productivity in the Barents Sea - Response to recent climate variability
The temporal and spatial dynamics of primary and secondary biomass/production in the Barents Sea since the late 1990s are examined using remote sensing data, observations and a coupled physical-biological model. Field observations of mesozooplankton biomass, and chlorophyll a data from transects (different seasons) and large-scale surveys (autumn) were used for validation of the remote sensing products and modeling results. The validation showed that satellite data are well suited to study temporal and spatial dynamics of chlorophyll a in the Barents Sea and that the model is an essential tool for secondary production estimates. Temperature, open water area, chlorophyll a, and zooplankton biomass show large interannual variations in the Barents Sea. The climatic variability is strongest in the northern and eastern parts. The moderate increase in net primary production evident in this study is likely an ecosystem response to changes in climate during the same period. Increased open water area and duration of open water season, which are related to elevated temperatures, appear to be the key drivers of the changes in annual net primary production that has occurred in the northern and eastern areas of this ecosystem. The temporal and spatial variability in zooplankton biomass appears to be controlled largely by predation pressure. In the southeastern Barents Sea, statistically significant linkages were observed between chlorophyll a and zooplankton biomass, as well as between net primary production and fish biomass, indicating bottom-up trophic interactions in this region
Photonic-chip assisted correlative light and electron microscopy
Correlative light-electron microscopy (CLEM) unifies the versatility of light
microscopy (LM) with the high resolution of electron microscopy (EM), allowing
one to zoom into the complex organization of cells. Most CLEM techniques use
ultrathin sections, and thus lack the 3D-EM structural information, and
focusing on a very restricted field of view. Here, we introduce photonic chip
assisted CLEM, enabling multi-modal total internal reflection fluorescence
(TIRF) microscopy over large field of view and high precision localization of
the target area of interest within EM. The chip-based direct stochastic optical
reconstruction microscopy (dSTORM), and 3D high precision correlation of
biological processes by focused ion beam-scanning electron microscopy (FIB-SEM)
is further demonstrated. The core layer of the photonic chips are used as a
substrate to hold, to illuminate and the cladding layer is used to enable
high-precision landmarking of the sample through specially designed grid-like
numbering systems. The landmarks are fabricated on the cladding of the photonic
chips as extruding pillars from the waveguide surface, thus remaining visible
for FIB-SEM after resin embedding during sample processing. Using this approach
we demonstrate its applicability for tracking the area of interest, imaging the
3D structural organization of nano-sized morphological features on liver
sinusoidal endothelial cells such as fenestrations, and correlating specific
endo-lysosomal compartments with its cargo protein upon endocytosis. We
envisage that photonic chip equipped with landmarks can be used in the future
to automatize the work-flow for both LM and EM for high-throughput CLEM,
providing the resolution needed for insights into the complex intracellular
communication and the relation between morphology and function in health and
disease.Comment: 23 Pages, 11 Figure
High-resolution visualization and assessment of basal and OXPHOS-induced mitophagy in H9c2 cardiomyoblasts
Mitochondria are susceptible to damage resulting from their activity as energy providers. Damaged mitochondria can cause harm to the cell and thus mitochondria are subjected to elaborate quality-control mechanisms including elimination via lysosomal degradation in a process termed mitophagy. Basal mitophagy is a house-keeping mechanism fine-tuning the number of mitochondria according to the metabolic state of the cell. However, the molecular mechanisms underlying basal mitophagy remain largely elusive. In this study, we visualized and assessed the level of mitophagy in H9c2 cardiomyoblasts at basal conditions and after OXPHOS induction by galactose adaptation. We used cells with a stable expression of a pH-sensitive fluorescent mitochondrial reporter and applied state-of-the-art imaging techniques and image analysis. Our data showed a significant increase in acidic mitochondria after galactose adaptation. Using a machine-learning approach we also demonstrated increased mitochondrial fragmentation by OXPHOS induction. Furthermore, super-resolution microscopy of live cells enabled capturing of mitochondrial fragments within lysosomes as well as dynamic transfer of mitochondrial contents to lysosomes. Applying correlative light and electron microscopy we revealed the ultrastructure of the acidic mitochondria confirming their proximity to the mitochondrial network, ER and lysosomes. Finally, exploiting siRNA knockdown strategy combined with flux perturbation with lysosomal inhibitors, we demonstrated the importance of both canonical as well as non-canonical autophagy mediators in lysosomal degradation of mitochondria after OXPHOS induction. Taken together, our high-resolution imaging approaches applied on H9c2 cells provide novel insights on mitophagy during physiologically relevant conditions. The implication of redundant underlying mechanisms highlights the fundamental importance of mitophagy
The role of the Barents Sea in the Arctic climate system
Present global warming is amplified in the Arctic and accompanied by unprecedented sea ice decline. Located along the main pathway of Atlantic Water entering the Arctic, the Barents Sea is the site of coupled feedback processes that are important for creating variability in the entire Arctic air-ice-ocean system. As warm Atlantic Water flows through the Barents Sea, it loses heat to the Arctic atmosphere. Warm periods, like today, are associated with high northward heat transport, reduced Arctic sea ice cover, and high surface air temperatures. The cooling of the Atlantic inflow creates dense water sinking to great depths in the Arctic Basins, and ~60% of the Arctic Ocean carbon uptake is removed from the carbon-saturated surface this way. Recently, anomalously large ocean heat transport has reduced sea ice formation in the Barents Sea during winter. The missing Barents Sea winter ice makes up a large part of observed winter Arctic sea ice loss, and in 2050, the Barents Sea is projected to be largely ice free throughout the year, with 4°C summer warming in the formerly ice-covered areas. The heating of the Barents atmosphere plays an important role both in “Arctic amplification” and the Arctic heat budget. The heating also perturbs the large-scale circulation through expansion of the Siberian High northward, with a possible link to recent continental wintertime cooling. Large air-ice-ocean variability is evident in proxy records of past climate conditions, suggesting that the Barents Sea has had an important role in Northern Hemisphere climate for, at least, the last 2500 years
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