Angiomatosis retinae

Neðst á síðunni er að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenCase report. Angiomatosis retinae is diagnosed in a diabetic woman on routine diabetic retinopathy screening.Hraust kona kemur í eftirlit til augnlæknis vegna sykursýki. Einkennalaust æðaæxli (angiomatosis retinae) finnst í sjónhimnu

Host-Parasite Interactions and Population Dynamics of Rock Ptarmigan

Populations of rock ptarmigan (Lagopus muta) in Iceland fluctuate in multiannual cycles with peak numbers c. every 10 years. We studied the ptarmigan-parasite community and how parasites relate to ptarmigan age, body condition, and population density. We collected 632 ptarmigan in northeast Iceland in early October from 2006 to 2012; 630 (99.7%) were infected with at least one parasite species, 616 (98%) with ectoparasites, and 536 (85%) with endoparasites. We analysed indices for the combined parasite community (16 species) and known pathogenic parasites, two coccidian protozoans Eimeria muta and Eimeria rjupa, two nematodes Capillaria caudinflata and Trichostrongylus tenuis, one chewing louse Amyrsidea lagopi, and one skin mite Metamicrolichus islandicus. Juveniles overall had more ectoparasites than adults, but endoparasite levels were similar in both groups. Ptarmigan population density was associated with endoparasites, and in particular prevalence of the coccidian parasite Eimeria muta. Annual aggregation level of this eimerid fluctuated inversely with prevalence, with lows at prevalence peak and vice versa. Both prevalence and aggregation of E. muta tracked ptarmigan population density with a 1.5 year time lag. The time lag could be explained by the host specificity of this eimerid, host density dependent shedding of oocysts, and their persistence in the environment from one year to the next. Ptarmigan body condition was negatively associated with E. muta prevalence, an indication of their pathogenicity, and this eimerid was also positively associated with ptarmigan mortality and marginally inversely with fecundity. There were also significant associations between fecundity and chewing louse Amyrsidea lagopi prevalence (negative), excess juvenile mortality and nematode Capillaria caudinflata prevalence (positive), and adult mortality and skin mite Metamicrolichus islandicus prevalence (negative). Though this study is correlational, it provides strong evidence that E. muta through time-lag in prevalence with respect to host population size and by showing significant relations with host body condition, mortality, and fecundity could destabilize ptarmigan population dynamics in Iceland.This work was supported by the Icelandic Research Fund, grant number 090207021: salary including funding of this work; Hunting Card Fund: salary including funding of this work; Landsvirkjun Energy Fund: salary and funding of this work; Institute for Experimental Pathology, Keldur, University of Iceland:Peer Reviewe

Changes in attitudes of Icelandic adolescents towards democracy in the classroom over a five-year period

Eitt af meginmarkmiðum núgildandi aðalnámskrár (Mennta- og menningarmálaráðuneytið, 2011/2013) er að búa nemendur undir þátttöku í lýðræðislegu samfélagi. Samkvæmt þessu á grunnskólinn að vera sá staður sem veitir nemendum svigrúm til að öðlast reynslu af lýðræðislegu starfi og vera þátttakendur í því. Markmið þessarar rannsóknar var að kanna mögulegar breytingar á viðhorfum nemenda í þessum efnum yfir fimm ára tímabil, 2010 til 2015. Tveir hópar nemenda í 6.–10. bekk (Nalls = 627) voru spurðir um afstöðu sína til lýðræðis og lýðræðisþátttöku með fimm ára millibili. Rannsóknin var gerð í samvinnu við tíu skóla sem söfnuðu gögnum við reglubundið sjálfsmat. Niðurstöður sýna að viðhorf nemenda til lýðræðis í grunnskólum á Íslandi og lýðræðisþátttaka virðist hafa tekið mjög litlum breytingum á framangreindu tímabili. Engar breytingar var að finna á því sem kallað hefur verið frjálslynd lýðræðissjónarmið, svo sem tjáningarfrelsi og samkeppni í skólastofunni. Aftur á móti mátti greina smávægilega jákvæða breytingu á viðhorfum til þess sem kallað hefur verið samstarfslýðræði, þ.e. til þátttöku og samvinnu. Mikilvægi lýðræðisþátttöku að mati nemendanna virtist dala lítillega yfir þetta fimm ára tímabil. Niðurstöðurnar voru bornar saman við danska rannsókn frá árinu 2001 sem þessi rannsókn tók mið af. Enginn afgerandi munur fannst á viðhorfum dönsku og íslensku ungmennanna. Þó virtust frjálslynd lýðræðissjónarmið vera traustari hjá dönsku ungmennunum.The Icelandic national curriculum guide for compulsory schools published in 2011 specially emphasized the importance of preparing students for active participation in a democratic society: “It is expected that children and youth learn democracy by learning about democracy in a democracy” (Mennta- og menningarmálaráðuneytið, p. 19). Democracy was furthermore emphasized as one of six fundamental pillars of the Icelandic education system together with literacy, sustainability, health and welfare, human rights, equality, and creativity. Accordingly, knowledge about changes in attitudes towards democracy and democratic participation since the introduction of this new conception in 2011 is of importance. The increased emphasis on issues related to democracy introduced in the Icelandic national curriculum guide for compulsory schools were to be fully implemented in 2013. Studies on how Icelandic students are prepared for an active participation in the constantly changing democratic society are few and far between. Therefore, the results of this study can be considered of importance for education stakeholders such as teachers, parents, students, and scholars. The theoretical model used in the study is based on the works of Danish researchers (Jacobsen, Jensen, Madsen, Sylvestersen, & Vincent, 2004), where democratic perspectives in a Western tradition are conceived as liberal democracy (e.g., emphasizing the rights of the individual) and republican democracy (e.g., emphasizing solidarity). According to the model, both perspectives need to be in place for a democracy to function, and it is in the tension between these two perspectives a democratic process becomes active. The goal of this study is to contribute to an increased theoretical and empirical knowledge about democratic processes and democratic participation in public schools. The research was intended to detect possible changes in the responses of children to questions related to liberal and republican democracy after the full implementation of the Icelandic national curriculum guide from 2011. The goals of the study were approached by asking two groups of children in Grades 6 through 10 (Ntotal = 627) about their attitudes towards democracy and democratic participation in the classroom. The first data collection was conducted in 2010 and the second data collection was conducted in 2015. The study was conducted in collaboration with 10 schools that carried out the data collection as a part of their own internal evaluation. The results show that attitudes towards democracy and democratic participation over the above depicted period had changed remotely during the five-year period. No changes were found in attitudes related to a liberal democracy. A slight positive change was detected regarding opportunities for participation and collaboration in a republican democracy. However, the importance of democratic participation showed a slight decline during this five-year period. According to the model of Jacobsen et. al. (2004) one of the prerequisites for liberal democracy is individuality. A comparison with Danish result from 2001 showed that about 61% of the Danish adolescents indicated that it was very important to “be the way they are” but only 47% of the Icelandic adolescents responded the same way in 2015. These results were in accordance with other manifestations of liberal democracy in the survey, which seemed stronger among the Danish adolescents. The limited change in the attitudes of adolescents towards democracy and democratic participation raises questions about whether compulsory schools had the resources to implement the changes in policy recommended by the 2011 national curriculum guide. More research is needed to explore what was done in schools to increase democracy in the classroom during the 2011-2013 implementation period. Furthermore, it is important to conduct further research to identify efficient ways for teachers and school administrators to meet the policy recommendation for an increased emphasis of democracy in Icelandic classrooms. Finally, comparison with results from other countries give reason to conduct more research on manifestations of liberal democracy (e.g., opportunities for an open and democratic discussion; respect for individuality) among Icelandic adolescents.Peer Reviewe

Elucidation of different cold-adapted Atlantic cod (Gadus morhua) trypsin X isoenzymes

Trypsins from Atlantic cod (Gadus morhua), consisting of several isoenzymes, are highly active cold-adapted serine proteases. These trypsins are isolated for biomedical use in an eco-friendly manner from underutilized seafood by-products. Our group has explored the biochemical properties of trypsins and their high potential in biomedicine. For broader utilization of cod trypsins, further characterization of biochemical properties of the individual cod trypsin isoenzymes is of importance. For that purpose, a benzamidine purified trypsin isolate from Atlantic cod was analyzed. Anion exchange chromatography revealed eight peaks containing proteins around 24 kDa with tryptic activity. Based on mass spectrometric analysis, one isoenzyme gave the best match to cod trypsin I and six isoenzymes gave the best match to cod trypsin X. Amino terminal sequencing of two of these six trypsin isoenzymes showed identity to cod trypsin X. Three sequence variants of trypsin X were identified by cDNA analysis demonstrating that various forms of this enzyme exist. One trypsin X isoenzyme was selected for further characterization based on abundance and stability. Stepwise increase in catalytic efficiency (kcat/Km) of this trypsin X isoenzyme was obtained with substrates containing one to three amino acid residues. The study demonstrates that the catalytic efficiency of this trypsin X isoenzyme is comparable to that of cod trypsin I, the most abundant and highly active isoenzyme in the benzamidine cod trypsin isolate. Differences in pH stability and sensitivity to inhibitors of the trypsin X isoenzyme compared to cod trypsin I were detected that may be important for practical use.Research funded by AVS R&D Fund of Ministry of Fisheries and Agriculture in Iceland (R069-08, R11 028-11, R14 044-14) | Science and Technology Development Fund (120852-0611, 131804-0611)Ritrýnt tímaritPeer ReviewedPre-Prin

Biochemical characterization of a native group III trypsin ZT from Atlantic cod (Gadus morhua)

Publisher's version (útgefin grein)Atlantic cod trypsin ZT is biochemically characterized for the first time in this report in comparison to a group I trypsin (cod trypsin I). To our knowledge, trypsin ZT is the first thoroughly characterized group III trypsin. A more detailed understanding of trypsin ZT biochemistry may give insight into its physiological role as well as its potential use within the biotechnology sector. Stability is an important factor when it comes to practical applications of enzymes. Compared to trypsin I, trypsin ZT shows differences in pH and heat stability, sensitivity to inhibitors and sub-site substrate specificity as shown by multiplex substrate profiling analysis. Based on the analysis, trypsin ZT cleaved at arginine and lysine as other trypsins. Furthermore, trypsin ZT is better than trypsin I in cleaving peptides containing several consecutive positively charged residues. Lysine- and arginine-rich amino acid sequences are frequently found in human viral proteins. Thus, trypsin ZT may be effective in inactivating human and fish viruses implying a possible role for the enzyme in the natural defence of Atlantic cod. The results from this study can lead to multiple practical applications of trypsin ZT.This work was supported by the AVS R&D Fund of Ministry of Fisheries and Agriculture in Iceland [grant reference number: R15 046-15 , R069-08 , R11 028-11 and R14 044-14 ]; and Technology Development Fund (The Icelandic Centre for Research ) [grant reference number: 120852-0611 and 131804-0611 ]. The funding source had no involvement in study design; in the collection, analysis and interpretation of data; in the writing of the report; or in the decision to submit the article for publication.Peer Reviewe

Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts