46 research outputs found
Does the use of cannabis increase the risk for psychosis and the development of schizophrenia?
Efst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinnÁ síðustu 30 árum hefur vísbendingum fjölgað um að kannabisreykingar auki hættu á geðrofi (psychosis) sem geti þróast áfram í geðklofa hjá hluta slíkra einstaklinga. Síðasta áratug hafa verið birtar margar rannsóknir sem skýra tengsl kannabis og geðrofs. Markmið þessarar yfirlitsgreinar er að taka saman og fjalla um þessi tengsl. Farið er yfir niðurstöður 14 ferilrannsókna á 9 rannsóknarþýðum og 9 tilfellaviðmiðarannsókna. Þegar niðurstöður þeirra eru teknar saman styðja þær ótvírætt að notkun kannabis sé sjálfstæður áhættuþáttur fyrir geðrof og að öllum líkindum einnig fyrir þróun langvinnra geðrofssjúkdóma eins og geðklofa. Um skammtaháð samband er að ræða þar sem áhættan eykst með tíðari neyslu. Einnig sýna rannsóknir að notkun kannabis á unglingsaldri hefur sterkari tengsl við geðrof en neysla sem hefst á fullorðinsárum. Frekari rannsókna er þó þörf enda geta geðrofssjúkdómar verið lengi í þróun og vandasamt að mæla skýribreytu og svarbreytu og flókið samband þeirra. Við teljum mikilvægt að auka þekkingu almennings á alvarlegum afleiðingum kannabisnotkunar og þeirri staðreynd að ekki er hægt að spá fyrir um hverjir þeirra sem nota efnið reglulega veikist af skammvinnu geðrofi og hverjir af langvinnum geðrofssjúkdómi.Over the past 30 years evidence has been growing that cannabis use increases the risk for psychosis which could develop into schizophrenia in a proportion of cases. Over the past decade many studies have been published which clarify the association between cannabis use and psychosis. The aim of this review is to examine this association. A systematic search yielded 14 cohort studies carried out in 9 cohorts and 9 case-control studies. When the results of these studies are taken together they unambiguously support that cannabis use is an independent risk factor for psychosis and may also give rise to chronic psychotic disorders like schizophrenia. A dose dependent link is present because more frequent use associates with greater risk. The studies also show that cannabis-use in adolescence is associated with greater risk of developing psychosis than commencing the use of cannabis in adulthood. Further studies are needed to explain this association since psychotic disorders take years to evolve and it remains difficult to measure both the explanatory and the response variable and their complex relationship. The results emphasize the need to enhance public knowledge on the possible consequences of cannabis use and the fact that it cannot be predicted who will experience transient psychosis and who will develop a chronic psychotic disorder
Association of eGFR and mortality with use of a joint model : results of a nationwide study in Iceland
© The Author(s) 2023. Published by Oxford University Press on behalf of the ERA.BACKGROUND AND OBJECTIVES: Prior studies on the association of eGFR and mortality have failed to include methods to account for repeated estimated glomerular filtration rate (eGFR) determinations. The aim of this study was to estimate the association between eGFR and mortality in the general population in Iceland employing a joint model. METHODS: We obtained all serum creatinine and urine protein measurements from all clinical laboratories in Iceland in the years 2008-2016. Clinical data were obtained from nationwide electronic medical records. eGFR was calculated using the CKD-EPI equation and categorized as follows: 0-29, 30-44, 45-59, 60-74, 75-89, 90-104 and >104 mL/min/1.73 m2. A multiple imputation method was used to account for missing urine protein data. A joint model was used to assess risk of all-cause mortality. RESULTS: We obtained 2 120 147 creatinine values for 218 437 individuals, of whom 84 364 (39%) had proteinuria measurements available. Median age was 46 (range, 18-106) years and 47% were men. Proteinuria associated with increased risk of death for all eGFR categories both in persons of all ages. In persons ≤ 65 years, the lowest risk was observed for eGFR of 75-89 mL/min/1.73 m2 without proteinuria. For persons aged > 65 years, the lowest risk was observed for eGFR of 60-74 mL/min/1.73 m2 without proteinuria. eGFR of 45-59 mL/min/1.73 m2 without proteinuria did not associate with enhanced mortality risk in this age group. eGFR >104 mL/min/1.73 m2 associated with increased mortality. CONCLUSIONS: These results lend further support to the use of age-adapted eGFR thresholds for defining CKD. Very high eGFR needs to be studied in more detail with regard to mortality.Peer reviewe
Differential gene expression during early development in recently evolved and sympatric Arctic charr morphs
Phenotypic differences between closely related taxa or populations can arise through genetic variation or be environmentally induced, leading to altered transcription of genes during development. Comparative developmental studies of closely related species or variable populations within species can help to elucidate the molecular mechanisms related to evolutionary divergence and speciation. Studies of Arctic charr (Salvelinus alpinus) and related salmonids have revealed considerable phenotypic variation among populations and in Arctic charr many cases of extensive variation within lakes (resource polymorphism) have been recorded. One example is the four Arctic charr morphs in the ∼10,000 year old Lake Thingvallavatn, which differ in numerous morphological and life history traits. We set out to investigate the molecular and developmental roots of this polymorphism by studying gene expression in embryos of three of the morphs reared in a common garden set-up. We performed RNA-sequencing, de-novo transcriptome assembly and compared gene expression among morphs during an important timeframe in early development, i.e., preceding the formation of key trophic structures. Expectedly, developmental time was the predominant explanatory variable. As the data were affected by some form of RNA-degradation even though all samples passed quality control testing, an estimate of 3′-bias was the second most common explanatory variable. Importantly, morph, both as an independent variable and as interaction with developmental time, affected the expression of numerous transcripts. Transcripts with morph effect, separated the three morphs at the expression level, with the two benthic morphs being more similar. However, Gene Ontology analyses did not reveal clear functional enrichment of transcripts between groups. Verification via qPCR confirmed differential expression of several genes between the morphs, including regulatory genes such as AT-Rich Interaction Domain 4A (arid4a) and translin (tsn). The data are consistent with a scenario where genetic divergence has contributed to differential expression of multiple genes and systems during early development of these sympatric Arctic charr morphs.he project was funded by The Icelandic Center for Research (grant number: 100204011) to Sigurður S. Snorrason, Arnar Pálsson, Zophonías O. Jónsson and Bjarni K. Kristjánsson. The University of Iceland Doctoral Fund to Jóhannes Guðbrandsson and University of Iceland research fund to Arnar Pálsson, Sigurður S. Snorrason and Zophonías O. Jónsson. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer Reviewe
Extensive genetic differentiation between recently evolved sympatric Arctic charr morphs
Publisher's version (útgefin grein)The availability of diverse ecological niches can promote adaptation of trophic specializations and related traits, as has been repeatedly observed in evolutionary radiations of freshwater fish. The role of genetics, environment, and history in ecologically driven divergence and adaptation, can be studied on adaptive radiations or populations showing ecological polymorphism. Salmonids, especially the Salvelinus genus, are renowned for both phenotypic diversity and polymorphism. Arctic charr (Salvelinus alpinus) invaded Icelandic streams during the glacial retreat (about 10,000 years ago) and exhibits many instances of sympatric polymorphism. Particularly, well studied are the four morphs in Lake Þingvallavatn in Iceland. The small benthic (SB), large benthic (LB), planktivorous (PL), and piscivorous (PI) charr differ in many regards, including size, form, and life history traits. To investigate relatedness and genomic differentiation between morphs, we identified variable sites from RNA‐sequencing data from three of those morphs and verified 22 variants in population samples. The data reveal genetic differences between the morphs, with the two benthic morphs being more similar and the PL‐charr more genetically different. The markers with high differentiation map to all linkage groups, suggesting ancient and pervasive genetic separation of these three morphs. Furthermore, GO analyses suggest differences in collagen metabolism, odontogenesis, and sensory systems between PL‐charr and the benthic morphs. Genotyping in population samples from all four morphs confirms the genetic separation and indicates that the PI‐charr are less genetically distinct than the other three morphs. The genetic separation of the other three morphs indicates certain degree of reproductive isolation. The extent of gene flow between the morphs and the nature of reproductive barriers between them remain to be elucidated.This project was supported by The Icelandic Center for Research (RANNIS
#100204011) to SSS and coworkers, The University of Iceland Doctoral
Fund to JG and University of Iceland research fund to AP, SSS and ZOJ.Peer reviewe
Transcriptional dynamics of a conserved gene expression network associated with craniofacial divergence in Arctic charr
Background
Understanding the molecular basis of craniofacial variation can provide insights into key developmental mechanisms of adaptive changes and their role in trophic divergence and speciation. Arctic charr (Salvelinus alpinus) is a polymorphic fish species, and, in Lake Thingvallavatn in Iceland, four sympatric morphs have evolved distinct craniofacial structures. We conducted a gene expression study on candidates from a conserved gene coexpression network, focusing on the development of craniofacial elements in embryos of two contrasting Arctic charr morphotypes (benthic and limnetic).
Results
Four Arctic charr morphs were studied: one limnetic and two benthic morphs from Lake Thingvallavatn and a limnetic reference aquaculture morph. The presence of morphological differences at developmental stages before the onset of feeding was verified by morphometric analysis. Following up on our previous findings that Mmp2 and Sparc were differentially expressed between morphotypes, we identified a network of genes with conserved coexpression across diverse vertebrate species. A comparative expression study of candidates from this network in developing heads of the four Arctic charr morphs verified the coexpression relationship of these genes and revealed distinct transcriptional dynamics strongly correlated with contrasting craniofacial morphologies (benthic versus limnetic). A literature review and Gene Ontology analysis indicated that a significant proportion of the network genes play a role in extracellular matrix organization and skeletogenesis, and motif enrichment analysis of conserved noncoding regions of network candidates predicted a handful of transcription factors, including Ap1 and Ets2, as potential regulators of the gene network. The expression of Ets2 itself was also found to associate with network gene expression. Genes linked to glucocorticoid signalling were also studied, as both Mmp2 and Sparc are responsive to this pathway. Among those, several transcriptional targets and upstream regulators showed differential expression between the contrasting morphotypes. Interestingly, although selected network genes showed overlapping expression patterns in situ and no morph differences, Timp2 expression patterns differed between morphs.
Conclusion
Our comparative study of transcriptional dynamics in divergent craniofacial morphologies of Arctic charr revealed a conserved network of coexpressed genes sharing functional roles in structural morphogenesis. We also implicate transcriptional regulators of the network as targets for future functional studies.This project was supported by The Icelandic Centre for Research (RANNIS/IRF, grant 100204) and The University of Iceland Research Fund.Peer Reviewe
Differential expression of the aryl hydrocarbon receptor pathway associates with craniofacial polymorphism in sympatric Arctic charr
Background
The developmental basis of craniofacial morphology hinges on interactions of numerous signalling systems. Extensive craniofacial variation in the polymorphic Arctic charr, a member of the salmonid family, from Lake Thingvallavatn (Iceland), offers opportunities to find and study such signalling pathways and their key regulators, thereby shedding light on the developmental pathways, and the genetics of trophic divergence.
Results
To identify genes involved in the craniofacial differences between benthic and limnetic Arctic charr, we used transcriptome data from different morphs, spanning early development, together with data on craniofacial expression patterns and skeletogenesis in model vertebrate species. Out of 20 genes identified, 7 showed lower gene expression in benthic than in limnetic charr morphs. We had previously identified a conserved gene network involved in extracellular matrix (ECM) organization and skeletogenesis, showing higher expression in developing craniofacial elements of benthic than in limnetic Arctic charr morphs. The present study adds a second set of genes constituting an expanded gene network with strong, benthic–limnetic differential expression. To identify putative upstream regulators, we performed knowledge-based motif enrichment analyses on the regulatory sequences of the identified genes which yielded potential binding sites for a set of known transcription factors (TFs). Of the 8 TFs that we examined using qPCR, two (Ahr2b and Ap2) were found to be differentially expressed between benthic and limnetic charr. Expression analysis of several known AhR targets indicated higher activity of the AhR pathway during craniofacial development in benthic charr morphotypes.
Conclusion
These results suggest a key role of the aryl hydrocarbon receptor (AhR) pathway in the observed craniofacial differences between distinct charr morphotypes.This project was supported by The Icelandic Centre for Research (RANNIS/IRF, Grant 100204), The University of Iceland Research Fund and the Eimskip University Fund.Peer Reviewe
Pneumococcal vaccination: Direct and herd effect on carriage of vaccine types and antibiotic resistance in Icelandic children
Background
Since the introduction of pneumococcal conjugate vaccines, vaccine type pneumococcal carriage and disease has decreased world-wide. The aim was to monitor changes in the nasopharyngeal carriage of pneumococci, the distribution of serotypes and antimicrobial resistance in children before and after initiation of the 10-valent pneumococcal vaccination in 2011, in a previously unvaccinated population.
Methods
Repeated cross-sectional study at 15 day-care centres in greater Reykjavik area. Nasopharyngeal swabs were collected yearly in March from 2009 to 2015. The swabs were selectively cultured for pneumococci, which were serotyped using latex agglutination and/or PCR and antimicrobial susceptibility determined. Two independent studies were conducted.
In study 1, on total impact, isolates from children aged <4 years were included. The vaccine-eligible-cohort (birth-years: 2011–2013, sampled in 2013–2015) was compared with children at the same age born in 2005–2010 and sampled in 2009–2012. In study 2 on herd effect, isolates from older non-vaccine-eligible children (3.5–6.3 years) were compared for the periods before and after the vaccination (2009–2011 vs 2013–2015. Vaccine impact was determined using 1-odds-ratio.
Results
Following vaccination, the vaccine impact on vaccine type acquisition was 94% (95% CI: 91–96%) in study 1 and 56% (95% CI: 44–65%) in study 2. The impact on serotype 6 A was 33% (95% CI: −9%; 59%) in study 1 and 42% (95% CI: 10–63%) in study 2 with minimal effect on 19A. The non-vaccine serotypes/groups 6C, 11, 15 and 23B were the most common serotypes/groups after vaccination. Isolates from the vaccine-eligible-cohort had lower penicillin MICs, less resistance to erythromycin and co-trimoxazole and less multi resistance than isolates from the control-group.
Conclusions
The efficacy of the vaccination on vaccine serotypes was high, and a milder effect on vaccine-associated-serotype 6A was observed for the vaccine-eligible-cohort. There was a significant herd effect on vaccine types in older non-vaccine-eligible children. Overall antimicrobial non-susceptibility was reduced.Funding for this study was provided by GlaxoSmithKline Biologicals SA and a grant was received from the Landspitali University Hospital Research Fund. GlaxoSmithKline Biologicals SA was provided the opportunity to review a draft version of this manuscript but the authors are solely responsible for final content and interpretation. The authors received no financial support or other form of compensation related to the development of the manuscript.Peer Reviewe
Er enn stefnt að nýskipan í opinberum rekstri?
Almenn greinNýskipan í opinberum rekstri er hugmyndafræði og safn verkfæra sem á rætur sínar að rekja til Bretlands en er þó einnig vel merkjanleg stefna í alþjóðlegu samhengi síðustu árin. Í þessari grein er leitast við að líta til þessara strauma í opinberum rekstri, reynt að meta hvaða áherslur eru framundan og þannig skapa umræðu um þróun og framtíð íslenskrar stjórnsýslu
Getur framhaldsskóli nýtt sér þekkingarsafn í kennslu og til aukins félagsstarfs
Á þessu ári lauk verkefni sem ég tók þátt í ásamt hópi einstaklinga að uppbyggingu rafræns þekkingarsafns. Markmið þekkingarsafnsins er að búa til auðvelda og skiljanlega leið svo leiðbeinendur öðlist skilning á einhverfunni og þeim aðferðum sem nýst hafa vel í vinnu með einstaklingum á einhverfurófi.
Í ritgerðinni mun ég velta því fyrir mér hvort hægt sé að nota þekkingarsafnið fyrir einstaklinga með aðra fötlun en einhverfu á sérnámsdeild Fjölbrautaskólans við Ármúla. Í fyrsta kafla útskýri ég stuttlega fötlun og þær gagntæku þroskaraskanir sem hafa allmarga undirflokka og mynda einhverfurófið. Síðan fer ég nánar í sjálfsmynd einstaklinga með fötlun. Félagshæfni og sjálfsmynd eru tengd því með aukinni félagsfærni styrkist sjálfsmyndin. Til þess að styrkja félagshæfni hjá börnum og unglingum með einhverfu er stuðst við aðferðir eins og cat-kassann, sem er kennsluefni í hugrænni tilfinningalegri þjálfun og einnig félagshæfnisögur. Ég fjalla einnig um TEACCH, sem er skipulögð kennsla sem hentar mjög vel einstaklingum með röskun á einhverfurófi. Með því að skipuleggja umhverfið, setja upp dagskrá, vinnukerfi, sjónrænt boðskiptakerfi. En við vinnu á þekkingarsafninu var tekið fram að þessi þáttur væri mikilvægur að setja upp fyrir þátttakendur á sumarnámskeiðinu. Ég lagði könnun fyrir starfsfólk sérnámsbrautar Fjölbrautarskólans við ármúla. En með henni vildi ég fá fram þeirra skoðun á því að hvort hægt væri að nota þekkingarsafnið til aukinnar fræðslu starfsfólks
Music is streaming
Árið 2015 urðu tímamót í tónlistariðnaðinum en það var fyrsta árið síðan 1999 sem hann í heild sinni sýndi fram á tekjuvöxt. Afrakstur af aðlögun breyttra aðstæðna og róttækri neyslubreytingu almennings lítur dagsins ljós og mögulegt útlit er fyrir arðbærara umhverfi fyrir tónlistarmenn. Markmið með verkefninu var að skoða betur hvernig tónlistarneysla hefur þróast og hvaða þættir skýra breytingu á greiðsluvilja á streymi, sem fer vaxandi í sölu tónlistar á heimsvísu. Framkvæmd var megindleg rannsókn með greiningu á fyrirliggjandi gögnum ásamt hefðbundinni spurningakönnun (e. observational) og tilraun (e. experimental) til að skoða neyslu og greiðsluvilja.
Alls svaraði 491 þátttakandi spurningalista um neyslu og greiðsluvilja og sýndi rannsóknin fram á sambærilegar niðurstöður og erlendar rannsóknir um vöxt á notkun streymisþjónustu. Útvarp er jafnframt einn helsti vettvangur á neyslu tónlistar ásamt lifandi tónlistarflutningi og vínylsölu. Tilraun til rannsóknar á áhrifum tekjuflæðis af áskriftargjaldinu á greiðsluvilja voru ómarktækar en áhugaverðar niðurstöður sýndu að meðaltalsgreiðsluvilji var 2.840 kr. - fyrir áskrift af streymisþjónustu sem er hærra en 1.200 kr.- markaðsverðs dagsins í dag.In 2015 the music industry as a whole reached a cornerstone in revenue growth since 1999. The results of adapting to radical changes in circumstances and digital consumption of music is starting to create a more profitable environment for musicians and right holders. The aim of this thesis is to look at how music consumption has developed over the last years and explore what factors explain changes in consumers willingness to pay for music streaming when subscription demand for music as a service (MaaS) is growing. Secondary data was analyzed and a quantitative experimental research was conducted to measure music consumption in Iceland and their willingness to pay for a monthly subscription of streaming music.
A quantitative study was conducted. The research consisted of an online questionnaire, which included both a survey part and an experimental part, 491 participantans answered the survey and results showed interesting results and similar from external studies on music consumption patterns and platform usage. Streaming is growing in popularity, radio is still one of the most used platforms for music listening as is the live sector and vinyl sales. An experimental attempt was made to explain various willingness to pay between participants when given different information facts (positive, negative, neutral) on local musicians revenue from streaming services. Although results were insignificant they showed that participant‘s average willingness to pay was 2.840 ISK (23 EUR) for a monthly subscription, which is somewhat higher then the current market price for streaming, i.e. 9,99 EUR