Et skandinavisk nasjonsbyggingsprosjekt : Skandinavisk Selskab (1864-1871)

I 1864 ble den skandinaviske bevegelsen institusjonalisert i Norge med Skandinavisk Selskab (1864-1871). Dette er en studie av Skandinavisk Selskabs oppkomst, virksomhet og fall. Hovedfokus er på selskapets program for politisk samling av Skandinavia og det nasjonalistiske tankegodset som ble knyttet til dette programmet. De sentrale problemstillingene i oppgaven er: Hva kjennetegnet Skandinavisk Selskabs politiske prosjekt? Hvordan begrunnet kretsen rundt Skandinavisk Selskab sitt program for politisk samling av Skandinavia? Studien belyser også hvilke virkemidler de ønsket å bruke for å fremme saken, hvordan den skandinavistiske nasjonsbyggingen skulle foregå i praksis. Det blir også sett nærmere på utgangspunktet og omstendighetene rundt stiftelsen av selskapet. Et annet sentralt moment i undersøkelsen er å søke en forklaring på hvorfor selskapets virksomhet døde ut og selskapet gikk i oppløsning, hvor splittesen av miljøet i 1867 står sentralt. Dessuten blir Nordiska Nationalföreningen i Stockholm vurdert som parallell til selskapet i Christiania. De sentrale aktørene som trekkes frem i oppgaven er: Torkel Halvorsen Aschehoug, Michael Birkeland, Ole Jacob Broch, Ludvig Kristensen Daa, Ole Andreas Bachke, Jacob Løkke og Otto Løvenskiold

Allocentric representation in the human amygdala and ventral visual stream

The hippocampus and the entorhinal cortex are considered the main brain structures for allocentric representation of the external environment. Here, we show that the amygdala and the ventral visual stream are involved in allocentric representation. Thirty-one young men explored 35 virtual environments during high-resolution functional magnetic resonance imaging (fMRI) of the medial temporal lobe (MTL) and were subsequently tested on recall of the allocentric pattern of the objects in each environment-in other words, the positions of the objects relative to each other and to the outer perimeter. We find increasingly unique brain activation patterns associated with increasing allocentric accuracy in distinct neural populations in the perirhinal cortex, parahippocampal cortex, fusiform cortex, amygdala, hippocampus, and entorhinal cortex. In contrast to the traditional view of a hierarchical MTL network with the hippocampus at the top, we demonstrate, using recently developed graph analyses, a hierarchical allocentric MTL network without a main connector hub

Is intracranial volume a risk factor for IDH-mutant low-grade glioma? A case-control study

Purpose Risk of cancer has been associated with body or organ size in several studies. We sought to investigate the relationship between intracranial volume (ICV) (as a proxy for lifetime maximum brain size) and risk of IDH-mutant low-grade glioma. Methods In a multicenter case–control study based on population-based data, we included 154 patients with IDH-mutant WHO grade 2 glioma and 995 healthy controls. ICV in both groups was calculated from 3D MRI brain scans using an automated reverse brain mask method, and then compared using a binomial logistic regression model. Results We found a non-linear association between ICV and risk of glioma with increasing risk above and below a threshold of 1394 ml (p < 0.001). After adjusting for ICV, sex was not a risk factor for glioma. Conclusion Intracranial volume may be a risk factor for IDH-mutant low-grade glioma, but the relationship seems to be non-linear with increased risk both above and below a threshold in intracranial volume.publishedVersio

Traumatic Brain Injury Assessment: Sensitivity and Specificity with Inclusion of QEEG Parameters

Addressing issues with sensitivity and specificity in TBI assessment this study compared the performance on neuropsychological tests and results from qEEG assessment between a heterogeneous TBI (N=20) group and a matched normal control group (N=20). The TBI group was performed worse on all measures. Significant differences in performance were found in the domains of information processing speed and executive function. Effect sizes of these differences were large. This was also true for the amplitude of the qEEG parameter P3NoGo along with P3Go latency and theta power in the temporal and frontal lobes. Binary logistic regression revealed higher sensitivity and specificity when combining neuropsychological tests and qEEG parameters, suggesting qEEG parameters in&nbsp; combination with neuropsychological tests to be good assets in TBI assessment

Long-term Effects of Seeding in an Alpine Environment: and a comparison of the effect of native Festuca ovina and non-native Festuca rubra on the establishment of native Betula nana

As human induced disturbance in alpine ecosystems have increased, more knowledge is needed about the long-term effects of restoration efforts in such environments. There are benefits with using native species in restoration in alpine ecosystems, but the establishment success of native species compared to non-native species, and their effect on the establishment of native species has not been evaluated in detail. We examined ten disturbed alpine sites 21 years after seeding with a commercial seed mix, with regard to vegetation cover, species richness and soil conditions, and compared them with reference sites in close vicinity. After 21 years seeded sites had more vegetation cover, but native vegetation cover and species richness was larger in reference sites. Soil material did have a significant effect on vegetation cover, with less vegetation establishing as dominating soil particle size increased. However, native vegetation cover remained the same with increasing soil material. The effects of a native species, Festuca ovina, was compared with the effects of the main ingredient from the commercial seed mix used in 1989, Festuca rubra, on the establishment of the native Betula nana. Festuca rubra established slightly better than F. ovina on all soil types in the greenhouse experiment, but had larger plant size. B. nana experienced competition from both Festuca species, but less from F. ovina. The species F. ovina facilitated for B. nana on coarse soil. Even though these findings indicate that the native F. ovina is the best alternative with regard to establishment of a native species in the greenhouse, these patterns may not always be expected in nature due to other environmental factors, like wind. However the findings in this study indicate that using native species is the best alternative in alpine ecosystem restoration

How Does the Accuracy of Intracranial Volume Measurements Affect Normalized Brain Volumes? Sample Size Estimates Based on 966 Subjects from the HUNT MRI Cohort

BACKGROUND AND PURPOSE: The intracranial volume is commonly used for correcting regional brain volume measurements for variations in head size. Accurate intracranial volume measurements are important because errors will be propagated to the corrected regional brain volume measurements, possibly leading to biased data or decreased power. Our aims were to describe a fully automatic SPM-based method for estimating the intracranial volume and to explore the practical implications of different methods for obtaining the intracranial volume and normalization methods on statistical power. MATERIALS AND METHODS: We describe a method for calculating the intracranial volume that can use either T1-weighted or both T1- and T2-weighted MR images. The accuracy of the method was compared with manual measurements and automatic estimates by FreeSurfer and SPM-based methods. Sample size calculations on intracranial volume–corrected regional brain volumes with intracranial volume estimates from FreeSurfer, SPM, and our proposed method were used to explore the benefits of accurate intracranial volume estimates. RESULTS: The proposed method for estimating the intracranial volume compared favorably with the other methods evaluated here, with mean and absolute differences in manual measurements of −0.1% and 2.2%, respectively, and an intraclass correlation coefficient of 0.97 when using T1-weighted images. Using both T1- and T2-weighted images for estimating the intracranial volume slightly improved the accuracy. Sample size calculations showed that both the accuracy of intracranial volume estimates and the method for correcting the regional volume measurements affected the sample size. CONCLUSIONS: Accurate intracranial volume estimates are most important for ratio-corrected regional brain volumes, for which our proposed method can provide increased power in intracranial volume–corrected regional brain volume data

Poor Response Inhibition and Symptoms of Inattentiveness Are Core Characteristics of Lifetime Illicit Substance Use among Young Adults in the General Norwegian Population: The HUNT Study

Background Impairments in neurocognitive functioning are associated with substance use behavior. Previous studies in neurocognitive predictors of substance use typically use self-report measures rather than neuropsychological performance measures and suffer from low sample sizes and use of clinical diagnostic cut offs. Methods Crossectional data from the HUNT4 Study (Helseundersøkelsen i Trøndelag) was used to study executive neuropsychological performance and self-reported measures of neurocognitive function associated with a history of illicit substance use in a general population sample of young adults in Norway. We performed both between group comparisons and logistic regression modeling and controlled for mental health symptomatology. Results Subjects in our cohort with a self-reported use of illicit substances had significantly higher self-reported mental health and neurocognitive symptom load. A logistic regression model with substance use as response included sex, commission errors and self-reported inattentiveness and anxiety as significant predictors. After 10-fold cross-validation this model achieved a moderate area under the receiver-operator curve of 0.63. To handle the class imbalance typically found in such population data, we also calculated balanced accuracy with a optimal model cut off of 0.234 with a sensitivity of 0.50 and specificity of 0.76 as well as precision recall—area under the curve of 0.28. Conclusions Subtle cognitive dysfunction differentiates subjects with and without a history of illicit substance use. Neurocognitive factors outperformed the effects of depressive symptoms on substance use behavior in this cohort. We highlight the need for using adequate statistical tools for evaluating the performance of models in unbalanced datasets

Does risk of brain cancer increase with intracranial volume? A population-based case control study

Background Glioma is the most common primary brain tumor and is believed to arise from glial stem cells. Despite large efforts, there are limited established risk factors. It has been suggested that tissue with more stem cell divisions may exhibit higher risk of cancer due to chance alone. Assuming a positive correlation between the number of stem cell divisions in an organ and size of the same organ, we hypothesized that variation in intracranial volume, as a proxy for brain size, may be linked to risk of high-grade glioma. Methods Intracranial volume was calculated from pretreatment 3D T1-weighted MRI brain scans from 124 patients with high-grade glioma and 995 general population–based controls. Binomial logistic regression analyses were performed to ascertain the effect of intracranial volume and sex on the likelihood that participants had high-grade glioma. Results An increase in intracranial volume of 100 mL was associated with an odds ratio of high-grade glioma of 1.69 (95% CI: 1.44‒1.98; P < 0.001). After adjusting for intracranial volume, female sex emerged as a risk factor for high-grade glioma (odds ratio for male sex = 0.56, 95% CI: 0.33‒0.93; P = 0.026). Conclusions Intracranial volume is strongly associated with risk of high-grade glioma. After correcting for intracranial volume, risk of high-grade glioma was higher in women. The development of glioma is correlated to brain size and may to a large extent be a stochastic event related to the number of cells at risk

5 Years of Exercise Intervention Did Not Benefit Cognition Compared to the Physical Activity Guidelines in Older Adults, but Higher Cardiorespiratory Fitness Did. A Generation 100 Substudy

Background: Aerobic exercise is proposed to attenuate cognitive decline in aging. We investigated the effect of different aerobic exercise interventions and cardiorespiratory fitness (CRF) upon cognition throughout a 5-year exercise intervention in older adults. Methods: 106 older adults (52 women, age 70-77 years) were randomized into high-intensity interval training (HIIT; ∼90% peak heart rate), moderate-intensity continuous training (MICT; ∼70% peak heart rate), or control for 5 years. The HIIT and MICT groups performed supervised training twice weekly, while the control group was asked to follow the national physical activity guidelines (30 min of physical activity/day). At baseline, 1-, 3-, and 5-year follow-up, participants partook in cognitive testing (spatial memory, verbal memory, pattern separation, processing speed, working memory, and planning ability), underwent clinical testing, and filled out health-related questionnaires. Linear mixed models were used to assess the effects of the exercise group and CRF (measured as peak and max oxygen uptake) on each cognitive test. The effects of changes in CRF on changes in each cognitive test score throughout the intervention were also assessed. The associations between baseline CRF and cognitive abilities at the follow-ups were investigated using linear regressions. Results: There was no group-by-time interaction on the cognitive measures, and neither HIIT nor MICT participation was associated with better cognitive performance than control at any time point during the 5-year intervention. All groups increased their CRF similarly during the 1st year and subsequently declined back to baseline levels after 5 years. A higher CRF was associated with higher processing speed throughout the intervention while increasing CRF during the intervention was associated with better working memory and worse pattern separation. Higher CRF at baseline predicted consistently better processing speed and verbal memory performance. Conclusion: In this first 5-year randomized controlled trial investigating the effects of HIIT, MICT, and physical activity according to national guidelines on cognition, we observed no effect of exercise intervention group on cognition when compared to following the national physical activity guidelines. Still, the results showed that higher CRF and increasing CRF benefited multiple, but not all, cognitive abilities in older adults