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| 2. |
- Hibar, D. P., et al.
(författare)
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Subcortical volumetric abnormalities in bipolar disorder
- 2016
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Ingår i: Molecular Psychiatry. - : Springer Science and Business Media LLC. - 1359-4184 .- 1476-5578. ; 21:12, s. 1710-1716
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Tidskriftsartikel (refereegranskat)abstract
- Considerable uncertainty exists about the defining brain changes associated with bipolar disorder (BD). Understanding and quantifying the sources of uncertainty can help generate novel clinical hypotheses about etiology and assist in the development of biomarkers for indexing disease progression and prognosis. Here we were interested in quantifying case-control differences in intracranial volume (ICV) and each of eight subcortical brain measures: nucleus accumbens, amygdala, caudate, hippocampus, globus pallidus, putamen, thalamus, lateral ventricles. In a large study of 1710 BD patients and 2594 healthy controls, we found consistent volumetric reductions in BD patients for mean hippocampus (Cohen's d=-0.232; P=3.50 × 10 -7) and thalamus (d=-0.148; P=4.27 × 10 -3) and enlarged lateral ventricles (d=-0.260; P=3.93 × 10 -5) in patients. No significant effect of age at illness onset was detected. Stratifying patients based on clinical subtype (BD type I or type II) revealed that BDI patients had significantly larger lateral ventricles and smaller hippocampus and amygdala than controls. However, when comparing BDI and BDII patients directly, we did not detect any significant differences in brain volume. This likely represents similar etiology between BD subtype classifications. Exploratory analyses revealed significantly larger thalamic volumes in patients taking lithium compared with patients not taking lithium. We detected no significant differences between BDII patients and controls in the largest such comparison to date. Findings in this study should be interpreted with caution and with careful consideration of the limitations inherent to meta-analyzed neuroimaging comparisons. © 2016 Macmillan Publishers Limited, part of Springer Nature.
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| 3. |
- Bensch, Staffan, et al.
(författare)
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Selection for Heterozygosity Gives Hope to a Wild Population of Inbred Wolves
- 2006
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 1:1
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Tidskriftsartikel (refereegranskat)abstract
- Recent analyses have questioned the usefulness of heterozygosity estimates as measures of the inbreeding coefficient (f ), a finding that may have dramatic consequences for the management of endangered populations. We confirm that f and heterozygosity is poorly correlated in a wild and highly inbred wolf population. Yet, our data show that for each level of f, it was the most heterozygous wolves that established themselves as breeders, a selection process that seems to have decelerated the loss of heterozygosity in the population despite a steady increase of f. The markers contributing to the positive relationship between heterozygosity and breeding success were found to be located on different chromosomes, but there was a substantial amount of linkage disequilibrium in the population, indicating that the markers are reflecting heterozygosity over relatively wide genomic regions. Following our results we recommend that management programs of endangered populations include estimates of both f and heterozygosity, as they may contribute with complementary information about population viability.
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| 4. |
- Berk, M, et al.
(författare)
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Neuroprotection after a first episode of mania: a randomized controlled maintenance trial comparing the effects of lithium and quetiapine on grey and white matter volume
- 2017
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Ingår i: Translational psychiatry. - : Springer Science and Business Media LLC. - 2158-3188. ; 7:1, s. e1011-
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Tidskriftsartikel (refereegranskat)abstract
- Lithium and quetiapine are effective treatments for bipolar disorder, but their potential neuroprotective effects in humans remain unclear. A single blinded equivalence randomized controlled maintenance trial was conducted in a prospective cohort of first-episode mania (FEM) patients (n=26) to longitudinally compare the putative protective effects of lithium and quetapine on grey and white matter volume. A healthy control sample was also collected (n=20). Using structural MRI scans, voxel-wise grey and white matter volumes at baseline and changes over time in response to treatment were investigated. Patients were assessed at three time points (baseline, 3 and 12-month follow-up), whereas healthy controls were assessed at two time points (baseline and 12-month follow-up). Patients were randomized to lithium (serum level 0.6 mmol l−1, n=20) or quetiapine (flexibly dosed up to 800 mg per day, n=19) monotherapy. At baseline, compared with healthy control subjects, patients with FEM showed reduced grey matter in the orbitofrontal cortex, anterior cingulate, inferior frontal gyrus and cerebellum. In addition, patients had reduced internal capsule white matter volume bilaterally (t1,66>3.20, P<0.01). Longitudinally, there was a significant treatment × time effect only in the white matter of the left internal capsule (F2,112=8.54, P<0.01). Post hoc testing showed that, compared with baseline, lithium was more effective than quetiapine in slowing the progression of white matter volume reduction after 12 months (t1,24=3.76, P<0.01). Our data support the role of lithium but not quetiapine therapy in limiting white matter reduction early in the illness course after FEM.
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| 6. |
- Erlinge, S, et al.
(författare)
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Predation on brown hare and ring-necked pheasant populations on southern Sweden
- 1984
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Ingår i: Holarctic Ecology. ; 7:3, s. 300-304
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Tidskriftsartikel (refereegranskat)abstract
- in an open field area in southern Sweden. Biomass and numbers of hares and pheasants eaten by the predators were calculated from data on food habits, food requirements, and numbers of the mammalian and avian predators present (11 species). At the same time estimates of numbers and production of hares and pheasants were obtained. At least 40% of the estimated annual production of hares and almost 60% of subadult-adultp heasants in autumn were consumed by the predators. Estimated numbers of hares and pheasants taken by the predators greatly exceeded shootinga nd road mortality.F oxes and cats were the predominantp reda-tors on hares( about9 0%o f total harec onsumption). Foxesa ccountedf or aboutt wo-thirds of predation on pheasants; cats and goshawks were of secondary importance. Pheasant nests were preyed upon by hooded crows and also by badgers. Hares and pheasantsc ontributedo nly about 3 and 1%, respectively,o f the food of the predators.
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| 8. |
- Liberg, B., et al.
(författare)
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The neural correlates of self-paced finger tapping in bipolar depression with motor retardation
- 2013
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Ingår i: Acta Neuropsychiatrica. - : Cambridge University Press (CUP). - 0924-2708 .- 1601-5215. ; 25:1, s. 43-51
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Motor retardation is a characteristic feature of bipolar depression, and is also a core feature of Parkinson's disease. Within the framework of the functional deafferentiation theory in Parkinson's disease, we hypothesised that motor retardation in bipolar depression is mediated by disrupted subcortical activation, leading to decreased activation of cortical motor areas during finger tapping. Methods: We used functional magnetic resonance imaging to investigate neural activity during self-paced finger tapping to elucidate whether brain regions that mediate preparation, control and execution of movement are activated differently in subjects with bipolar depression (n = 9) compared to healthy controls (n = 12). Results: An uncorrected whole-brain analysis revealed significant group differences in dorsolateral and ventromedial prefrontal cortex. Corrected analyses showed non-significant differences in patients compared to controls: decreased and less widespread activation of the left putamen and left pallidum; increased activity in the left thalamus and supplementary motor area; decreased activation in the left lateral pre- and primary motor cortices; absence of activation in the pre-supplementary motor area; activation of the bilateral rostral cingulate motor area. Conclusion: Both movement preparation and execution may be affected in motor retardation, and the activity in the whole left-side motor circuit is altered during self-initiated motor performance in bipolar depression.
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| 9. |
- Liberg, O, et al.
(författare)
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Severe inbreeding depression in a wild wolf (Canis lupus) population
- 2005
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Ingår i: Biology letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 1:1, s. 17-20
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Tidskriftsartikel (refereegranskat)abstract
- The difficulty of obtaining pedigrees for wild populations has hampered the possibility of demonstrating inbreeding depression in nature. In a small, naturally restored, wild population of grey wolves in Scandinavia, founded in 1983, we constructed a pedigree for 24 of the 28 breeding pairs established in the period 1983-2002. Ancestry for the breeding animals was determined through a combination of field data (snow tracking and radio telemetry) and DNA microsatellite analysis. The population was founded by only three individuals. The inbreeding coefficient F varied between 0.00 and 0.41 for wolves born during the study period. The number of surviving pups per litter during their first winter after birth was strongly correlated with inbreeding coefficients of pups (R-2 = 0. 39, p < 0.00 1). This inbreeding depression was recalculated to match standard estimates of lethal equivalents (213), corresponding to 6.04 (2.58-9.48, 95% CI) litter-size-reducing equivalents in this wolf population.
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| 10. |
- Lin, X., et al.
(författare)
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Positioning for the Internet of Things : A 3GPP Perspective
- 2017
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Ingår i: IEEE Communications Magazine. - : Institute of Electrical and Electronics Engineers (IEEE). - 0163-6804 .- 1558-1896. ; 55:12, s. 179-185
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Tidskriftsartikel (refereegranskat)abstract
- Many use cases in the Internet of Things (IoT) will require or benefit from location information, making positioning a vital dimension of the IoT. The 3GPP has dedicated a significant effort during its Release 14 to enhance positioning support for its IoT technologies to further improve the 3GPPbased IoT eco-system. In this article, we identify the design challenges of positioning support in LTE-M and NB-IoT, and overview the 3GPP's work in enhancing the positioning support for LTE-M and NB-IoT. We focus on OTDOA, which is a downlink based positioning method. We provide an overview of the OTDOA architecture and protocols, summarize the designs of OTDOA positioning reference signals, and present simulation results to illustrate the positioning performance.
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| 13. |
- Rahm, C, et al.
(författare)
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Negative symptoms in schizophrenia show association with amygdala volumes and neural activation during affective processing
- 2015
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Ingår i: Acta neuropsychiatrica. - : Cambridge University Press (CUP). - 1601-5215 .- 0924-2708. ; 27:4, s. 213-220
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Tidskriftsartikel (refereegranskat)abstract
- Negative symptoms in schizophrenia have been associated with structural and functional alterations of the amygdala. We hypothesised that there would be between-group differences in amygdala volume and neural activation patterns during processing of affective stimuli among patients with schizophrenia and healthy controls. We further hypothesised correlations between neuroimaging metrics and clinical ratings of negative symptoms in patients with schizophrenia.MethodsWe used structural and functional magnetic resonance imaging to assess volume and neural activation of the amygdala in 28 patients with schizophrenia and 28 healthy controls.ResultsWe found no between-group differences in amygdala volume or neural activation. However, we found a significant negative correlation between emotional blunting and neural activation in the left amygdala during processing of positive affect. We also found a significant negative correlation between stereotyped thinking and the volume of right amygdala.ConclusionOur findings implicate the amygdala in a subgroup of negative symptoms in schizophrenia that are characterised by reduced expression with blunted affect and stereotyped thinking.
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