| 1. |
- Stephan, K., et al.
(författare)
-
Regions of interest on Ganymede's and Callisto's surfaces as potential targets for ESA's JUICE mission
- 2021
-
Ingår i: Planetary and Space Science. - : Elsevier. - 0032-0633 .- 1873-5088. ; 208
-
Tidskriftsartikel (refereegranskat)abstract
- The JUpiter Icy moons Explorer (JUICE) will investigate Ganymede's and Callisto's surfaces and subsurfaces from orbit to explore the geologic processes that have shaped and altered their surfaces by impact, tectonics, possible cryovolcanism, space weathering due to micrometeorites, radiation and charged particles as well as explore the structure and properties of the icy crust and liquid shell (Grasset et al., 2013). The best possible synergy of the JUICE instruments is required to answer the major science objective of this mission and to fully exploit the po-tential of the JUICE mission. Therefore, the JUICE team is aiming to define high priority targets on both Gany-mede's and Callisto's surfaces to support the coordination of the planning activities by the individual instrument teams. Based on the science objectives of the JUICE mission and the most recent knowledge of Ganymede's and Callisto's geologic evolution we propose a collection of Regions of Interest (RoIs), which characterize surface features and terrain types representing important traces of geologic processes, from past and/or present cryovolcanic and tectonic activity to space weathering processes, which are crucial to understand the geologic evolution of Ganymede and Callisto. The proposed evaluation of RoIs is based on their scientific importance as well as on the opportunities and conditions to observe them during the currently discussed mission profile.
|
|
| 2. |
|
|
| 3. |
- Jokinen, H., et al.
(författare)
-
Global Burden of Small Vessel Disease-Related Brain Changes on MRI Predicts Cognitive and Functional Decline
- 2020
-
Ingår i: Stroke. - : Ovid Technologies (Wolters Kluwer Health). - 0039-2499 .- 1524-4628. ; 51:1, s. 170-178
-
Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose- Cerebral small vessel disease is characterized by a wide range of focal and global brain changes. We used a magnetic resonance imaging segmentation tool to quantify multiple types of small vessel disease-related brain changes and examined their individual and combined predictive value on cognitive and functional abilities. Methods- Magnetic resonance imaging scans of 560 older individuals from LADIS (Leukoaraiosis and Disability Study) were analyzed using automated atlas- and convolutional neural network-based segmentation methods yielding volumetric measures of white matter hyperintensities, lacunes, enlarged perivascular spaces, chronic cortical infarcts, and global and regional brain atrophy. The subjects were followed up with annual neuropsychological examinations for 3 years and evaluation of instrumental activities of daily living for 7 years. Results- The strongest predictors of cognitive performance and functional outcome over time were the total volumes of white matter hyperintensities, gray matter, and hippocampi (P<0.001 for global cognitive function, processing speed, executive functions, and memory and P<0.001 for poor functional outcome). Volumes of lacunes, enlarged perivascular spaces, and cortical infarcts were significantly associated with part of the outcome measures, but their contribution was weaker. In a multivariable linear mixed model, volumes of white matter hyperintensities, lacunes, gray matter, and hippocampi remained as independent predictors of cognitive impairment. A combined measure of these markers based on Z scores strongly predicted cognitive and functional outcomes (P<0.001) even above the contribution of the individual brain changes. Conclusions- Global burden of small vessel disease-related brain changes as quantified by an image segmentation tool is a powerful predictor of long-term cognitive decline and functional disability. A combined measure of white matter hyperintensities, lacunar, gray matter, and hippocampal volumes could be used as an imaging marker associated with vascular cognitive impairment.
|
|
| 4. |
- Lindberg, O., et al.
(författare)
-
Effects of amyloid pathology and the APOE epsilon 4 allele on the association between cerebrospinal fluid A beta 38 and A beta 40 and brain morphology in cognitively normal 70-years-olds
- 2021
-
Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580. ; 101, s. 1-12
-
Tidskriftsartikel (refereegranskat)abstract
- The association between cerebrospinal fluid (CSF) amyloid beta (A beta) A beta 38 or A beta 40 and brain grey- and white matter integrity is poorly understood. We studied this in 213 cognitively normal 70-year-olds, and in subgroups defined by presence/absence of the APOE epsilon 4 allele and A beta pathology: A beta-/APOE-, A beta+/APOE-, A beta-/APOE+ and A beta+/APOE+. CSF A beta was quantified using ELISA and genotyping for APOE was performed. Low CSF A beta 42 defined A beta plaque pathology. Brain volumes were assessed using Freesurfer-5.3, and white matter integrity using tract-based statistics in FSL. A beta 38 and A beta 40 were positively correlated with cortical thickness, some subcortical volumes and white matter integrity in the total sample, and in 3 of the subgroups: A beta-/APOE-, A beta+/APOE- and A beta-/APOE+. In A beta+/APOE+ subjects, higher A beta 38 and A beta 40 were linked to reduced cortical thickness and subcortical volumes. We hypothesize that production of all A beta species decrease in brain regions with atrophy. In A beta+/APOE+, A beta-dysregulation may be linked to cortical atrophy in which high A beta levels is causing pathological changes in the gray matter of the brain. (C) 2020 The Author(s). Published by Elsevier Inc.
|
|
| 5. |
- Milillo, A., et al.
(författare)
-
Investigating Mercury's Environment with the Two-Spacecraft BepiColombo Mission
- 2020
-
Ingår i: Space Science Reviews. - : Springer Science and Business Media LLC. - 0038-6308 .- 1572-9672. ; 216:5
-
Forskningsöversikt (refereegranskat)abstract
- The ESA-JAXA BepiColombo mission will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at Mercury as well as their interactions with the solar wind, radiation, and interplanetary dust. Many scientific instruments onboard the two spacecraft will be completely, or partially devoted to study the near-space environment of Mercury as well as the complex processes that govern it. Many issues remain unsolved even after the MESSENGER mission that ended in 2015. The specific orbits of the two spacecraft, MPO and Mio, and the comprehensive scientific payload allow a wider range of scientific questions to be addressed than those that could be achieved by the individual instruments acting alone, or by previous missions. These joint observations are of key importance because many phenomena in Mercury's environment are highly temporally and spatially variable. Examples of possible coordinated observations are described in this article, analysing the required geometrical conditions, pointing, resolutions and operation timing of different BepiColombo instruments sensors.
|
|
| 6. |
|
|
| 7. |
- Rydén, Lina, 1982, et al.
(författare)
-
Atrial Fibrillation, Stroke, and Silent Cerebrovascular Disease A Population-based MRI Study
- 2021
-
Ingår i: Neurology. - : Ovid Technologies (Wolters Kluwer Health). - 0028-3878 .- 1526-632X. ; 97:16, s. E1608-E1619
-
Tidskriftsartikel (refereegranskat)abstract
- Background and Objectives Atrial fibrillation (AF) has been associated with cognitive decline and dementia. However, the mechanisms behind these associations are not clear. Examination of cerebrovascular pathology on MRI may shed light on how AF affects the brain. This study aimed to determine whether AF is associated with a broad range of cerebrovascular diseases beyond the well-known association with symptomatic stroke, including silent infarcts and markers of small vessel disease, i.e., cerebral microbleeds (CMBs), white matter hyperintensities (WMHs), and lacunes, in a population-based sample of 70-year-olds. Methods Data were obtained from the Gothenburg H70 Birth Cohort Studies, in which individuals are invited based on birthdate. This study has a cross-sectional design and includes individuals born in 1944 who underwent structural brain MRI in 2014 to 2017. AF diagnoses were based on self-report, ECG, and register data. Symptomatic stroke was based on self-report, proxy interviews, and register data. Brain infarcts and CMBs were assessed by a radiologist. WMH volumes were measured on fluid-attenuated inversion recovery images with the Lesion Segmentation Tool. Multivariable logistic regression was used to study the association between AF and infarcts/CMBs, and multivariable linear regression was used to study the association between AF and WMHs. Results A total of 776 individuals were included, and 65 (8.4%) had AF. AF was associated with symptomatic stroke (odds ratio [OR] 4.5, 95% confidence interval [CI] 2.1-9.5) and MRI findings of large infarcts (OR 5.0, 95% CI 1.5-15.9), lacunes (OR 2.7, 95% CI 1.2-5.6), and silent brain infarcts (OR 3.5; 95% CI 1.6-7.4). Among those with symptomatic stroke, individuals with AF had larger WMH volumes (0.0137 mL/total intracranial volume [TIV], 95% CI 0.0074-0.0252) compared to those without AF (0.0043 mL/TIV, 95% CI 0.0029-0.0064). There was no association between AF and WMH volumes among those without symptomatic stroke. In addition, AF was associated to CMBs in the frontal lobe. Discussion AF was associated with a broad range of cerebrovascular pathologies. Further research is needed to establish whether cerebrovascular MRI markers can be added to current treatment guidelines to further personalize anticoagulant treatment in patients with AF and to further characterize the pathogenetic processes underlying the associations between AF and cerebrovascular diseases, as well as dementia.
|
|
| 8. |
- Shebanits, O., et al.
(författare)
-
Saturn's near-equatorial ionospheric conductivities from in situ measurements
- 2020
-
Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- Cassini's Grand Finale orbits provided for the first time in-situ measurements of Saturn's topside ionosphere. We present the Pedersen and Hall conductivities of the top near-equatorial dayside ionosphere, derived from the in-situ measurements by the Cassini Radio and Wave Plasma Science Langmuir Probe, the Ion and Neutral Mass Spectrometer and the fluxgate magnetometer. The Pedersen and Hall conductivities are constrained to at least 10(-5)-10(-4) S/m at (or close to) the ionospheric peak, a factor 10-100 higher than estimated previously. We show that this is due to the presence of dusty plasma in the near-equatorial ionosphere. We also show the conductive ionospheric region to be extensive, with thickness of 300-800 km. Furthermore, our results suggest a temporal variation (decrease) of the plasma densities, mean ion masses and consequently the conductivities from orbit 288 to 292.
|
|
| 9. |
- Tofiq, A., et al.
(författare)
-
Effects of Peroral Omega-3 Fatty Acid Supplementation on Cerebrospinal Fluid Biomarkers in Patients with Alzheimer's Disease: A Randomized Controlled Trial-The OmegAD Study
- 2021
-
Ingår i: Journal of Alzheimers Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 83:3, s. 1291-1301
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Studies have suggested a connection between a decrease in the levels of polyunsaturated fatty acids (PUFAs) and Alzheimer's disease (AD). We aimed to assess the effect of supplementation with omega-3 fatty acids (n-3 FAs) on biomarkers analyzed in the cerebrospinal fluid (CSF) of patients diagnosed with AD. Objective: To investigate the effects of daily supplementation with 2.3 g of PUFAs in AD patients on the biomarkers in CSF described below. We also explored the possible correlation between these biomarkers and the performance in the cognitive test Mini-Mental State Examination (MMSE). Methods: Thirty-three patients diagnosed with AD were randomized to either treatment with a daily intake of 2.3 g of n-3 FAs (n = 18) or placebo (n = 15). CSF samples were collected at baseline and after six months of treatment, and the following biomarkers were analyzed: A beta 38, A beta 40, A beta 42, t-tau, p-tau, neurofilament light (NfL), chitinase-3-like protein 1 (YKL-40), acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), soluble IL-1 receptor type II (sIL-1RII), and IL-6. Results: There were no significant differences between the groups concerning the level of the different biomarkers in the CSF at baseline. Within the treatment group, there was a small but significant increase in both YKL-40 (p = 0.04) and NfL (p = 0.03), while the other CSF biomarkers remained stable. Conclusion: Supplementation with n-3 FAs had a statistically significant effect on NfL and YKL-40, resulting in an increase of both biomarkers, indicating a possible increase of inflammatory response and axonal damage. This increase in biomarkers did not correlate with MMSE score.
|
|
