| 1. |
- Bensi, M., et al.
(författare)
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Deep flow variability offshore south-west Svalbard (fram strait)
- 2019
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Ingår i: Water. - : MDPI AG. - 2073-4441. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- - Water mass generation and mixing in the eastern Fram Strait are strongly influenced by the interaction between Atlantic and Arctic waters and by the local atmospheric forcing, which produce dense water that substantially contributes to maintaining the global thermohaline circulation. The West Spitsbergen margin is an ideal area to study such processes. Hence, in order to investigate the deep flow variability on short-term, seasonal, and multiannual timescales, two moorings were deployed at ~1040 m depth on the southwest Spitsbergen continental slope. We present and discuss time series data collected between June 2014 and June 2016. They reveal thermohaline and current fluctuations that were largest from October to April, when the deep layer, typically occupied by Norwegian Sea Deep Water, was perturbed by sporadic intrusions of warmer, saltier, and less dense water. Surprisingly, the observed anomalies occurred quasi-simultaneously at both sites, despite their distance (~170 km). We argue that these anomalies may arise mainly by the effect of topographically trapped waves excited and modulated by atmospheric forcing. Propagation of internal waves causes a change in the vertical distribution of the Atlantic water, which can reach deep layers. During such events, strong currents typically precede thermohaline variations without significant changes in turbidity. However, turbidity increases during April-June in concomitance with enhanced downslope currents. Since prolonged injections of warm water within the deep layer could lead to a progressive reduction of the density of the abyssal water moving toward the Arctic Ocean, understanding the interplay between shelf, slope, and deep waters along the west Spitsbergen margin could be crucial for making projections on future changes in the global thermohaline circulation. © 2019 by the authors.
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| 2. |
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| 3. |
- Aarsland, D, et al.
(författare)
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Frequency and case identification of dementia with Lewy bodies using the revised consensus criteria
- 2008
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Ingår i: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1421-9824 .- 1420-8008. ; 26:5, s. 445-452
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Tidskriftsartikel (refereegranskat)abstract
- <i>Objective:</i> To find the proportion of dementia with Lewy bodies (DLB) in a referral cohort of patients with a first-time diagnosis of mild dementia. <i>Background:</i> The proportion of DLB among the dementia sufferers is not known and the clinical consensus criteria have low sensitivity. We employed the revised DLB criteria to study the proportion with DLB in a community sample of patients with mild dementia. <i>Methods:</i> From March 2005 to March 2007, we included 196 patients from referrals to all geriatric medicine, old age psychiatry and neurology outpatient clinics in Rogaland and Hordaland counties in Western Norway. Standardized clinical instruments and diagnostic criteria were employed. <i>Results:</i> 65% had Alzheimer dementia, 20% DLB (16% probable DLB), 5.6% vascular dementia, 5.6% Parkinson disease with dementia, 2.0% frontotemporal dementia and 1.5% alcoholic dementia. There were no significant differences in the proportion with DLB according to age bands and dementia severity groups. The revised criteria for a clinical diagnosis of DLB increased the proportion of probable DLB by 25% compared to the previous criteria. <i>Conclusion:</i> DLB is common in patients with mild dementia, and is the second most common type of dementia. The introduction of new clinical criteria for DLB leads to an increase in the proportion diagnosed with probable DLB.
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| 4. |
- Gonzalez-Ortiz, Fernando, 1990, et al.
(författare)
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Plasma brain-derived tau is an amyloid-associated neurodegeneration biomarker in Alzheimer's disease.
- 2024
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Ingår i: Nature communications. - 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- Staging amyloid-beta (Aβ) pathophysiology according to the intensity of neurodegeneration could identify individuals at risk for cognitive decline in Alzheimer's disease (AD). In blood, phosphorylated tau (p-tau) associates with Aβ pathophysiology but an AD-type neurodegeneration biomarker has been lacking. In this multicenter study (n=1076), we show that brain-derived tau (BD-tau) in blood increases according to concomitant Aβ ("A") and neurodegeneration ("N") abnormalities (determined using cerebrospinal fluid biomarkers); We used blood-based A/N biomarkers to profile the participants in this study; individuals with blood-based p-tau+/BD-tau+ profiles had the fastest cognitive decline and atrophy rates, irrespective of the baseline cognitive status. Furthermore, BD-tau showed no or much weaker correlations with age, renal function, other comorbidities/risk factors and self-identified race/ethnicity, compared with other blood biomarkers. Here we show that blood-based BD-tau is a biomarker for identifying Aβ-positive individuals at risk of short-term cognitive decline and atrophy, with implications for clinical trials and implementation of anti-Aβ therapies.
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| 6. |
- Skogseth, R, et al.
(författare)
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Neuropsychiatric correlates of cerebrospinal fluid biomarkers in Alzheimer's disease
- 2008
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Ingår i: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1421-9824 .- 1420-8008. ; 25:6, s. 559-563
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Tidskriftsartikel (refereegranskat)abstract
- <i>Background:</i> The aim of this study was to explore the relationship between cerebrospinal fluid biomarkers and neuropsychiatric symptoms in people with Alzheimer’s disease. Psychosis, agitation, apathy and depression were assessed using standardised measures in 32 patients with mild Alzheimer’s disease. <i>Methods:</i> The levels of the 42-amino-acid form of β-amyloid (Aβ<sub>1–42</sub>), tau and p-tau (phosphorylated at threonine 181) were quantified using the conventional enzyme-linked immunosorbent assay method. <i>Results:</i> Our result shows that apathy is significantly correlated with tau and p-tau but not with Aβ<sub>1–42</sub>. There were no significant correlations between indices of psychosis/agitation,or depression and cerebrospinal fluid Aβ<sub>1–42</sub>, tau or p-tau concentrations. <i>Conclusion:</i> Our finding suggests that apathy is associated with the level of neurofibrillary tangles in people with mild Alzheimer’s disease. In contrast, the overall levels of neurofibrillary tangles or amyloid plaques do not seem to be associated with depression or psychosis, indicating that other brain changes contribute to these symptoms.
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