| 1. |
- Beekman, Jan, et al.
(author)
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Long-term population trends and shifts in distribution of Bewick's swans cygnus columbianus bewickii wintering in northwest Europe
- 2020
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In: Wildfowl. - 0954-6324. ; :69, s. 73-102
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Journal article (peer-reviewed)abstract
- Coordinated international censuses of the Northwest European Bewick's Swan Cygnus columbianus bewickii population have been undertaken across the swans' wintering range at c. 5-year intervals since 1984. During the early years of the study, numbers increased steadily to a peak of 29,780 individuals in January 1995, but then declined by 39.4% to 18,057 swans counted in January 2010 before showing a partial recovery to 20,149 recorded in January 2015. Changes in distribution across the wintering range were also recorded; a higher proportion of the population now remains in more easterly countries (notably Germany) in mid-winter, whilst only a handful of birds migrated to Ireland (at the western edge of the range) during the 2000s compared to >1,000 wintering there at the start of the study. Variation between censuses in the proportion of swans recorded in different parts of the range were attributable to weather conditions, with more swans wintering further north in warmer years. The overall percentage of cygnets recorded in each of the census years ranged from 9.6% in 2010 to 13.2% in 2005, with no obvious consistency over time in the distribution of cygnets across the wintering range. There were however changes between 1990 and 2015 in the swans' use of feeding habitats, with a decline in the proportion of birds on pasture and a corresponding increase in those on arable land. Decreases in the total population size and changes in distribution in the 21st century have implications for the designation and resultant protection of sites of international importance for the species.
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| 2. |
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| 3. |
- Laubek, Bjarke, et al.
(author)
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Whooper swan cygnus cygnus January population censuses for northwest mainland Europe, 1995-2015
- 2020
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In: Wildfowl. - 0954-6324. ; :69, s. 103-122
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Journal article (peer-reviewed)abstract
- Internationally coordinated censuses of Whooper Swans Cygnus cygnus across continental northwest Europe were undertaken in mid-winter 1995, 2000, 2005, 2010 and 2015. The estimate of 138,500 birds in 2015, the highest to date, represented a more than doubling of the population size (at an annual increase of 4.1%) since the first census total of 59,000 swans in 1995. The largest increase was in Denmark, where numbers almost trebled from 21,740 in 1995 to 62,620 in 2015. More than 97% of all swans were counted in just six countries. The percentage of total numbers increased significantly between 1995 and 2015 in Denmark (from 36.5% to 45.2%) and Germany (26.0% to 34.7%), but declined significantly in Sweden (14.2% to 8.4%), Norway (13.1% to 3.6%), Poland (6.2% to 4.0%) and the Netherlands (2.4% to 1.7%). The counts show an increasing discrepancy between national trends in abundance for Whooper Swans in Sweden and especially in Denmark in comparison with results obtained only from mid-winter International Waterbird Count (IWC) site coverage. This demonstrates the increasing tendency for Whooper Swans to winter in areas away from traditionally counted IWC sites and confirms the continued need for a regular cycle of coordinated dedicated swan counts to anchor population trends generated from other data sources.
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| 4. |
- Rickhag, Mattias, et al.
(author)
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Rapid and long-term induction of effector immediate early genes (BDNF, Neuritin and Arc) in peri-infarct cortex and dentate gyrus after ischemic injury in rat brain.
- 2007
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In: Brain Research. - : Elsevier BV. - 1872-6240 .- 0006-8993. ; 1151, s. 203-210
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Journal article (peer-reviewed)abstract
- The genomic response following brain ischemia is very complex and involves activation of both protective and detrimental signaling pathways. Immediate early genes (IEGs) represent the first wave of gene expression following ischemia and are induced in extensive regions of the ischemic brain including cerebral cortex and hippocampus. Brain-derived neurotrophic factor (BDNF), Neuritin and Activity-regulated cytoskeleton-associated protein (Arc) belong to a subgroup of immediate early genes implicated in synaptic plasticity known as effector immediate early genes. Here, we investigated the spatial and temporal activation pattern for these genes during the first 24 h of reperfusion following 2-h occlusion of the middle cerebral artery. Neuritin showed a persistent activation in frontal-cingulate cortex while Arc displayed a biphasic response. Also, in dentate gyrus, activation was observed at 0–6 h of reperfusion for Neuritin and 0–12 h of reperfusion for Arc while BDNF was induced 0–9 h of reperfusion. Our study demonstrates a rapid and long-term activation of effector immediate early genes in distinct brain areas following ischemic injury in rat. Effector gene activation may be part of long-term synaptic responses of ischemic brain tissue.
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| 5. |
- Rodrigues Gomes, Joao Carlos, et al.
(author)
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Excitotoxicity Downregulates TrkB.FL Signaling and Upregulates the Neuroprotective Truncated TrkB Receptors in Cultured Hippocampal and Striatal Neurons.
- 2012
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In: The Journal of Neuroscience : the official journal of the Society for Neuroscience. - 1529-2401. ; 32:13, s. 4610-4622
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Journal article (peer-reviewed)abstract
- Brain-derived neurotrophic factor (BDNF) plays an important role in neuronal survival through activation of TrkB receptors. The trkB gene encodes a full-length receptor tyrosine kinase (TrkB.FL) and its truncated (T1/T2) isoforms. We investigated the changes in TrkB protein levels and signaling activity under excitotoxic conditions, which are characteristic of brain ischemia, traumatic brain injury, and neurodegenerative disorders. Excitotoxic stimulation of cultured rat hippocampal or striatal neurons downregulated TrkB.FL and upregulated a truncated form of the receptor (TrkB.T). Downregulation of TrkB.FL was mediated by calpains, whereas the increase in TrkB.T protein levels required transcription and translation activities. Downregulation of TrkB.FL receptors in hippocampal neurons correlated with a decrease in BDNF-induced activation of the Ras/ERK and PLCγ pathways. However, calpain inhibition, which prevents TrkB.FL degradation, did not preclude the decrease in signaling activity of these receptors. On the other hand, incubation with anisomycin, to prevent the upregulation of TrkB.T, protected to a large extent the TrkB.FL signaling activity, suggesting that truncated receptors may act as dominant-negatives. The upregulation of TrkB.T under excitotoxic conditions was correlated with an increase in BDNF-induced inhibition of RhoA, a mediator of excitotoxic neuronal death. BDNF fully protected hippocampal neurons transduced with TrkB.T when present during excitotoxic stimulation with glutamate, in contrast with the partial protection observed in cells overexpressing TrkB.FL or expressing GFP. These results indicate that BDNF protects hippocampal neurons by two distinct mechanisms: through the neurotrophic effects of TrkB.FL receptors and by activation of TrkB.T receptors coupled to inhibition of the excitotoxic signaling.
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| 6. |
- Ruscher, Karsten, et al.
(author)
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Effect of 3,4-Methylenedioxyamphetamine on Dendritic Spines Dynamics in Rat Neocortical Neurons - Involvement of Heat Shock Protein 27.
- 2011
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In: Brain Research. - : Elsevier BV. - 1872-6240 .- 0006-8993. ; 1370, s. 43-52
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Journal article (peer-reviewed)abstract
- Along with chronic neurotoxic effects, the long-term consumption of amphetamines has been associated to psychiatric symptoms and memory disturbances. Dendritic spine dynamics have been discussed as a possible morphological correlate. However, the underlying mechanisms are still elusive. 3,4-Methylenedioxyamphetamine (MDA), a major drug of abuse and a main metabolite after 3,4-methylenedioxymethamphetamine (MDMA) intake, provokes a loss of dendritic spine like protrusions in primary cultures of rat cortical neurons. 3,4-Methylenedioxyamphetamine also induced a rapid activation of the p38 mitogen activated protein kinase (p38 MAPK) pathway and phosphorylation of heat shock protein 27 (hsp27) indicative for its decreased chaperone activity. Concurrent pharmacological inhibition of the p38 MAPK by SB203580 abolished hsp27 phosphorylation and diminished the loss of dendritic spine-like protrusions. Moreover, upon MDA treatment dendritic spine-like protrusions were stabilized in neurons constitutively expressing hsp27. In parallel experiments we observed a robust activation of the heat shock transcription factor 1 (HSF-1) and a subsequent increase of hsp27 and hsp70. The regulation of small heat shock proteins corroborates the existence of a neuronal stress response after MDA treatment. Pharmacological targeting of small heat shock protein phosphorylation may provide a new strategy to preserve spine integrity after amphetamine exposure.
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| 7. |
- Teilum, Maria, et al.
(author)
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Hypothermia Affects Translocation of Numerous Cytoplasmic Proteins Following Global Cerebral Ischemia.
- 2007
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In: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 6:7, s. 2822-2832
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Journal article (peer-reviewed)abstract
- Using a decapitation ischemia model, we studied translocation of proteins to and from the cytosol in normothermic (NT) and hypothermic (HT) rat brains. 2D gel analysis identified 74 proteins whose cytosolic level changed significantly after 15 min of ischemia. HT preserved the cytosolic levels of several glycolytic enzymes, as well as many plasticity related proteins, otherwise decreased following NT ischemia. The levels of redox-related proteins was lower in HT than in NT. Our results indicate that translocation of proteins to and from the cytosol is an important issue during ischemia.
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| 8. |
- Wiklund, Karolin, et al.
(author)
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Amino acids predict prognosis in patients with acute dyspnea
- 2021
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In: BMC Emergency Medicine. - : Springer Science and Business Media LLC. - 1471-227X. ; 21:1
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Journal article (peer-reviewed)abstract
- Background: To identify amino acids that can predict risk of 90-day mortality in patients with acute dyspnea. Method: Plasma levels of nine amino acids were analyzed 663 adult patients admitted to the Emergency Department (ED) with acute dyspnea. Cox proportional hazards models were used to examine the relation between amino acid levels and the risk of 90-day mortality. Result: Eighty patients (12.1%) died within 90 days of admission. An “Amino Acid Mortality Risk Score” (AMRS), summing absolute plasma levels of glycine, phenylalanine and valine, demonstrated that among the patients belonging to quartile 1 (Q1) of the AMRS, only 4 patients died, compared to 44 patients in quartile 4. Using Q1 of the AMRS as reference, each increment of 1 SD in the AMRS was associated with a hazard ratio (HR) of 2.15 for 90-day mortality, and the HR was > 9 times higher in Q4. Conclusion: Glycine, phenylalanine and valine are associated with a risk of 90-day mortality in patients admitted to the ED for acute dyspnea, suggesting that these amino acids may be useful in risk assessments.
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