| 411. |
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| 412. |
- Oettershagen, Lutz, et al.
(författare)
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A Higher-Order Temporal H-Index for Evolving Networks
- 2023
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Ingår i: KDD 2023. - : Association for Computing Machinery (ACM). ; , s. 1770-1782
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Konferensbidrag (refereegranskat)abstract
- The H-index of a node in a static network is the maximum value h such that at least h of its neighbors have a degree of at least h. Recently, a generalized version, the n-th order H-index, was introduced, allowing to relate degree centrality, H-index, and the k-core of a node. We extend the n-th order H-index to temporal networks and define corresponding temporal centrality measures and temporal core decompositions. Our n-th order temporal H-index respects the reachability in temporal networks leading to node rankings, which reflect the importance of nodes in spreading processes. We derive natural decompositions of temporal networks into subgraphs with strong temporal coherence. We analyze a recursive computation scheme and develop a highly scalable streaming algorithm. Our experimental evaluation demonstrates the efficiency of our algorithms and the conceptional validity of our approach. Specifically, we show that the n-th order temporal H-index is a strong heuristic for identifying possible super-spreaders in evolving social networks and detects temporally well-connected components.
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| 413. |
- Olsen, Jesper, et al.
(författare)
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Lacustrine evidence of Holocene environmental change from three Faroese lakes: a multiproxy XRF and stable isotope study
- 2010
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Ingår i: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791. ; 29:19-20, s. 2764-2780
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Tidskriftsartikel (refereegranskat)abstract
- The vegetation history of the Faroe Islands has been investigated in numerous studies all broadly showing that the early-Holocene vegetation of the islands largely consisted of fellfield with gravely and rocky soils formed under a continental climate which shifted to an oceanic climate around 10,000 cal yr BP when grasses, sedges and finally shrubs began to dominant the islands. Here we present data from three lake sediment cores and show a much more detailed history from geochemical and isotope data. These data show that the Faroe Islands were deglaciated by the end of Younger Dryas (11,700 10,300 cal yr BP), at this time relatively high sedimentation rates with high delta C-13 imply poor soil development. delta C-13, Ti and chi data reveal a much more stable and warm mid-Holocene until 7410 cal yr BP characterised by increasing vegetation cover and build up of organic soils towards the Holocene thermal maximum around 7400 cal yr BP. The final meltdown of the Laurentide ice sheet around 7000 cal yr BP appears to have impacted both ocean and atmospheric circulation towards colder conditions on the Faroe Islands. This is inferred by enhanced weathering and increased deposition of surplus sulphur (sea spray) and erosion in the highland lakes from about 7400 cal yr BP. From 4190 cal yr BP further cooling is believed to have occurred as a consequence for increased soil erosion due to freeze/thaw sequences related to oceanic and atmospheric variability. This cooling trend appears to have advanced further from 3000 cal yr BR A short period around 1800 cal yr BP appears as a short warm and wet phase in between a general cooling characterised by significant soil erosion lasting until 725 cal yr BP. Interestingly, increased soil erosion seems to have begun at 1360 cal yr BP, thus significantly before the arrival of the first settlers on the Faroe Island around 1150 cal yr BP, although additional erosion took place around 1200 cal yr BP possibly as a consequence of human activities. Hence it appears that if humans caused a change in the Faroe landscape in terms of erosion they in fact accelerated a process that had already started. Soil erosion was a dominant landscape factor during the Little Ice Age, but climate related triggers can hardly be distinguished from human activities. (c) 2010 Elsevier Ltd. All rights reserved.
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| 414. |
- Parker, Victoria E. R., et al.
(författare)
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Cotadutide promotes glycogenolysis in people with overweight or obesity diagnosed with type 2 diabetes
- 2023
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Ingår i: Nature Metabolism. - : NATURE PORTFOLIO. - 2522-5812. ; 5, s. 2086-2093
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Tidskriftsartikel (refereegranskat)abstract
- Cotadutide is a dual glucagon-like peptide 1 and glucagon receptor agonist under development for the treatment of non-alcoholic steatohepatitis and type 2 diabetes mellitus (T2DM) and chronic kidney disease. Non-alcoholic steatohepatitis is a complex disease with no approved pharmacotherapies, arising from an underlying state of systemic metabolic dysfunction in association with T2DM and obesity. Cotadutide has been shown to improve glycaemic control, body weight, lipids, liver fat, inflammation and fibrosis. We conducted a two-part, randomized phase 2a trial in men and women with overweight or obesity diagnosed with T2DM to evaluate the efficacy and safety of cotadutide compared with placebo and liraglutide. The primary endpoints were change from baseline to day 28 of treatment in postprandial hepatic glycogen (part A) and to day 35 of treatment in fasting hepatic glycogen (part B) with cotadutide versus placebo. Secondary endpoints in part B were changes in fasting hepatic glycogen with cotadutide versus the mono glucagon-like peptide 1 receptor agonist, liraglutide, and change in hepatic fat fraction. The trial met its primary endpoint. We showed that cotadutide promotes greater reductions in liver glycogen and fat compared with placebo and liraglutide. Safety and tolerability findings with cotadutide were comparable to those of previous reports. Thus, this work provides evidence of additional benefits of cotadutide that could be attributed to glucagon receptor engagement. Our results suggest that cotadutide acts on the glucagon receptor in the human liver to promote glycogenolysis and improve the metabolic health of the liver. ClinicalTrials.gov registration: NCT03555994. In a two-part randomized phase 2a trial in men and women with overweight or obesity and type 2 diabetes mellitus, cotadutide promoted greater reductions in liver glycogen and fat than placebo and liraglutide.
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| 415. |
- Perng, Bo Hao, et al.
(författare)
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Mapping distribution of woody plant species richness from field rapid assessment and machine learning
- 2024
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Ingår i: Taiwania. - 0372-333X. ; 69, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- Sustainable forest management needs information on spatial distribution of species richness. The objectives of this study were to understand whether knowledge, method, and effort of a rapid assessment affected accuracy and consistency in mapping species richness. A simulation study was carried out with nine 25–50 ha census plots located in tropical, subtropical, and temperate zones. Each forest site was first tessellated into non-overlapping cells. Rapid assessment was conducted in all cells to generate a complete coverage of proxies of the underlying species richness. Cells were subsampled for census, where all plant individuals were identified to species in these census cells. An artificial neural network model was built using the census cells that contain rapid assessment and census information. The model then predicted species richness of cells that were not censused. Results showed that knowledge level did not improve the accuracy and consistency in mapping species richness. Rapid assessment effort and method significantly affected the accuracy and consistency. Increasing rapid assessment effort from 10 to 40 plant individuals could improve the accuracy and consistency up to 2.2% and 2.8%, respectively. Transect reduced accuracy and consistency by up to 0.5% and 0.8%, respectively. This study suggests that knowing at least half of the species in a forest is sufficient for a rapid assessment. At least 20 plant individuals per cell is recommended for rapid assessment. Lastly, a rapid assessment could be carried out by local communities that are familiar with their forests; thus, further supporting sustainable forest management.
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| 416. |
- Persson, Kajsa P., et al.
(författare)
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Evaluation of Human Liver Slices and Reporter Gene Assays as Systems for Predicting the Cytochrome P450 Induction Potential of Drugs in Vivo in Humans
- 2006
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Ingår i: Pharmaceutical research. - New York : Springer. - 0724-8741 .- 1573-904X. ; 23:1, s. 56-69
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Tidskriftsartikel (refereegranskat)abstract
- PurposeThe aim of the study was to investigate the feasibility of predicting human in vivo cytochrome P450 (CYP) induction properties of drugs using in vitro methods.MethodsThe CYP induction potential of compounds was tested in human liver slices and in reporter gene assays for the aryl hydrocarbon receptor (AhR) and the pregnane X receptor (PXR).ResultsIn human liver slices, CYP activities decreased dramatically over the experimental period, whereas mRNA levels could reliably be used to investigate CYP1A, 2C9, and 3A4 induction. However, the interindividual variations and demanding experimentation limit the use of liver slices in screening programs. Reporter gene assays are robust and reliable assays, amenable to high throughput screening. Several compounds activated AhR. The relevance of this activation, however, needs to be further investigated since there are no clear reports on drugs inducing CYP1A in vivo. The results from the PXR assay could be used to correctly classify compounds with known CYP3A induction properties when relating in vivo AUCtot to PXR EC50 values.ConclusionsLiver slices are a valuable model to study the regulation of a larger number of enzymes by single compounds. The PXR reporter gene assay could be used as a reliable screening method to predict CYP3A induction in vivo. © 2006 Springer Science + Business Media, Inc.
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| 417. |
- Qiu, Chunjing, et al.
(författare)
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ORCHIDEE-PEAT (revision 4596), a model for northern peatland CO2, water, and energy fluxes on daily to annual scales
- 2018
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Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 11:2, s. 497-519
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Tidskriftsartikel (refereegranskat)abstract
- Peatlands store substantial amounts of carbon and are vulnerable to climate change. We present a modified version of the Organising Carbon and Hydrology In Dynamic Ecosystems (ORCHIDEE) land surface model for simulating the hydrology, surface energy, and CO2 fluxes of peatlands on daily to annual timescales. The model includes a separate soil tile in each 0.5° grid cell, defined from a global peatland map and identified with peat-specific soil hydraulic properties. Runoff from non-peat vegetation within a grid cell containing a fraction of peat is routed to this peat soil tile, which maintains shallow water tables. The water table position separates oxic from anoxic decomposition. The model was evaluated against eddy-covariance (EC) observations from 30 northern peatland sites, with the maximum rate of carboxylation (Vcmax) being optimized at each site. Regarding short-term day-to-day variations, the model performance was good for gross primary production (GPP) (r2 Combining double low line 0.76; Nash-Sutcliffe modeling efficiency, MEF Combining double low line 0.76) and ecosystem respiration (ER, r2 Combining double low line 0.78, MEF Combining double low line 0.75), with lesser accuracy for latent heat fluxes (LE, r2 Combining double low line 0.42, MEF Combining double low line 0.14) and and net ecosystem CO2 exchange (NEE, r2 Combining double low line 0.38, MEF Combining double low line 0.26). Seasonal variations in GPP, ER, NEE, and energy fluxes on monthly scales showed moderate to high r2 values (0.57-0.86). For spatial across-site gradients of annual mean GPP, ER, NEE, and LE, r2 values of 0.93, 0.89, 0.27, and 0.71 were achieved, respectively. Water table (WT) variation was not well predicted (r2<0.1), likely due to the uncertain water input to the peat from surrounding areas. However, the poor performance of WT simulation did not greatly affect predictions of ER and NEE. We found a significant relationship between optimized Vcmax and latitude (temperature), which better reflects the spatial gradients of annual NEE than using an average Vcmax value.
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| 418. |
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| 419. |
- Reijs, Babette L R, et al.
(författare)
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The Central Biobank and Virtual Biobank of BIOMARKAPD: A Resource for Studies on Neurodegenerative Diseases.
- 2015
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Ingår i: Frontiers in neurology. - : Frontiers Media SA. - 1664-2295. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Biobanks are important resources for biomarker discovery and assay development. Biomarkers for Alzheimer's and Parkinson's disease (BIOMARKAPD) is a European multicenter study, funded by the EU Joint Programme-Neurodegenerative Disease Research, which aims to improve the clinical use of body fluid markers for the diagnosis and prognosis of Alzheimer's disease (AD) and Parkinson's disease (PD). The objective was to standardize the assessment of existing assays and to validate novel fluid biomarkers for AD and PD. To support the validation of novel biomarkers and assays, a central and a virtual biobank for body fluids and associated data from subjects with neurodegenerative diseases have been established. In the central biobank, cerebrospinal fluid (CSF) and blood samples were collected according to the BIOMARKAPD standardized pre-analytical procedures and stored at Integrated BioBank of Luxembourg. The virtual biobank provides an overview of available CSF, plasma, serum, and DNA samples at each site. Currently, at the central biobank of BIOMARKAPD samples are available from over 400 subjects with normal cognition, mild cognitive impairment (MCI), AD, frontotemporal dementia (FTD), vascular dementia, multiple system atrophy, progressive supranuclear palsy, PD, PD with dementia, and dementia with Lewy bodies. The virtual biobank contains information on over 8,600 subjects with varying diagnoses from 21 local biobanks. A website has been launched to enable sample requests from the central biobank and virtual biobank.
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| 420. |
- Rost, Christian, et al.
(författare)
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Sequential changes in myocardial function after valve replacement for aortic stenosis by speckle tracking echocardiography
- 2010
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Ingår i: European Journal of Echocardiography. - : Oxford Journals. - 1525-2167 .- 1532-2114. ; 11:7, s. 584-589
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Tidskriftsartikel (refereegranskat)abstract
- Aims Regional myocardial function may change differently in different pathology. Speckle tracking echocardiography (STE) was applied to evaluate longitudinal, radial, and circumferential function in patients with aortic stenosis (AS) before, within 1 week, and 6 months after aortic valve replacement (AVR). Methods and results In 40 consecutive patients with severe AS, we acquired apical four-, three-, and two-chamber views and standard short-axis view pre- and post-AVR and after 6 months. Longitudinal, radial, and circumferential (LS, RS, and CS) were calculated by commercial STE software. Further, we analysed diastolic myocardial function by measuring E/e′ ratio. With AVR, valve area increased and remained stable at 6 months follow-up. Left ventricular mass was unchanged 1 week after AVR (270 ± 58 g vs. 267 ± 58 g, n.s.) but decreased significantly during the next 6 months (219 ± 50 g, P < 0.05). Left ventricular ejection fraction remained unchanged. Strain values did not change significantly within 1 week after AVR but increased significantly after 6 months (LS by 16%, RS by 21%, and CS by 28% of baseline values). E/e′ ratio was highly augmented before AVR (26.1 ± 12.5) and decreased significantly 6 months after AVR (15.9 ± 5.9). Conclusion Myocardial function significantly recovers after replacing the stenosed aortic valve. However, there is a considerable difference between the response of longitudinal, radial, and circumferential function. Our data suggest that echocardiographic assessment of regional function is feasible and of potential clinical importance.
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