12 research outputs found
SANOM results for OAEI 2018
Simulated annealing-based ontology matching (SANOM) participates for the second time at the ontology alignment evaluation initiative (OAEI) 2018. This paper contains the configuration of SANOM and its results on the anatomy and conference tracks. In comparison to the OAEI 2017, SANOM has improved significantly, and its results are competitive with the state-of-the-art systems. In particular, SANOM has the highest recall rate among the participated systems in the conference track, and is competitive with AML, the best performing system, in terms of F-measure. SANOM is also competitive with LogMap on the anatomy track, which is the best performing system in this track with no usage of particular biomedical background knowledge. SANOM has been adapted to the HOBBIT platfrom and is now available for the registered users. abstract environment.Information and Communication TechnologyWeb Information System
SANOM-HOBBIT: Simulated annealing-based ontology matching on HOBBIT platform
Ontology alignment is an important and inescapable problem for the interconnections of two ontologies stating the same concepts. Ontology alignment evaluation initiative (OAEI) has been taken place for more than a decade to monitor and help the progress of the field and to compare systematically existing alignment systems. As of 2018, the evaluation of systems is partly transitioned to the HOBBIT platform. This paper contains the description of our alignment system, simulated annealing-based ontology matching (SANOM), and its adaption into the HOBBIT platform. The outcomes of SANOM on the HOBBIT for several OAEI tracks are reported, and the results are compared with other competing systems in the corresponding tracks.Information and Communication TechnologyWeb Information System
The Rotterdam Scan Study: Design and update up to 2012
Neuroimaging plays an important role in etiologic research on neurological diseases in the elderly. The Rotterdam Scan Study was initiated as part of the ongoing Rotterdam Study with the aim to unravel causes of neurological disease by performing neuroimaging in a population-based longitudinal setting. In 1995 and 1999 random subsets of the Rotterdam Study underwent neuroimaging, whereas from 2005 onwards MRI has been implemented into the core protocol of the Rotterdam Study. In this paper, we discuss the background and rationale of the Rotterdam Scan Study. We also describe the imaging protocol and post-processing techniques, and highlight the main findings to date. Finally, we make recommendations for future research, which will also be the main focus of investigation in the Rotterdam Scan Study.Imaging Science and TechnologyApplied Science
The Rotterdam Scan Study: Design update 2016 and main findings
Imaging plays an essential role in research on neurological diseases in the elderly. The Rotterdam Scan Study was initiated as part of the ongoing Rotterdam Study with the aim to elucidate the causes of neurological disease by performing imaging of the brain in a prospective population-based setting. Initially, in 1995 and 1999, random subsamples of participants from the Rotterdam Study underwent neuroimaging, whereas from 2005 onwards MRI has been implemented into the core protocol of the Rotterdam Study. In this paper, we discuss the background and rationale of the Rotterdam Scan Study. Moreover, we describe the imaging protocol, image post-processing techniques, and the main findings to date. Finally, we provide recommendations for future research, which will also be topics of investigation in the Rotterdam Scan Study.ImPhys/Imaging PhysicsApplied Science
Altered tract-specific white matter microstructure is related to poorer cognitive performance. The Rotterdam Study
White matter microstructural integrity has been related to cognition. Yet, the potential role of specificwhite matter tracts on top of a global white matter effect remains unclear, especially when consideringspecific cognitive domains. Therefore, we determined the tract-specific effect of white matter micro-structure on global cognition and specific cognitive domains. In 4400 nondemented and stroke-freeparticipants (mean age 63.7 years, 55.5% women), we obtained diffusion magnetic resonance imagingparameters (fractional anisotropy and mean diffusivity) in 14 white matter tracts using probabilistictractography and assessed cognitive performance with a cognitive test battery. Tract-specific whitematter microstructure in all supratentorial tracts was associated with poorer global cognition. Lowerfractional anisotropy in association tracts, primarily the inferior fronto-occipital fasciculus, and highermean diffusivity in projection tracts, in particular the posterior thalamic radiation, most strongly relatedto poorer cognition. Altered white matter microstructure related to poorer information processing speed,executive functioning, and motor speed, but not to memory. Tract-specific microstructural changes mayaid in better understanding the mechanism of cognitive impairment and neurodegenerative diseases.ImPhys/Quantitative Imagin
HASE: Framework for efficient high-dimensional association analyses
High-throughput technology can now provide rich information on a person's biological makeup and environmental surroundings. Important discoveries have been made by relating these data to various health outcomes in fields such as genomics, proteomics, and medical imaging. However, cross-investigations between several high-throughput technologies remain impractical due to demanding computational requirements (hundreds of years of computing resources) and unsuitability for collaborative settings (terabytes of data to share). Here we introduce the HASE framework that overcomes both of these issues. Our approach dramatically reduces computational time from years to only hours and also requires several gigabytes to be exchanged between collaborators. We implemented a novel meta-analytical method that yields identical power as pooled analyses without the need of sharing individual participant data. The efficiency of the framework is illustrated by associating 9 million genetic variants with 1.5 million brain imaging voxels in three cohorts (total N = 4,034) followed by meta-analysis, on a standard computational infrastructure. These experiments indicate that HASE facilitates high-dimensional association studies enabling large multicenter association studies for future discoveries.ImPhys/Quantitative Imagin
Older age relates to worsening of fine motor skills: A population-based study of middle-aged and elderly persons
Introduction: In a population-based study of 1,912 community-dwelling persons of 45 years and older, we investigated the relation between age and fine motor skills using the Archimedes spiral-drawing test. Also, we studied the effect of brain volume on fine motor skills. Methods: Participants were required to trace a template of a spiral on an electronic drawing board. Clinical scores from this test were obtained by visual assessment of the drawings. Quantitative measures were objectively determined from the recorded data of the drawings. As tremor is known to occur increasingly with advancing age, we also rated drawings to assess presence of tremor. Results: We found presence of a tremor in 1.3% of the drawings. In the group without tremor, we found that older age was related to worse fine motor skills. Additionally, participants over the age of 75 showed increasing deviations from the template when drawing the spiral. Larger cerebral volume and smaller white matter lesion volume were related to better spiral-drawing performance, whereas cerebellar volume was not related to spiral-drawing performance. Conclusion: Older age is related to worse fine motor skills, which can be captured by clinical scoring or quantitative measures of the Archimedes spiral-drawing test. Persons with a tremor performed worse on almost all measures of the spiral-drawing test. Furthermore, larger cerebral volume is related to better fine motor skills.ImPhys/Imaging PhysicsApplied Science
The Thyroid Hormone Receptor Alpha Locus and White Matter Lesions: A Role for the Clock Gene REV-ERB?
Background: Thyroid disorders are associated with an increased risk of cognitive impairment and Alzheimer's disease. Both small vessel disease and neurodegeneration have a role in the pathogenesis of cognitive impairment and Alzheimer's disease. Thyroid hormone receptor alpha (TR?) is the predominant TR in brain. The circadian clock gene REV-ERB? overlaps with the TR? gene and interferes with TR? expression. Limited data are available on the role of the TR?/REV-ERB? locus in small vessel disease and neurodegeneration. We therefore studied genetic variation in the TR?/REV-ERB? locus in relation to brain imaging data, as early markers for small vessel disease and neurodegeneration. Methods: Fifteen polymorphisms, covering the TR?/REV-ERB? locus, were studied in relation to white matter lesion (WML), total brain, and hippocampal volumes in the Rotterdam Study I (RS-I, n=454). Associations that remained significant after multiple testing correction were subsequently studied in an independent population for replication (RS-II, n=607). Results: No associations with total brain or hippocampal volumes were detected. A haplotype block in REV-ERB? was associated with WML volumes in RS-I. Absence of this haplotype was associated with larger WML volumes in women (0.38%±0.18% [?±SE], p=0.007), but not in men (0.04%±0.11%, p=0.24), which was replicated in RS-II (women: 0.15%±0.05%, p=0.04; men: 0.05%±0.07%, p=0.80). Meta-analysis of the two populations showed that women lacking this haplotype have a 1.9 times larger WML volume (p=0.001). Conclusion: Our results suggest a role for REV-ERB? in the pathogenesis of WMLs.IST/Imaging Science and TechnologyApplied Science
Determinants of carotid atherosclerotic plaque burden in a stroke-free population
Background and aims In a large stroke-free population, we sought to identify cardiovascular risk factors and carotid plaque components associated with carotid plaque burden, lumen volume and stenosis. Methods The carotid arteries of 1562 stroke-free participants from The Rotterdam Study were imaged on a 1.5-Tesla MRI scanner. Inner and outer wall of the carotid arteries were automatically segmented and lumen volume (mm3), wall volume (outer wall–inner wall) and plaque burden (wall volume/outer wall volume) (%) were quantified. Plaque components were visually determined and luminal stenosis was assessed. We analyzed associations of cardiovascular risk factors and carotid plaque components with plaque burden and lumen volumes using regression analysis. Results We investigated 2821 carotid plaques and found that women had larger plaque burden (50.7 ± 7.8% vs. 49.2 ± 7.7%, p <0.0001) and smaller lumen volumes (933 ± 286 mm3 vs. 1078 ± 334 mm3, p <0.0001) than men. In women, age, HDL-cholesterol and systolic blood pressure, and in men, total cholesterol, non-HDL cholesterol and statin use were independently associated with higher plaque burden and lumen volume. Furthermore, smoking and diabetes were associated with lumen volume in men (respectively p = 0.04 and p = 0.002). Intraplaque hemorrhage (IPH) and lipid were related to a larger plaque burden (OR 1.30 [1.05–1.60] and OR 1.28[1.06–1.55]). Finally, within the highest quartile of plaque burden, IPH was strongly associated with luminal stenosis independent of age, sex, plaque burden and composition (Beta = 15.2; [11.8–18.6]). Conclusions Several cardiovascular risk factors and plaque components, in particular IPH, are associated with higher plaque burden. Carotid IPH is strongly associated with an increased luminal stenosis.ImPhys/Quantitative Imagin
White matter microstructure improves stroke risk prediction in the general population
Background and Purpose - The presence of subclinical vascular brain disease, including white matter lesions and lacunar infarcts, substantially increases the risk of clinical stroke. White matter microstructural integrity is considered an earlier, potentially better, marker of the total burden of vascular brain disease. Its association with risk of stroke, a focal event, remains unknown. Methods - From the population-based Rotterdam Study, 4259 stroke-free participants (mean age: 63.6 years, 55.6% women) underwent brain magnetic resonance imaging, including diffusion magnetic resonance imaging, between 2006 and 2011. All participants were followed up for incident stroke until 2013. Cox proportional hazards models were used to associate markers of the microstructure of normal-appearing white matter with risk of stroke, adjusting for age, sex, white matter lesion volume, lacunar infarcts, and additionally for cardiovascular risk factors. Finally, we assessed the predictive value of white matter microstructural integrity for stroke beyond the Framingham Stroke Risk Profile. Results - During 18 476 person-years of follow-up, 58 people experienced a stroke. Both lower fractional anisotropy and higher MD increased risk of stroke, independent of age, sex, cardiovascular risk factors, white matter lesion volume, and lacunar infarcts (hazard ratio per SD increase in: fractional anisotropy: 0.75 [95% confidence interval, 0.57-0.98] and MD: 1.50 [95% confidence interval, 1.08-2.09]). MD improved stroke prediction beyond the Framingham Stroke Risk Profile (continuous net reclassification improvement: 0.52 [95% confidence interval, 0.24-0.81]). Conclusions - Future stroke is predicted not only by prevalent vascular lesions but also by subtle alterations in the microstructure of normal-appearing white matter. Inclusion of this effect in risk prediction models produces a significant advantage in stroke prediction compared with the existing Framingham Stroke Risk Profile.ImPhys/Quantitative Imagin