On Quantifying Qualitative Geospatial Data: A Probabilistic Approach

Living in the era of data deluge, we have witnessed a web content explosion, largely due to the massive availability of User-Generated Content (UGC). In this work, we specifically consider the problem of geospatial information extraction and representation, where one can exploit diverse sources of information (such as image and audio data, text data, etc), going beyond traditional volunteered geographic information. Our ambition is to include available narrative information in an effort to better explain geospatial relationships: with spatial reasoning being a basic form of human cognition, narratives expressing such experiences typically contain qualitative spatial data, i.e., spatial objects and spatial relationships. To this end, we formulate a quantitative approach for the representation of qualitative spatial relations extracted from UGC in the form of texts. The proposed method quantifies such relations based on multiple text observations. Such observations provide distance and orientation features which are utilized by a greedy Expectation Maximization-based (EM) algorithm to infer a probability distribution over predefined spatial relationships; the latter represent the quantified relationships under user-defined probabilistic assumptions. We evaluate the applicability and quality of the proposed approach using real UGC data originating from an actual travel blog text corpus. To verify the quality of the result, we generate grid-based maps visualizing the spatial extent of the various relations

Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life

Γεωχωρική πληροφορία σε δεδομένα χρηστών: εξαγωγή, μοντελοποίηση και εφαρμογές

With the proliferation of the Internet as the primary medium for data publishing and information exchange, we have seen an explosion in the amount of online content available on the Web. Thus, in addition to professionally-produced material being offered free on the Internet, the public has also been allowed, indeed encouraged, making its content available online to everyone. The volumes of such User-Generated Content (UGC) are already staggering and constantly growing. Our goal has to be to take advantage of this data explosion, which applied to the spatial domain translates to massively collecting and sharing knowledge to ultimately digitize the world. User-Generated geospatial content is also commonly referred to as Volunteered Geographic Information (VGI). There are several forms of VGI. In the current thesis, we will work on VGI from textual and GPS data.Subsumed under VGI, non-expert users have been providing a wealth of quantitative geospatial data online. With spatial reasoning being a basic form of human cognition, narratives expressing geospatial experiences, e.g., travel blogs, would provide an even bigger source of geospatial data. Textual narratives typically contain qualitative data in the form of objects and spatial relationships. One of the main scopes of this thesis is (i) to extract these relationships from user-generated texts, (ii) to quantify them and (iii) to reason about object locations based only on this qualitative data.Moreover, with the extracted and modeled spatial relations and by employing Bayesian inference, we obtain probabilistic measures of spatial connectedness of PoIs according to the crowd. Applying this measure to the corresponding road network, we obtain an altered cost function which does not exclusively rely on distance, and enriches an actual road networks taking crowdsourced spatial relations into account. With this we aim at obtaining paths that do not only minimize distance but also lead through more popular areas using knowledge generated by users. The last objective of this thesis, is to introduce the problem of continuous and non-continuous monitoring of nearest trajectories based on GPS data. In contrast to other similar approaches, we are interested in monitoring moving objects taking into account at each timestamp not only their current positions but their recent trajectory in a defined time window. We rst describe generic baseline algorithms for this problem, which applies for any aggregate function used to compute trajectory distances between objects, and without any restrictions on the movement of the objects. Using this as a framework, we continue to derive optimized algorithm for the cases where the distance between two moving objects in a time window is determined by their maximum or minimum distance in all contained timestamps. Furthermore, we propose additional optimizations for the case that an upper bound on the velocities of the objects exists.Με την εξάπλωση του Διαδικτύου ως το κύριο μέσο για τη δημοσίευση στοιχείων και την ανταλλαγή πληροφοριών, έχουμε δει μια έκρηξη στον όγκο του περιεχομένου που είναι διαθέσιμο στο διαδίκτυο. ́Ετσι, εκτός από επαγγελματικό περιεχόμενο που είναι διαθέσιμο στο διαδίκτυο, το κοινό έχει επίσης τη δυνατότητα, να καθιστά το περιεχόμενό του διαθέσιμο σε όλους. Οι όγκοι της εν λόγω πληροφορίας από τους χρήστες είναι συνεχώς αυξανόμενοι. Στόχος μας πρέπει να είναι να επωφεληθούμε από αυτή την έκρηξη των δεδομένων, η οποία εφαρμοζόμενη στο γεοχωρικό πεδίο μεταφράζεται στη μαζική τη συλλογή και την ανταλλαγή γνώσης για την ψηφιοποίηση του κόσμου. Το περιεχόμενο που δημιουργείται από χρήστες στο γεωχωρικό πεδίο επίσης, αναφέρεται και ως εθελοντική γεωγραφική πληροφορία. Η εθελοντική γεωχωρική πληροφορία μπορεί να εμπεριέχεται σε πολλoύς τύπους δεδομένων. Στην παρούσα διατριβή, θα ασχοληθούμε με γεωχωρική πληροφορία από δεδομένα κειμένουκαι από δεδομένα πλοήγησης.Υπό τον όρο εθελοντική γεωγραφική πληροφορία, μη εξειδικευμένοι χρήστες παρέχουν έναν πλούτο ποσοτικών γεωχωρικών δεδομένων στο διαδίκτυο. Με τη χωρική συλλογιστική να είναι μια βασική μορφή της ανθρώπινης νόησης, αφηγήσεις που εκφράζουν γεωχωρικών εμπειρίες, π.χ., ταξιδιωτικά ιστολόγια, παρέχουν μια ακόμη μεγαλύτερη πηγή γεωχωρικών δεδομένων. Οι κειμενικές αφηγήσεις συνήθως περιέχουν ποιοτικά δεδομένα με τη μορφή χωρικών αντικειμένων και χωρικών σχέσεων. ́Ενας από τους βασικούς στόχους της παρούσας διατριβής είναι (1) για να εξαγάγουμε τις σχέσεις αυτές από κείμενα που δημιουργούνται από χρήστες, (2) να τις ποσοτικοποιήσουμε και (3) και να βγάλουμε συμπεράσματα για τις θέσεις αντικειμένων στο χώρο βασιζόμενοι μόνο σε αυτά τα ποιοτικά δεδομένα. ́Ενας επιπλέον στόχος της παρούσας διατριβής, είναι η χρησιμοποίηση των εξαγόμενων και ποσοτικά μοντελοποιημένων χωρικων σχέσεων σε συνδυασμό με πιθανοτική θεωρία, και την εφαρμογή τους για την επίλυση του προβλήματος του δημοφιλούς μονοπατιού. Συγκεκριμένα, χρησιμοποιούμε την χωρική πληροφορία που παράγεται από χρήστες και με αυτό στοχεύουμε στην απόκτηση μονοπατιών που δεν ελαχιστοποιούν μόνο την απόσταση, αλλά επίσης οδηγούν σε πιο δημοφιλείς περιοχές χρησιμοποιώντας γνώσης που παράγεται από τους ίδιους τους χρήστες.Ο τελευταίος στόχος της παρούσας διπλωματικής εργασίας, είναι να εισάγει το πρόβλημα της παρακολούθησης πλησιέστερων τροχιών με βάση δεδομένα πλοήγησης. Μελετούμε το πρόβλημα αυτό στη συνεχή και στη μή συνεχή περίπτωση. Παρουσιάζουμε αρχικά γενικούς και βασικούς αλγόριθμους για το πρόβλημα αυτό, και στην συνέχεια προτείνουμε επιπλέον βελτιστοποιήσεις με ακριβής και προσεγγιστικούς αλγορίθμους χρησιμοποιώντας πολλών τύπων χαρακτηριστικ

Carotid Artery Temperature Reduction with Statin Therapy in Patients with Familial Hyperlipidemia Syndromes

Background: Microwave radiometry (MWR) assesses non-invasive carotid artery temperatures reflecting inflammation. In the present study, we aimed to investigate the impact of hypolipidemic therapy either with simvastatin or with combination simvastatin plus ezetimibe on carotid artery temperatures of patients with familial hyperlipidemia syndromes (FHS). Methods: Consecutive patients with diagnosis of either familial heterozygous hypercholesterolemia (heFH) or familial combined hyperlipidemia (FCH) were included in the study. Patients were assigned to either simvastatin 40 mg or simvastatin 40 mg plus ezetimibe 10 mg, according to the discretion of the physician. FHS patients who refused statin therapy were used as a control group. Common carotid intima-media thickness (ccIMT) was measured and ΔΤ (maximum-minimum) temperature measurements were performed across each carotid during MWR evaluation. RESULTS: In total, 115 patients were included in the study. Of them, 40 patients received simvastatin (19 heFH and 21 FCH), 41 simvastatin + ezetimibe (31 heFH and 10 FCH), and 34 (21 heFH and 13 FCH) no statin. Carotid artery temperatures were significantly reduced at 6 months in FH patients who received hypolipidemic treatment (0.83 ± 0.34 versus 0.63 ± 0.24 °C, p = 0.004 for simvastatin, 1.00 ± 0.38 versus 0.69 ± 0.23 °C, p < 0.001 for simvastatin + ezetimibe), but no change was recorded in controls (0.72 ± 0.26 versus 0.70 ± 0.26 °C, p = 0.86). Conclusions: Hypolipidemic therapy reduced carotid temperatures in FHS patients

Prediction of cardiovascular events with levels of proprotein convertase subtilisin/kexin type 9: A systematic review and meta-analysis

Background and aims: Inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) reduces atherogenic lipoproteins and could lead to reduction of cardiovascular (CV) events. However, it is unclear whether blood PCSK9 levels predict future CV events. We performed a meta-analysis of all longitudinal studies to determine the ability of PCSK9 levels to predict risk of future CV events. Methods: A comprehensive search of electronic databases was conducted up to February 2016. Longitudinal studies that reported events or relative risk (RR) estimates with 95% confidence intervals (CI) were included. Results: All 9 studies included (12,081 participants, mean follow-up 6.62 years) reported results on total CV events. The pooled RR of total CV events for an increase in baseline PCSK9 by 1 standard deviation (SD) was 1.098 (95% CI, 1.02-1.18), corresponding to a risk increase of 10% (Z = 2.43, p = 0.015). The pooled RR of total CV events for subjects categorized in the highest tertile of baseline PCSK9 was 1.228 (95% CI, 1.035-1.457), corresponding to a risk increase of 23% (Z = 2.35, p = 0.019). When pooled estimates were derived independently for low-and high-CV risk populations, baseline PCSK9 levels predicted total CV events only in apparently healthy subjects (RR = 1.13, 95% CI: 1.050-1.222, Z = 3.21, p = 0.001) and not in populations with established CV or renal disease (RR = 1.09, 95% CI: 0.961-1.23, Z = 1.33, p = 0.182). Conclusions: PCSK9 levels are modestly but significantly associated with increased risk of total CV events. These results suggest a predictive role of PCSK9 levels on CV health and support the possible clinical role of PCSK9 inhibitors. (C) 2016 Elsevier Ireland Ltd. All rights reserved

Arterial aging mediates the effect of TNF-α and ACE polymorphisms on mental health in elderly individuals: insights from IKARIA study.

Background: Aging is characterized by an insidious decline in cognitive function. Several genetic and lifestyle factors have been implicated in the increased risk or early onset of dementia. Aim: We sought to assess the role of tumor necrosis factor (TNF) and angiotensin-converting enzyme (ACE) polymorphisms on the development of impaired mental health in respect to indices of arterial aging in nonagenarian individuals. Design: 178 consecutive subjects above 75 years that permanently inhabit in the island of IKARIA, Greece were recruited. Methods: Aortic distensibility (AoD) was calculated and genetic evaluation was performed on the ACE Insertion/Deletion gene polymorphism (intron 16) and the G/A transition (position -308) of the TNF gene. Cognitive function was evaluated using the Mini-mental State Examination (MMSE). Results: The DD genotype for ACE was independently associated ( b  = -0.44, P = 0.007) with AD while AoD remained an independent determinant of mental status (OR = 1.82, P = 0.036). Interestingly though, when a combined genetic index (GI) was calculated for both genes (ACE and TNF), subjects being double homozygous (DD for ACE and GG for TNF) for these loci presented significantly decreased MMSE (adjusted OR = 0.259, P = 0.033). This GI independently associated with AD (beta coefficient = -0.785, P = 0.002). When AoD was included, GI lost its predictive role (OR = 0.784, P = 0.783) towards MMSE. AoD has marginal indirect mediating effect in the association of the GI with MMSE ( P = 0.07). Conclusion: Vascular aging may modulates the genetic substrate of elderly subjects on the risk for developing dementia