Vibration-based monitoring of civil infrastructure: challenges and successes

Author's manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s13349-011-0009-5© Springer-Verlag 2011Co -published with International Society for Structural Health Monitoring of Intelligent InfrastructureStructural health monitoring (SHM) is a relatively new paradigm for civil infrastructure stakeholders including operators, consultants and contractors which has in the last two decades witnessed an acceleration of academic and applied research in related areas such as sensing technology, system identification, data mining and condition assessment. SHM has a wide range of applications including, but not limited to, diagnostic and prognostic capabilities. However, when it comes to practical applications, stakeholders usually need answers to basic and pragmatic questions about in-service performance, maintenance and management of a structure which the technological advances are slow to address. Typical among the mismatch of expectation and capability is the topic of vibration-based monitoring (VBM), which is a subset of SHM. On the one hand there is abundant reporting of exercises using vibration data to locate damage in highly controlled laboratory conditions or in numerical simulations, while the real test of a reliable and cost effective technology is operation on a commercial basis. Such commercial applications are hard to identify, with the vast majority of implementations dealing with data collection and checking against parameter limits. In addition there persists an unhelpful association between VBM and 'damage detection' among some civil infrastructure stakeholders in UK and North America, due to unsuccessful transfer of technology from the laboratory to the field, and this has resulted in unhealthy industry scepticism which hinders acceptance of successful technologies. Hence the purpose of this paper is showcase successful VBM applications and to make the case that VBM does provide valuable information in real world applications when used appropriately and without unrealistic expectations. © 2011 Springer-Verlag

Multipolar second-harmonic generation from high-Q quasi-BIC states in subwavelength resonators

We put forward the multipolar model which captures the physics behind linear and nonlinear response driven by high-quality (high-Q) supercavity modes in subwavelength particles. We show that the formation of such trapped states associated with bound states in the continuum (quasi-BIC) can be understood through multipolar transformations of coupled leaky modes. The quasi-BIC state appears with increasing the order of the dominating multipole, where dipolar losses are completely suppressed. The efficient optical coupling to this state in the AlGaAs nanodisk is implemented via azimuthally polarized beam illumination matching its multipolar origin. We establish a one-to-one correspondence between the standard phenomenological non-Hermitian coupled-mode theory and multipolar models. The derived multipolar composition of the generated second-harmonic radiation from the AlGaAs nanodisk is then validated with full-wave numerical simulations. Back-action of the second-harmonic radiation onto the fundamental frequency is taken into account in the coupled nonlinear model with pump depletion. A hybrid metal-dielectric nanoantenna is proposed to augment the conversion efficiency up to tens of per cent due to increasing quality factors of the involved resonant states. Our findings delineate novel promising strategies in the design of functional elements for nonlinear nanophotonics applications

Temporal Evolution of Island Arc Magmatism and Its Influence on Long-Term Climate: Insights From the Izu Intra-Oceanic Arc

Continental arcs have an episodic magmatic activity over long-time periods, which is believed to modulate long-term climate. Island arcs have also the potential to release large amount of CO2 into the atmosphere, but whether they display an episodic magmatic history throughout their lifespan that contributes to the long-term (>10 Ma) climate changes remains an open question. To set additional constraints on the magmatic history of island arcs, here we examine fresh basalts and mineral-hosted melt inclusions from the Izu intra-oceanic arc, shortly after the eruption of boninites (∼45 Ma ago). Using chemical markers, we show that the long-term magmatic activity of the mature Izu arc has been relatively continuous over its lifespan, except during opening of the Shikoku back-arc Basin (∼23–20 Ma). Because slab dehydration and slab melting trigger decarbonation and carbonate dissolution of the subducted plate, we use slab-fluid markers (Ba/Th, Cs/Th, Cs/Ba, Rb/Th, Th/Nb) to examine the variations of slab-derived CO2 captured by the arc magmas. The long-term steadiness in the arc magmatic activity and in the slab-fluid contribution suggests that the CO2 outgassed during mature arc volcanism may have remained relatively homogeneous for the past 40 Ma in Izu. If worldwide mature island arcs also maintain a relatively steady-state magmatic activity over their lifespan, the long-term CO2 outgassed by these arc volcanoes may be rapidly balanced by chemical weathering and tectonic erosion, which rapidly draw down the atmospheric CO2 (within 200–300 kyr). This rapid negative feedback to long-term volcanic degassing permits to sustain a viable atmospheric CO2 for millions of years. The lack of co-variations between the markers of climate changes (δ13O, δ18C) and the long-term averages of the markers of slab fluids further implies that long-term volcanic degassing of CO2 from mature island arcs might play a minor role in the slide into icehouse climatic conditions. This long-term degassing stability may be, instead, a contributor to maintaining a broadly stable climate over long timescales

The association between post-migration nutrition and lifestyle transition and the risk of developing chronic diseases among sub-Saharan African migrants: A mixed method systematic review protocol

Sub-Saharan African (SSA) migrants face nutrition and lifestyle changes upon arrival in a host country. The shift in diet and lifestyle reflects post-migration acculturation and could predispose migrants to nutrition-and lifestyle-related chronic diseases. A mixed-methods systematic review of published studies and the grey literature on post-migration nutrition and lifestyle transition among SSA migrants will be undertaken. Studies published in English and conducted from 2000 to 2020 using quantitative and/or qualitative methods will be included. Ten bibliographic databases will be searched: Scopus, Ovid MEDLINE, EMBASE, Global Health, CINAHL, PubMed, ProQuest, PsycINFO, Informit and Web of Science. Data extraction will be informed by the Cochrane PROGRESS-Plus framework and the Joanna Briggs Institute manual. The quality of the included studies will be appraised for risk of bias using validated tools. An integrated approach to quantitative and qualitative data synthesis through data transformation will be undertaken, and a narrative synthesis of the findings will be provided. This protocol is guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) guidelines and provides insight into the scope and parameters of the systematic review to be conducted. The aim of the review is to evaluate the association between post-migration nutrition and lifestyle transition and the risk of developing chronic diseases among SSA migrants in Australia. This review will provide insight into possible areas for interventions to improve the health of migrants. Systematic Review Registration: The protocol was registered with the PROSPERO international prospective register of systematic reviews CRD42020206560

Angiogenic gene expression and vascular density are reflected in ultrasonographic features of synovitis in early Rheumatoid Arthritis: an observational study.

INTRODUCTION: Neovascularization contributes to the development of sustained synovial inflammation in the early stages of Rheumatoid Arthritis. Ultrasound (US) provides an indirect method of assessing synovial blood flow and has been shown to correlate with clinical disease activity in patients with Rheumatoid Arthritis. This study examines the relationship of US determined synovitis with synovial vascularity, angiogenic/lymphangiogenic factors and cellular mediators of inflammation in a cohort of patients with early Rheumatoid Arthritis (RA) patients prior to therapeutic intervention with disease modifying therapy or corticosteroids. METHODS: An ultrasound guided synovial biopsy of the supra-patella pouch was performed in 12 patients with early RA prior to treatment. Clinical, US and biochemical assessments were undertaken prior to the procedure. Ultrasound images and histological samples were obtained from the supra-patella pouch. Histological samples were stained for Factor VIII and a-SMA (a-smooth muscle actin). Using digital imaging analysis a vascular area score was recorded. QT-PCR (quantitative-PCR) of samples provided quantification of angiogenic and lymphangiogenic gene expression and immunohistochemistry stained tissue was scored for macrophage, T cell and B cell infiltration using an existing semi-quantitative score. RESULTS: Power Doppler showed a good correlation with histological vascular area (Spearman r--0.73) and angiogenic factors such as vascular endothelial growth factor-A (VEGF-A), Angiopoietin 2 and Tie-2. In addition, lymphangiogenic factors such as VEGF-C and VEGF-R3 correlated well with US assessment of synovitis. A significant correlation was also found between power Doppler and synovial thickness, pro-inflammatory cytokines and sub-lining macrophage infiltrate. Within the supra-patella pouch there was no significant difference in US findings, gene expression or inflammatory cell infiltrate between any regions of synovium biopsied. CONCLUSION: Ultrasound assessment of synovial tissue faithfully reflects synovial vascularity. Both grey scale and power Doppler synovitis in early RA patients correlate with a pro-angiogenic and lymphangiogenic gene expression profile. In early RA both grey scale and power Doppler synovitis are associated with a pro-inflammatory cellular and cytokine profile providing considerable validity in its use as an objective assessment of synovial inflammation in clinical practice

Long-Term Consumption of 10 Food Groups and Cardiovascular Mortality: A Systematic Review and Dose Response Meta-Analysis of Prospective Cohort Studies

A large body of evidence exists on diet and cardiovascular mortality, but limited studies have investigated the long-term intake of food groups, which may have cumulative effects on cardiovascular health in the long term. This review therefore evaluated the relationship between the long-term consumption of 10 food groups and cardiovascular mortality. We conducted a systematic search in Medline, Embase, Scopus, CINAHL, and Web of Science till January 2022. Of the 5318 studies initially identified, 22 studies with a total of 70,273 participants with cardiovascular mortality were included. Summary HRs and 95% CIs were estimated using a random effects model. We found that a long-term high intake of whole grains (HR: 0.87; 95% CI: 0.80, 0.95; P = 0.001), fruits and vegetables (HR: 0.72; 95% CI: 0.61, 0.85; P < 0.0001), and nuts (HR: 0.73; 95% CI: 0.66, 0.81; P < 0.00001) significantly reduced cardiovascular mortality. Each 10-gram increase in whole grain consumption per day was associated with a 4% reduction in the risk of cardiovascular mortality, whereas each 10-gram increase in red/processed meat consumption per day was associated with a 1.8% increase in the risk of cardiovascular mortality. Compared with the lowest intake category, red/processed meat consumption in the highest category was associated with an increased risk of cardiovascular mortality (HR: 1.23; 95% CI: 1.09, 1.39; P = 0.006). High intake of dairy products (HR: 1.11; 95% CI: 0.92, 1.34; P = 0.28), and legumes (HR: 0.86; 95% CI: 0.53, 1.38; P = 0.53) were not associated with cardiovascular mortality. However, in the dose-response analysis, each 10-gram increase in legume intake per week was associated with a 0.5% reduction in cardiovascular mortality. We conclude that the long-term high intake of whole grains, vegetables, fruits, nuts, and a low intake of red/processed meat are associated with reduced cardiovascular mortality. More data on the long-term effects of legumes on cardiovascular mortality are encouraged. This study was registered at PROSPERO as CRD42020214679

Primates do not spontaneously use shape properties for object individuation: a competence or a performance problem?

Several recent studies have documented that non-human primates can individuate objects according to property and/or kind information in much the same way as human infants do from around one year of age when they begin to acquire language. Some studies suggest, however, that only some properties are used for the individuation of food items: color, but not shape. The present study investigated whether these findings reveal a true competence problem with shape properties in the food domain or whether they merely reveal a performance problem (e.g., lack of attention to shapes). We tested 25 great apes (chimpanzees, bonobos and gorillas) in two food individuation tasks. We manipulated subjects’ experience with differences in color and shape properties of food items. Results indicated (i) that all subjects, regardless of their prior experience, solved the color-based object individuation task and (ii) that only the group with previous experience with different shape properties succeeded in the shape-based individuation task. Great apes can thus be primed to take shape into account for individuating food objects, and this results clearly speaks in favor of a performance (rather than a competence) problem in using shape for object individuation of food items

SMART: Unique splitting-while-merging framework for gene clustering

Copyright @ 2014 Fa et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Successful clustering algorithms are highly dependent on parameter settings. The clustering performance degrades significantly unless parameters are properly set, and yet, it is difficult to set these parameters a priori. To address this issue, in this paper, we propose a unique splitting-while-merging clustering framework, named “splitting merging awareness tactics” (SMART), which does not require any a priori knowledge of either the number of clusters or even the possible range of this number. Unlike existing self-splitting algorithms, which over-cluster the dataset to a large number of clusters and then merge some similar clusters, our framework has the ability to split and merge clusters automatically during the process and produces the the most reliable clustering results, by intrinsically integrating many clustering techniques and tasks. The SMART framework is implemented with two distinct clustering paradigms in two algorithms: competitive learning and finite mixture model. Nevertheless, within the proposed SMART framework, many other algorithms can be derived for different clustering paradigms. The minimum message length algorithm is integrated into the framework as the clustering selection criterion. The usefulness of the SMART framework and its algorithms is tested in demonstration datasets and simulated gene expression datasets. Moreover, two real microarray gene expression datasets are studied using this approach. Based on the performance of many metrics, all numerical results show that SMART is superior to compared existing self-splitting algorithms and traditional algorithms. Three main properties of the proposed SMART framework are summarized as: (1) needing no parameters dependent on the respective dataset or a priori knowledge about the datasets, (2) extendible to many different applications, (3) offering superior performance compared with counterpart algorithms.National Institute for Health Researc

Ageing memory and glassiness of a driven vortex system

Many systems in nature, glasses, interfaces and fractures being some examples, cannot equilibrate with their environment, which gives rise to novel and surprising behaviour such as memory effects, ageing and nonlinear dynamics. Unlike their equilibrated counterparts, the dynamics of out-of- equilibrium systems is generally too complex to be captured by simple macroscopic laws. Here we investigate a system that straddles the boundary between glass and crystal: a Bragg glass formed by vortices in a superconductor. We find that the response to an applied force evolves according to a stretched exponential, with the exponent reflecting the deviation from equilibrium. After the force is removed, the system ages with time and its subsequent response time scales linearly with its age (simple ageing), meaning that older systems are slower than younger ones. We show that simple ageing can occur naturally in the presence of sufficient quenched disorder. Moreover, the hierarchical distribution of timescales, arising when chunks of loose vortices cannot move before trapped ones become dislodged, leads to a stretched-exponential response.Comment: 16 pages, 5 figure