Infrastructure Engineering - Research Publications

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    Editorial
    Tse, N ; Rajkowski, R (Informa UK Limited, 2015-06-01)
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    Multi-scale analysis of bias correction of soil moisture
    Su, C-H ; Ryu, D ( 2014-07-29)
    Abstract. Remote sensing, in situ networks and models are now providing unprecedented information for environmental monitoring. To conjunctively use multi-source data nominally representing an identical variable, one must resolve biases existing between these disparate sources, and the characteristics of the biases can be non-trivial due to spatiotemporal variability of the target variable, inter-sensor differences with variable measurement supports. One such example is of soil moisture (SM) monitoring. Triple collocation (TC) based bias correction is a powerful statistical method that increasingly being used to address this issue but is only applicable to the linear regime, whereas nonlinear method of statistical moment matching is susceptible to unintended biases originating from measurement error. Since different physical processes that influence SM dynamics may be distinguishable by their characteristic spatiotemporal scales, we propose a multi-time-scale linear bias model in the framework of a wavelet-based multi-resolution analysis (MRA). The joint MRA-TC analysis was applied to demonstrate scale-dependent biases between in situ, remotely-sensed and modelled SM, the influence of various prospective bias correction schemes on these biases, and lastly to enable multi-scale bias correction and data adaptive, nonlinear de-noising via wavelet thresholding.
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    Improving operational flood ensemble prediction by the assimilation of satellite soil moisture: comparison between lumped and semi-distributed schemes
    Alvarez-Garreton, C ; Ryu, D ; Western, AW ; Su, C-H ; Crow, WT ; Robertson, DE ; Leahy, C ( 2014-09-23)
    Abstract. Assimilation of remotely sensed soil moisture data (SM–DA) to correct soil water stores of rainfall-runoff models has shown skill in improving streamflow prediction. In the case of large and sparsely monitored catchments, SM–DA is a particularly attractive tool. Within this context, we assimilate active and passive satellite soil moisture (SSM) retrievals using an ensemble Kalman filter to improve operational flood prediction within a large semi-arid catchment in Australia (>40 000 km2). We assess the importance of accounting for channel routing and the spatial distribution of forcing data by applying SM–DA to a lumped and a semi-distributed scheme of the probability distributed model (PDM). Our scheme also accounts for model error representation and seasonal biases and errors in the satellite data. Before assimilation, the semi-distributed model provided more accurate streamflow prediction (Nash–Sutcliffe efficiency, NS = 0.77) than the lumped model (NS = 0.67) at the catchment outlet. However, this did not ensure good performance at the "ungauged" inner catchments. After SM–DA, the streamflow ensemble prediction at the outlet was improved in both the lumped and the semi-distributed schemes: the root mean square error of the ensemble was reduced by 27 and 31%, respectively; the NS of the ensemble mean increased by 7 and 38%, respectively; the false alarm ratio was reduced by 15 and 25%, respectively; and the ensemble prediction spread was reduced while its reliability was maintained. Our findings imply that even when rainfall is the main driver of flooding in semi-arid catchments, adequately processed SSM can be used to reduce errors in the model soil moisture, which in turn provides better streamflow ensemble prediction. We demonstrate that SM–DA efficacy is enhanced when the spatial distribution in forcing data and routing processes are accounted for. At ungauged locations, SM–DA is effective at improving streamflow ensemble prediction, however, the updated prediction is still poor since SM–DA does not address systematic errors in the model.
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    Estimating Annual Water Storage Variations Using Microwave-based Soil Moisture Retrievals
    Crow, WT ; Han, E ; Ryu, D ; Hain, CR ; Anderson, MC ( 2016-11-21)
    Abstract. Due to their shallow vertical support, remotely-sensed surface soil moisture retrievals are commonly regarded as being of limited value for water budget applications requiring the characterization of temporal variations in total terrestrial water storage (S). However, advances in our ability to estimate evapotranspiration remotely now allow for the direct evaluation of approaches for quantifying annual variations in S via water budget closure considerations. By applying an annual water budget analysis within a series of medium-scale (2,000–10,000 km2) basins within the United States, we demonstrate that, despite their clear theoretical limitations, surface soil moisture retrievals derived from passive microwave remote sensing contain significant information concerning relative inter-annual variations in S. This suggests the possibility of using (relatively) higher-resolution microwave remote sensing to enhance the spatial resolution of S estimates acquired from gravity remote sensing. However, challenging calibration issues regarding the relationship between S and surface soil moisture must be resolved before the approach can be used for absolute water budget closure.
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    Very early onset of amiodarone-induced pulmonary toxicity.
    Lee, W ; Ryu, DR ; Han, S-S ; Ryu, S-W ; Cho, BR ; Kwon, H ; Kim, BR (The Korean Society of Cardiology, 2013-10)
    Amiodarone is a widely used antiarrhythmic agent. Among its various adverse effects, amiodarone-induced pulmonary toxicity (APT) is the most life threatening complication, which has been described mostly in patients who have been in treatment with high accumulative doses for a long duration of time. However, amiodarone therapy in short-term duration induced APT was rarely reported. We describe a case of a 54-year-old man who is presented with symptoms of APT after a few days of therapy for post-myocardial infarction ventricular tachycardia. For early diagnosis and successful treatment, awareness and high suspicion of this rare type of early onset APT is crucial in patients with amiodarone therapy.
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    Loss of Sirt1 function improves intestinal anti-bacterial defense and protects from colitis-induced colorectal cancer.
    Lo Sasso, G ; Ryu, D ; Mouchiroud, L ; Fernando, SC ; Anderson, CL ; Katsyuba, E ; Piersigilli, A ; Hottiger, MO ; Schoonjans, K ; Auwerx, J ; Papa, S (Public Library of Science (PLoS), 2014)
    Dysfunction of Paneth and goblet cells in the intestine contributes to inflammatory bowel disease (IBD) and colitis-associated colorectal cancer (CAC). Here, we report a role for the NAD+-dependent histone deacetylase SIRT1 in the control of anti-bacterial defense. Mice with an intestinal specific Sirt1 deficiency (Sirt1int-/-) have more Paneth and goblet cells with a consequent rearrangement of the gut microbiota. From a mechanistic point of view, the effects on mouse intestinal cell maturation are mediated by SIRT1-dependent changes in the acetylation status of SPDEF, a master regulator of Paneth and goblet cells. Our results suggest that targeting SIRT1 may be of interest in the management of IBD and CAC.
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    Antibiotic use and abuse: a threat to mitochondria and chloroplasts with impact on research, health, and environment.
    Wang, X ; Ryu, D ; Houtkooper, RH ; Auwerx, J (Wiley, 2015-10)
    Recently, several studies have demonstrated that tetracyclines, the antibiotics most intensively used in livestock and that are also widely applied in biomedical research, interrupt mitochondrial proteostasis and physiology in animals ranging from round worms, fruit flies, and mice to human cell lines. Importantly, plant chloroplasts, like their mitochondria, are also under certain conditions vulnerable to these and other antibiotics that are leached into our environment. Together these endosymbiotic organelles are not only essential for cellular and organismal homeostasis stricto sensu, but also have an important role to play in the sustainability of our ecosystem as they maintain the delicate balance between autotrophs and heterotrophs, which fix and utilize energy, respectively. Therefore, stricter policies on antibiotic usage are absolutely required as their use in research confounds experimental outcomes, and their uncontrolled applications in medicine and agriculture pose a significant threat to a balanced ecosystem and the well-being of these endosymbionts that are essential to sustain health.
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    Eliciting the mitochondrial unfolded protein response by nicotinamide adenine dinucleotide repletion reverses fatty liver disease in mice.
    Gariani, K ; Menzies, KJ ; Ryu, D ; Wegner, CJ ; Wang, X ; Ropelle, ER ; Moullan, N ; Zhang, H ; Perino, A ; Lemos, V ; Kim, B ; Park, Y-K ; Piersigilli, A ; Pham, TX ; Yang, Y ; Ku, CS ; Koo, SI ; Fomitchova, A ; Cantó, C ; Schoonjans, K ; Sauve, AA ; Lee, J-Y ; Auwerx, J (Ovid Technologies (Wolters Kluwer Health), 2016-04)
    UNLABELLED: With no approved pharmacological treatment, nonalcoholic fatty liver disease (NAFLD) is now the most common cause of chronic liver disease in Western countries and its worldwide prevalence continues to increase along with the growing obesity epidemic. Here, we show that a high-fat high-sucrose (HFHS) diet, eliciting chronic hepatosteatosis resembling human fatty liver, lowers hepatic nicotinamide adenine dinucleotide (NAD(+) ) levels driving reductions in hepatic mitochondrial content, function, and adenosine triphosphate (ATP) levels, in conjunction with robust increases in hepatic weight, lipid content, and peroxidation in C57BL/6J mice. To assess the effect of NAD(+) repletion on the development of steatosis in mice, nicotinamide riboside, a precursor of NAD(+) biosynthesis, was added to the HFHS diet, either as a preventive strategy or as a therapeutic intervention. We demonstrate that NR prevents and reverts NAFLD by inducing a sirtuin (SIRT)1- and SIRT3-dependent mitochondrial unfolded protein response, triggering an adaptive mitohormetic pathway to increase hepatic β-oxidation and mitochondrial complex content and activity. The cell-autonomous beneficial component of NR treatment was revealed in liver-specific Sirt1 knockout mice (Sirt1(hep-/-) ), whereas apolipoprotein E-deficient mice (Apoe(-/-) ) challenged with a high-fat high-cholesterol diet affirmed the use of NR in other independent models of NAFLD. CONCLUSION: Our data warrant the future evaluation of NAD(+) boosting strategies to manage the development or progression of NAFLD.
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    Plastic weed matting is better than jute or woodchips for controlling the invasive wetland grass Phalaris arundinacea, but not Phragmites australis.
    Greet, J ; King, E ; Stewart-Howie, M (Polymeria Publishing, 2016)
    Woven polypropylene (plastic) weed matting, jute and eucalypt woodchips were trialled for controlling reed canary grass (Phalaris arundinacea L.) and common reed (Phragmites australis (Cav.) Trin. ex Steud.). At two sites, one dominated by reed canary grass and the other by common reed, 50 m x 20 m was mowed and sprayed and ten (10 m x 10 m) plots established, eight of which were fenced. Plots were covered with either plastic weed matting, jute or eucalypt woodchips, or were controls. All plots were planted with native trees and shrubs and understorey plants. Plastic weed matting was the most effective at reducing regrowth of reed canary grass (<5% cover after one year) and promoting the growth of native plantings (>60% cover). Both plastic weed and jute matting were similarly effective at reducing its regrowth (to 10%), but both matting types were compromised by common reed regrowth. While trees and shrubs grew well across all fenced treatments ( 100% survival), understorey plants only established and grew where weed regrowth was controlled. Unfenced unguarded trees and shrubs were virtually eliminated by browsing. Plastic weed matting (combined with other control measures, and protection from browsers where necessary) may provide the best opportunity to control reed canary grass and facilitate wetland restoration.
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    Internet of Things for Structural Health Monitoring
    SRIDHARA RAO, A ; Gubbi, J ; Ngo, T ; Mendis, P ; Palaniswami, M ; Epaarachchi, A ; Chanaka Kahandawa, G (CRC Press, 2016-05)
    The Internet revolution led to the interconnection between people at an unprecedented scale and pace. The ability of the sensor networks to send data over the Internet further enhanced the scope and usage of the sensor networks. The Internet uses unique address to identify the devices connected to the network. Structural Health Monitoring (SHM) implies monitoring of the state of the structures through sensor networks in an online mode and are pertinent to aircraft and buildings. SHM can be further divided into two categories: global health monitoring and local health monitoring. Continuous online SHM would be an ideal solution. SHM is performed by using acoustic sensors, ultrasonic sensors, strain gauges, optical fibers, and so on. Video cameras can also be used for SHM. SHM can be achieved in real-time and rich analytics. With the advent of smart sensors—sensors with programmable microprocessors, memory, and processing—has reduced load of central data processing, communication overhead while proving continuous SHM status.