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Microproteins (MPs) are a potentially rich source of uncharacterized metabolic regulators. Here, we use ribosome profiling (Ribo-seq) to curate 3,877 unannotated MP-encoding small ORFs (smORFs) in primary brown, white, and beige mouse adipocytes. Of these, we validated 85 MPs by proteomics, including 33 circulating MPs in mouse plasma. Analyses of MP-encoding mRNAs under different physiological conditions (high-fat diet) revealed that numerous MPs are regulated in adipose tissue in vivo and are co-expressed with established metabolic genes. Furthermore, Ribo-seq provided evidence for the translation of Gm8773, which encodes a secreted MP that is homologous to human and chicken FAM237B. Gm8773 is highly expressed in the arcuate nucleus of the hypothalamus, and intracerebroventricular administration of recombinant mFAM237B showed orexigenic activity in obese mice. Together, these data highlight the value of this adipocyte MP database in identifying MPs with roles in fundamental metabolic and physiological processes such as feeding.

The fraction of absorbed photosynthetically active radiation (fAPAR) is a key parameter for estimating the gross primary production (GPP) of trees. For continuous, dense forest canopies, fAPAR, is often equated with the intercepted fraction, fIPAR. This assumption is not valid for individual trees in urban environments or parkland settings where the canopy is sparse and there are well-defined tree crown boundaries. Here, the distinction between fAPAR and fIPAR can be strongly influenced by the background and large illumination variations due to multi-scattering and shadows of buildings. This study investigates the radiative budget of PAR bands using a coupled leaf-canopy radiative transfer model (PROSPECT-DART), considering a suite of tropical tree species over a wide range of assumed leaf chlorophyll contents. The analyses simulate hyperspectral images (5 nm bandwidth) of individual tree crowns for the selected background (concrete vs. grass) and illumination conditions. We then use an artificial neural network-based method to partition sunlit vs. shaded leaves within each crown, as the latter have lower fAPAR and fIPAR values. Our results show fAPAR of sunlit leaves decreases with the ratio of diffuse to direct scene irradiance (SKYL), while SKYL has minimal influence for shaded leaves. Both fAPAR and fIPAR decrease at more oblique solar zenith angles (SZA). Higher values of fAPAR and fIPAR occur with concrete backgrounds and the influence of the background is larger at higher diffuse ratio and solar zenith angles. The results show that fIPAR is typically 6–9% higher than fAPAR, and up to 14% higher for sunlit leaves with a concrete background at SKYL = 0. The differences between the fIPAR and fAPAR also depend on the health condition of the leaves, such as chlorophyll content. This study can improve the understanding of urban individual trees fAPAR/fIPAR and facilitate the development of protocols for fAPAR field measurements.

We present experimental observations and a conceptual model for understanding the compression and swelling characteristics of Old Alluvium (OA) from San Juan, Puerto Rico. Prior studies have classified OA as a transported, in situ weathered tropical soil whose intact macrostructure comprises a cemented, pseudo-silt with a mixture of quartz grains and aggregated clay particles. The aggregates include mixtures of kaolinite and smectite coated by Fe-oxides. The Fe-oxides also act as cementing agents between the particles. This study describes results from a series of high-pressure (up to 63 MPa) incremental consolidation tests. Breakdown of the clay aggregates and cemented structure is observed through changes in the compression properties, significant swelling during unloading, and an extraordinary reduction (i.e., by three orders of magnitude) in the coefficient of consolidation. These experimental observations are explained by a combination of mechanical processes, comminution and breakdown of cementing bonds, and physicochemical changes linking pore fluid in the intra- and inter-aggregate pore space. These processes alter the fundamental particle size distribution and macro-porosity of the soil and activate the swelling potential of the smectites concealed by the Fe-oxides coating in the intact material. The experimental observations provide the basis for the formulation of a constitutive model to describe macroscopic compression and swelling behavior of Old Alluvium and offer a framework to understand the response of piedmont transported residual soils found elsewhere.

©2019. The Authors. Nearly one billion people worldwide receive water through piped networks that are not continually pressurized and operate intermittently. The prevalence and persistence of these Intermittent Water Supplies (IWS) is surprising as this mode of operation induces water contamination and customer equity issues. Shortages of source water, customers' water demand, and leaking pipes are frequently cited as necessitating IWS. We propose a framework for understanding the persistence and operation of IWS. The supply system is represented by an average customer and a spatially averaged leakage rate. With this macroscopic hydraulic model, we relate customer demand satisfaction, source water availability, customer demand, and leakage. While this approach ignores the complexities of network topology, we find that the model approximates real systems well (calibrating to four intermittent reference networks achieved R2>0.87). The calibrated model is robust to moderate changes in demand and leakage (maintaining R2>0.81). Using the model, we show that the tipping point between satisfied demand and unsatisfied demand is a local optimum for utilities, which may explain the persistence of IWS. Beyond this point, the volume received by customers does not increase, but utilities must supply more water to the network. The generality of the proposed model enables its use when regulating and upgrading IWS. We demonstrate the latter by critiquing a performance-based contract that was intended to improve an intermittent supply in India. Demand satisfaction has profound implications for hydraulics and human welfare. We propose the degree of demand satisfaction as a metric for evaluating IWS and for tracking the United Nations Sustainable Development Goal 6.1.

Although water quality has extensively improved over the last decade, recreational uses of the canal network in Amsterdam are limited by variations in water quality associated with stormwater runoff and episodic harmful algal blooms. The current systems for monitoring water quality are based on a stationary network of sampling points, offline testing methods, and online measurements of conventional water quality parameters on board a boat that continuously navigates the urban canal network. Here we describe the development and deployment of online algal sensors on board the boat, including a prototype LED-induced fluorescence instrument for algal identification and quantification. We demonstrate that by using only a single patrol vessel, we are able to achieve enough sampling coverage to observe spatiotemporal heterogeneity of algal and chemical water quality within the canal network. The data provide encouraging evidence that opportunistic measurements from a small number of mobile platforms can enable high-resolution mapping and can be used to improve the monitoring of water quality across the city compared to the current network of fixed sampling locations. We also discuss the challenges of operating water quality sensors for long-term autonomous monitoring.

Collecting biofilm samples from drinking water distribution systems (DWDSs) is challenging due to limited access to the pipes during regular operations. We report here the analysis of microbial communities in biofilm and water samples collected from sensors installed in a DWDS where monochloramine is used as a residual disinfectant. A total of 52 biofilm samples and 14 bulk water samples were collected from 17 pipe sections representing different water ages. Prokaryotic genome copies (bacterial and archaeal 16S rRNA genes, Mycobacterium spp., ammonia-oxidizing bacteria (AOB), and cyanobacteria) were quantified with droplet digital PCR, which revealed the abundance of these genes in both biofilm and water samples. Prokaryotic 16S rRNA gene sequencing analysis was carried out for a subset of the samples (12 samples from four sites). Mycobacterium and AOB species were dominant in the DWDS sections with low water age and sufficient residual monochloramine, whereas Nitrospira species (nitrite-oxidizing bacteria) dominated in the sections with higher water age and depleted monochloramine level, suggesting the occurrence of nitrification in the studied DWDS. The present study provides novel information on the abundance and identity of prokaryotes in biofilms and water in a full-scale operational DWDS.

Collecting biofilm samples from drinking water distribution systems (DWDSs) is challenging due to limited access to the pipes during regular operations. We report here the analysis of microbial communities in biofilm and water samples collected from sensors installed in a DWDS where monochloramine is used as a residual disinfectant. A total of 52 biofilm samples and 14 bulk water samples were collected from 17 pipe sections representing different water ages. Prokaryotic genome copies (bacterial and archaeal 16S rRNA genes, Mycobacterium spp., ammonia-oxidizing bacteria (AOB), and cyanobacteria) were quantified with droplet digital PCR, which revealed the abundance of these genes in both biofilm and water samples. Prokaryotic 16S rRNA gene sequencing analysis was carried out for a subset of the samples (12 samples from four sites). Mycobacterium and AOB species were dominant in the DWDS sections with low water age and sufficient residual monochloramine, whereas Nitrospira species (nitrite-oxidizing bacteria) dominated in the sections with higher water age and depleted monochloramine level, suggesting the occurrence of nitrification in the studied DWDS. The present study provides novel information on the abundance and identity of prokaryotes in biofilms and water in a full-scale operational DWDS.

Collecting biofilm samples from drinking water distribution systems (DWDSs) is challenging due to limited access to the pipes during regular operations. We report here the analysis of microbial communities in biofilm and water samples collected from sensors installed in a DWDS where monochloramine is used as a residual disinfectant. A total of 52 biofilm samples and 14 bulk water samples were collected from 17 pipe sections representing different water ages. Prokaryotic genome copies (bacterial and archaeal 16S rRNA genes, Mycobacterium spp., ammonia-oxidizing bacteria (AOB), and cyanobacteria) were quantified with droplet digital PCR, which revealed the abundance of these genes in both biofilm and water samples. Prokaryotic 16S rRNA gene sequencing analysis was carried out for a subset of the samples (12 samples from four sites). Mycobacterium and AOB species were dominant in the DWDS sections with low water age and sufficient residual monochloramine, whereas Nitrospira species (nitrite-oxidizing bacteria) dominated in the sections with higher water age and depleted monochloramine level, suggesting the occurrence of nitrification in the studied DWDS. The present study provides novel information on the abundance and identity of prokaryotes in biofilms and water in a full-scale operational DWDS.

We estimate 250 million people receive water using private pumps connected directly to intermittently pressurized distribution networks. Yet no previous studies have quantified the presumed effects of these pumps. In this paper, we investigate the effects of installing pressure-sustaining valves at consumer connections. These valves mimic pump disconnection by restricting flow. Installing these valves during the dry season at 94% of connections in an affluent neighborhood in Delhi, India, cut the prevalence of samples with turbidity > 4 NTU by two thirds. But considering the poor reputation of pumps, installed valves had surprisingly small average effects on turbidity (-8%; p<0.01) and free chlorine (+0.05 mg/L; p<0.001; N = 1,031). These effects were much smaller than the high variability in water quality supplied to both control and valve-installed neighborhoods. Site-specific responses to this variability could have confounded our results. At the study site, installed valves increased network pressure during 88% of the typical supply window; valves had a maximum pressure effect of +0.62 m (95% CI [0.54, 0.71]; a 40% increase vs. control). Further research is needed to generalize beyond our study site. Nevertheless, this paper provides unique evidence showing how the deployed valves mitigated pump effects, increased network pressure and improved water safety.

The fraction of absorbed photosynthetically active radiation (fAPAR) is a key parameter for estimating the gross primary production (GPP) of trees. For continuous, dense forest canopies, fAPAR, is often equated with the intercepted fraction, fIPAR. This assumption is not valid for individual trees in urban environments or parkland settings where the canopy is sparse and there are well-defined tree crown boundaries. Here, the distinction between fAPAR and fIPAR can be strongly influenced by the background and large illumination variations due to multi-scattering and shadows of buildings. This study investigates the radiative budget of PAR bands using a coupled leaf-canopy radiative transfer model (PROSPECT-DART), considering a suite of tropical tree species over a wide range of assumed leaf chlorophyll contents. The analyses simulate hyperspectral images (5 nm bandwidth) of individual tree crowns for the selected background (concrete vs. grass) and illumination conditions. We then use an artificial neural network-based method to partition sunlit vs. shaded leaves within each crown, as the latter have lower fAPAR and fIPAR values. Our results show fAPAR of sunlit leaves decreases with the ratio of diffuse to direct scene irradiance (SKYL), while SKYL has minimal influence for shaded leaves. Both fAPAR and fIPAR decrease at more oblique solar zenith angles (SZA). Higher values of fAPAR and fIPAR occur with concrete backgrounds and the influence of the background is larger at higher diffuse ratio and solar zenith angles. The results show that fIPAR is typically 6–9% higher than fAPAR, and up to 14% higher for sunlit leaves with a concrete background at SKYL = 0. The differences between the fIPAR and fAPAR also depend on the health condition of the leaves, such as chlorophyll content. This study can improve the understanding of urban individual trees fAPAR/fIPAR and facilitate the development of protocols for fAPAR field measurements.

There is extensive data to show that heating and cooling produces irrecoverable deformations in clays under fully drained conditions. The effects are most pronounced for normally and lightly overconsolidated clays that undergo significant compression. Most constitutive models have key limitations for predicting the thermo-mechanical response of clays through long-term (seasonal) cycles of heating and cooling. The Tsinghua ThermoSoil model (TTS; Zhang and Cheng in Int J Numer Anal Methods Geomech 41(4):527–554, 2017) presents a novel theoretical framework for simulating the coupled thermo-mechanical response of clays. The model uses a double-entropy approach to capture effects of energy dissipation at the microscopic particulate contact level on continuum behavior. This paper proposes a simple procedure for calibrating input parameters and illustrates this process using recent laboratory data for Geneva Clay (Di Donna and Laloui in Eng Geol 190:65–76, 2015). We then investigate capabilities of the TTS model in simulating familiar aspects of thermal consolidation of clays as well as the long-term, progressive accumulation of strains associated with seasonal heating and cooling processes for shallow geothermal systems installed in clays. The model predicts the existence of a long-term steady-state condition where there is no further accumulation of strain. This state depends on the consolidation stress and stress history but is independent of the imposed range of temperature, Tcyc. However, the value of Tcyc does affect the rate of accumulation of strain with thermal cycles. Simulations for normally consolidated Geneva Clay find steady-state strain conditions ranged from 2.0 to 3.7% accumulating within N = 10–50 thermal cycles.

This paper presents a practical methodology for the flexible reconfiguration of existing water distribution infrastructure, which is adaptive to the water utility constraints and facilitates in operational management for pressure and water loss control. The network topology is reconfigured into a star-like topology, where the center node is a connected subset of transmission mains, that provides connection to water sources, and the nodes are the subsystems that are connected to the sources through the center node. In the proposed approach, the system is first decomposed into the main and subsystems based on graph theory methods and then the network reconfiguration problem is approximated as a single-objective linear programming problem, which is efficiently solved using a standard solver. The performance and resiliency of the original and reconfigured systems are evaluated through direct and surrogate measures. The methodology is demonstrated using two large-scale water distribution systems, showing the flexibility of the proposed approach. The results highlight the benefits and disadvantages of network decentralization., MIT-Technion Fellowship

Water distribution systems (WDS) are complex pipe networks with looped and branching topologies that often comprise thousands to tens of thousands of links and nodes. This work presents a generic framework for improved analysis and management of WDS by partitioning the system into smaller (almost) independent sub-systems with balanced loads and minimal number of interconnections. This paper compares the performance of three classes of unsupervised learning algorithms from graph theory for practical sub-zoning of WDS: (1) Global clustering – a bottom-up algorithm for clustering n objects with respect to a similarity function, (2) Community structure – a bottom-up algorithm based on the property of network modularity, which is a measure of the quality of network partition to clusters versus randomly generated graph with respect to the same nodal degree, and (3) Graph partitioning – a flat partitioning algorithm for dividing a network with n nodes into k clusters, such that the total weight of edges crossing between clusters is minimized and the loads of all the clusters are balanced. The algorithms are adapted to WDS to provide a practical decision support tool for water utilities. Visual qualitative and quantitative measures are proposed to evaluate models' performance. The three methods are applied for two large-scale water distribution systems serving heavily populated areas in Singapore., MIT-Technion Fellowship, Singapore-MIT Alliance for Research and Technology (SMART)

This paper proposes a novel methodology for understanding the meso-scale aggregation of clay platelets in water. We use Molecular Dynamics simulations using the CLAYFF force fields to represent the interactions between two layers of Wyoming montmorillonite (Na-smectite) in bulk water. The analyses are used to establish the potential of mean force at different spacings between the layers for edge-to-edge and face-to-face interactions. This is accomplished by finding the change in free energy as a function of the separation distance between the platelets using thermodynamic perturbation theory with a simple overlap sampling method. These nanoscale results are then used to calibrate the Gay–Berne (GB) potential that represents each platelet as a single-site ellipsoidal body. A coarse-graining upscaling approach then uses the GB potentials and molecular dynamics to represent the meso-scale aggregation of clay platelets (at submicron length scale). Results from meso-scale simulations obtain the equilibrium/jamming configurations for mono-disperse clay platelets. The results show aggregation for a range of clay platelets dimensions and pressures with mean stack size ranging from 3 to 8 platelets. The particle assemblies become more ordered and exhibit more pronounced elastic anisotropy at higher confining pressures. The results are in good agreement with previously measured nano-indentation moduli over a wide range of clay packing densities.

Within the social and physical context of practice, simulation is a technique that replicates ‘real-world’ activities, and provides students with the opportunity to explore their own learning in a controlled environment. Depending upon the specific situation, this student-centred approach may be utilised to support students (across numerous disciplines) to develop and apply theoretical knowledge, practical skills and hone personal aptitude within a safe environment. Through high quality simulation leaners may become immersed within a given situation or scenario, and are able to put emergent skills and knowledge into practice. For example, within paramedic or policing training, simulation may be utilised to imitate real-world working environments to develop a student’s professional attributes where they may be alerted to potential dangers of field work, and in raising awareness of potential dangers help support them to avoid taking unnecessary risks in practice. Pedagogically as a learning tool simulation has several significant benefits. Within a simulated learning environment because the scenario has been ‘designed’ to replicate reality scenarios may be open-ended. As such they provide the opportunity for students to anticipate and respond to the implications of an evolving scenario because of its nature leads to more engaging interactions by learners. Utilised in this way simulation promotes the use of critical and evaluative thinking. Simulation may also be utilised to expose students to situations that support learning but are not practical to explore in practice, for example geohazards. As such simulated learning has the potential to support inclusion, equality and diversity, for example enabling all students to experience an environment where the physical needs of an individual may otherwise limit or prevent them from engagement. Adopting a workshop format, this presentation will share for dissemination emergent cross-faculty, inter-disciplinary simulation act

Intermittent water supplies (IWS) deliver piped water to one billion people; this water is often microbially contaminated. Contaminants that accumulate while IWS are depressurized are flushed into customers’ homes when these systems become pressurized. In addition, during the steady-state phase of IWS, contaminants from higher-pressure sources (e.g., sewers) may continue to intrude where pipe pressure is low. To guide the operation and improvement of IWS, this paper proposes an analytic model relating supply pressure, supply duration, leakage, and the volume of intruded, potentially-contaminated, fluids present during flushing and steady-state. The proposed model suggests that increasing the supply duration may improve water quality during the flushing phase, but decrease the subsequent steady-state water quality. As such, regulators and academics should take more care in reporting if water quality samples are taken during flushing or steady-state operational conditions. Pipe leakage increases with increased supply pressure and/or duration. We propose using an equivalent orifice area (EOA) to quantify pipe quality. This provides a more stable metric for regulators and utilities tracking pipe repairs. Finally, we show that the volume of intruded fluid decreases in proportion to reductions in EOA. The proposed relationships are applied to self-reported performance indicators for IWS serving 108 million people described in the IBNET database and in the Benchmarking and Data Book of Water Utilities in India. This application shows that current high-pressure, continuous water supply targets will require extensive EOA reductions. For example, in order to achieve national targets, utilities in India will need to reduce their EOA by a median of at least 90%.

This paper considers the practical application of analytical solutions for estimating ground movements caused by shallow tunneling in soft ground using closed-form expressions presented in a companion paper based on linearly elastic and average-dilation models of soil behavior. The analytical solutions express two-dimensional distributions of ground deformations as functions of three parameters: the uniform convergence and relative ovalization of a circular tunnel cavity, and either the Poisson's ratio or the average dilation angle for elastic and plastic behavior, respectively. This paper shows that the analytical predictions can achieve very good representations of the distribution of far field deformations through a series of case studies in clays and sands. In some cases, the input parameters can be interpreted from a simple calibration to three independent measurements of ground displacements comprising surface settlements above the tunnel centerline and at a reference offset, and the lateral displacement at the spring line elevation, recorded by an inclinometer at an offset of one tunnel diameter from the centerline. However, it is generally more reliable to use a least-squares fitting method to obtain the model input parameters, using all available extensometer and inclinometer data. © 2013 American Society of Civil Engineers.

Temporary earth retaining structures help prevent collapse during construction excavation. To ensure that these structures are operating within design specifications, load forces on supports must be monitored. Current monitoring approaches are expensive, sparse, off-line, and thus difficult to integrate into predictive models. This work aims to show that wirelessly connected battery powered sensors are feasible, practical, and have similar accuracy to existing sensor systems. We present the design and validation of ReStructure, an end-to-end prototype wireless sensor network for collection, communication, and aggregation of strain data. ReStructure was validated through a 6-month deployment on a real-life excavation site with all but one node producing valid and accurate strain measurements at higher frequency than existing ones. These results and the lessons learnt provide the basis for future widespread wireless temporary earth retaining structure monitoring that increase measurement density and integrate closely with predictive models to provide timely alerts of damage or potential failure.

Within the social and physical context of practice, simulation is a technique that replicates ‘real-world’ activities, and provides students with the opportunity to explore their own learning in a controlled environment. Depending upon the specific situation, this student-centred approach may be utilised to support students (across numerous disciplines) to develop and apply theoretical knowledge, practical skills and hone personal aptitude within a safe environment. Through high quality simulation leaners may become immersed within a given situation or scenario, and are able to put emergent skills and knowledge into practice. For example, within paramedic or policing training, simulation may be utilised to imitate real-world working environments to develop a student’s professional attributes where they may be alerted to potential dangers of field work, and in raising awareness of potential dangers help support them to avoid taking unnecessary risks in practice. Pedagogically as a learning tool simulation has several significant benefits. Within a simulated learning environment because the scenario has been ‘designed’ to replicate reality scenarios may be open-ended. As such they provide the opportunity for students to anticipate and respond to the implications of an evolving scenario because of its nature leads to more engaging interactions by learners. Utilised in this way simulation promotes the use of critical and evaluative thinking. Simulation may also be utilised to expose students to situations that support learning but are not practical to explore in practice, for example geohazards. As such simulated learning has the potential to support inclusion, equality and diversity, for example enabling all students to experience an environment where the physical needs of an individual may otherwise limit or prevent them from engagement. Adopting a workshop format, this presentation will share for dissemination emergent cross-faculty, inter-disciplinary simulation act

This paper considers the anisotropy associated with the interparticle contact network and interconnected pore space, which is quantified through a scalar quantity based on the fabric tensor. The study focused on the anisotropy associated with subsets of contacts and pores. It is shown that the stress ratio can be directly related to the geometric anisotropy of strong and non-sliding contacts, and that the anisotropy of pores is correlated with the anisotropy of contacts.

Production of oil from shallow reservoirs typically involves drilling highly deviated wells through unconsolidated (or poorly lithified) rocks or clays. This paper describes numerical analyses of the deformations and stability of deviated wellbores within a K0-consolidated clay. The analyses consider planar deformations in the plane orthogonal to the wellbore using a quasi threedimensional (3D) finite element model that represents coupled flow and deformations within the soil mass. Cross-anisotropic mechanical properties of the clay are described by a generalized effective stress model, MIT-E3, with parameters previously calibrated from laboratory thick-walled cylinder tests. The analyses compute the relationship between the drilling mud pressure and wellbore stability associated with either the onset of localized failure mechanisms or large plastic deformations around the cavity. The results show that short-term, undrained stability requires mud pressures in excess of the in situ formation pore pressures for more highly deviated wellbores at inclinations greater than 45°. The analyses examine the mechanisms for further destabilization, due to consolidation within the formation, and how they are affected by drainage conditions at the wellbore wall. The results provide qualitative information for the design and control of drilling operations for deviated wellbores in unconsolidated formations., BP (Firm), BP-MIT Major Projects Research Program

Many ports in the US are located in areas of high seismicity and remain vulnerable to damage from large earthquake events. Waterfront structures such as pile-supported wharves are particularly vulnerable to damage associated with lateral spreading of the underlying loose soil fills. This paper describes results of analyses to understand the performance of a typical pile-supported wharf and the effectiveness of mitigation measures. The analyses use a sub-structuring approach in which the ‘free-field’ response of the soil fill is simulated using finite element analyses that are able to represent the complex non-linear stress-strain properties of sands under seismic loading using the model proposed by Dafalias and Manzari (DM, 2004). Ground deformations and excess pore water pressures are then treated as boundary conditions in modeling the response of the pile-supported wharf structure, using a macro-element proposed by Varun and Assimaki (2012) to represent local soil-structure interaction. The paper presents the performance of the pile-supported wharf for a suite of 56 ground motions, and highlights the occurrence of deep-seated failure mechanisms in the supporting rows of piles. The effects of lateral spreading in the soil fill can be addressed by installing full-depth Pre-fabricated Vertical (PV) drains at locations behind the crest of the fill. Analyses with this mitigation system show that structural damage is limited to the pile-deck connections enabling much simpler designs for structural retrofitting., Singapore-MIT Alliance. Center for Environmental Sensing and Modeling, National Science Foundation (U.S.) (grant No. CMS-0530478), Linde Presidential Fellowship, Education and European Culture Foundation, Alexander S. Onassis Public Benefit Foundation

This paper presents new insights into the deformation response of sheared granular assemblies by characterising pore space properties from discrete element simulations of monodisperse particle assemblies in two-way cyclic shearing. Individual pores are characterized by a modified Delaunay tessellation, where tetrahedral Delaunay cells can be merged to form polyhedral cells. This leads to a natural partition of the pore space between individual pores with tetrahedral and polyhedral geometry. These are representative of small compact pores and larger well-connected pores, respectively. A scalar measure of pore orientation anisotropy during shearing is introduced. For triaxial shearing, larger pores align in the loading direction, while small pores are aligned perpendicular to the larger pores. Pore anisotropy mobilises at a slower rate than contact anisotropy or macroscopic stress state, and hence, is an important element to characterise in granular assemblies. Further, the distribution of pore volume remains isotropic. Pore shape was found to be a good micro-scale indicator of macroscopic density, with a strong relationship between averaged shape factor and macroscopic void ratio. Combining results for pore shape and orientation reveals an interesting interplay, where large elongated pores were aligned with the loading direction. These results highlight the importance of considering pore space characteristics in understanding the behaviour of granular materials. Keywords: Pore characterisation; Pore geometry; Orientation tensor; Anisotropy; Shape factor

Prefabricated vertical (PV) drain arrays have been proposed as a minimally intrusive technique for mitigating seismically induced ground deformations in sandy liquefiable slopes. This paper describes the representation of individual PV drains as line elements within a finite-element program. The elements can represent laminar or fully turbulent discharge regimes, based on classic Darcy-Weisbach pipe flow, as well as fluid storage above the water table. Two-dimensional, plane strain simulations of coupled flow and deformation are performed using the proposed PV drain elements, with equivalent permeability properties for the surrounding soil mass, and a constitutive soil model describing the nonlinear effective stress-strain behavior of the sand. The numerical predictions are evaluated through comparisons with pore pressures and deformations measured in a centrifuge model test. The results highlight the role of the PV drains and their discharge characteristics in controlling deformation mechanisms.

The occurrence of pathogenic bacteria in drinking water distribution systems (DWDSs) is a major health concern, and our current understanding is mostly related to pathogenic species such as Legionella pneumophila and Mycobacterium avium but not to bacterial species closely related to them. In this study, genomic-based approaches were used to characterize pathogen-related species in relation to their abundance, diversity, potential pathogenicity, genetic exchange, and distribution across an urban drinking water system. Nine draft genomes recovered from 10 metagenomes were identified as Legionella (4 draft genomes), Mycobacterium (3 draft genomes), Parachlamydia (1 draft genome), and Leptospira (1 draft genome). The pathogenicity potential of these genomes was examined by the presence/absence of virulence machinery, including genes belonging to Type III, IV, and VII secretion systems and their effectors. Several virulence factors known to pathogenic species were detected with these retrieved draft genomes except the Leptospira-related genome. Identical clustered regularly interspaced short palindromic repeats-CRISPR-associated proteins (CRISPR-Cas) genetic signatures were observed in two draft genomes recovered at different stages of the studied system, suggesting that the spacers in CRISPR-Cas could potentially be used as a biomarker in the monitoring of Legionella related strains at an evolutionary scale of several years across different drinking water production and distribution systems. Overall, metagenomics approach was an effective and complementary tool of culturing techniques to gain insights into the pathogenic characteristics and the CRISPR-Cas signatures of pathogen-related species in DWDSs.

Thyroid hormones (THs) act in the brain to modulate energy balance. We show that central triiodothyronine (T3) regulates de novo lipogenesis in liver and lipid oxidation in brown adipose tissue (BAT) through the parasympathetic (PSNS) and sympathetic nervous system (SNS), respectively. Central T3 promotes hepatic lipogenesis with parallel stimulation of the thermogenic program in BAT. The action of T3 depends on AMP-activated protein kinase (AMPK)-induced regulation of two signaling pathways in the ventromedial nucleus of the hypothalamus (VMH): decreased ceramide-induced endoplasmic reticulum (ER) stress, which promotes BAT thermogenesis, and increased c-Jun N-terminal kinase (JNK) activation, which controls hepatic lipid metabolism. Of note, ablation of AMPKα1 in steroidogenic factor 1 (SF1) neurons of the VMH fully recapitulated the effect of central T3, pointing to this population in mediating the effect of central THs on metabolism. Overall, these findings uncover the underlying pathways through which central T3 modulates peripheral metabolism., Funding Agencies:European Community, Projektnr. 260464, 281854Xunta de Galicia, Projektnr. ED431C-2016-025, ED341D-R2016-032, 2015-CP080, 2016-PG057, 2015-CP079, 2016-PG068, ED481A-2016/094, 2016-2019, ED431G/05 Junta de Andalucia, Projektnr. P12-FQM-01943Gobierno Vasco-Departamento de Salud, Projektnr. 2013111114EITB, Projektnr. BIO15/CA/014Ayudas para apoyar grupos de investigacion del sistema Universitario Vasco, Projektnr. IT971-16Generalitat de Catalunya, Projektnr. 2014SGR465Fundacio La Marato de TV3, Projektnr. 87/C/2016Instituto de Salud Carlos III - FEDER, Projektnr. RD16/0008/ 0003, PIE14/00031Ministerio de Economia y Competitividad (MINECO) - FEDER Program of EU, Projektnr. SAF2014-52223-C2-2-R, BFU2014-57581-P -P, BFU2013-44229-R, BFU2014-55871-P, SAF2014-54658-R, SAF2015-64352-R, BFU2015-70664R, SAF2013-43506-R, SAF2014 55725, SAF2015-71026-R, BFU2015-70454-REDT/Adipoplast Asociacion Espanola contra el CancerMedical Research Council (MRC) Metabolic Diseases Unit, Projektnr. MRC_MC_UU_12012/1, MRC_UU_12015/5 MRC Programme Grant, Projektnr. G9824984MRC Disease Model CoreDeutsche Forschungsgemeinschaft, Projektnr. Mi1242/2-1American Heart Association (EIA), Projektnr. 14EIA18860041University of Iowa Fraternal Order of Eagles Diabetes Research CenterEuropean Foundation for the Study of DiabetesAtresmedia CorporacionISCIII , Projektnr. CD14/0007, CP12/03121MINECO, Projektnr. IJDC-2014-19681, BES-2015-072743, FPU12/01827, SEV-2015-0505AECC, Projektnr. AIO2013Pro-CNIC Foundation

Water loss through burst events or leaks is a significant problem affecting water utilities worldwide and is exacerbated by deterioration of the underground infrastructure. This paper shall report on our method to localize the source of a pipe burst by estimating the arrival time of the pressure transients at sensor nodes. Our proposed method uses Short Time Fourier Transform that has shown to overcome the limitation of Fourier Transform temporal deficiency. The paper will in addition report on the results obtained from a real leakage data obtained on the WaterWiSe@SG test-bed, which shows the superiority of our method compared to multi-level wavelet transform.

Thyroid hormones (THs) act in the brain to modulate energy balance. We show that central triiodothyronine (T3) regulates de novo lipogenesis in liver and lipid oxidation in brown adipose tissue (BAT) through the parasympathetic (PSNS) and sympathetic nervous system (SNS), respectively. Central T3 promotes hepatic lipogenesis with parallel stimulation of the thermogenic program in BAT. The action of T3 depends on AMP-activated protein kinase (AMPK)-induced regulation of two signaling pathways in the ventromedial nucleus of the hypothalamus (VMH): decreased ceramide-induced endoplasmic reticulum(ER) stress, which promotes BAT thermogenesis, and increased c-Jun N-terminal kinase (JNK) activation, which controls hepatic lipid metabolism. Of note, ablation of AMPK alpha 1 in steroidogenic factor 1 (SF1) neurons of the VMH fully recapitulated the effect of central T3, pointing to this population in mediating the effect of central THs on metabolism. Overall, these findings uncover the underlying pathways through which central T3 modulates peripheral metabolism.

Water loss through burst events or leaks is a significant problem affecting water utilities worldwide and is exacerbated by deterioration of the underground infrastructure. This paper shall report on our method to localize the source of a pipe burst by estimating the arrival time of the pressure transients at sensor nodes. Our proposed method uses Short Time Fourier Transform that has shown to overcome the limitation of Fourier Transform temporal deficiency. The paper will in addition report on the results obtained from a real leakage data obtained on the WaterWiSe@SG test-bed, which shows the superiority of our method compared to multi-level wavelet transform.

Water distribution systems (WDS) are complex pipe networks with looped and branching topologies that often comprise of thousands of links and nodes. This work presents a generic framework for improved analysis and management of WDS by partitioning the system into smaller (almost) independent sub-systems with balanced loads and minimal number of interconnections. This paper compares the performance of three classes of unsupervised learning algorithms from graph theory for practical sub-zoning of WDS: (1) Graph clustering – a bottom-up algorithm for clustering n objects with respect to a similarity function, (2) Community structure – a bottom-up algorithm based on network modularity property, which is a measure of the quality of network partition to clusters versus randomly generated graph with respect to the same nodal degree, and (3) Graph partitioning – a flat partitioning algorithm for dividing a network with n nodes into k clusters, such that the total weight of edges crossing between clusters is minimized and the loads of all the clusters are balanced. The algorithms are adapted to WDS to provide a decision support tool for water utilities. The proposed methods are applied and results are demonstrated for a large-scale water distribution system serving heavily populated areas in Singapore.

This paper presents a miniaturized MEMS (microelectromechanical systems)-based electrochemical aptasensor, which utilizes aptamer as the recognition element for simple, sensitive and rapid detection of norovirus. The novelty of this work is integration of micro fabrication technology with aptamers to develop a miniaturized and portable electrochemical sensor for environmental pathogen monitoring. The binding capability between aptamers and on-chip sensing electrodes was investigated and the performance of the proposed MEMS electrochemical aptasensor was evaluated with respect to sensor response to different titers of murine norovirus, a model of human norovirus. This research forms initial basis for the development of an electrochemical MEMS-aptasensor platform and its application for virus detection., Singapore. Ministry of Education, Singapore. National Research Foundation, Singapore-MIT Alliance for Research and Technology. Center for Environmental Sensing and Modeling

In recent years, sustainability concerns have played an increasingly important role in building design, leading to rapid adoption of shallow geothermal heating/cooling systems. Understanding the heat exchange with the ground and associated thermo-hydro-mechanical processes involved is critical to ensure safe, efficient long-term performance of these geothermal systems. The current study considers heating/cooling loads for a large office building in Chicago, based on recommendations for typical DOE Commercial Benchmark Buildings and solves the coupled thermo-hydro-mechanical response of different soil types using the Code_Bright program. The paper considers a closed-loop system comprising an array of 80 m deep vertical heat exchangers that operates on a seasonal cycle with zero net heat transfer to the ground and can supply a heating load up to 2440 kW. Using estimated thermal properties of the Chicago clays, the THM analyses show negligible drift in the temperature within the surrounding ground for long-term operation of the geothermal system. However, when thermo-elastoplastic properties are considered, the analyses show that thermal cycling induces long-term settlements of the building.

Temporary earth retaining structures (TERS) help prevent collapse during construction excavation. To ensure that these structures are operating within design specifications, load forces on supports must be monitored. Current monitoring approaches are expensive, sparse, off-line, and thus difficult to integrate into predictive models. This work aims to show that wirelessly connected battery powered sensors are feasible, practical, and have similar accuracy to existing sensor systems. We present the design and validation of ReStructure, an end-to-end prototype wireless sensor network for collection, communication, and aggregation of strain data. ReStructure was validated through a six months deployment on a real-life excavation site with all but one node producing valid and accurate strain measurements at higher frequency than existing ones. These results and the lessons learnt provide the basis for future widespread wireless TERS monitoring that increase measurement density and integrate closely with predictive models to provide timely alerts of damage or potential failure.

Urban water supply and distribution infrastructure is aging rapidly and the frequency of pipe burst increases. These events can be very expensive due to water supply disruptions, and damage to surrounding properties and infrastructures. Therefore, methods of detecting and localizing underground burst events in real time can be very helpful in mitigating these impacts. This paper is a part of the WaterWiSe@SG project in Singapore. In this paper, a cost-effective wireless sensor network was developed for a real-time monitoring, analyzing, and modeling of urban water distribution systems. This paper presents an application of joint time-frequency analysis (JTFA) for detecting events in water distribution pipelines. The idea behind this method is based on the detection of pressure fluctuations induced by the burst. This proposed approach for event detection employs a spectrogram, one of the JTFA approaches. The feasibility of the proposed method is tested through emulated leak-off experiments and validated with monitoring data in an operational system. The results demonstrate that the proposed method has the potential to assist in the management of water infrastructure by monitoring existing conditions and providing real-time feedback in case of the failure.

The complex mechanical behaviour of granular materials is commonly studied by considering the evolving particle contact network. An often overlooked feature is the influence of micro-scale geometric configuration of pores on the macroscopic response. This paper presents a series of tools to quantify the shape, volume distribution and orientation characteristics of the pore space. The proposed approach is compared against data extracted from physical and numerical experiments with monodisperse assemblies of spheres. Individual pores are represented by polyhedral pore unit cells obtained by combining the Delaunay tessellation with an algorithm for merging Delaunay cells based on the concept of maximal inscribed sphere, after Al-Raoush et al. (Soil Sci Soc Am J 67(6):1687–1700, 2003). A pore shape parameter is proposed that considers pore volume and surface, and is analytically related to the void ratio and the number of edges forming the polyhedral pore unit cell. The pore volume distribution is shown to be uniquely described by the analytical k-gamma distribution proposed by Aste and Di Matteo (Phys Rev E 77(2):021309, 2008). A pore orientation tensor is introduced to define the principal orientation of individual pore units. This is subsequently used to define a global orientation tensor that reveals an isotropic pore network for the reference monodisperse assemblies. The global orientation tensor is analytically expressed in terms of the parameters defining the pore volume distribution., Australian Research Council (Grant DP150104123)

The basement of the Stata Center building on the MIT campus required 12.8 m deep excavations covering a large open-plan site and underlain by more than 25 m of lightly overconsolidated Boston Blue Clay. The excavations were supported by a floating, perimeter diaphragm and braced with a system of internal corner struts, rakers, and tieback anchors. The project involved a complex sequence of berms, access ramps, and phased construction of the concrete mat foundation. One of the key goals of the design was to limit ground movements in order to prevent damage to adjacent structures, including the Alumni Pool building, which was founded on shallow caissons and located less than 1.5 m from the south wall. Lateral wall movements and building settlements were closely monitored throughout construction, while photos from a network of webcams located around the open-plan site provide a detailed time history of the construction processes. This paper describes the development of a comprehensive three-dimensional (3D) finite-element (FE) model for the Stata Center basement excavation, which has been enabled by recent advances made available in a FE software package, including efficient multicore iterative solving capabilities, importing of geometric data from computer-aided design files, and use of embedded pile elements to represent tieback anchors. The analyses highlight the effects of the 3D excavation and support geometry on wall and ground movements. The base case results using a simple elasto-plastic Mohr–Coulomb soil model with undrained conditions in the clay are generally in very good agreement with measured performance. The effects of refined constitutive modeling and partial drainage within the clay have a secondary role in numerical predictions for this project., Republic of Kazakhstan (Bolashak Scholarship)

Construction of the Silverline Courthouse Station in South Boston involved 18-m-deep excavations at a site underlain by more than 24 m of normally and lightly overconsolidated Boston blue clay (BBC). The excavations were supported by 27-m-deep floating diaphragm wall panels and five levels of preloaded cross-lot bracing. This paper compares the measured performance of the excavation support system with the Class A finite-element (FE) predictions prepared during the original design phase and with the results of Class C analyses using information obtained during construction. The numerical analyses used data from a special test program of laboratory and in situ tests at a nearby site. The analyses represent coupled consolidation within the soil mass and the anisotropic stress-strain-strength properties of BBC using the MIT-E3 soil model. The Class A analyses generally overestimate the lateral wall deflections and underestimate the measured strut loads, as preloading was not included in the original FE model. However, they provide remarkably consistent predictions of the measured soil deformations, including settlements, lateral spreading, and subgrade basal heave. The Class C analyses refine the stratigraphic section, in situ pore pressures, construction time frame, and strut preloads using the data available at the time of construction but make nominal changes in soil properties. With these limited changes, the Class C model is able to achieve excellent agreement with the measured data.

This paper presents a probabilistic approach to evaluating the geotechnical stability problem by incorporating the stochastic spatial variability of soil property within the numerical limit analyses (NLAs). The undrained shear strength and unit weight of soil are treated as a random field which is characterized by a log-normal distribution and a spatial correlation length. The current calculations use a Cholesky Decomposition technique to incorporate these random properties in NLAs. The Random Field Numerical Limit Analyses are applied to evaluate the effects of spatial variability of soil property on the slope stability and failure mechanism of slope. Monte Carlo iterations are then used to interpret the slope reliability and the dimension for collapsed slope for selected ranges of the coefficient of variation in soil property and the ratio of correlation length to slope height. Finally, the variation in the dimension of collapsed slope is examined in terms of the variability of slope reliability., Japan Society for the Promotion of Science (KAKENHI Grant 25289149)

The basement of the Stata Center building on the MIT campus required 12.8 m deep excavations covering a large open-plan site and underlain by more than 25 m of lightly overconsolidated Boston Blue Clay. The excavations were supported by a floating, perimeter diaphragm and braced with a system of internal corner struts, rakers, and tieback anchors. The project involved a complex sequence of berms, access ramps, and phased construction of the concrete mat foundation. One of the key goals of the design was to limit ground movements in order to prevent damage to adjacent structures, including the Alumni Pool building, which was founded on shallow caissons and located less than 1.5 m from the south wall. Lateral wall movements and building settlements were closely monitored throughout construction, while photos from a network of webcams located around the open-plan site provide a detailed time history of the construction processes. This paper describes the development of a comprehensive three-dimensional (3D) finite-element (FE) model for the Stata Center basement excavation, which has been enabled by recent advances made available in a FE software package, including efficient multicore iterative solving capabilities, importing of geometric data from computer-aided design files, and use of embedded pile elements to represent tieback anchors. The analyses highlight the effects of the 3D excavation and support geometry on wall and ground movements. The base case results using a simple elasto-plastic Mohr–Coulomb soil model with undrained conditions in the clay are generally in very good agreement with measured performance. The effects of refined constitutive modeling and partial drainage within the clay have a secondary role in numerical predictions for this project., Republic of Kazakhstan (Bolashak Scholarship)

Construction of the Silverline Courthouse Station in South Boston involved 18-m-deep excavations at a site underlain by more than 24 m of normally and lightly overconsolidated Boston blue clay (BBC). The excavations were supported by 27-m-deep floating diaphragm wall panels and five levels of preloaded cross-lot bracing. This paper compares the measured performance of the excavation support system with the Class A finite-element (FE) predictions prepared during the original design phase and with the results of Class C analyses using information obtained during construction. The numerical analyses used data from a special test program of laboratory and in situ tests at a nearby site. The analyses represent coupled consolidation within the soil mass and the anisotropic stress-strain-strength properties of BBC using the MIT-E3 soil model. The Class A analyses generally overestimate the lateral wall deflections and underestimate the measured strut loads, as preloading was not included in the original FE model. However, they provide remarkably consistent predictions of the measured soil deformations, including settlements, lateral spreading, and subgrade basal heave. The Class C analyses refine the stratigraphic section, in situ pore pressures, construction time frame, and strut preloads using the data available at the time of construction but make nominal changes in soil properties. With these limited changes, the Class C model is able to achieve excellent agreement with the measured data.

This paper presents a probabilistic approach to evaluating the geotechnical stability problem by incorporating the stochastic spatial variability of soil property within the numerical limit analyses (NLAs). The undrained shear strength and unit weight of soil are treated as a random field which is characterized by a log-normal distribution and a spatial correlation length. The current calculations use a Cholesky Decomposition technique to incorporate these random properties in NLAs. The Random Field Numerical Limit Analyses are applied to evaluate the effects of spatial variability of soil property on the slope stability and failure mechanism of slope. Monte Carlo iterations are then used to interpret the slope reliability and the dimension for collapsed slope for selected ranges of the coefficient of variation in soil property and the ratio of correlation length to slope height. Finally, the variation in the dimension of collapsed slope is examined in terms of the variability of slope reliability., Japan Society for the Promotion of Science (KAKENHI Grant 25289149)

The complex mechanical behaviour of granular materials is commonly studied by considering the evolving particle contact network. An often overlooked feature is the influence of micro-scale geometric configuration of pores on the macroscopic response. This paper presents a series of tools to quantify the shape, volume distribution and orientation characteristics of the pore space. The proposed approach is compared against data extracted from physical and numerical experiments with monodisperse assemblies of spheres. Individual pores are represented by polyhedral pore unit cells obtained by combining the Delaunay tessellation with an algorithm for merging Delaunay cells based on the concept of maximal inscribed sphere, after Al-Raoush et al. (Soil Sci Soc Am J 67(6):1687–1700, 2003). A pore shape parameter is proposed that considers pore volume and surface, and is analytically related to the void ratio and the number of edges forming the polyhedral pore unit cell. The pore volume distribution is shown to be uniquely described by the analytical k-gamma distribution proposed by Aste and Di Matteo (Phys Rev E 77(2):021309, 2008). A pore orientation tensor is introduced to define the principal orientation of individual pore units. This is subsequently used to define a global orientation tensor that reveals an isotropic pore network for the reference monodisperse assemblies. The global orientation tensor is analytically expressed in terms of the parameters defining the pore volume distribution., Australian Research Council (Grant DP150104123)

A program of K[subscript 0]-consolidated undrained triaxial compression tests has been performed to investigate the effects of consolidation stress level on the compression and shear behavior of resedimented Boston blue clay (RBBC). Specimens were consolidated to maximum vertical effective stresses in the range 0.15–10 MPa and tested at three overconsolidation ratios (OCR): 1, 2, and 4. The results show that the virgin compression curves are essentially linear in e–log σ[' over v] space over the consolidation stress range. However, the normally consolidated K[subscript 0] stress ratio increases with the level of consolidation stress. The stress–strain–strength properties measured in undrained shear are significantly affected by the consolidation stress level at each OCR and show indications of non-normalizable behavior. At high pressures, the undrained shear stress–strain behavior becomes more ductile, requiring larger strains to mobilize peak resistance and exhibiting less post-peak strain-softening. The undrained strength ratio (s[subscript u]/σ[' over vc]) is not uniquely controlled by OCR as suggested by the SHANSEP equation, but consistently decreases with increasing consolidation effective stress. There is notable reduction in the stiffness ratio (E[subscript u]/σ[' over vc]) with stress level, and significant decrease in the large-strain friction angle., BP America (Firm), BP–MIT Major Projects Program

This paper presents closed-form analytical solutions for estimating far-field ground deformations caused by shallow tunnelling in a linear elastic soil mass with cross-anisotropic stiffness properties. The solutions describe two-dimensional ground deformations for uniform convergence (u [subscript ε]) and ovalisation (u [subscript δ]) modes of a circular tunnel cavity, based on the complex formulation of planar elasticity and superposition of fundamental singularity solutions. The analyses are used to interpret measurements of ground deformations caused by open-face shield construction of a Jubilee Line Extension (JLE) tunnel in London Clay at a well-instrumented site in St James's Park. Anisotropic stiffness parameters are estimated from hollow-cylinder tests on intact block samples of London Clay (from the Heathrow Airport Terminal 5 project), and the selection of the two input parameters is based on a least-squares optimisation using measurements of ground deformations. The results show consistent agreement with the measured distributions of surface and subsurface, vertical and horizontal displacement components, and anisotropic stiffness properties appear to have little effect on the pattern of ground movements. The results provide an interesting counterpoint to prior studies using finite-element analyses that have reported difficulties in predicting the distribution of ground movements for the instrumented section of the JLE tunnel., George and Marie Vergottis Fellowship, Goldberg-Zoino Fellowship

This paper describes the implementation of a real-time hydraulic model of a water distribution system in Singapore. This on-line system is based on the Integration of real-time hydraulic data with hydraulic computer simulation models and statistical prediction tools. To facilitate this implementation, a network of wireless sensor nodes continuously sample hydraulic data such as pressure and flow rate, transmitting it to cloud-based servers for processing and archiving. Then, data streams from the sensor nodes are integrated into an on-line hydraulic modeling subsystem that is responsible for on-line estimation and prediction of the water distribution system's hydraulic state for a rolling planning horizon of 24 hours ahead. This online hydraulic model is one of the components of the WaterWiSe (Wierless Water Sentinel) platform which is an end-to-end integrated hardware and software system for monitoring, analyzing, and modeling urban water distribution systems in real-time., Singapore. National Research Foundation, Singapore-MIT Alliance for Research and Technology. Center for Environmental Sensing and Modeling