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The properties of artificially grown thin films are strongly affected by surface processes during growth. Coherent X-rays provide an approach to better understand such processes and fluctuations far from equilibrium. Here we report results for vacuum deposition of C$_{60}$ on a graphene-coated surface investigated with X-ray Photon Correlation Spectroscopy in surface-sensitive conditions. Step-flow is observed through measurement of the step-edge velocity in the late stages of growth after crystalline mounds have formed. We show that the step-edge velocity is coupled to the terrace length, and that there is a variation in the velocity from larger step spacing at the center of crystalline mounds to closely-spaced, more slowly propagating steps at their edges. The results extend theories of surface growth, since the behavior is consistent with surface evolution driven by processes that include surface diffusion, the motion of step-edges, and attachment at step edges with significant step-edge barriers., Comment: 14 pages and 7 figures

Accumulating experimental evidence has indicated that long non-coding RNAs (lncRNAs) are critical for the regulation of cellular biological processes implicated in many human diseases. However, only relatively few experimentally supported lncRNA-disease associations have been reported. Developing effective computational methods to infer lncRNA-disease associations is becoming increasingly important. Current network-based algorithms typically use a network representation to identify novel associations between lncRNAs and diseases. But these methods are concentrated on specific entities of interest (lncRNAs and diseases) and they do not allow to consider networks with more than two types of entities. Considering the limitations in previous computational methods, we develop a new global network-based framework, LncRDNetFlow, to prioritize disease-related lncRNAs. LncRDNetFlow utilizes a flow propagation algorithm to integrate multiple networks based on a variety of biological information including lncRNA similarity, protein-protein interactions, disease similarity, and the associations between them to infer lncRNA-disease associations. We show that LncRDNetFlow performs significantly better than the existing state-of-the-art approaches in cross-validation. To further validate the reproducibility of the performance, we use the proposed method to identify the related lncRNAs for ovarian cancer, glioma, and cervical cancer. The results are encouraging. Many predicted lncRNAs in the top list have been verified by the biological studies.

Background There is a lack of comprehensive echocardiographic data to allow discrimination of normal versus abnormal mechanical prosthetic tricuspid valve (MPTV) leaflet function. The identification of such parameters is essential to optimize diagnostic and therapeutic measures. Methods The authors investigated bileaflet MPTV function by comparing transthoracic echocardiographic data from 21 episodes of leaflet dysfunction due to valve thrombosis in 12 patients with data from 56 individuals with normal MPTV function. All episodes of dysfunction were confirmed by transesophageal echocardiography and/or cine fluoroscopy. Transthoracic echocardiography–derived two-dimensional, color, and spectral Doppler variables, including MPTV peak early diastolic velocity (E velocity), mean gradient, pressure half-time, time-velocity integral (TVI) of the MPTV, ratio of TVIMPTV to TVI of the left ventricular outflow tract (LVOT) and TVI of the right ventricular outflow tract (RVOT), and continuity-derived effective orifice area, were measured in both groups. Results Most episodes of MPTV dysfunction resulted from simultaneous involvement of both leaflets (57%), with leaflet(s) often immobilized in the open or semiopen position (71%). Transthoracic and transesophageal echocardiography performed similarly in detecting abnormal leaflet motion (90% vs 88%, P = .68), whereas transesophageal echocardiography was better in identifying MPTV thrombosis (31% vs 14%, respectively, P = .01). Color Doppler demonstrated flow propagation abnormalities in 67% of episodes of leaflet dysfunction but not in the control group (P 1.6 m/sec, mean gradient > 5 mm Hg, PHT > 157 msec, TVIMPTV > 42 cm, TVIMPTV/TVILVOT > 2.3, TVIMPTV/TVIRVOT > 3.0, and continuity-derived effective orifice area ≤ 1.1 cm2, with most variables showing high and similar accuracy (area under the curve ≥ 95%). Conclusions This study represents the first comprehensive echocardiographic assessment of MPTV leaflet dysfunction that provides parameters and criteria to distinguish normal versus abnormal prosthetic valve function.

Aim: To detect and quantify early subtle left ventricular (LV) systolic dysfunction using Tissue Doppler Imaging in type 2 diabetic patients with apparently normal LV ejection fraction. Methods: Ninety age and sex matched subjects were enrolled in the study, sixty of them were suffering from type 2 diabetes mellitus (DM) whom were divided according to HbAlc into 2 groups, 30 uncontrolled diabetic patients with HbAlc > 8% and 30 controlled diabetic patients with HbAlc

We propose a method to evaluate public transport network vulnerability. We study the evolution of the passenger Volume Over Capacity (VOC) ratio throughout the network to measure the spatial and temporal extent of the impacts caused by an unplanned service segment disruption. The VOC ratio provides an indication of the on-board travel comfort, an important level-of-service indicator, as well as reflects the residual capacity for absorbing additional demand. Because of the dynamic nature of public transport systems, disturbances propagate through the network in both time and space. Our modelling approach is able to capture transit system dynamics and quantify the extent to which the network exhibits spillover effects. We apply the method to the case of the rapid public transport system of Stockholm Sweden We demonstrate how the changes in network saturation and the corresponding recovery time can be quantified.

We present observations of Io's Loki Patera taken with the 10-m Keck telescopes between 1998 and 2016. Adding these data to those published by Rathbun and Spencer (2006) and the Gemini data of de Kleer and de Pater (2016a, 2017) results in a database of 3.5–3.8 µm emission from Loki Patera over almost 3 decades. Data presented here contain adaptive optics (AO) observations of Io's sunlit hemisphere at wavelengths between 1.6 and 5 µm, AO observations of Io in eclipse at 2–5 µm, and non-AO observations of Io in eclipse at 1.6–12 µm. The non-AO data were taken in September of 1999, during the early phase of a brightening event that was documented by Howell et al. (2001). Dual-component Io Flow model (IFM) fits to our 1999 observations show a mostly cool lava crust over almost the entire patera floor, with a relatively small hotter component making up less than 1% of the total area, consistent with previous observations. The 30-year timeline of Loki Patera revealed that, after an apparent cessation of, or change in, brightening events in 2002, Loki Patera became active again in 2009. The more recent activity may have a slightly shorter periodicity than observed by Rathbun et al. (2002), and the direction of flow propagation appears to have reversed. Since 2009 the flow direction is in the clockwise direction, starting in the north or north-east corner and propagating along the patera towards the south-west. During the Galileo era the propagation was in the counter-clockwise direction, starting in the south-west and propagating towards the east. Both the 30-year timeline and the 1.6–12 µm spectrum that was obtained during the brightening event in 1999 agree well with Matson et al.’s (2006) overturning lava lake model, as modified by de Kleer and de Pater (2017).

We consider dynamic equilibria for flows over time under the fluid queuing model. In this model, queues on the links of a network take care of flow propagation. Flow enters the network at a single source and leaves at a single sink. In a dynamic equilibrium, every infinitesimally small flow particle reaches the sink as early as possible given the pattern of the rest of the flow. Although this model has been examined for many decades, progress has been relatively recent. In particular, the derivatives of dynamic equilibria have been characterized as thin flows with resetting, which allows for more structural results. Our two main results are based on the formulation of thin flows with resetting as a linear complementarity problem and its analysis. We present a constructive proof of existence for dynamic equilibria if the inflow rate is right-monotone. The complexity of computing thin flows with resetting, which occurs as a subproblem in this method, is still open. We settle it for the class of two-terminal, series-parallel networks by giving a recursive algorithm that solves the problem for all flow values simultaneously in polynomial time.

This paper presents a two-dimensional experimental study of the interaction of wet dam-break bores with a fixed structure, regarding the evolution of the incident flows and the resultant green water events on the deck. The study employs image-based techniques to analyse flow propagation from videos taken by high-speed cameras, considering five different shipping water cases. The features of small air-cavities formed in some green water events of the plunging-dam-break type were analysed. Then, the spatial and temporal distribution of water elevations of the incident bores and green water were investigated, providing a database to be used for model validations. Some guidelines for the selection of the freeboard exceedance, which is of relevance for green water simulations, were provided. Finally, the relationship between the incident bore and water-on-deck kinematics was discussed. The proposed study can be used as a reference for performing simplified and systematic analyses of green water in a different two-dimensional setup, giving high-resolution data that visually capture the flow patterns and allow model validations to be performed.

In this paper, a novel mesoscopic multilane model is proposed to enable simultaneous simulation of mandatory and discretionary lane-changing behaviors to realistically capture multilane traffic dynamics. The model considers lane specific fundamental diagrams to simulate dynamic heterogeneous lane flow distributions on expressways. Moreover, different priority levels are identified according to different lane-changing motivations and the corresponding levels of urgency. Then, an algorithm is proposed to estimate the dynamic mandatory and discretionary lane-changing demands. Finally, the lane flow propagation is defined by the reaction law of the demand–supply functions, which can be regarded as an extension of the Incremental-Transfer and/or Priority Incremental-Transfer principles. The proposed mesoscopic multilane cell transmission model is calibrated and validated on a complex weaving section of the State Route 241 freeway in Orange County, California, showing both the positive and negative impact of lane changing maneuvers, e.g., balancing effect and capacity drop, respectively. Moreover, the empirical study verifies that the model requires no additional data other than the cell transmission model does. Thus, the proposed model can be deployed as a simple simulation tool for accessing dynamic mesoscopic multilane traffic state from data available to most management centers, and also the potential application in predicting the impact of traffic incident or lane control strategy.

The Kinematic Wave Model (KWM), representing a simplification of the Full Wave Model (FWM) under the shallow-water approximation, is still used for predicting flood propagation requiring a reduced computational effort and for being more easily coupled with high-resolution topographic data. It is as suitable approach also for predicting debris and mud-flows. In this work the applicability of the KWM for reproducing the propagation of mud-flows characterized by a power-law shear-thinning rheology is investigated. The power-law model is suitable for fluids with negligible yield stress, named mud-flows, such as fine sediment-water mixtures which are often encountered in natural estuaries or in landsides. For this reason, it is very important to individuate the hydraulic conditions in which the KWM can be safely applied for predicting mud flow propagation. In this study the power-law shallow-layer model of Ng and Mei (1994) is considered for the analysing the applicability conditions of the KWM through an unsteady analysis. Comparing the flow depth profiles predicted by KWM with those of the Full Wave Model the applicability conditions are characterized by evaluating the error on the dimensionless maximum flow depth along the channel. The preliminary results presented herein confirm a strong dependency from the rheology and indicate that criteria for clear-water flows do not apply to shearthinning fluids. Moreover, the error increases moving in the downstream direction and higher errors pertain to lower wave durations of the discharge hydrograph. Further investigations will provide specific criteria for the applicability of the KWM for predicting mud-flows propagation.

Traffic flow modelling is the most significant component undertaken by the static and dynamic network loading models in the traffic assignment. In particular, dynamic network loading models represent the fundamental element in estimating the dynamic interaction between demand and supply in oversaturation conditions. In this context, when traffic conditions get worse, queue spillback evaluation is necessary to prevent gridlocks and excessive delays. To this aim, this paper proposes a novel dynamic spillback model based on a mesoscopic network loading model using the Greenshields speed-density relationship. We introduce a link-based model where the dynamic spillback of the queue is explicitly simulated. The proposed model is applied to a simple network for easily assessing the spillback impact. Moreover, a comparison with a commercial traffic simulator is provided to highlight the effectiveness of the proposed model in oversaturation conditions.

We propose a method to evaluate public transport network vulnerability. We study the evolution of the passenger Volume Over Capacity (VOC) ratio throughout the network to measure the spatial and temporal extent of the impacts caused by an unplanned service segment disruption. The VOC ratio provides an indication of the on-board travel comfort, an important level-of-service indicator, as well as reflects the residual capacity for absorbing additional demand. Because of the dynamic nature of public transport systems, disturbances propagate through the network in both time and space. Our modelling approach is able to capture transit system dynamics and quantify the extent to which the network exhibits spillover effects. We apply the method to the case of the rapid public transport system of Stockholm Sweden We demonstrate how the changes in network saturation and the corresponding recovery time can be quantified.

The Jet Transport method has emerged as a powerful tool for the numerical integration of ordinary differential equations; it uses polynomial expansions to approximate the flow map associated to the differential equation in the neighbourhood of a reference solution. One of the main drawbacks of the method is that the region of accuracy becomes smaller along the integration. In this paper we introduce a procedure to determine a ball covering the set of given initial conditions that keeps the accuracy of the integration within a selected threshold. The paper gives detailed explanations of the algorithm illustrated with some examples of applicability, as well as a comparison with a previous existing method for the same purpose

Taking time-varying parking demands and supplies into account, this paper develops a dynamic parking choice model to simulate drivers’ searching for parking spaces between parking lots. In this study, each parking lot has one access passage and vehicles can move or wait for entering the park in the access passage. The flow propagation formula in the access passage of parking lots is established to obtain the number of vehicles entering the parking lot from the access passage within each time interval. This paper brings forward the instantaneous dynamic user-optimal condition of dynamic parking choice, constructs an equivalent variational inequality (VI) model and develops a diagonalization algorithm to solve the model. A numerical example demonstrates the rate of in-flow, the rate of out-flow, link flow, instantaneous travel time on each link or access passage of the parking lot, and the amount and routes of cruising traffic at each time point.

Purpose – Whether a fire can be initiated in an explosion accident depends on the explosion and deflagration process. In the methane-air explosion in a tunnel, the flame accelerates from the ignition point. However, where it begins to decelerate is not clear. The purpose of this paper is to examine the explosion overpressure, flow and flame propagation beyond the premixed area of methane-air in a tunnel. Design/methodology/approach – The numerical simulation was used to study the explosion processes of methane-air mixtures in a tunnel. Based on the numerical simulation and its analysis, the explosion overpressure, flow and flame propagation rules beyond the premixed area were demonstrated for a methane-air explosion. Findings – The peak overpressure of methane-air mixture explosion was observed to reach its maximum beyond the original premixed area of methane-air. The hazardous effects beyond the premixed area may be stronger than those within the premixed area for a methane-air explosion in a tunnel. Under the conditions of this study, the ratio between the length of combustion area (40 m) and that of original premixed area (28 m) reaches 1.43. Originality/value – Little attention has been devoted to investigating the explosion overpressure, flow and flam propagations beyond the original premixed area of methane-air in a tunnel. Based on the numerical simulation and the analysis, the propagation rule of overpressure wave and flow inside and outside the space occupied by methane/air mixture at the volume fraction of 9.5 percent in a tunnel were obtained in this work.

The Ni silicides and Si metal-semiconductor contacts are a vital element in the state-of-the-art commercial transistor devices. The contact formation process needs to be precisely engineered in order to achieve reproducible electrical properties over billions of transistors, especially for ultra-scaled transistors when contact resistance contribution is significant. The latest source/drain (S/D) engineering technology designs the S/D crystal structure (e.g. intentional incorporation of stacking faults) that strains the channel to enhance device performance. Understanding the role of structural alternation, or defects, in Si-Ni reaction is therefore important in achieving precise control of the contact formation process at an atomic scale. Here, we present a study of Si-Ni reaction by lattice-resolved in-situ transmission electron microscopy (TEM) and found that presence of defects in Si can fundamentally change the silicide nucleation mechanism and growth behavior. We use vapor-liquid-solid (VLS) grown Si nanowire (NW) as the Si source and incorporate two types of defects (twin boundaries (TB) running down NW axial direction and grain boundaries (GB) on NW surface). Si NWs are dispersed on silicon nitride (50nm) TEM membrane and react with photolithography defined Ni electrodes, at 300C on an in-situ TEM heating stage. Dynamic high resolution TEM imaging resolves the axial growth of NiSi2 into Si NW as layer-wise repeating nucleation and propagation of NiSi2 (111) plane. Previously reported studies show 2D Ni silicides nucleate homogeneously in the center of defect-free NWs (Figure a-b), and the growth proceeds in a layer-by-layer manner with long incubation time between sequential layer growth (Figure c). We captured the nucleation of each NiSi2 layer at the initial stage and demonstrated that TB and GBs are preferred heterogeneous nucleation sites. An example of nucleation and step propagation from the TB is shown in Figure d. Experimentally measured growth rate (Figure e) qualitatively fit with our analytical model based on classic nucleation theory, which consider the energy of different defects. Defective sites with the heterogeneous nucleation barrier in descending order are TB, "corner", and GB, (Figure f) suggesting that higher degree of defectivity suppresses the nucleation barrier more effectively. We further extend our model to depict NiSi2 nucleation as a biased random walk stochastic process and show that twin defects in NiSi2have high interfacial energies (in contrast to other typical FCC materials like copper or silicon). We calculate this defect energy, which together with our experimental observations, should alert and guide contact silicide formation processes and strain engineering in future Si-based technology nodes. Figure captions: (a-b) homogeneous nucleation of Ni silicide in a single crystal Si NW (c) Layer-by-layer repeating homogeneous nucleation in silicide growth (d) NiSi2 heterogeneously nucleates from the “corner” site. Scale bar is 3 nm. (e) The silicide grows at a steady rate when guided by the TB. Inset shows layer-by-layer growth behaviour in the heterogeneous nucleation NiSi2 growth. (f) Reduction in the nucleation barrier at different heterogeneous sites noted in the inset schematic which is a 3D view of three different heterogeneous nucleation sites in a defective Si nanowire.

This article extends the stochastic cell transmission model (SCTM) to simulate traffic flows on networks with stochastic demand and supply. The SCTM divides a roadway segment into cells and accepts the means and variances of stochastic travel demand and supply functions as exogenous inputs, and produces the corresponding cell traffic densities over time. This article defines the rules of flow propagation for freeway corridors, traffic merges/diverges and signalised junctions based on a kind of link-node model. In the numerical studies, we simulate the proposed model with a hypothetical network. We apply the SCTM to estimate the queues and delays at signalised intersections. Compared with some well-known delay and queue estimation formulas, e.g. Webster, Beckmann, McNeil and Akcelik, the results show good consistency between the SCTM and these formulas. In addition, the SCTM describes the temporal behaviour of the queue and delay distributions at signalised junctions with stochastic supply functions and (n...

Various applications like finding web communities, detecting the structure of social networks , or even analyzing a graph’s structure to uncover Internet attacks are just some of the applications for which community detection is important. In this paper, we propose an algorithm that finds the entire community structure of a network, based on local interactions between neighboring nodes and on an unsupervised distributed hierarchical clustering algorithm. In this paper, we describe two novel community detection algorithms, one for full graph communities detection and one for single community detection. The novelty of the first proposed approach, named SCCD (to stand for Synthetic Coordinate Community Detection), is the fact that the algorithm is based on the use of Vivaldi synthetic network coordinates computed by a distributed algorithm . We also present an extended version of said algorithm, modified to deal efficiently with community detection on dynamic graphs . Finally, we present a new algorithm which partially analyzes a graph to detect the community of a single node. The current paper not only presents two efficient community finding algorithms, but also demonstrates that synthetic network coordinates could be used to derive efficient solutions to a variety of problems. Experimental results and comparisons with other methods from the literature are presented for a variety of benchmark graphs with known community structure, derived by varying a number of graph parameters and real dataset graphs. The experimental results and comparisons to existing methods with similar computation cost on real and synthetic data sets demonstrate the high performance and robustness of the proposed scheme.

This study aims to investigate the measurement of left ventricular flow propagation velocity, V p, using phase contrast magnetic resonance imaging and to assess the discrepancies resulting from inflow jet direction and individual left ventricular size. Three V p measuring techniques, namely non-adaptive (NA), adaptive positions (AP) and adaptive vectors (AV) method, were suggested and compared. We performed the comparison on nine healthy volunteers and nine post-infarct patients at four measurement positions, respectively, at one-third, one-half, two-thirds and the conventional 4 cm distances from the mitral valve leaflet into the left ventricle. We found that the V p measurement was affected by both the inflow jet direction and measurement positions. Both NA and AP methods overestimated V p, especially in dilated left ventricles, while the AV method showed the strongest correlation with the isovolumic relaxation myocardial strain rate (r = 0.53, p

Floods are frequent and widespread in Italy and pose a severe risk for the population. Local administrations commonly use flow propagation models to delineate the flood prone areas. These modeling approaches require a detail geo-environmental data knowledge, intensive calculation and long computational times. Conversely, statistical methods can be used to asses flood hazard over large areas, or to extend the flood hazard zonation to the portion of the river networks where hydraulic models have still not been applied or can be applied with difficulties. In this paper, we describe a statistical approach to prepare flood hazard maps for the whole of Italy. The proposed method is based on a multivariate machine learning algorithm calibrated using in input flood hazard maps delineated by the local authorities and terrain elevation data. The preliminary results obtained in several major Italian catchments indicate good performances of the statistical algorithm in matching the training data. Results are promising giving the possibility to obtain reliable delineations of flood prone areas obtained in the rest of the Italian territory.

Flow routing models are an essential tool for water systems planning and management. In the last few years, advances in modelling capability, enhanced data availability, and increasing computational power have made the use of large, process-based, flow-routing models more common. However, the computational burden of such models still prevents their systematic application for operational purposes. This paper presents an alternative, data-driven approach to the identification of a flow-routing model both in one-step-ahead prediction and simulation mode, and demonstrates it by application to the Red River network, in Northern Vietnam. In particular, MIMO time-invariant models for the network are considered, their parameters are estimated using subspace model identification techniques and their performance is assessed with respect to the available data. Results show that the non-linear process of flow propagation is accurately reproduced both in prediction and simulation using very low order models.

Objective: Diastolic dysfunction precedes systolic dysfunction during the development of myocardial ischemia. Detecting diastolic dysfunction during stress test for coronary artery disease (CAD) could improve diagnostic sensitivity of the test. Flow propagation velocity (FPV) derived from color M-mode Doppler has been proposed as a sensitive marker to detect diastolic dysfunction. Methods: The FPVs at baseline and at peak dobutamine infusion were measured using color M-mode Doppler during dobutamine stress echocardiography in 90 patients. The results are compared among the groups divided on the results of coronary angiography. Results: The FPV was similar at baseline among the groups. At peak dobutamine infusion, the FPV increased significantly in the non-CAD group (from 56 ± 19 cm/s to 66 ± 25 cm/s), whereas it failed to increase in the groups with CAD. As a result, the peak FPV was significantly lower in the groups with CAD than in the non-CAD group. Receiver operating characteristic analysis showed that the peak FPV and ΔFPV had good diagnostic property to detect CAD (the areas under the curves were 0.77 and 0.73, respectively). Adopting these FPV criteria, sensitivity of DSE was improved. Conclusion: FPV measurement during DSE detects ischemic left ventricular diastolic dysfunction. Adding the assessment of peak FPV to conventional DSE increases the sensitivity and the ability to reliably exclude CAD. (Echocardiography 2011;28:335-341)

Mitral regurgitation (MR) can affect left ventricular diastolic parameters because of interference with regurgitation flow. This study compared left ventricular diastolic parameters between patients with and without significant MR. The MR group included 57 consecutive patients with significant MR. Fifty-seven age-, sex- and Tei index-matched patients without significant MR were selected as the reference group. Baseline characteristics and Tei index and its components were comparable between the MR and reference groups. The MR group had higher left atrial volume index, transmitral E wave velocity (E), ratio of E to transmitral A wave velocity, early diastolic mitral annular velocity (Ea), E/Ea, and ratio of E to isovolumic relaxation flow propagation velocity (IRFPV) (p ≤ 0.025), and lower E-wave deceleration time (p = 0.019) and late diastolic mitral annular velocity (p < 0.001). However, the two groups had similar IRFPV (p = 0.844). In conclusion, MR apparently affects E and Ea, but not IRFPV. IRFPV could potentially be a reliable relaxation parameter in patients with significant MR, but further confirmation by invasive studies is needed.

Dike overtopping is an important issue in both scientific and practical aspects of sediment embankment erosion. This research is concerned with the validation of a one-dimensional numerical code applied to an unsteady two-phase flow over an initially trapezoidal-shaped sediment dike, including the transition from sub- to supercritical flows and the flow propagation over a steep slope. The approach is based on the shallow-water equations coupled with a sediment erosion code. The numerical results are compared with recent laboratory experiments, resulting in a reasonable prediction of the temporal free surface and bed evolution. The remaining model inaccuracies mainly originate from overflow initiation with extremely small flow depths, streamline curvature effects with the related underestimation of flowvelocities close to the sediment surface, and the changing saturation in the dike body not accounted for in the model. Despite these deficiencies, the computational model will be helpful, particularly in flood risk assessment and management.

The experimental procedure and test data on assessment of rates of air filtration flow are reported. Permeability of the test specimens differ by more than four orders in the range of linear filtration. The tests with core specimens under the gas pressures of 0.5, 1, 2, 5, 10 MPa established relationships between the gas propagation rate, gas pressure, structure and hydrodynamic characteristics of the specimens.

OBJECTIVE This study investigates the change in flow propagation velocity (FPV) in uremic patients who undergo regular hemodialysis (H/D). MATERIALS AND METHODS We studied 93 uremic patients (44 men and 49 women; 59 +/- 14-years-old) receiving regular hemodialysis. Patients were separated by baseline left ventricular ejection fraction (LVEF): 71 patients with LVEF > 50% (group 1), 13 patients with LVEF 35-50% (group 2), 7 patients with LVEF 50%, FPV after H/D was almost always lower, regardless of H/D amount. But there was different response in patients with baseline LVEF 50%.

Arterial stiffness is increasingly recognized as an important determinant of cardiovascular risk and may be directly involved in the process of atherosclerosis. As atherosclerosis leads to increased arterial resistance and decrease the flow propagation speed within the arterial lumen, a similar decrease in aortic flow propagation with increased downstream resistance is detected, so aortic flow propagation velocity AVP was evaluated in many studies as a new parameter of aortic stiffness. Aim: To measure arterial stiffness using the new parameter AVP and compare it to flow mediated dilatation FMD as a parameter of endothelial dysfunction in patients with metabolic syndrome MS. Methods: AVP (assessed by transthoracic echocardiography) and FMD (assessed by brachial artery reactivity test) were measured in 100 patients with MS (Group 1) and were compared to 14 normal subjects (Group 2). Results: Patients with MS had significantly lower values of AVP as compared to the normal subjects; 36 ± 5 cm/s vs 57 ± 5, p

In this article, we propose a framework for travel time prediction based on a time-discrete, mesoscopic traffic flow model, in which the measure of travel time is obtained as a link performance resulting from a dynamic network loading process. The spatiotemporal flow propagation on the road network is simulated incorporating the mesoscopic model and a linear link performance model, based on a travel time function. Acceleration levels are calculated explicitly, as a result of a fixed point problem. The traffic assignment to the network has been carried out through a completely new model, based on the Bee Colony Optimization (BCO) metaheuristics. In comparison with results of simulations carried out by using another mesoscopic model (DYNASMART), the travel times obtained with the proposed method appear more realistic. (C) 2015 Elsevier Ltd. All rights reserved.

To test the applicability of isovolumic relaxation flow propagation velocity (IRFPV) as an indicator of relaxation, 38 patients undergoing cardiac catheterization for chest pain were included. The time constant of isovolumic left ventricular (LV) pressure decline (tau) had a significant correlation with the LV end-diastolic pressure, the peak negative dp/dt, the LV end-diastolic dimension, the fractional shortening, the late diastolic transmitral flow velocity, the early and late diastolic mitral annular velocities, the rapid filling flow propagation velocity, and the natural logarithms of heart rate, ejection fraction, LV end-systolic dimension and IRFPV (r = -0.773, p0.001). IRFPV was selected as the major independent determinant of tau, explaining 46% of its variance. In prediction of tauor =42 ms, the sensitivity and specificity were 100% and 83% for IRFPVor =104 cm/s, 77% and 67% for the rapid filling flow propagation velocityor =50 cm/s, and 58% and 67% for the early diastolic mitral annular velocityor =8 cm/s, respectively. In conclusion, our data suggest that IRFPV could be a better marker of LV relaxation than other parameters, as the rapid filling flow propagation velocity or the early diastolic mitral annular velocity.

Background: The purpose of the present study was to establish the normal values of flow propagation velocity (FPV) in healthy children and examine the variables that affect FPV in clinical situations. Methods: Two hundred and thirty- five healthy children and adolescents were assessed (aged 0–22.6 years, mean age 7.4 ± 5.4 years; male, n = 142; female, n = 93). FPV was obtained from an apical four-chamber view and determined as the slope of aliasing velocity of early diastolic transmitral flow on the color M-mode using Aloka SSD-5500 with 5.0 MHz transducer. Aliasing velocity was set at 50–70% of the peak transmitral flow velocity. Peak transmitral flow velocities in early diastole (E) and during atrial contraction (A), and the ratio of early to late peak velocity (E/A) were obtained. Tei index was also measured for analysis of general left ventricular performance. Left ventricular mass index (LVMI) was obtained from conventional echo measurement. E, E/A, Tei index and LVMI were compared with FPV in healthy subjects. Results: FPV obtained from all subjects ranged from 23.7 to 96.0 cm/s (61.3 ± 13.6 cm/s). Normal value of FPV was less dependent on age, body size, heart rate and left ventricular dimension. In contrast, although there was no significant correlation between FPV and ejection fraction, statistically significant correlation was found between FPV, LVMI (P = 0.0008) and Tei index (P = 0.025). Conclusions: FPV is independent of age, body size and heart rate and is useful to assess left ventricular relaxation in children.

We propose a flow propagation algorithm (FlowPro) that finds the community surrounding a node in a complex network. In each iteration of the main process of FlowPro, the initial node propagates a flow that is shared among its neighbors. Each node is able to store, propagate to its neighbors, and return, part of the flow it receives to the initial node. When the algorithm converges, the flow stored in the nodes that belong to the community of the initial node, is generally higher than the flow stored in the rest of the graph nodes, thus the requested community emerges. The novelty of the proposed approach lies in the fact that FlowPro is local, allows to visualize the community and does not require the knowledge of the entire graph as most of the existing methods found in the literature. This makes possible the application of FlowPro in extremely large graphs or in cases where the entire graph is unknown like in most social networks.