Flow Metrics Research Articles

Unrestricted ramping rates and long‐term trends in the food web metrics of a boreal river

AbstractLong‐term monitoring of the food web of a regulated hydropeaking river was conducted to assess if previously documented effects of changing ramping rates (RRs) were maintained with the addition of 6 years of data. Using carbon and nitrogen stable isotope analyses, we hypothesized that: (1) macroinvertebrates and fish inhabiting areas below peaking hydrodams would be higher in δ15N and lower in δ13C due to increased flow velocity and the influence of light respired dissolved inorganic carbon, relative to those sampled from areas with a natural flow regime; (2) the increase in δ15N of macroinvertebrates would lead a shorter food web length in the regulated river, but δ13C and niche width would be similar between the restricted and unrestricted RR periods (i.e., the BACI analysis); and (3) isotopic metrics (e.g., δ13C, δ15N, niche width [SEAB], and food chain length [Δ15N]) would correlate with variations in flow characteristics through time. Consistent with previous analysis conducted over a shorter time period, a shift toward higher δ15N values was observed for both fish and invertebrates, but, contrarily, only invertebrates (not fish) had a lower δ13C value downstream of the dam. Over the long term, the before‐after‐control‐impact analysis found no effect of RRs on any of the food web metrics, implying that the change in operation did not affect the river food web. However, analysis of the time series data indicated that flow metrics and trophic metrics were often correlated, including a negative effect of RR (invertebrates) and discharge (fish) on food chain length. This study illustrates the difficulty in detecting changes in food web structure and function under changing flow regime influenced by natural and anthropogenic effects. As such, this study highlights the need for considering large spatial and temporal scales to differentiate between confounding effects of climate, natural variability, and altered flow regimes on food webs in regulated rivers.

Modelling the impacts of grassland to cropland conversion on river flow regimes in Skunk Creek watershed, Upper Midwest United States

AbstractConversion of grassland to cultivated cropland has been linked to downstream alteration of flow regimes. This study used the Soil and Water Assessment Tool (SWAT) to construct seven “what if” scenarios for quantifying the impacts of grassland to cropland and vice versa conversion (i.e., replacement of grassland with selected agricultural crops) on river flow regimes in Skunk Creek watershed. The Cropland Data Layer for the year 2011 in conjunction with historical climate data was used to create SWAT models for scenario simulations over 19 years, from 1996 to 2014. The model developed for the historical climate records (baseline) was compared with the scenarios examined using stream flow metrics for a range of flow regimes, including magnitude, duration, frequency, and timing of annual low‐ and high‐flow conditions. The simulation results suggest that grassland conversion to cultivated cropland would generally increase river flows compared with conversion of cultivated cropland to grassland, which may reduce flows in the watershed. Low and moderate flows increased by 2–8% from the baseline scenario with conversion of grass crop and by 1–20% decreases with crop–grass conversion. High flows increased by 3–7% and decreased by 1–18% when grass is converted to crop and crop to grass, respectively. The analysis also suggests that grassland establishment may attenuate the peaks of prolonged small floods and shorter but earlier large floods.

Breaking the flow: a study of contradictions in information systems development (ISD)

PurposeThe purpose of this paper is to examine contradictions (specifically tertiary and quaternary contradictions) that can disrupt the flow of work in contemporary systems development methods.Design/methodology/approachThis study uses Activity theory (AT) as a theoretical lens to: examine ISD flow as an interrelated activity system; and identify contradictions. AT is pertinent in the context of this study as rather than view contradictions as a threat to prematurely abandon the use of flow tools and metrics, it shows how contradictions can act as a motor for change and continuity. This study adopts a longitudinal single case study approach including face-to-face interviews with management and software development project teams, as well as direct observations and document analysis.FindingsThis study identifies tertiary and quaternary contradictions, and highlights the influence of contradictions on flow-based systems development.Social implicationsThis study provides a set of contradictions for researchers and practitioners. It shows that contradictions can be culturally or politically challenging to confront, and even when resolved, can have intended or unintended consequences.Originality/valueThis paper fulfils an identified need to study ISD flow from the perspective of interrelated activity systems and beyond its initial implementation phase.

Assessing Controls on the Displacement of Tracers in Gravel-Bed Rivers

Particle travel length is one of the main dimensions of bedload and strongly influences river morpho-dynamics, particularly when exploring the interactions between sediment transport and channel morphology. This process has been traditionally studied by using tagged stones that allow tracking the movement experienced by individual grains during transport episodes. In this paper, we relate measured particle travel lengths to flow metrics and river channel parameters. First, we link the event-based bedload volumes to the active-layer dimensions, and the product between the average bedload rates and the duration of competent flows. We then hypothesize that travel length depends on channel width, surface grain-size, particle size, bed structure, flow strength, and duration of competent flow. The results from this approach are, subsequently, tested with a set of tracer observations from eight rivers that were available in the literature. The relationship between travel length and flow metrics was found to be statistically strong and has the potential to allow us to quantitatively assess the one-day dynamics of particles moving along streambeds. We also analyzed the influence of channel morphology and bed structure and identified morphological signatures for particle transport in gravel-bed rivers.

The effects of mean wind speed uncertainty on project finance debt sizing for offshore wind farms

Financing costs for offshore projects depend, among many other variables, on the quality of mean wind speed predictions. Financial institutions determine the amount of debt that can be reasonably supported by the project, based on probabilistic cash flow metrics derived from estimated mean wind speeds. Within the offshore wind industry, it is widely believed that longer wind resource campaigns or more precise wind measurement devices that decrease mean wind speed uncertainty lead to lower LCOE values. This paper shows that this is not always true, while a decrease in mean wind speed uncertainty may result in better financing conditions, it typically requires higher development expenditure. We build a theoretical cost modelling framework, which includes detailed project financing constraints, and then apply this to an industrial case study to analyse project financing of different types of offshore wind farms. We show that developers need to find the right balance between a decrease in financing costs and an increase in development expenditure. For projects limited by the maximum gearing or with an unfavourable trade-off between the development expenditure and the increased P90 annual energy production, more precise resource estimation can result in higher LCOE values. This paper suggests a new way of understanding the effects of wind resource assessment campaigns by integrating project finance constraints into cost calculations and highlighting the importance of detailed cost modelling for optimal design of offshore wind farms.

Application of Landsat derived indices and hydrological alteration matrices to quantify the response of floodplain wetlands to river hydrology in arid regions based on different dam operation strategies

The response of floodplain wetlands to changes in river hydrology caused by different dam operation strategies in arid regions has attracted worldwide attention in recent decades. However, less is known about quantifying the effects of dam operations on wetlands in different lateral zones located in low-gradient floodplains in arid regions using remote sensing and hydrological time series. In this study, hydrological time series from 1975 to 1985 and 2008–2014 were used to quantify 67 flow metrics during different dam operation periods. Time series of remote sensing data (39 periods in total) from 1975 to 1977 and 2008–2014 were analysed to quantify the spatiotemporal dynamics in floodplain wetland types (river, bare wet land and wetland vegetation areas). In addition, a correlation analysis was performed to quantify the relationship between each wetland type and the flow metrics in different lateral zones. The results indicate that approximately 90% of the water and bare wet land area were located in the continuously and frequently inundated zones. Vegetation was the main wetland type in the regularly and extremely rarely inundated zones, and a 45.7% decrease in the vegetation area of these two belts occurred; in contrast, a 20.14 km2 of increase in vegetation occurred in the frequently inundated zone after the uniform scheduling was implemented for the entire river. Linear correlation and regression analysis showed that the different dam operation strategies resulted in various wetland changes in the different lateral zones. The decrease in high flows and increase in low flows caused a decrease in the vegetation cover area in the regularly and extremely rarely inundated zones and led to vegetation encroachment in the frequently inundated zone. Our study can improve the management of wetlands and water resources in arid region floodplains.

A Phase II, Multicenter, Single-Arm Study of Mipsagargin (G-202) as a Second-Line Therapy Following Sorafenib for Adult Patients with Progressive Advanced Hepatocellular Carcinoma.

Background: Mipsagargin (G-202) is a thapsigargin-based prodrug with cytotoxic activity masked by a peptide that is cleaved by prostate-specific membrane antigen (PSMA), a protease expressed in prostate cancer cells and the endothelium of tumor vasculature. It was hypothesized that PSMA-mediated activation of mipsagargin would result in disruption of the tumor vasculature, leading to a decrease in blood flow, and in direct cytotoxic effects on tumor cells, resulting in anti-tumor activity. Method: In this open-label, Phase II study, mipsagargin was administered intravenously on Days 1, 2, and 3 of a 28-day cycle to patients with hepatocellular carcinoma (HCC) who progressed on or after treatment with sorafenib or intolerant of sorafenib. Assessments included time to disease progression (TTP), response rate, progression-free survival (PFS), overall survival (OS), and safety. Blood flow metrics in hepatic lesions were evaluated using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Results: Of 25 treated patients, 19 were evaluable for efficacy. None had an objective response, 12 (63.2%) had a best response of stable disease, and 12 (63.2%) showed radiologic progression; seven patients (36.8%) were censored. The median TTP was 134.0 days, median PFS was 129.0 days, and median OS was 205.0 days. Of five patients with DCE-MRI data for 11 HCC lesions, all demonstrated a reduced Ktrans (mean, 52%). The most common treatment-emergent AEs were Grade 1–2 and consisted of increased blood creatinine (68.0%), fatigue (56.0%), and nausea (44.0%). Conclusions: Mipsagargin is relatively well tolerated and promotes prolonged disease stabilization in patients with advanced HCC that had progressed on prior treatment with sorafenib. A significant decrease in Ktrans upon treatment suggests mipsagargin reduces blood flow in hepatic lesions.

Climate change will both exacerbate and attenuate urbanization impacts on streamflow regimes in southern Willamette Valley, Oregon

AbstractInteractions between climate change and urbanization may affect stream ecosystems in unexpected ways. With an integrated modelling framework, we assessed the combined hydrological impacts of climate change and urbanization under historical and future climate regimes across varied development scenarios in three watersheds in the Willamette Valley, Oregon. First, through an agent‐based land use change model Envision, we created four development scenarios that consisted of 2 × 2 combinations of regional growth (compact population growth in urban cores vs. dispersed growth into rural areas) and stormwater management scenarios (with vs. without integrated stormwater management, ISM). ISM was defined as the integration of strategic organization of land uses with site‐scale stormwater best management practices. Next, two future climate regimes were developed by statistically downscaling projections from two general circulation models (CanESM2 and CNRM‐CM5) that performed well in replicating historical climate. The hydrological assessment of these scenarios was then conducted with the Soil and Water Assessment Tool. Using 10 ecologically significant flow metrics, we evaluated each scenario based on the magnitude of change in each metric and the degree to which such changes could be mitigated. Climate change alone led to a drying trend in flow regimes under both future climates. Combined with urbanization, it magnified changes in six of 10 metrics but attenuated impacts for three other measures of flashiness in at least one basin. The combination of compact growth and ISM effectively mitigated alterations for seven (out of nine) metrics sensitive to the combined impacts in at least one basin, with ISM being more effective than compact growth. The modelling framework teased out both nuanced differences and generalizable trends in hydrological impacts of urbanization and climate change and offers key methodological innovations towards an integrated framework capable of linking landscape planning mechanisms with the goal of sustaining stream ecosystem health.

Improved Macular Capillary Flow on Optical Coherence Tomography Angiography After Panretinal Photocoagulation for Proliferative Diabetic Retinopathy

This study evaluated the macular microvascular changes in eyes with proliferative diabetic retinopathy (PDR) following panretinal photocoagulation (PRP). Using optical coherence tomographic angiography (OCTA), we prospectively studied 10 eyes of 10 subjects with high-risk PDR immediately before, at 1month, and at 3-6months following PRP, using a 3-× 3-mm OCTA scan at each visit. The following parameters were calculated for the superficial (SCP), middle (MCP), and deep capillary plexuses (DCP): parafoveal vessel density (VD), adjusted flow index (AFI), and percent area of nonperfusion (PAN). Parafoveal SCP vessel-length density (VLD) was also evaluated. We performed univariate and multivariable statistics, adjusting for age and signal strength. To model the hemodynamic effect of PRP, we also present a mathematical model based on electrical circuits. We found no significant difference for the vascular density parameters following PRP, except for decreased density at the MCP at the latest timepoint in the adjusted multivariable model. PAN, a metric of nonperfusion adjusted for noise, and AFI, a surrogate metric of blood flow, showed significant increases at all capillary levels in the adjusted model. Our mathematical model explained how PRP would increase macular blood flow. Using OCTA, we found an overall increase in the flow metrics of all capillary layers in the macula following PRP, unrelated to macular edema or thickening, in line with the mathematical model. Our results suggest an overall redistribution of blood flow to the posterior pole following PRP, adding a new dimension to our understanding of the complex biologic effects of PRP in PDR. NOTE: Publication of this article is sponsored bythe American Ophthalmological Society.

MP28: Reigniting improvements in emergency departments – New approaches to resolving unsolvable problems

Background: In 2016 The Fraser Health Authority's Emergency Network established a priority to standardize patient access and flow through their 13 emergency departments (ED). A Model of Care (MOC) was developed after an extensive review of the literature and current practices across BC. Aim Statement: The ED Model of Care (MOC) specifies best practice expectations with respect to emergency patient access and flow. Rather than a ‘top-down’ mandate of expected practices, the MOC provided the opportunity for site-based teams to promote solutions that were ‘locally actioned and regionally enabled’. Measures & Design: ED Quality Improvement (QI) teams were developed at all sites. The ED Network developed a “QI Bootcamp”, a one-day course focused on imparting tools to drive improvements, providing a baseline understanding of how to launch and sustain local QI initiatives. Using Prosci's change approach, an emphasis was placed on using local ingenuity to implement plans, analyze feedback and diagnose gaps. This approach measured utilization of the changes to tangibly link initiatives and change to specific outcomes. As part of this strategy, an online scorecard was created to measure local results against best practice outcomes. The scorecard tracked quantitative access metrics such as ED Length of Stay (EDLOS), Left Without Being Seen rate, and triage time. Measures such as forming a QI team, identifying a QI project and completing a PDSA cycle were included in the scorecard Evaluation/Results: The MOC change management strategy was launched in May of 2018. By December 2018 all 13 EDs had formed a local QI team and identified a project. Twelve sites had completed at least one PDSA cycle and 10 sites had at least 75% of their members attend the QI Bootcamp. The scorecard displayed improvements in flow metrics. Highlights include the average arrival to triage time decreasing by 36% at one site, EDLOS for moderately ill patients decreased from 4.8 to 3.4 hours at another, and a community hospital had low acuity patient EDLOS decrease from 3.52 to 2.37 hours. Discussion/Impact: A standardized approach to patient access and flow in the ED (MOC), combined with the engaging grass roots approach to inspiring local innovation, allied with a concrete change management approach demonstrated significant results for patients accessing and moving through EDs. This pattern that is more likely to sustain itself because the results are felt and locally owned.

The accuracy of ecological flow metrics derived using a physics‐based distributed rainfall–runoff model in the Great Plains, USA

AbstractThe development of a hydrologic foundation, essential for advancing our understanding of flow‐ecology relationships, was developed using the high‐resolution physics‐based distributed rainfall–runoff model Vflo in a semi‐arid region. We compared the accuracy and bias associated with flow metrics that were generated using Vflo, gauge data, and drainage area ratios at both a daily and monthly time step in the Canadian River basin, USA. First, we calibrated and applied bias correction to the Vflo model to simulate streamflow at ungauged catchment locations. Next, flow metrics were calculated using simulated and observed data from stream gauge locations. We found discharge predictions using Vflo were more accurate than drainage area ratios. General correspondence between predicted discharge and the gauge data was apparent; however, flow metrics calculated using the Vflo output did not accurately represent flow variability. Results from the Vflo model showed systematic discharge over‐predictions in the upper basin and isolated over‐predictions in the lower basin, likely due to hail events and sparse rainfall data across the large catchment. Goodness‐of‐fit statistics (Nash–Sutcliffe efficiency, root‐mean square error, and the coefficient of variation) indicated the drainage area ratio and Vflo were more accurate at a monthly rather than daily time step, even after quantile mapping. This finding limits the number of streamflow metrics available to develop ecological models, but more importantly, the coarser resolution may hinder our understanding of ecological processes that occur at a submonthly time step. Our approach provides a framework for selecting flow metrics that best represent hydrologic patterns across a large semi‐arid catchment with the necessary accuracy to address the ecological questions of interest.

Measuring polycentricity via network flows, spatial interaction and percolation

Polycentricity, or the number of central urban places, is commonly measured by location-based metrics (e.g. employment density/total number of workers, above a threshold). While these metrics are good indicators of location ‘centricity’, results are sensitive to threshold choice. We consider the alternative idea that a centre’s status depends on its connectivity to other locations through trip inflows/outflows: this is inherently a network rather than place idea. Three flow and network-based centricity metrics for measuring metropolitan area polycentricity using journey-to-work data are presented: (a) trip-based; (b) density-based; and (c) accessibility-based. Using these measures, polycentricity is computed and rank-centricity distributions are plotted to test Zipf-like or Christaller-like behaviours. Further, a percolation theory framework is proposed for the full origin–destination matrix, where trip flows are used as a thresholding parameter to count the number of sub-centres. Trip flows prove to be an effective measure to count and hierarchically organise metropolitan areas and sub-centres, tackling the arbitrariness of defining any threshold on employment statistics to count sub-centres. Applications on data from the Greater Sydney region show that the proposed framework helps to characterise polycentricity and sub-regional organisation more robustly, and provide unexpected insights into the connections between land use, labour market organisation, transport and urban structure.

Differentiating Glioblastomas from Solitary Brain Metastases Using Arterial Spin Labeling Perfusion− and Diffusion Tensor Imaging−Derived Metrics

We sought to differentiate glioblastomas from solitary brain metastasis using arterial spin labeling perfusion (ASL)- and diffusion tensor imaging (DTI)-derived metrics. A prospective study was done on 36 patients with provisional diagnosis of glioblastomas versus brain metastasis who underwent ASL and DTI of the brain. The tumor blood flow (TBF) and DTI metrics (fractional anisotropy [FA] and mean diffusivity [MD]) of the enhancing tumoral and peritumoral parts were measured. There was a significant difference of TBF (P= 0.001) and MD (P= 0.001) of the tumoral and peritumoral parts of glioblastoma and metastasis (P= 0.001). There was a significant difference of FA of peritumoral part (P= 0.001) and insignificant difference of tumoral part (P= 0.06) between glioblastomas and metastasis. The cutoff of TBF of tumoral and peritumoral parts used for differentiation were 29.7 and 17.8 (mL/100 g/minute) revealed an area under the curve (AUC) of 0.943 and 0.937 with accuracy of 91.7% and 88.9%. The cutoff of MD of tumoral and peritumoral parts were 1.27 and 1.33 (10-3 mm2/second) revealed AUC of 0.840 and 0.987 and accuracy of 83.3% and 91.7%, respectively. Combined TBF, MD, and FA of the peritumoral part revealed AUC of 0.984 and accuracy of 91.7%. A combination of ASL- and DTI-derived metrics of the peritumoral part can be used for differentiation of glioblastomas from solitary brain metastasis.

Targeted hydrologic model calibration to improve prediction of ecologically-relevant flow metrics

River flows exert dominant controls on in-stream biota. Quantifying linkages between hydrology and biology is important for assessing the effects of flow alteration on ecological functions. Hydrologic models are often used to quantify these flow-ecology relationships and guide management actions. Traditional model calibration techniques typically focus on a best overall fit criterion that may not be suitable for environmental flow applications where certain elements of the flow regime exert a dominant influence on biotic composition. We present an approach for hydrologic model calibration that improves the accuracy of calculated flow metrics known to be significant drivers of ecosystem response. First, we developed regional flow-ecology relationships based on streamflow gage and benthic macroinvertebrate data from southern California to determine which streamflow metrics best explain variability in taxonomic and trait-based biotic indices. Next, we developed and calibrated a series of hydrologic models to minimize error in these important flow metrics. For our study sites, flow flashiness and low flow frequency (indicative of drying) were found to best explain biotic condition. Hydrologic models calibrated specifically to minimize errors in these flow metrics predicted macroinvertebrate indices better than models calibrated to maximize fit to the overall flow regime. This ecological-calibration approach requires some a priori knowledge of flow-ecology relationships, but it produces results that can improve assessment of the impacts of changing flow regimes on biota and guide the development of strategies to mitigate ecological degradation.

Designing efficient emergency departments: Discrete event simulation of internal-waiting areas and split flow sorting

ObjectiveEvaluate nine different models, the interaction of three flow models (ESI, intake attending physician, and no split flow) and three physical design typologies (zero, one, and two internal-waiting areas), on Emergency Department (ED) flow and patient-centered metrics. MethodsDiscrete Event Simulation (DES) was used to systematically manipulate flow and physical design. Three base models were developed and validated using ED and patient specific data. Subsequently, systematic manipulations of flow and internal-waiting areas were performed on other models. Five outcomes of interest were tracked – length of stay (LOS), bed utilization rate, door to provider time, left without being seen rate, and number of movements per patient. Models were compared for statistical significance and effect size using ANOVA, and linear and non-linear regression. ResultsThe shortest LOS (mean 175.2 min) and highest bed utilization rate (5.02 patients/bed/day) were obtained with flow split by an intake attending physician with two internal-waiting areas. These represented improvements of 54 min and 1.48 patients/bed/day over the control model. Two-way ANOVA demonstrated that both physical design and flow type were statistically significant predictors of all outcomes of interest (p < .0001). Depending on flow type, adding one additional internal-waiting area resulted in decreased LOS (range 10.6–21.8 min), increased bed utilization (range 0.23–0.40 patients/bed/day), decreased D2P (range 1.3–4.8 min), and decreased LWBS (0.66%–2.0%). ConclusionBased on a DES model with empirical data from a single institution, combining flow split by an intake attending physician and multiple internal-waiting areas resulted in improved ED operational and patient-centered metrics.

Applied rheology and architectural coating performance

Paint rheology is understood to play a vital role in both product performance and customer acceptance. Consequently, the ability to formulate paints having the necessary flow properties is essential for paint technologists. Experienced formulators have said that as much as half the cost of new product development can be consumed in getting the rheology right. In fact, the quality-control viscosity measurement devices in everyday use in the development laboratory are of little help in this endeavor. Among other shortcomings, most such instruments apply shear stresses which are far from those involved in important coating flow processes. The rheological properties required for a successful coating must be defined with due regard to the prevailing conditions of stress involved in application and film formation. This requires that measurements should be taken over a wide range of shear stress and timescales. The task for the applied rheologist is to bridge rheology and technology, but it is often unclear how to connect rheological data with the “real-world” performance of paints, due to the complexity of coating flows. This review in part discusses the use of controlled-stress rheometry to characterize coatings, and presents ways of applying the results effectively to the analysis of paint flow. The methodology is fundamental but not unduly time-consuming, since the objective is to provide sound yet timely guidance to formulators. Thirteen commercial semigloss latex paints were analyzed rheologically to develop correlations to paint performance. Using the method of shear stress mapping, key regions of the non-equilibrium flow curve are identified for the control of paint flow processes. With this approach, simple but strong correlations were obtained of paint flow metrics to viscosity chosen at the relevant stresses. The fact of high correlation means one can expect that an appropriate viscosity adjustment will correspondingly improve performance. It is argued that shear stress, not shear rate, is the correct independent variable both for experimentation and for the graphical presentation and analysis of viscosity data. The yield stress parameter, particle flocculation, and sedimentation are also discussed, and an oscillatory shear method of direct measurement of yield stress is described.

Hydrodynamic Modeling Improves Green River Reconnection with Floodplain Wetlands for Endangered Fish Species Recovery

AbstractWe performed two‐dimensional (2D) hydrodynamic modeling to aid recovery of the endangered razorback sucker (Xyrauchen texanus) by reconnecting the Green River with its historic bottomland floodplain wetlands at Ouray National Wildlife Refuge, Utah. Reconnection allows spring flood flows to overtop the river levee every two to three years, and passively transport razorback sucker larvae to the wetlands to grow in critical habitat. This study includes (1) river hydrologic analysis, (2) simulation of a levee breach/weir, overtopping of river flood flows, and 2D flow through the wetlands using Hydrologic Engineering Center River Analysis System 2D, and (3) modeling flow and restoration scenarios. Indicators of hydrologic alteration were used to evaluate river flow metrics, in particular flood magnitudes, frequency, and duration. Results showed a target spring flow of 16,000 cfs (453 m3/s) and a levee breach elevation of 4,663 ft (1,421 m) amsl would result in a median flow &gt;6,000 acre‐feet (7.4 million m3) over five days into the wetlands, which is adequate for razorback sucker larvae transport and rearing. Modeling of flow/restoration scenarios showed using gated water control structures and passive low‐water crossings between wetland units can provide adequate control of flow movement into and storage in multiple units. Levee breaching can be a relatively simple, cost‐effective method to reconnect rivers and historic floodplains, and hydrodynamic modeling is an important tool for analyzing and designing wetland reconnection.

RETRACTED: Flow online identification method for the encrypted Skype

Abstract The machine learning algorithm is gaining prominence in traffic identification research as it offers a way to overcome the shortcomings of port-based and deep packet inspection, especially for P2P-based Skype. However, recent studies have focused mainly on traffic identification based on a full-packet dataset, which poses great challenges to identifying online network traffic. This study aims to provide a new flow identification algorithm by taking the sampled flow records as the object. The study constructs flow records from a Skype set as the dataset, considers the inherent NETFLOW and extended flow metrics as features, and uses a fast correlation-based filter algorithm to select highly correlated features. The study also proposes a new NFI method that adopts a Bayesian updating mechanism to improve the classifier model. The experimental results show that the proposed scheme can achieve much better identification performance than existing state-of-the-art traffic identification methods, and a typical feature metric is analyzed in the sampling environment. The NFI method improves identification accuracy and reduces false positives and false negatives compared to other methods.

Change detection and attribution of flow regime: A case study of Allegheny river catchment, PA (US)

The present study focuses on change detection and attribution analysis for a case study of Allegheny river catchment (at two unregulated sites namely Eldred and Salamanca) in USA. The proposed methodology involves, multiple change-point detection (MCPD) techniques i.e., Binary Segmentation based cumulative sum algorithms with Monte Carlo based threshold (BSCSth) and Bayesian Information Criteria (BIC) based penalty (BSCSBIC) and validating the two techniques using standard performance measures for different hypothetical riverflow time-series. The proposed BSCSth technique was applied to the Allegheny river at two sites for the series of different hydrological alteration indicators to identify the location of change-point in mean, and the hydrological regime shifts. To perform attribution analysis, hydrologic simulations were carried out using Sacramento model for the identified segments. The overall hydrologic alterations of selected annual flow metrics extracted from daily simulated flows and observed flow values were also estimated. The results of MCPD analysis showed that overall three hydrological regimes comprising of three segments i.e., near natural period (NNP, 1940–1955), low impact period (LIP, 1956–1966) and high impact period (HIP, 1967–2014) were identified for both the sites. The results of attribution analysis for the three cases (case-1: NNP & LIP; case-2: LIP & HIP; case-3: NNP & HIP) showed that for the case-1, the changes of flow regimes in Eldred and Salamanca were predominantly affected by climate-induced processes. But, for case-2 and case-3, it was seen that there were magnification of human-induced changes probably due to the landuse change (forest and rangeland increased by 18.31% (19.79%) for Eldred (Salamanca) from 1940 to 1992), construction of Kinzua dam (in the year 1966) and other anthropogenic pressures. Thus, the results of the study can be helpful for quantifying the main drivers of hydrological changes in river basin, and planning suitable water resource management strategies in the basin.

Evaluation of CSF flow metrics in patients with communicating hydrocephalus and idiopathic intracranial hypertension.

To search for CSF dynamics of idiopathic intracranial hypertension (IIH) and communicating hydrocephalus and any correlation between MRI findings, CSF metrics and CSF opening pressure in IIH. Healthy subjects (30) and subjects with IIH (29) and high-pressure communicating hydrocephalus (43) were enrolled. Nonparametric Kruskal-Wallis test (p = 0.05) was used to compare three groups, Mann-Whitney U test with Bonferroni correction to compare two groups (p = 0.016). Correlation of MRI findings of IIH with CSF metrics and CSF opening pressure was analyzed by Spearman's Rank correlation coefficient (p = 0.05). In IIH, no correlation between MRI findings and aqueductal stroke volume (ASV) but statistically significantly CSF opening pressure in the presence of transverse sinus compression was noted. Comparing with healthy subjects, ASV was nonsignificantly lower and standardized diastolic and sum and difference of systolic and diastolic flow durations were statistically significantly lower. Comparing with hydrocephalus, the width of prepontine cistern (PPC)/the width of aqueductus sylvii (AS) was significantly higher and other CSF metrics with standardized systolic and sum of systolic and diastolic flow durations were significantly lower. In hydrocephalus, ASV and peak velocities were significantly higher. Compared with normal group, PPC/AS and reverse/forward flow duration were significantly lower and other CSF metrics were significantly higher. In hydrocephalus, significant increase in ASV and peak velocities were noted. In IIH, CSF opening pressure was statistically significantly high in the presence of transverse sinus compression and standardized diastolic flow durations were statistically significantly short that are probably effects of increased impedance of CSF flow against increased intracranial pressure and unchanged or even decreased intraventricular CSF volume.