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Understanding the alterations in spatial–temporal water level dynamics caused by natural and anthropogenic changes is essential for water resources management in estuaries, as this can directly impact the estuarine morphology, sediment transport, salinity intrusion, navigation conditions, and other factors. Here, we propose a simple triple linear regression model linking the water level variation on a daily timescale to the hydrodynamics at both ends of an estuary. The model was applied to the upper Yangtze River estuary (YRE) to examine the influence of the world's largest dam, the Three Gorges Dam (TGD), on the spatial–temporal water level dynamics within the estuary. It is shown that the regression model can accurately reproduce the water level dynamics in the upper YRE, with a root mean squared error (RMSE) of 0.061–0.150 m seen at five gauging stations for both the pre- and post-TGD periods. This confirms the hypothesis that the response of water level dynamics to hydrodynamics at both ends is mostly linear in the upper YRE. The regression model calibrated during the pre-TGD period was used to reconstruct the water level dynamics that would have occurred in the absence of the TGD's freshwater regulation. Results show that the spatial–temporal alterations in water levels during the post-TGD period are mainly driven by the variation in freshwater discharge due to the regulation of the TGD, which results in increased discharge during the dry season (from December to March) and a dramatic reduction in discharge during the wet-to-dry transitional period. The presented method to quantify the separate contributions made by changes in boundary conditions and geometry to spatial–temporal water level dynamics is particularly useful for determining scientific strategies for sustainable water resources management in dam-controlled or climate-driven estuaries worldwide. [ABSTRACT FROM AUTHOR]

Reconstructing tidal signals is indispensable for verifying altimetry products, forecasting water levels, and evaluating long-term trends. Uncertainties in the estimated tidal parameters must be carefully assessed to adequately select the relevant tidal constituents and evaluate the accuracy of the reconstructed water levels. Customary harmonic analysis uses ordinary least squares (OLS) regressions for their simplicity. However, the OLS may lead to incorrect estimations of the regression coefficient uncertainty due to the neglect of the residual autocorrelation. This study introduces two residual resamplings (moving-block and semiparametric bootstraps) for estimating the variability of tidal regression parameters and shows that they are powerful methods to assess the effects of regression errors with nontrivial autocorrelation structures. A Monte Carlo experiment compares their performance to four analytical procedures selected from those provided by the RT_Tide, UTide, and NS_Tide packages and the robustfit.m MATLAB function. In the Monte Carlo experiment, an iteratively reweighted least squares (IRLS) regression is used to estimate the tidal parameters for hourly simulations of one-dimensional water levels. Generally, robustfit.m and the considered RT_Tide method overestimate the tidal amplitude variability, while the selected UTide and NS_Tide approaches underestimate it. After some substantial methodological corrections the selected NS_Tide method shows adequate performance. As a result, estimating the regression variance–covariance with the considered RT_Tide, UTide, and NS_Tide methods may lead to the erroneous selection of constituents and underestimation of water level uncertainty, compromising the validity of their results in some applications. Significance Statement: At many locations, the production of reliable water level predictions for marine navigation, emergency response, and adaptation to extreme weather relies on the precise modeling of tides. However, the complicated interaction between tides, weather, and other climatological processes may generate large uncertainties in tidal predictions. In this study, we investigate how different statistical methods may lead to different quantification of tidal model uncertainty when using data with completely known properties (e.g., knowing the tidal signal, as well as the amount and structure of noise). The main finding is that most commonly used statistical methods may estimate incorrectly the uncertainty in tidal parameters and predictions. This inconsistency is due to some specific simplifying assumptions underlying the analysis and may be reduced using statistical techniques based on data resampling. [ABSTRACT FROM AUTHOR]

Understanding the alterations in spatial-temporal water level dynamics caused by natural and anthropogenic changes is essential for water resources management in estuaries, as this can directly impact the estuarine morphology, sediment transport, salinity intrusion, navigation conditions, and other factors. Here, we propose a simple triple linear regression model linking the water level variation 5 on a daily timescale to the hydrodynamics at both ends of an estuary. The model was applied to the Yangtze River estuary (YRE) for examining the influence of the world's largest dam, the Three Gorges Dam (TGD), on the spatial-temporal water level dynamics within the estuary. It is shown that the regression model can accurately reproduce the water level dynamics in the YRE, with a root mean squared error (RMSE) of 0.063-0.151 m seen at five gauging stations for both the pre- and post-TGD periods. This confirms the hypothesis that the response of water level dynamics to hydrodynamics at both ends is mostly linear in the YRE. The regression model calibrated during the pre-TGD period was used to reconstruct the water level dynamics that would have occurred in absence of the TGD's freshwater regulation. Results show that the spatial-temporal alterations in water levels during the post-TGD period are mainly driven by the variation in freshwater discharge due to the regulation of the TGD, which results in increased discharge during the dry season (from December to March) and a dramatic reduction in discharge during the wet-to-dry transitional period. The presented method to quantify the separate contributions made by changes in boundary conditions and geometry on spatial-temporal water level dynamics is particularly useful for determining scientific strategies for sustainable water resources management in dam-controlled estuaries worldwide. [ABSTRACT FROM AUTHOR]

A fast, physically based, fully nonlinear, and nonsteady reach-averaged river model is developed to provide instantaneous freshwater discharge rates in the tidally influenced stretch of the St. Lawrence River (Canada) from water level measurements alone at two tide gauge stations. The model does not require any a priori knowledge of the river geometry (width and depth) or hydraulic conditions (hydraulic slope and friction coefficient) as those parameters are inferred by inverse modeling. The model is fast in that several decades of hourly discharges can be reproduced in few seconds on any modern desktop computer. The method is accurate in that it reproduces to within 3% the observed tidal discharge variability at 8 different cross-sections distributed along the tidally influenced portion of the St. Lawrence River. Although much simpler, the new method performs as well as, or better than, much more sophisticated models for reproducing daily and monthly discharge averages. Being physically based, it is also shown that the model can perform well outside the limited range of measurements that are generally available for calibration. The method is simple and easy to manage in that the main function only contains a few lines of code such that it could be readily implemented as a tool for real-time discharge monitoring of the St. Lawrence River near Québec City. Being physically based, the model developed here could likely be applied more generally to highly unsteady tidal rivers with flow reversals. [ABSTRACT FROM AUTHOR]

Assessing the impacts of both natural (e.g. tidal forcing from the ocean) and human-induced changes (e.g. dredging for navigation and land reclamation) on estuarine morphology is particularly important for the protection and management of the estuarine environment. In this study, a novel analytical approach is proposed for the assessment of estuarine morphological evolution in terms of tidally averaged depth on the basis of the observed water levels along the estuary. The key lies in deriving a relationship between wave celerity and tidal damping or amplification. For given observed water levels at two gauging stations, it is possible to have a first estimation of both wave celerity (distance divided by tidal travelling time) and tidal damping or amplification rate (tidal range difference divided by distance), which can then be used to predict the morphological changes via an inverse analytical model for tidal hydrodynamics. The proposed method is applied to the Lingdingyang Bay of the Pearl River Estuary, located on the southern coast of China, to analyse the historical development of the tidal hydrodynamics and morphological evolution. The analytical results show surprisingly good correspondence with observed water depth and volume in this system. The merit of the proposed method is that it provides a simple approach for understanding the decadal evolution of the estuarine morphology through the use of observed water levels, which are usually available and can be easily measured. [ABSTRACT FROM AUTHOR]

Assessing the impacts of both natural (e.g., tidal forcing from the ocean) and human-induced changes (e.g., dredging for navigation, land reclamation) on estuarine morphology is particularly important for the protection and management of the estuarine environment. In this study, a novel analytical approach is proposed for the assessment of estuarine morphological evolution in terms of tidally averaged depth on the basis of the observed water levels along the estuary. The key lies in deriving a relationship between wave celerity and tidal damping or amplification. For given observed water levels at two gauging stations, it is possible to have a first estimation of both wave celerity (distance divided by tidal travelling time) and tidal damping or amplification rate (tidal range difference divided by distance), which can then be used to predict the morphological changes via an inverse analytical model for tidal hydrodynamics. The proposed method is applied to the Lingdingyang Bay of the Pearl River Estuary, located on the southern coast of China, to analyse the historical development of the tidal hydrodynamics and morphological evolution. The analytical results show surprisingly good correspondence with observed water depth and volume in this system. The merit of the proposed method is that it provides a simple approach for understanding the decadal evolution of the estuarine morphology through the use of observed water levels, which are usually available and can be easily measured. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Remote Sensing is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Accurately characterizing the spatiotemporal dynamics of residual and tidal flows is essential for understanding transport processes in tidal rivers and estuaries, as they directly affect salinity intrusion, water renewal capacity, sediment transport, and morphological evolution. This paper aims at characterizing the longitudinal and temporal variability of tidal discharges and currents in the St. Lawrence fluvial estuary (SLFE), under a wide range of river flow and tidal conditions. Tidal discharges and currents are reconstructed by cubature from nonstationary tidal analyses of water levels for a highly variable year, in terms of observed river flows, at 10 river cross-sections of the SLFE, distributed from the fluvial estuary entrance to the head of the tide. An analysis of the spatiotemporal variability in residual and tidal flows is hereby provided, with an emphasis on ebb-flood characteristics, residual currents, tidal constituent properties and tidal wave propagation characteristics at the intratidal, neap-spring and seasonal scales along the system. The main drivers and mechanisms responsible for this variability include (1) the system's hydrology and its associated watershed and meteorological characteristics, which dictate river flow intensity and seasonality, (2) the landward-travelling tides originating from the ocean, responsible for intratidal and tidal monthly variability in tides and currents, (3) nonlinear river-tide interactions, dissipating tidal energy, modulating tidal properties and inducing a surface level gradient, and (4) channel convergence and floodplain morphology, contributing to tidal asymmetry in horizontal and vertical tides. These factors ultimately influence tidal wave propagation and damping properties within estuaries, both longitudinally and at the neap-spring and seasonal scales. Highlights • Tidal discharges and currents are derived from nonstationary tidal analyses of water levels through continuity. • Drivers of flow variability include hydrology, ocean tides, river-tide interactions, and channel and floodplain morphology. • Flood velocities reduce in presence of tidal flats and respond the most strongly to changes in river flow during neap tides. • Flow duration asymmetry is temporally lagged with respect to tidal duration asymmetry due to neap-spring storage effects. • Fortnightly variations in tidal damping are driven by changes in friction closely linked to the neap-spring reversal of LW. [ABSTRACT FROM AUTHOR]

Numerous tidal phenomena, including river tides, internal tides, and tides in ice‐covered bay, are nonstationary, which pose a great challenge for traditional tidal analysis methods. Based on the independent point scheme and cubic spline interpolation, a new approach, namely the enhanced harmonic analysis, is developed to deal with nonstationary tides. A MATLAB toolbox, S_TIDE, developed from the widely used T_TIDE, is used to realize the approach. The efficiency of S_TIDE is validated by analyzing a set of hourly water level observations from stations on the lower Columbia River. In all stations, the hindcast of S_TIDE is more accurate than NS_TIDE that is a powerful nonstationary tidal analysis tool adapted to river tides. The changing mean water level and tidal constituent properties obtained by S_TIDE are similar to those obtained by NS_TIDE, continuous wavelet transform, and empirical mode decomposition and highly consistent with theory on river tides. Moreover, different from NS_TIDE that only can be applied to river tides, enhanced harmonic analysis is free of dynamic content, assuming only known tidal frequencies. Therefore, S_TIDE can be applied to all kinds of nonstationary tides theoretically. Though powerful, S_TIDE also has some limitations: S_TIDE cannot be used for prediction and too many independent points in S_TIDE may induce computational memory overflow and unrealistic results. Plain Language Summary: Based on the independent point scheme and cubic spline interpolation, a new approach, enhanced harmonic analysis, was developed to deal with nonstationary tides. Enhanced harmonic analysis is realized by a MATLAB toolbox, S_TIDE, which is developed from the widely used T_TIDE. S_TIDE assumes only known tidal frequencies and theoretically can be applied to all kinds of nonstationary tides and stationary tides. In this study, S_TIDE is applied to analyzing records of river rides that is one of the simplest kinds of nonstationary tides for which ample data are available. The method is compared with other methods to show its efficiency. Key Points: A MATLAB toolbox, S_TIDE, is used to realize enhanced harmonic analysis (EHA) for nonstationary tidesS_TIDE can separate oscillations in MWL, amplitudes, and phases on different time scales within a given frequency band using different number of IPsFor D4 constituents, not only the time variations but also the along‐channel variations are dominated by river flow [ABSTRACT FROM AUTHOR]

Abstract: Knowledge of tidal flows in rivers and estuaries is often scarce yet vital in determining flushing properties and sediment transport rates. While many rivers still remain ungauged, methodological difficulties often arise in gauged systems, resulting in short flow records compared to historical water level data. Notwithstanding, discharge reconstructions in estuaries are possible using indirect methods based on long‐term tidal data. In this paper, we revisit the method of cubature, integrating the continuity equation for discharges at different sections. The method consists in computing temporal changes in water volume from simultaneous tidal heights readings along the river and storage width estimations. These water balance estimates remain challenging to produce, because they require spatial interpolation of gappy tidal records and an accurate representation of inundated areas over time. Improvements on the method are made by using a 1‐D nonstationary tidal harmonic model that provides continuous tidal data along the estuary, with no temporal or spatial gaps. Second, a 2‐D finite element discretization is used to compute the time‐varying wetted surface area, relying on detailed topographic data over intertidal flats. The method is applied to the St. Lawrence fluvial estuary (SLFE) and validated against discharge data collected along nine cross sections of the river, reaching relative RMSE below 4% of the diurnal tidal discharge range at downstream locations and below 9% upstream. One year reconstructions conducted in the SLFE also show the potential of the method to reproduce the tidal discharge variability along the tidal‐river continuum, for a wide range of temporal scales. [ABSTRACT FROM AUTHOR]

Purpose: By increasing lung volume and decreasing respiration-induced tumour motion amplitude, administration of continuous positive airway pressure (CPAP) during stereotactic ablative radiotherapy (SABR) could allow for better sparing of the lungs and heart. In this study, we evaluated the effect of CPAP on lung volume, tumour motion amplitude and baseline shift, as well as the dosimetric impact of the strategy.Methods: Twenty patients with lung tumours referred for SABR underwent 4D-computed tomography (CT) scans with and without CPAP (CPAP/noCPAP) at two timepoints (T0/T1). First, CPAP and noCPAP scans were compared for lung volume, tumour motion amplitude, and baseline shift. Next, CPAP and noCPAP treatment plans were computed and compared for lung dose parameters (mean lung dose (MLD), lung volume receiving 20 Gy (V20Gy), 13 Gy (V13Gy), and 5 Gy (V5Gy)) and mean heart dose (MHD).Results: On average, CPAP increased lung volume by 8.0% (p < 0.001) and 6.3% (p < 0.001) at T0 and T1, respectively, but did not change tumour motion amplitude or baseline shift. As a result, CPAP administration led to an absolute decrease in MLD, lung V20Gy, V13Gy and V5Gy of 0.1 Gy (p = 0.1), 0.4% (p = 0.03), 0.5% (p = 0.04) and 0.5% (p = 0.2), respectively, while having no significant influence on MHD.Conclusions: In patients referred for SABR for lung tumours, CPAP increased lung volume without modifying tumour motion or baseline shift. As a result, CPAP allowed for a slight decrease in radiation dose to the lungs, which is unlikely to be clinically significant. [ABSTRACT FROM AUTHOR]

This is the second part of an investigation aimed at documenting the tidal hydrodynamics of the St. Lawrence fluvial estuary (SLFE). In Part I, the calibration and validation of a high-resolution, two-dimensional (2D), time-dependent hydrodynamic model of the SLFE was presented. Herein, the process-based (structural) validation procedure used to quantitatively assess the ability of the model to reproduce spatial and temporal patterns observed in the field data is presented. Tidal and flow features were found to be reproduced satisfactorily in terms of their lateral and longitudinal variability at both the intratidal and fortnightly scales. These properties can be used to describe the real system dynamics, including flooding--drying processes, tidal propagation and modulation, and transient momentum balance, providing insights into the general physical processes of the SLFE and of large tidal rivers globally. [ABSTRACT FROM AUTHOR]

In this study, a high-resolution, two-dimensional (2D), time-dependent hydrodynamic model of the St. Lawrence fluvial estuary was developed with the objective of documenting the tidal hydrodynamics of this complex yet poorly understood region. The hydrodynamic model solves the shallow-water equations over a finite-element--discretized domain, with an average spatial resolution of 50 m, and includes a drying--wetting component for the treatment of shallow intertidal areas. The numerical terrain model is composed of high-density topographic data and detailed friction fields associated with bottom substrate and macrophytes. Calibration and validation were carried out using recently acquired data for water level and velocity. Results show very good accuracy in water levels, with prediction skills higher than 0.99 at all stations (where a skill of 1 means perfect agreement between model and observations in terms of their relative average error) and root-mean-square errors (RMSEs) less than 5% of local tidal ranges downstream; at upstream stations where tidal ranges are significantly reduced, RMSEs were lower than 6 cm. Discharges were reproduced with similarly good accuracy, with errors lower than 6% of the maximum observed discharges at 11 of the 13 surveyed transects; the two remaining sections are subject to larger interpolation and bathymetric uncertainties. In this paper, critical aspects of model development are discussed, including the 2D approximation, temporal and spatial resolution, bathymetric uncertainty, error in the boundary conditions, and calibration under nonstationary conditions. This work is the first part of a two-part investigation serving as a methodological framework for model setup, calibration, and validation in large tidal rivers. [ABSTRACT FROM AUTHOR]

Copyright of Atmosphere -- Ocean (Taylor & Francis Ltd) is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cross-sectional gradients in water levels and velocities play a determining role in the circulation dynamics of tidal rivers and estuaries. Documenting and analyzing their variability throughout a tidal cycle require observations with high spatial and temporal resolution. A survey strategy and a data analysis procedure have been designed to obtain continuous and synoptic water level and velocity fields over a tidal cycle, along 13 cross-sections of the St. Lawrence fluvial estuary dominated by large tidal ranges. The method combines both RTK GPS and ADCP technologies for the simultaneous measurement of water levels and velocities along repeated boat transects, allowing fast data acquisition over wide river sections and under rapidly changing conditions. The reconstruction of continuous and synoptic fields is made by interpolation. Simplifying assumptions about data stationarity and/or homogeneity are avoided by adapting the interpolation procedures to the shape and distribution of the underlying data in a space-time reference frame, thus minimizing distortion in the reconstructed quantities. The capabilities and limitations of the method are assessed through error computations and comparisons with alternate data analysis methods and complementary data sets from tide gauges. With these latest observations, new insights into the tidal hydrodynamics of the St. Lawrence fluvial estuary are gained in regions of contrasting tidal and fluvial properties, specifically related to the effects of channel curvature and bathymetry on tidal propagation and cross-channel flow properties at the intratidal scale. [ABSTRACT FROM AUTHOR]

Measuring temporal and spatial variations in water level with high resolution and accuracy can provide fundamental insights into the hydrodynamics of marine and riverine systems. Real-time kinematic global positioning systems (RTK GPS), and by extension postprocessed kinematic (PPK) positioning, have provided the opportunity to achieve this goal, by allowing fast and straightforward measurements with subdecimeter accuracy. However, boat-mounted GPS are subject to movements of the water surface (e.g., waves, long-period heaves) as well as to the effects of dynamic draft. The latter contaminate the records and need to be separated and removed from the data. A method is proposed to postcorrect the elevation data using tilt information measured by an attitude sensor-in this case, an acoustic Doppler current profiler (ADCP) equipped with internal pitch and roll sensors. The technique uses iteratively reweighted least squares (IRLS) regressions to determine the position of the center of rotation (COR) of the boat that leads to optimal corrections. The COR is also allowed to change in time by performing the IRLS analyses on data subsamples, thus accounting for changes in weight distribution, for example, due to personnel movements. An example of application is presented using data collected in the Saint Lawrence fluvial estuary. The corrections exhibit significant reductions associated with the boat motion while keeping subtle variations in water levels likely related to local hydrodynamics. [ABSTRACT FROM AUTHOR]

One of the most challenging areas in tidal analysis is the study of nonstationary signals with a tidal component, as they confront both current analysis methods and dynamical understanding. A new analysis tool has been developed, NS_TIDE, adapted to the study of nonstationary signals, in this case, river tides. It builds the nonstationary forcing directly into the tidal basis functions. It is implemented by modification of T_TIDE; however, certain concepts, particularly the meaning of a constituent and the Rayleigh criterion, are redefined to account for the smearing effects on the tidal spectral lines by nontidal energy. An error estimation procedure is included that constructs a covariance matrix of the regression coefficients, based on either an uncorrelated or a correlated noise model. The output of NS_TIDE consists of time series of subtidal water levels [mean water level (MWL)] and tidal properties (amplitudes and phases), expressed in terms of external forcing functions. The method was tested using records from a station on the Columbia River, 172 km from the ocean entrance, where the tides are strongly altered by river flow. NS_TIDE hindcast explains 96.4% of the signal variance with a root-mean-square error of 0.165 m obtained from 288 parameters, far better than traditional harmonic analysis (38.5%, 0.604 m, and 127 parameters). While keeping the benefits of harmonic analysis, its advantages compared to existing tidal analysis methods include its capacity to distinguish frequencies within tidal bands without losing resolution in the time domain or data at the endpoints of the time series. [ABSTRACT FROM AUTHOR]

Water level modeling is a critical component of flood warning systems. A high-quality forecast requires the development of a hydraulic model that reliably accounts for the main sources of uncertainty. In this paper, a 1D hydraulic model with adaptive flow-based calibration was developed. This calibration resulted in roughness-flow relationships that allow Manning coefficients to be updated as a function of river flow, to limit errors throughout the flood cycle. An uncertainty analysis is then conducted for independent events, considering as the main source of uncertainty the error in the estimated input flows (upstream and lateral), and in the calibrated roughness coefficients. A set of parameters is generated by Latin Hypercube Sampling (LHS) from the characterization of these errors to evaluate their propagation to the variables of interest, namely water level and flow. These are evaluated by performance metrics (scores) such as the reliability diagram and the continuous rank probability score (CRPS). The adaptive flow-based calibration considerably reduced the error of the 1D model and improved its performance over time and throughout the flood events. The uncertainty analysis resulted in consistent accuracy improvements over a deterministic simulation with gains of 20% to 32%, depending on the combined parameters. Good reliability is also reached for most stations, with resulting spreads and Root Mean Square Error (RMSE) close to one another. The proposed methodology has the potential to improve the descriptive capability of 1D river hydraulic models and to increase their reliability when included in forecasting systems. [ABSTRACT FROM AUTHOR]

We investigated the tidal propagation in the Lower Fraser River (LFR) in British Columbia, Canada using observed water elevations, river discharge, and a hydrodynamic model. The observed water elevations and discharge are analyzed using a tidal analysis package called NS_Tide. The results indicate that the amplitudes of the two principal tides (lunar semidiurnal, M 2 , and luni-solar diurnal, K 1) decrease from the river mouth to the upstream. The amplitudes in the high flow season (spring and summer) are lower than those in the low flow season (fall and winter). The amplitudes of the overtides and compound tides amplify from the downstream to the upstream in the low flow season; however, in the high flow season, the amplitudes only amplify in the lower part (0–35 km from the river mouth) and then decrease in the upper part (60–78 km from the river mouth). The temporal variation of tidal amplitudes are strongly correlated to the river discharge. Using the model results in 2013, we analyzed the momentum balance in the river channel and examined the significance of the Pitt River and Pitt Lake system. The momentum balance in the river channel is dominated by the balance between the pressure gradient and the bottom friction. The river-tide interaction plays an important role in the friction term in the lower part of the river channel, while the river flow explains most of the variability moving upstream. The system of the Pitt River and Pitt Lake is important for the tidal propagation in the river channel. Modelling tides without including this system systematically leads to significant inaccuracies of the tides in the river channel of the LFR. • Tides in the lower Fraser River are temporally and spatially variable. • Tides are damped due to the river discharge. • The river-tide interaction plays an important role in the bottom friction term in the lower part of the river channel. • The system of the Pitt River and Pitt Lake is important for the tidal propagation in the river channel. [ABSTRACT FROM AUTHOR]

Modeling the spatial distribution of mobile organisms under rapidly changing environmental conditions is a challenging endeavor that has to be undertaken whenever the impacts of alterations have to be assessed in dynamic scenarios. We modeled habitat suitability for Lake sturgeon (Acipenser fulvescens) and White perch (Morone americana , both had have been followed by hydro-acoustic telemetry) in an estuarine river section with rapidly changing tidal and hydrodynamic conditions using deep feed-forward Artificial Neural Networks (ANN). Descriptors used were of many types: intrinsic features (species, sexual maturity and gender, and individual character), terrain features, hydraulic and tidal conditions, and time. A set of ANN models with varying degree of complexity, in terms of their number of hidden layers, number of nodes per layers, and regularization parameters, were tried and evaluated using cross-validation. The best model has three layers with 100, 50, and 20 nodes and classified 94.0 % of observations as presence (and 60.6 % of pseudo absences as absences, overall correct classification: 77.3 %) during the trials. The study highlights that tidal and hydraulic models, coupled with acoustic telemetry and machine learning, can be used to predict the spatial distribution of mobile organisms even in extremely variable ecosystems such as estuaries. • We modeled the habitat of two fishes: Lake sturgeon and White perch. • Habitat is located in the St. Lawrence River estuary, near Île d'Orléans. • We used a deep Artificial Neural Network model with many types of descriptors. • The model classified 94.0% of observations as presence during cross-validation. • Descriptors often displayed non-linearity and varied among the environment. [ABSTRACT FROM AUTHOR]

Background:  Postoperative pulmonary recovery after lobectomy has showed early benefits for the video-assisted thoracoscopic surgery and sparing open techniques over nonsparing techniques. Robotic-assisted procedures offer benefits in term of clinical outcomes, but their advantages on pulmonary recovery and quality of life have not yet been distinctly prospectively studied., Methods:  Eighty-six patients undergoing lobectomy over a period of 29 months were prospectively studied for their pulmonary function recovery and pain score level during the in-hospital stay and at 1, 2, and 6 months. Quality of life was evaluated at 2 and 6 months. Forty-five patients were operated by posterolateral limited thoracotomy and 41 patients by robotic approach. The postoperative analgesia protocol differed for the two groups, being lighter for the robotic group., Results:  The pulmonary tests were not significantly different during the in-hospital stay. At 1 month, the forced expiratory volume in 1 second, forced vital capacity, vital capacity, and maximal expiratory pressure were significantly better for the robotic group ( p  = 0.05, 0.04, 0.05, and 0.02, respectively). There was no significant difference left at 2 and 6 months. Pain intensity was equivalent during the in-hospital stay but was significantly lower for the robotic group at 1 month ( p  = 0.02). At 2 and 6 months, pain and quality of life were comparable., Conclusion:  Robotic technique can offer similar pulmonary and pain recovery during the in-hospital stay with a lighter analgesia protocol. It clearly favors the early term recovery compared with the open limited technique. The objective and subjective functional recovery becomes equivalent at 2 and 6 months., Competing Interests: None declared., (Thieme. All rights reserved.)