In this paper, we investigate the problem of trajectory tracking control for marine surface vehicles (MSVs), which are subject to dynamic uncertainties, external disturbances and unmeasurable ...velocities. To recover the unmeasurable velocities, a novel adaptive neural network-based (NN-based) state observer is constructed. To guarantee the transient and steady-state tracking performance of the system, a novel nonlinear transformation method is proposed by employing a tracking error transformation together with a newly constructed performance function, which is characterized by a user-defined settling time and tracking control accuracy. With the aid of the state observer and the nonlinear transformation method in combination with the adaptive NN technique and vector-backstepping design tool, an adaptive neural output-feedback trajectory tracking control scheme with predefined performance is developed. With regard to the developed control scheme, uncertainties can be reconstructed only by utilizing the position and heading of the MSVs. Independent designs of the state observer and the controller can be achieved, and the position tracking error can be guaranteed to fall into a predefined residual set in the user-defined time frame and remain in the above set. A rigorous stability analysis validates that all signals in the closed-loop trajectory tracking control system for MSVs are uniformly ultimately bounded. Simulation results verify the effectiveness of the developed adaptive neural output-feedback trajectory tracking control scheme.
The antibacterial property of thyme essential oil due to different volatile compounds, has been well documented in the literature. To overcome the high volatility of essential oil components, ...encapsulation has emerged as a new alternative. In this work, chitosan and thyme essential oil-loaded chitosan nanoparticles (TEO-CSNPs) and nanocapsules (TEO-CSNCs) were prepared by nanoprecipitation and nanoencapsulation, respectively. The morphology, encapsulation efficiency, release kinetics, and inhibitory activity were evaluated. Average size of nanocapsules (9.1±1.6nm) was slightly higher than nanoparticles (6.4±0.5nm). The percentage encapsulation of thymol and carvacrol, more than 68%, was similar for nanoparticles and nanocapsules. However, thymol and carvacrol release time from TEO-CSNPs was faster compared to TEO-CSNCs. The release kinetics data were fitted to three analytical kinetic models with no statistical differences among them. The inhibitory activity was higher for nanoparticles than for nanocapsules when tested against six foodborne bacteria. The inhibitory effect of TEO-CSNPs was the highest against Staphylococcus aureus (inhibition halo 4.3cm) and for TEO-CSNCs it was against Bacillus cereus (inhibition halo 1.9cm).
The laundering of synthetic fabrics has been identified as an important and diffuse source of microplastic (<5 mm) fibre contamination to wastewater systems. Home laundering can release up to 13 ...million fibres per kg of fabric, which end up in wastewater treatment plants. During treatment, 72-99% of microplastics are retained in the residual sewage sludge, which can contain upwards of 56 000 microplastics per kg. Sewage sludge is commonly disposed of by application to agricultural land as a soil amendment. In some European countries, application rates are up to 91%, representing an important pathway for microplastics to enter the terrestrial environment, which urgently requires quantification. Sewage sludge also often contains elevated concentrations of metals and metalloids, and some studies have quantified metal(loid) sorption onto various microplastics. The sorption of metals and metalloids is strongly influenced by the chemical properties of the sorbate, the solution chemistry, and the physicochemical properties of the microplastics themselves. Plastic-water partition coefficients for the sorption of cadmium, mercury and lead onto microplastics are up to 8, 32, and 217 mL g
respectively. Sorptive capacities of microplastics may increase over time, due to environmental degradation processes increasing the specific surface area and surface density of oxygen-containing functional groups. A range of metal(loid)s, including cadmium, chromium, and zinc, have been shown to readily desorb from microplastics under acidic conditions. Sorbed metal(loid)s may therefore become more bioavailable to soil organisms when the microplastics are ingested, due to the acidic gut conditions facilitating desorption. Polyester (polyethylene terephthalate) should be of particular focus for future research, as few quantitative sorption studies currently exist, it is potentially overlooked from density separation studies due to its high density, and it is by far the most widely used fibre in apparel textiles production.
There is an increasing interest in the development of meat processed products enriched with antioxidant dietary fiber to augment the consumption of these health beneficial compounds. This study aimed ...to evaluate the nutritional, nutraceutical, and antioxidant potential, as well as the physicochemical properties of minced tilapia fillets (meat) gels with added amaranth seed or sprout flours (0%, 2%, 4%, 8%, and 10%
/
). Dietary fiber content was significantly increased with the addition of amaranth seed (1.25-1.75-fold) and sprout flours (1.99-3.21-fold). Tilapia gels with added 10% amaranth seed flour showed a high content of extractable dihydroxybenzoic acid and cinnamic acid, whereas the addition of 10% amaranth sprout flour provided a high and wide variety of bioactive compounds, mainly amaranthine and bound ferulic acid. The addition of amaranth seed and sprout flours increased hardness (1.01-1.73-fold) without affecting springiness, decreased luminosity (1.05-1.15-fold), and increased redness and yellowness. Therefore, amaranth seed and sprout flours could be used as functional ingredients for the development of fish products rich in bioactive compounds.
Ecological processes are centered to water availability in drylands; however, less known nutrient stoichiometry can help explain much of their structure and ecological interactions. Here we look to ...the foliar stoichiometry of carbon (C), nitrogen (N), and phosphorus (P) of 38 dominant plant species from the Sonoran Desert, grouped in four different functional types to describe ecological characteristics and processes. We found that foliar N, C:N, C:P, and N:P stoichiometric ratios, but not P, were higher than those known to most other ecosystems and indicate P but not N limitations in leaves. Biological N fixers (BNF) had even higher leaf N concentrations, but bio-elemental concentrations and stoichiometry ratios were not different to other non-N-fixing legume species which underscores the need to understand the physiological mechanisms for high N, and to how costly BNF can succeed in P-limiting drylands environments. Stoichiometry ratios, and to lesser extent elemental concentrations, were able to characterize BNF and colonizing strategies in the Sonoran Desert, as well as explain leaf attribute differences, ecological processes, and biogeochemical niches in this dryland ecosystem, even when no direct reference is made to other water-limitation strategies.
•Camera self-calibration procedure with 5 levels of hierarchy and 12 different cases.•Completely autonomous system, independent of the position of the camera.•Focal average error<5%, pitch average ...error<3.2°, roll average error<0.7°.•Occlusion management ratio=91% single frame and 95% multi-frame.•From a total of 2269 objects, the system has obtained a detection rate of 93.3%.
In this paper, a hierarchical monocular camera auto-calibration method is presented for applications in the framework of intelligent transportation systems (ITS). It is based on vanishing point extraction from common static elements present on the scene, and moving objects as pedestrians and vehicles. This process is very useful to recover metrics from images or applying information of 3D models to estimate 2D pose of targets, making a posterior object detection and tracking more robust to noise and occlusions. Moreover, the algorithm is independent of the position of the camera, and it is able to work with variable pan-tilt-zoom (PTZ) cameras in fully self-adaptive mode. The objective is to obtain the camera parameters without any restriction in terms of constraints or the need of prior knowledge, to deal with most traffic scenarios and possible configurations. The results achieved up to date in real traffic conditions are presented and discussed.
Autonomous vehicles navigate in dynamically changing environments under a wide variety of conditions, being continuously influenced by surrounding objects. Mod - elling interactions among agents is ...essential for accurately forecasting other agents' behaviour and achieving safe and comfortable motion planning. In this work, we propose SCOUT, a novel Attention-based Graph Neural Network that uses a flexible and generic representation of the scene as a graph for modelling interactions, and predicts socially - consistent trajec - tories of vehicles and Vulnerable Road Users (VRU s) under mixed traffic conditions. We explore three different attention mechanisms and test our scheme with both bird-eye - view and on-vehicle urban data, achieving superior performance than existing state-of - the-art approaches on InD and ApolloScape Trajectory benchmarks. Additionally, we evaluate our model's flexibility and transferability by testing it under completely new scenarios on RounD dataset. The importance and influence of each interaction in the final prediction is explored by means of Integrated Gradients technique and the visualization of the attention learned.
ABSTRACT
Introduction: In this study we propose electrodiagnostic criteria for early reversible conduction failure (ERCF) in axonal Guillain–Barré syndrome (GBS) and apply them to a cohort of GBS ...patients. Methods: Serial nerve conduction studies (NCS) were retrospectively analyzed in 82 GBS patients from 3 centers. The criteria for the presence of ERCF in a nerve were: (i) a 50% increase in amplitude of distal compound muscle action potentials or sensory nerve action potentials; or (ii) resolution of proximal motor conduction block with an accompanying decrease in distal latencies or compound muscle action potential duration or increase in conduction velocities. Results: Of 82 patients from 3 centers, 37 (45%) had ERCF, 21 (26%) had a contrasting evolution pattern, and 8 (10%) had both. Sixteen patients did not show an amplitude increase of at least 50%. Conclusion: Our proposed criteria identified a group of patients with a characteristic evolution of NCS abnormality that is consistent with ERCF. Muscle Nerve 56: 919–924, 2017
This is the first study that seeks to establish the prognostic value of circulating tumor cell (CTC) (determined by CellSearch system) in patients with stage III CRC.
Our results suggest that given ...the low number of CTC in patients with localized CRC and the particular pattern of metastatic dissemination in patients with CRC, it is likely that CTC does not have a prognostic role in this setting.
The prognostic role of circulating tumor cells (CTC) in early colorectal cancer (CRC) has not been determined yet. We evaluated the potential prognostic value of CTC in stage III CRC patients.
Prospective multicenter study of 519 patients with stage III CRC recruited between January 2009 and June 2010. CTC were enumerated with the CellSearch System after primary tumor resection and before the start of adjuvant therapy. A total of 472 patients were included in the analysis.
CTC ≥1, ≥2, ≥3 and ≥5 were detected in 166 (35%), 93 (20%), 57 (12%) and 34 (7%) patients, respectively. Median follow-up was 40 months. In the overall population, CTC ≥1 (disease-free survival (DFS): HR 0.97,P = 0.85; overall survival (OS): HR 1.03,P = 0.89), ≥2 (DFS: HR 1.07,P = 0.76; OS: HR 1.02,P = 0.95), ≥3 (DFS: HR 0.96,P = 0.87; OS: HR 0.74,P = 0.41) and ≥5 (DFS: HR 0.72,P = 0.39; OS: HR 0.48,P = 0.21) were not associated with worse DFS and OS. No clinicopathological characteristics were significantly associated with the presence of CTC. In patients with disease relapse, the proportion with CTC ≥1 was not significantly different between those with single versus multiple metastatic locations (37.9% versus 31.4%,P = 0.761). In the multivariate analysis, CTC ≥1 was not an independent prognostic factor for DFS (HR 0.97,P = 0.87) and OS (HR 0.96,P = 0.89).
CTC detection was not associated with worse DFS and OS in patients with stage III CRC. Given the scarcity of CTC in these patients, it is likely that CTC determined by CellSearch system does not have a prognostic role in this setting. However, a longer follow-up is needed.
Real-time system for monitoring driver vigilance Bergasa, L.M.; Nuevo, J.; Sotelo, M.A. ...
IEEE transactions on intelligent transportation systems,
03/2006, Volume:
7, Issue:
1
Journal Article
Peer reviewed
Open access
This paper presents a nonintrusive prototype computer vision system for monitoring a driver's vigilance in real time. It is based on a hardware system for the real-time acquisition of a driver's ...images using an active IR illuminator and the software implementation for monitoring some visual behaviors that characterize a driver's level of vigilance. Six parameters are calculated: Percent eye closure (PERCLOS), eye closure duration, blink frequency, nodding frequency, face position, and fixed gaze. These parameters are combined using a fuzzy classifier to infer the level of inattentiveness of the driver. The use of multiple visual parameters and the fusion of these parameters yield a more robust and accurate inattention characterization than by using a single parameter. The system has been tested with different sequences recorded in night and day driving conditions in a motorway and with different users. Some experimental results and conclusions about the performance of the system are presented
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