Landslide Susceptibility Mapping along the Anninghe Fault Zone in China using SVM and ACO-PSO-SVM Models

AbstractIn the present study, a hybrid machine learning model was designed by integrating ant colony optimization (ACO), particle swarm optimization (PSO), and support vector machine (SVM) algorithms. The model was used to map the landslide susceptibility of the Anninghe fault zone in Sichuan Province, China. Based on this, 12 conditioning factors associated with landslides were considered, namely, altitude, slope angle, cutting depth, slope aspect, relief amplitude, stream power index (SPI), gully density, lithology, rainfall, road density, distance to fault, and peak ground acceleration (PGA). The overall performance of the two resulting models was tested using the receiver operating characteristic (ROC), area under the ROC curve (AUC), Cohen’s kappa coefficient, and five statistical evaluation measures. The success rates of the ACO-PSO-SVM model and the SVM model were 0.898 and 0.814, respectively, while the prediction rates of the two models were 0.887 and 0.804, respectively. The results show that the ACO-PSO-SVM model yields better overall performance and accurate results than the SVM model. Therefore, in conclusion, the ACO-PSO-SVM model can be applied as a new promising method for landslide susceptibility mapping in subsequent studies. The results of this study will be useful for land-use planning, hazard prevention, and risk management

Facile and effective synthesis of hierarchical TiO2 spheres for efficient dye-sensitized solar cells

National Natural Science Foundation of China [51072170, 21021002]; National Basic Research Program of China [2012CB932900]Three-dimensional (3D) crystalline anatase TiO2 hierarchical spheres were successfully derived from Ti foils via a fast, template-free, low-temperature hydrothermal route followed by a calcination post-treatment. These dandelion-like TiO2 spheres are composed of numerous ultrathin nanoribbons, which were subsequently split into fragile nanoflakes as a result of the decomposition of Ti-complex intermediates to TiO2 and H2O at high temperature. The dye-sensitized solar cells (DSSCs) employing such hierarchically structured TiO2 spheres as the photoanodes exhibited a light-to-electricity conversion efficiency of 8.50%, yielding a 28% enhancement in comparison with that (6.64%) of P25-based DSSCs, which mainly benefited from the enhanced capacity of dye loading in combination with effective light scattering and trapping from hierarchical architecture

Efficacy of physical exercise on the physical ability, cardiac function and cardiopulmonary fitness of patients with atrial fibrillation: a systematic review and meta-analysis

ObjectiveIt is advised that patients engage in physical activity to enhance their quality of life and achieve better results. The purpose of the current study was to measure the efficacy of exercise on the physical ability, cardiac function and cardiopulmonary fitness of patients with AF.MethodA comprehensive systematic literature search was performed in PubMed, Embase, and Web of Science from 1991 to 2023 for RCTs comparing physical exercise combined with AF routine treatments to routine treatments alone. The meta-analysis was conducted following PRISMA guidelines. Our main outcomes were physical ability (measured by the 6-min walk test, 6MWT), cardiac function (measured by left ventricular ejection fraction, LVEF) and cardiopulmonary fitness (measured by peak oxygen uptake and resting heart rate). Quality assessments were conducted using the Cochrane Collaboration tool.ResultsThirteen trials involving 672 patients met the criteria for analysis. The results showed that physical exercise increased physical ability by improving the 6MWT (m) performance (MD = 96.99, 95% CI: 25.55–168.43; Z = 2.66; p = 0.008); and enhanced peak VO2 (ml/kg per min) (MD = 4.85, 95% CI: 1.55–8.14; Z = 2.89; p = 0.004) while reducing resting heart rate (beats per minute, bpm) (MD = −6.14, 95% CI: −11.30 to −0.98; Z = 2.33; p = 0.02). However, the results showed that regular exercise could improve LVEF (%) inpatients clinically, which had no statistic difference between experimental and control group (MD = 1.49, 95% CI: −0.25–3.24; Z = 1.68; p = 0.09).ConclusionOur meta-analysis shows that physical exercise is an effective intervention to improve the exercise ability and cardiopulmonary fitness for AF patients. Meanwhile, we also do not exclude the positive effect of exercise on the improvement of cardiac function (LVEF) in patients with AF. To this end, doctors should consider the positive impact of exercise on patients and give advice on exercise limits in practical clinical practice

Famílies botàniques de plantes medicinals

Facultat de Farmàcia, Universitat de Barcelona. Ensenyament: Grau de Farmàcia, Assignatura: Botànica Farmacèutica, Curs: 2013-2014, Coordinadors: Joan Simon, Cèsar Blanché i Maria Bosch.Els materials que aquí es presenten són els recull de 175 treballs d’una família botànica d’interès medicinal realitzats de manera individual. Els treballs han estat realitzat per la totalitat dels estudiants dels grups M-2 i M-3 de l’assignatura Botànica Farmacèutica durant els mesos d’abril i maig del curs 2013-14. Tots els treballs s’han dut a terme a través de la plataforma de GoogleDocs i han estat tutoritzats pel professor de l’assignatura i revisats i finalment co-avaluats entre els propis estudiants. L’objectiu principal de l’activitat ha estat fomentar l’aprenentatge autònom i col·laboratiu en Botànica farmacèutica

Stability reliability of a cutting slope in Laohuzui Hydropower Station in Tibet of China

The Hoek–Brown empirical formulas are widely used to estimate the mechanical parameters of a rock mass. However, there exists a problem of variability and uncertainty in the mechanical parameters of a rock mass estimated by the Hoek–Brown empirical formulas. To do this, we present a method to implement a reliability analysis of the rock mass stability directly starting with the basic variables of the Hoek–Brown empirical formulas. First, a quantitative assessment of the disturbance factor is recommended to overcome the subjectivity and limitation of estimating the disturbance factor according to the guidelines by Hoek et al. Second, a performance function is built up together with the safety factor of a micro-unit. Third, the Rosenblueth point estimate method is chosen to estimate the mean and standard deviation of the factor of safety. Finally, the stability reliability of a cutting slope in Laohuzui Hydropower Station in Tibet of China is analyzed. The results of the cutting slope show good agreement with the rock mass failure that occurred

Effect of drag force on stability of residual soil slopes under surface runoff

To investigate the effect of drag force on stability of residual soil slopes, a modified approach based on the limit equilibrium method is proposed by establishing a nonlinear coupled mathematical model to calculate the seepage velocities in soils and the runoff velocities at a fluid–solid interface. In this mathematical model, the Navier–Stokes equation and Brinkman-extended Darcy equation are used to describe the incompressible surface runoff and seepage in soils, respectively. Then, the drag force can be derived by adopting Newton's law of internal friction, and the factor of safety (FOS) of residual soil slopes considering drag force can be calculated based on the limit equilibrium method. The modified approach was applied to analyse the stability of rainfall-induced landslides in residual soils in Nanjiang, Sichuan, China, 2011. We found that the runoff depth can significantly control the FOS of the residual soil slopes and cause slope failures. The results of sensitivity analysis highlight the significance for considering drag force due to surface runoff when calculating the FOS of the residual soil slope. The FOS obtained from the modified approach is more reasonable, and this modified approach also can be used for evaluating or predicting rainfall-induced slope instability in residual soils

A Return Mapping Algorithm for Nonlinear Yield Criteria with the Equivalent Mohr–Coulomb Strength Parameters

This paper proposes a modified return mapping algorithm for a series of nonlinear yield criteria. The algorithm is established in the principal stress space and ignores the effect of the intermediate principal stress. Three stress return schemes are derived in this paper: return to the yield surface, return to the curve, and return to the apex point. The conditions used for determining the correct stress return type are also constructed. After the proposed algorithm is programmed in the finite element software, we merely need the equivalent Mohr–Coulomb (M-C) strength parameters, the derivatives of their functions, and the tensile strength of these nonlinear yield criteria. In addition, the Hoek–Brown (H-B) yield criterion is taken as an example to validate the proposed method. The results show that the updated stresses and the final principal stresses obtained by the proposed method are in good agreement with those obtained by other methods. Furthermore, the proposed method is more suitable for the associated plastic-flow rule

How to build and evaluate an integrated health care system for chronic patients: study design of a clustered randomised controlled trial in rural China

Background: While integrated health care system has been proved an effective way to help improving patient health and system efficiency, the exact behaviour model and motivation approach are not so clear in poor rural areas where health human resources and continuous service provision are urgently needed. To gather solid evidence, we initiated a comprehensive intervention project in Qianjiang District, southwest part of rural China in 2012. And after one-year's pilot, we developed an intervention package of team service, comprehensive pathway and prospective- and performance-based payment system.Methods: To testify the potential influence of payment interventions, we use clustered randomised controlled trial, 60 clusters are grouped into two treatment groups and one control group to compare the time and group differences. Difference-in-differences model and structural equation modelling will be used to analyse the intervention effects and pathway. The outcomes are: quality of care, disease burden, supplier cooperative behaviour and patient utilisation behaviour and system efficiency. Repeated multivariate variance analysis will be used to statistically examine the outcome differences.Discussion: This is the first trial of its kind to prove the effects and efficiency of integrated care. Though we adopted randomised controlled trial to gather the highest rank of evidence, still the fully randomisation was hard to realise in health policy reform experiment. To compensate, the designer should take efforts on control for the potential confounders as much as possible. With this trial, we assume the effects will come from: (1) improvement on the quality of life through risk factors control and lifestyles change on patient's behaviours; (2) improvement on quality of care through continuous care and coordinated supplier behaviours; (3) improvement on the system efficiency through active interaction between suppliers and patients.Conclusion: The integrated care system needs collaborative work from different levels of caregivers. So it is extremely important to consider the supplier cooperative behaviour. In this trial, we introduced payment system to help the delivery system integration through providing financial incentives to motivate people to play their roles. Also, the multidisciplinary team, the multi-institutional pathway and system global budget and pay-for-performance payment system could afford as a solution