Detecting Toe-Off Events Utilizing a Vision-Based Method.

Detecting gait events from video data accurately would be a challenging problem. However, most detection methods for gait events are currently based on wearable sensors, which need high cooperation from users and power consumption restriction. This study presents a novel algorithm for achieving accurate detection of toe-off events using a single 2D vision camera without the cooperation of participants. First, a set of novel feature, namely consecutive silhouettes difference maps (CSD-maps), is proposed to represent gait pattern. A CSD-map can encode several consecutive pedestrian silhouettes extracted from video frames into a map. And different number of consecutive pedestrian silhouettes will result in different types of CSD-maps, which can provide significant features for toe-off events detection. Convolutional neural network is then employed to reduce feature dimensions and classify toe-off events. Experiments on a public database demonstrate that the proposed method achieves good detection accuracy.

Factors Affecting the Repurchase Intention of Organic Tea among Millennial Consumers: An Empirical Study.

The study aims to identify the factors affecting consumers' intention to repurchase organic tea in an emerging country such as Bangladesh. The study adopted the Stimulus-Organism-Response (SOR) theory, which uses seven constructs as the predictor of repurchase intention. This is a quantitative and empirical study that adopted cross-sectional survey methods. The convenience sampling method was used to collect data from 340 young respondents who visited supermarkets in Dhaka between October and November 2021. In order to analyze the obtained primary data, the structural equation modeling (SEM) approach was used. The findings revealed that product satisfaction, perceived values and brand trust are the predictors of repurchase intention. Surprisingly, we did not find that promotional efforts effected repurchase intention. The study also identified food quality and information quality as the antecedents of perceived value and product satisfaction, while the antecedents of brand trust were product satisfaction, food quality, brand image, information quality and promotional effort. The study suggested numerous theoretical and policy implications to improve repurchase intention of organic tea in the context of emerging economies such as Bangladesh.

Effects of His bundle pacing and right ventricular apex pacing on cardiac electrical and mechanical synchrony and cardiac function in patients with heart failure and atrial fibrillation.

OBJECTIVE: To investigate the effects of right ventricular apex pacing and His bundle pacing on cardiac mechanical and electrical synchrony and cardiac function in patients with heart failure and atrial fibrillation. METHODS: A total of 72 patients with heart failure and atrial fibrillation who received permanent pacemaker implantation in our hospital were randomly divided into two groups, with 36 patients in each group. The control group received the right ventricular apex pacing, and the study group received His bundle pacing. In the two groups, the pacing parameters, cardiac function, cardiac electricity, mechanical synchrony, complications and living quality were compared. RESULTS: During operation and 12 months after the operation, the study group's pacing threshold was higher than the pacing threshold of the control group (all P<0.001). Compared with that before the procedure, NYHA grade and LVEDD of the two groups 12 months after operation were decreased (all P<0.001), while LVEF and various quality of life scores were increased (all P<0.001). The study group's NYHA grade and LVEDD were lower than those of the control group 12 months after operation (all P<0.001), while the study group's quality of life scores and LVEF were higher than those of the control group (all P<0.001). Twelve months after operation, the study group's QRS width and IVMD were lower than QRS width and IVMD of the control group (all P<0.001). The study group's complication rate was 5.56% (2/36), which was lower than the control group's complication rate (22.22% (8/36), P<0.05). CONCLUSION: Compared with right ventricular apical pacing, His bundle pacing in the treatment of heart failure with atrial fibrillation can better maintain the cardiac electrical and mechanical synchronization, promote the recovery of cardiac function, improve living quality, and has fewer complications and significant advantages.

The effect of controlling the heart rate on the heart failure index and on heart function in heart failure patients with atrial fibrillation.

OBJECTIVE: To explore the effect of controlling the heart rate on the heart failure index and on heart function in patients with heart failure and atrial fibrillation. METHODS: 82 patients with heart failure and atrial fibrillation were divided into a control group (n=41) and a study group (n=41). The patients in the control group underwent conventional treatment. In addition to the conventional treatment, the patients in the study group were administered metoprolol to actively control their heart rates and to decrease their resting heart rates down to 55-60 beats/min as the target heart rate. After three months of treatment, the heart function, the levels of N terminal pro B type natriuretic peptide (NT-proBNP), and the inflammatory factors were compared between the two groups. At the same time, the readmission rates and prognoses were calculated. RESULTS: After the treatment, the left ventricular ejection fraction (LVEF) and the cardiac output (CO) levels in the two groups were increased, and the levels in the study group were higher than the levels in the control group; there were opposite trends in the left ventricular end-systolic diameter (LVESD) levels, the left ventricular end-diastolic dimension (LVEDD) levels, and the NT-proBNP, serum CRP, TNF-α and IL-6 levels (all P<0.05). After a six month follow up, the readmission and heart failure rates, and the incidence of adverse events in the study group were lower than they were in the control group (all P<0.05). CONCLUSION: The effective control of the ventricular rate can more significantly benefit the heart failure symptoms and atrial fibrillation, alleviate the inflammatory response, and thus improve the heart function and prognoses of heart failure patients with atrial fibrillation.

Geometrically robust image watermarking by sector-shaped partitioning of geometric-invariant regions.

In a feature-based geometrically robust watermarking system, it is a challenging task to detect geometric-invariant regions (GIRs) which can survive a broad range of image processing operations. Instead of commonly used Harris detector or Mexican hat wavelet method, a more robust corner detector named multi-scale curvature product (MSCP) is adopted to extract salient features in this paper. Based on such features, disk-like GIRs are found, which consists of three steps. First, robust edge contours are extracted. Then, MSCP is utilized to detect the centers for GIRs. Third, the characteristic scale selection is performed to calculate the radius of each GIR. A novel sector-shaped partitioning method for the GIRs is designed, which can divide a GIR into several sector discs with the help of the most important corner (MIC). The watermark message is then embedded bit by bit in each sector by using Quantization Index Modulation (QIM). The GIRs and the divided sector discs are invariant to geometric transforms, so the watermarking method inherently has high robustness against geometric attacks. Experimental results show that the scheme has a better robustness against various image processing operations including common processing attacks, affine transforms, cropping, and random bending attack (RBA) than the previous approaches.

Association between Polymorphisms of the AKT1 Gene Promoter and Risk of the Alzheimer's Disease in a Chinese Han Population with Type 2 Diabetes.

AIMS: Alzheimer's disease (AD) is a multifactor disease that has been reported to have a close association with type 2 diabetes (T2D) where the v-akt murine thymoma viral oncogene homolog 1 (AKT1) plays an important role in the protein synthesis pathways and cell apoptosis processes. Evidence has been shown that AKT1 protein may be related to AD risk among patients with T2D. The aim of this study was to analyze the potential association between single nucleotide polymorphisms of AKT1 promoter and the risk of AD among patients with T2D. METHODS: The association between AKT1 polymorphisms and AD risk in patients with T2D was assessed among 574 consecutive unrelated subjects including 112 AD patients with T2D, 231 patients with AD, and 231 healthy controls in a case-control study. The cognitive function of all subjects was assessed using MMSE. Six single nucleotide polymorphisms with minor allele frequency >0.2 (rs2498786, rs74090038, rs2494750, rs2494751, rs5811155, and rs2494752) in AKT1 promoter were analyzed by polymerase chain reaction (PCR), and the concentration of AKT1 protein in serum was tested using enzyme-linked immunosorbent assay (ELISA). RESULTS: Overall, there was statistically significant difference in AKT1 rs2498786 polymorphism. The CC frequency of AKT1 rs2498786 polymorphism in AD with T2D group and AD control group was significantly higher than that in healthy control group (PAD+T2D vs. health < 0.0001, PAD vs. health < 0.0001). However, the difference was not found between AD with T2D group and AD control group. Compared with healthy control group, the plasma levels of AKT1 protein in AD with T2D group (PAD+T2D vs. health < 0.0001) and AD control group (PAD vs. health = 0.0003) decreased significantly. Among genotypes of AKT1 rs2498786 polymorphism, the AKT1 protein level in GG genotype was significantly higher than that in GC genotype (PGG vs. GC < 0.0001) and CC genotype (PGG vs. CC < 0.0001). CONCLUSION: The study suggests that AKT1 rs2498786 polymorphism in insulin signaling pathway may be associated with AD risk and different genotypes may affects levels of protein expression. However, the polymorphism is not shown to be exclusive in AD patients with T2D.

Salient region detection by fusing bottom-up and top-down features extracted from a single image.

Recently, some global contrast-based salient region detection models have been proposed based on only the low-level feature of color. It is necessary to consider both color and orientation features to overcome their limitations, and thus improve the performance of salient region detection for images with low-contrast in color and high-contrast in orientation. In addition, the existing fusion methods for different feature maps, like the simple averaging method and the selective method, are not effective sufficiently. To overcome these limitations of existing salient region detection models, we propose a novel salient region model based on the bottom-up and top-down mechanisms: the color contrast and orientation contrast are adopted to calculate the bottom-up feature maps, while the top-down cue of depth-from-focus from the same single image is used to guide the generation of final salient regions, since depth-from-focus reflects the photographer's preference and knowledge of the task. A more general and effective fusion method is designed to combine the bottom-up feature maps. According to the degree-of-scattering and eccentricities of feature maps, the proposed fusion method can assign adaptive weights to different feature maps to reflect the confidence level of each feature map. The depth-from-focus of the image as a significant top-down feature for visual attention in the image is used to guide the salient regions during the fusion process; with its aid, the proposed fusion method can filter out the background and highlight salient regions for the image. Experimental results show that the proposed model outperforms the state-of-the-art models on three public available data sets.

LDFT-based watermarking resilient to local desynchronization attacks.

Up to now, a watermarking scheme that is robust against desynchronization attacks (DAs) is still a grand challenge. Most image watermarking resynchronization schemes in literature can survive individual global DAs (e.g., rotation, scaling, translation, and other affine transforms), but few are resilient to challenging cropping and local DAs. The main reason is that robust features for watermark synchronization are only globally invariable rather than locally invariable. In this paper, we present a blind image watermarking resynchronization scheme against local transform attacks. First, we propose a new feature transform named local daisy feature transform (LDFT), which is not only globally but also locally invariable. Then, the binary space partitioning (BSP) tree is used to partition the geometrically invariant LDFT space. In the BSP tree, the location of each pixel is fixed under global transform, local transform, and cropping. Lastly, the watermarking sequence is embedded bit by bit into each leaf node of the BSP tree by using the logarithmic quantization index modulation watermarking embedding method. Simulation results show that the proposed watermarking scheme can survive numerous kinds of distortions, including common image-processing attacks, local and global DAs, and noninvertible cropping.