Voxel selection in fMRI data analysis based on sparse representation

Multivariate pattern analysis approaches toward detection of brain regions from fMRI data have been gaining attention recently. In this study, we introduce an iterative sparse-representation-based algorithm for detection of voxels in functional MRI (fMRI) data with task relevant information. In each iteration of the algorithm, a linear programming problem is solved and a sparse weight vector is subsequently obtained. The final weight vector is the mean of those obtained in all iterations. The characteristics of our algorithm are as follows: 1) the weight vector (output) is sparse; 2) the magnitude of each entry of the weight vector represents the significance of its corresponding variable or feature in a classification or regression problem; and 3) due to the convergence of this algorithm, a stable weight vector is obtained. To demonstrate the validity of our algorithm and illustrate its application, we apply the algorithm to the Pittsburgh Brain Activity Interpretation Competition 2007 functional fMRI dataset for selecting the voxels, which are the most relevant to the tasks of the subjects. Based on this dataset, the aforementioned characteristics of our algorithm are analyzed, and a comparison between our method with the univariate general-linear-model-based statistical parametric mapping is performed. Using our method, a combination of voxels are selected based on the principle of effective/sparse representation of a task. Data analysis results in this paper show that this combination of voxels is suitable for decoding tasks and demonstrate the effectiveness of our method

Consolidation considering clogging

In land reclamation projects, the vacuum preloading method has been widely used to strengthen dredged fills by removing water. However, during the improvement process, clogging inevitably occurs in the drains and soils, hindering water drainage and causing inhomogeneous consolidation results. Therefore, it is essential to evaluate the effect of clogging on the consolidation behavior of dredged slurry at different radii. In this study, analytical solutions are derived under an uneven strain assumption to calculate the consolidation in the clogging zone and the normal zone, with time-dependent discharge capacity and clogging in the soil considered. Results calculated by the proposed solutions indicated that the clogging effect slows down the development of consolidation, reduces the final consolidation degree, and increases the difference between consolidations at different radii. It is found that the influence of the clogging effect's varies with the speed of the discharge capacity decay, the value of the initial discharge capacity of the drain, the permeability, and the radius of the clogging zone. Finally, a practical application of the proposed solution is discussed, and the proposed solution is suggested for the calculation of consolidation when treating high-water-content slurry

An Expanded Gene Catalog of Mouse Gut Metagenomes

High-quality and comprehensive reference gene catalogs are essential for metagenomic research. The rather low diversity of samples used to construct existing catalogs of the mouse gut metagenome limits the numbers of identified genes in existing catalogs. We therefore established an expanded catalog of genes in the mouse gut metagenome (EMGC) containing >5.8 million genes by integrating 88 newly sequenced samples, 86 mouse gut-related bacterial genomes, and 3 existing gene catalogs. EMGC increases the number of nonredundant genes by more than 1 million genes compared to the so-far most extensive catalog. More than 60% of the genes in EMGC were assigned to Bacteria, with 54.20% being assigned to a phylum and 35.33% to a genus, while 30.39% were annotated at the KEGG orthology level. Nine hundred two metagenomic species (MGS) assigned to 122 taxa are identified based on the EMGC. The EMGC-based analysis of samples from groups of mice originating from different animal providers, housing laboratories, and genetic strains substantiated that diet is a major contributor to differences in composition and functional potential of the gut microbiota irrespective of differences in environment and genetic background. We envisage that EMGC will serve as a valuable reference data set for future metagenomic studies in mice.publishedVersio

Role of G-protein coupled receptors in cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of death globally, with CVDs accounting for nearly 30% of deaths worldwide each year. G-protein-coupled receptors (GPCRs) are the most prominent family of receptors on the cell surface, and play an essential regulating cellular physiology and pathology. Some GPCR antagonists, such as β-blockers, are standard therapy for the treatment of CVDs. In addition, nearly one-third of the drugs used to treat CVDs target GPCRs. All the evidence demonstrates the crucial role of GPCRs in CVDs. Over the past decades, studies on the structure and function of GPCRs have identified many targets for the treatment of CVDs. In this review, we summarize and discuss the role of GPCRs in the function of the cardiovascular system from both vascular and heart perspectives, then analyze the complex ways in which multiple GPCRs exert regulatory functions in vascular and heart diseases. We hope to provide new ideas for the treatment of CVDs and the development of novel drugs

Flow characteristics in pressurized oxy-fuel fluidized bed under hot condition

Pressurized oxy-fuel fluidized bed (POFB) combustion is regarded as a promising technology for carbon capture from coal-fired power plants. High pressure and temperature conditions have important impacts on the flow characteristic of fluidized bed, and understanding them will help to optimize the design and operation of the POFB boiler. In this work, experiments were carried out in two pressurized fluidized bed (PFB) devices (a hot PFB and a “visual PFB”) both operated under high temperature (20-800 °C) and high pressure conditions (0.1-1.0 MPa). Four parameters including the minimum fluidization velocity (umf), the minimum bubbling velocity (umb), bubble diameter (Db) and bubble frequency (f) were examined in this study. Results showed that the umf decreases with rising pressure and temperature. Based on our results a formula was fitted for calculating the minimum fluidization velocity in PFB, with a relative error less than 15%. With the increase of fluidization number (w), the bubble size and tail vortex increased gradually, the bubbles tended to merge, and the shape of bubbles became more irregular. The Db decreases with the increase of temperature and pressure at the same w. The f increases with increased w, while it decreased with the increase of temperature and pressure