No abstract

Land-use classification using remote sensing images covers a wide range of applications. With more detailed spatial and textural information provided in very high resolution (VHR) remote sensing images, a greater range of objects and spatial patterns can be observed than ever before. This offers us a new opportunity for advancing the performance of land-use classification. In this paper, we first introduce an effective midlevel visual elements-oriented land-use classification method based on "partlets," which are a library of pretrained part detectors used for midlevel visual elements discovery. Taking advantage of midlevel visual elements rather than low-level image features, a partlets-based method represents images by computing their responses to a large number of part detectors. As the number of part detectors grows, a main obstacle to the broader application of this method is its computational cost. To address this problem, we next propose a novel framework to train coarse-to-fine shared intermediate representations, which are termed "sparselets," from a large number of pretrained part detectors. This is achieved by building a single-hidden-layer autoencoder and a single-hidden-layer neural network with an L0-norm sparsity constraint, respectively. Comprehensive evaluations on a publicly available 21-class VHR land-use data set and comparisons with state-of-the-art approaches demonstrate the effectiveness and superiority of this paper.

The binding targets of aptamers, the interaction probing methods, and the main binding forces mediating the interaction have been summarized.

Fluorescent aptamer probes physisorbed on graphene oxide (GO) have recently emerged as a useful sensing platform. Signal is generated by analyte-induced probe desorption. To address non-specific probe displacement and false positive signal, we herein report a covalently linked aptamer probe for ATP detection. A fluorophore and amino dual-modified aptamer was linked to the carboxyl group on GO with a coupling efficiency of ~50%. The linearity, specificity, stability, and regeneration of the covalent sensor was systematically studied and compared to the physisorbed probe. Both sensors have similar sensitivity, but the covalent one is more resistant to non-specific probe displacement by proteins. The covalent sensor has a dynamic range from 0.125 mM to 2 mM ATP in buffer at room temperature and is resistance to DNase I. Intracellular ATP imaging was demonstrated using the covalent sensor, which generated higher fluorescence signal than the physisorbed sensor. After stimulating the cells with 5 mM Ca 2+ for ATP production, the intracellular signal enhanced by 31.8%. This work highlights the advantages of covalent aptamer sensors using GO as both a quencher and a delivery vehicle for intracellular metabolite detection.3

No abstract