143 research outputs found

    Feature extraction of hyperspectral images using boundary semi-labeled samples and hybrid criterion

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    Feature extraction is a very important preprocessing step for classification of hyperspectral images. The linear discriminant analysis (LDA) method fails to work in small sample size situations. Moreover, LDA has poor efficiency for non-Gaussian data. LDA is optimized by a global criterion. Thus, it is not sufficiently flexible to cope with the multi-modal distributed data. We propose a new feature extraction method in this paper, which uses the boundary semi-labeled samples for solving small sample size problem. The proposed method, which called hybrid feature extraction based on boundary semi-labeled samples (HFE-BSL), uses a hybrid criterion that integrates both the local and global criteria for feature extraction. Thus, it is robust and flexible. The experimental results with three real hyperspectral images show the good efficiency of HFE-BSL compared to some popular and state-of-the-art feature extraction methods

    Overlap-based feature weighting: The feature extraction of Hyperspectral remote sensing imagery

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    Hyperspectral sensors provide a large number of spectral bands. This massive and complex data structure of hyperspectral images presents a challenge to traditional data processing techniques. Therefore, reducing the dimensionality of hyperspectral images without losing important information is a very important issue for the remote sensing community. We propose to use overlap-based feature weighting (OFW) for supervised feature extraction of hyperspectral data. In the OFW method, the feature vector of each pixel of hyperspectral image is divided to some segments. The weighted mean of adjacent spectral bands in each segment is calculated as an extracted feature. The less the overlap between classes is, the more the class discrimination ability will be. Therefore, the inverse of overlap between classes in each band (feature) is considered as a weight for that band. The superiority of OFW, in terms of classification accuracy and computation time, over other supervised feature extraction methods is established on three real hyperspectral images in the small sample size situation

    Murine obscurin and Obsl1 have functionally redundant roles in sarcolemmal integrity, sarcoplasmic reticulum organization, and muscle metabolism

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    Biological roles of obscurin and its close homolog Obsl1 (obscurin-like 1) have been enigmatic. While obscurin is highly expressed in striated muscles, Obsl1 is found ubiquitously. Accordingly, obscurin mutations have been linked to myopathies, whereas mutations in Obsl1 result in 3M-growth syndrome. To further study unique and redundant functions of these closely related proteins, we generated and characterized Obsl1 knockouts. Global Obsl1 knockouts are embryonically lethal. In contrast, skeletal muscle-specific Obsl1 knockouts show a benign phenotype similar to obscurin knockouts. Only deletion of both proteins and removal of their functional redundancy revealed their roles for sarcolemmal stability and sarcoplasmic reticulum organization. To gain unbiased insights into changes to the muscle proteome, we analyzed tibialis anterior and soleus muscles by mass spectrometry, uncovering additional changes to the muscle metabolism. Our analyses suggest that all obscurin protein family members play functions for muscle membrane systems

    An endogenous peptide marker differentiates SOD1 stability and facilitates pharmacodynamic monitoring in SOD1 amyotrophic lateral sclerosis

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    The discovery of novel biomarkers has emerged as a critical need for therapeutic development in amyotrophic lateral sclerosis (ALS). For some subsets of ALS, such as the genetic superoxide dismutase 1 (SOD1) form, exciting new treatment strategies, such as antisense oligonucleotide-mediated (ASO-mediated) SOD1 silencing, are being tested in clinical trials, so the identification of pharmacodynamic biomarkers for therapeutic monitoring is essential. We identify increased levels of a 7-amino acid endogenous peptide of SOD1 in cerebrospinal fluid (CSF) of human SOD1 mutation carriers but not in other neurological cases or nondiseased controls. Levels of peptide elevation vary based on the specific SOD1 mutation (ranging from 1.1-fold greater than control in D90A to nearly 30-fold greater in V148G) and correlate with previously published measurements of SOD1 stability. Using a mass spectrometry-based method (liquid chromatography-mass spectrometry), we quantified peptides in both extracellular samples (CSF) and intracellular samples (spinal cord from rat) to demonstrate that the peptide distinguishes mutation-specific differences in intracellular SOD1 degradation. Furthermore, 80% and 63% reductions of the peptide were measured in SOD1G93A and SOD1H46R rat CSF samples, respectively, following treatment with ASO, with an improved correlation to mRNA levels in spinal cords compared with the ELISA measuring intact SOD1 protein. These data demonstrate the potential of this peptide as a pharmacodynamic biomarker

    Value of physical examination in the diagnosis of developmental hip dislocation in preterm infants

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    Background: Developmental dislocation of the hip joint is among joint abnormalities and lack of its early diagnosis leads to irreversible complications and disabilities. Methods: The current cross sectional study was conducted on 210 eighteen - month - old premature infants. Premature infants at term gestational age were examined by a neonatologist and underwent a sonographic scanning by a skilled radiologist. The results of the physical examination and ultrasound reports were collected and analyzed. Results: In the clinical assessment, hip joint examination was diagnosed abnormal in 22 cases (10.4) and joint dislocation was diagnosed by ultrasonographic examination in 17 patients (8.1). In one high - risk case, despite normal clinical examination (0.48), the dislocation was diagnosed by ultrasonographic evaluation. There was a significant relationship between hip dislocation rate, and reduced mean gestational age and birth weight (P 0.05). In diagnosis of joint dislocation, clinical examination (the results of the Ortolani and the Barlow tests) had sensitivity of 94 and specificity of 97 compared with sonography; the positive and negative predictive values were 73 and 99, respectively. Conclusions: Clinical examination has high sensitivity and specificity for early diagnosis of developmental hip dislocation. If there are risk factors, ultrasonographic scanning is recommended despite normal physical examination, and ultrasound is not necessary in case of normal physical examination and the absence of risk factors. © 2018, Journal of Comprehensive Pediatrics

    Ethylene Synthesis and Regulated Expression of Recombinant Protein in Synechocystis sp PCC 6803

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    The ethylene-forming enzyme (EFE) from Pseudomonas syringae catalyzes the synthesis of ethylene which can be easily detected in the headspace of closed cultures. A synthetic codon-optimized gene encoding N-terminal His-tagged EFE (EFEh) was expressed in Synechocystis sp. PCC 6803 (Synechocystis) and Escherichia coli (E. coli) under the control of diverse promoters in a self-replicating broad host-range plasmid. Ethylene synthesis was stably maintained in both organisms in contrast to earlier work in Synechococcus elongatus PCC 7942. The rate of ethylene accumulation was used as a reporter for protein expression in order to assess promoter strength and inducibility with the different expression systems. Several metal-inducible cyanobacterial promoters did not function in E. coli but were well-regulated in cyanobacteria, albeit at a low level of expression. The E. coli promoter P(trc) resulted in constitutive expression in cyanobacteria regardless of whether IPTG was added or not. In contrast, a Lac promoter variant, P(A1lacO-1), induced EFE-expression in Synechocystis at a level of expression as high as the Trc promoter and allowed a fine level of IPTG-dependent regulation of protein-expression. The regulation was tight at low cell density and became more relaxed in more dense cultures. A synthetic quorum-sensing promoter system was also constructed and shown to function well in E. coli, however, only a very low level of EFE-activity was observed in Synechocystis, independent of cell density

    Downsizing a human inflammatory protein to a small molecule with equal potency and functionality

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    A significant challenge in chemistry is to rationally reproduce the functional potency of a protein in a small molecule, which is cheaper to manufacture, non-immunogenic, and also both stable and bioavailable. Synthetic peptides corresponding to small bioactive protein surfaces do not form stable structures in water and do not exhibit the functional potencies of proteins. Here we describe a novel approach to growing small molecules with protein-like potencies from a functionally important amino acid of a protein. A 77-residue human inflammatory protein (complement C3a) important in innate immunity is rationally transformed to equipotent small molecules, using peptide surrogates that incorporate a turn-inducing heterocycle with correctly positioned hydrogen-bond-accepting atoms. Small molecule agonists (molecular weigh
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