Inverse-Based Approach to Explaining and Visualizing Convolutional Neural Networks.

This article presents a new method for understanding and visualizing convolutional neural networks (CNNs). Most existing approaches to this problem focus on a global score and evaluate the pixelwise contribution of inputs to the score. The analysis of CNNs for multilabeled outputs or regression has not yet been considered in the literature, despite their success on image classification tasks with well-defined global scores. To address this problem, we propose a new inverse-based approach that computes the inverse of a feedforward pass to identify activations of interest in lower layers. We developed a layerwise inverse procedure based on two observations: 1) inverse results should have consistent internal activations to the original forward pass and 2) a small amount of activation in inverse results is desirable for human interpretability. Experimental results show that the proposed method allows us to analyze CNNs for classification and regression in the same framework. We demonstrated that our method successfully finds attributions in the inputs for image classification with comparable performance to state-of-the-art methods. To visualize the tradeoff between various methods, we developed a novel plot that shows the tradeoff between the amount of activations and the rate of class reidentification. In the case of regression, our method showed that conventional CNNs for single image super-resolution overlook a portion of frequency bands that may result in performance degradation.

Transparent Body-Attachable Multifunctional Pressure, Thermal, and Proximity Sensor and Heater.

A multifunctional sensor capable of simultaneous sensing of temperature, pressure, and proximity has been developed. This transparent and body-attachable device is also capable of providing heat under low voltage. The multi-sensor consists of metal fibers fabricated by electrospinning and electroplating. The device comprises randomly deposited metal fibers, which not only provide heating but also perform as thermal and proximity sensors, and orderly aligned metal fibers that act as a pressure sensor. The sensor is fabricated by weaving straight rectangular electrodes on a transparent substrate (a matrix). The sensitivity is readily enhanced by installing numerous matrices that facilitate higher sensing resolution. The convective heat transfer coefficient of the heater is h = 0.014 W·cm-2·°C-1. The temperature coefficient of resistivity (TCR) and pressure sensitivity (ηP) are 0.038 °C-1 and 5.3 × 10-3 kPa-1, respectively. The superior sensitivity of the device is confirmed via quantitative comparison with similar devices. This multifunctional device also has a superior convective heat transfer coefficient than do other heaters reported in the literature.

Wearable transparent thermal sensors and heaters based on metal-plated fibers and nanowires.

Electrospun metal-plated nanofibers and supersonically sprayed nanowires were used to fabricate hybrid films exhibiting a superior low sheet resistance of 0.18 Ω sq-1, a transparency of 91.1%, and a figure-of-merit of 2.315 Ω-1. The films are suitable to serve as thermal sensors and heaters. Such hybrid transparent conducting films are highly flexible and thus wearable. They can be used as body-temperature monitors and heaters. The employed hybrid approach improved the sheet resistance diminishing it to a minimum, while maintaining transparency. In addition, the low sheet resistance of the films facilitates their powering with a low-voltage battery and thus, portability. The thermal sensing and heating capabilities were demonstrated for such films with various sheet resistances and degrees of transparency. The temperature sensing was achieved by the resistance change of the film; the resistance value was converted back to temperature. The sensing performance increased with the improvement in the sheet resistance. The temperature coefficient of resistivity was TCR = 0.0783 K-1. The uniform distribution of the metal-plated nanofibers and nanowires resulted in a uniform Joule heating contributing to an efficient convection heat transfer from the heaters to the surrounding, demonstrated by an improved convective heat transfer coefficient.

Re-adjusting the cut-off score of the Korean version of the Childhood Autism Rating Scale for high-functioning individuals with autism spectrum disorder.

AIM: The current cut-off score of the Korean version of the Childhood Autism Rating Scale (K-CARS) does not seem to be sensitive enough to precisely diagnose high-functioning autism. The aim of this study was to identify the optimal cut-off score of K-CARS for diagnosing high-functioning individuals with autism spectrum disorders (ASD). METHODS: A total of 329 participants were assessed by the Korean versions of the Autism Diagnostic Interview - Revised (K-ADI-R), Autism Diagnostic Observation Schedule (K-ADOS), and K-CARS. IQ and Social Maturity Scale scores were also obtained. RESULTS: The true positive and false negative rates of K-CARS were 77.2% and 22.8%, respectively. Verbal IQ (VIQ) and Social Quotient (SQ) were significant predictors of misclassification. The false negative rate increased to 36.0% from 19.8% when VIQ was >69.5, and the rate increased to 44.1% for participants with VIQ > 69.5 and SQ > 75.5. In addition, if SQ was >83.5, the false negative rate increased to 46.7%, even if the participant's VIQ was ≤69.5. Optimal cut-off scores were 28.5 (for VIQ ≤ 69.5 and SQ ≤ 75.5), 24.25 (for VIQ > 69.5 and SQ > 75.5), and 24.5 (for SQ > 83.5), respectively. CONCLUSION: The likelihood of a false negative error increases when K-CARS is used to diagnose high-functioning autism and Asperger's syndrome. For subjects with ASD and substantial verbal ability, the cut-off score for K-CARS should be re-adjusted and/or supplementary diagnostic tools might be needed to enhance diagnostic accuracy for ASD.

Surveyor assay to diagnose persistent Müllerian duct syndrome in Miniature Schnauzers.

Persistent Müllerian duct syndrome (PMDS) is a pseudohermaphroditism in males characterized by the presence of Müllerian duct derivatives. As PMDS dogs often lack clinical symptoms, a molecular diagnosis is essential to identify the syndrome in these animals. In this study, a new molecular method using DNA mismatch-specific Surveyor nuclease was developed. The Surveyor nuclease assay identified the AMHR2 mutation that produced PMDS in a Miniature Schnauzer as accurately as that obtained by using the conventional method based on restriction digestion. As an alternative to the current molecular diagnostic method, the new method may result in increased accuracy when detecting PMDS.

Surface display expression of Bacillus licheniformis lipase in Escherichia coli using Lpp'OmpA chimera.

The lipase from Bacillus licheniformis ATCC14580 was displayed on the cell surface of Escherichia coli using Lpp'OmpA as the anchoring protein. The expressed Lpp'OmpA-lipase fusion protein has a molecular weight of approximately 35 kDa, which was confirmed by SDS-PAGE and western blot analysis. The Lpp'OmpA-lipase fusion protein was located on the cell surface, as determined by immunofluorescence confocal microscopy and flow cytometry. The enzyme activity of the surface-displayed lipase showed clear halo around the colony. The cell surface-displayed lipase showed the highest activity of 248.12 ± 9.42 U/g (lyophilized cell) at the optimal temperature of 37°C and pH 8.0. The enzyme exhibited the highest activity toward the substrate p-nitrophenyl caprylate (C8). These results suggest that E. coli, which displayed the lipase on its surface, could be used as a whole cell biocatalyst.

Body mass index as a predictor of advanced colorectal neoplasia.

BACKGROUND: Colorectal cancer (CRC) is the third frequent cancer in Korea. There are several risk factors including male sex, older age, smoking and family history of colon cancer. Recently, obesity is thought to be a risk factor for CRC and advanced colon polyps. Therefore, we designed a cross-sectional study to determine the association between BMI and advanced colorectal neoplasia. METHODS: A total of 256 patients with advanced colorectal neoplasia who were diagnosed using colonoscopy between May, 2004 and December, 2011 were included in this study. Advanced colorectal neoplasia was defined large (≥1 cm) adenoma or adenocarcinoma. We compared these patients to a control group consisting of 217 subjects with normal colonoscopic findings recruited during the same period. RESULTS: Of the 256 patients, there were 132 (51.6%) men, and the mean age was 56.4±12.3 years. The rate of males, alcohol drinker and current smokers was significantly higher in the advanced colorectal neoplasia compared to control group. In the subgroup analysis, the mean age and body mass index (BMI, kg/m(2)) of advanced colorectal neoplasia were higher than control group in the female subjects. However, there were no significant differences between two groups in the male subjects. Multiple logistic regression analysis identified overweight (BMI 23.0-24.9 kg/m(2), odds ratios [OR]=2.022) and obesity (BMI≥25 kg/m(2), OR=2.383) as independent risk factors for advanced colorectal neoplasia. CONCLUSIONS: We suggest that BMI should be considered as an independent risk factor for advanced colorectal neoplasia, and people with high BMI should be recommended to undergo colonocoscopy screening earlier than scheduled.

Prevention of free fatty acid-induced hepatic lipotoxicity by carnitine via reversal of mitochondrial dysfunction.

BACKGROUND: Mitochondria are the main sites for fatty acid oxidation and play a central role in lipotoxicity and nonalcoholic steatohepatitis. AIMS: We investigated whether carnitine prevents free fatty acid (FFA)-induced lipotoxicity in vitro and in vivo. METHODS: HepG2 cells were incubated with FFA, along with carnitine and carnitine complexes. Mitochondrial ß-oxidation, transmembrane potential, intracellular ATP levels and changes in mitochondrial copy number and morphology were analysed. Otsuka Long-Evans Tokushima Fatty and Long-Evans Tokushima Otsuka rats were segregated into three experimental groups and fed for 8 weeks with (i) normal chow, (ii) a methionine choline-deficient (MCD) diet or (iii) an L-carnitine-supplemented MCD diet. RESULTS: Carnitine prevented FFA-induced apoptosis (16% vs. 3%, P < 0.05). FFA treatment resulted in swollen mitochondria with increased inner matrix density and loss of cristae. However, mitochondria co-treated with carnitine had normal ultrastructure. The mitochondrial DNA copy number was higher in the carnitine treatment group than in the palmitic acid treatment group (375 vs. 221 copies, P < 0.05). The carnitine group showed higher mitochondrial ß-oxidation than did the control and palmitic acid treatment groups (597 vs. 432 and 395 ccpm, P < 0.05). Carnitine treatment increased the mRNA expression of carnitine palmitoyltransferase 1A and peroxisome proliferator-activated receptor-γ, and carnitine-lipoic acid further augmented the mRNA expression. In the in vivo model, carnitine-treated rats showed lower alanine transaminase levels and lesser lobular inflammation than did the MCD-treated rats. CONCLUSIONS: Carnitine and carnitine-lipoic acid prevent lipotoxicity by increasing mitochondrial ß-oxidation and reducing intracellular oxidative stress.

Expressional diversity of wheat nsLTP genes: evidence of subfunctionalization via cis-regulatory divergence.

Previously, the wheat non-specific lipid transfer proteins (TaLTP), members of a small multigene family, were reported to evidence a complex pattern of expression regulation. In order to assess further the expression diversity of the TaLTP genes, we have attempted to evaluate their expression profiles in responses to abiotic stresses, using semi-quantitative RT-PCR. The expression profiles generated herein revealed that the TaLTP genes in group A evidenced highly similar responses against abiotic stresses, whereas differential expression patterns among genes in each group were also observed. A total of seven promoters were fused to a GUS reporter gene and the recombinants were introduced into Arabidopsis, while three promoters evidenced non-detectible GUS activity. The promoters of TaLTP1, TaLTP7, and TaLTP10 included in group A drove strong expressions during plant development with overlapping patterns, in large part, but also exhibited distinct expression pattern, thereby suggesting subfunctionalization processing over evolutionary time. However, only trace expression in cotyledons, young emerged leaves, and epidermal cell layers of flower ovaries was driven by the promoter of TaLTP3 of group B. These results indicate that their distinct physiological functions appear to be accomplished by a subfunctionalization process involving degenerative mutations in regulatory regions.