103 research outputs found

    Facial Image Analysis for Body Mass Index, Makeup and Identity

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    The principal aim of facial image analysis in computer vision is to extract valuable information(e.g., age, gender, ethnicity, and identity) by interpreting perceived electronic signals from face images. In this dissertation, we develop facial image analysis systems for body mass index (BMI) prediction, makeup detection, as well as facial identity with makeup changes and BMI variations.;BMI is a commonly used measure of body fatness. In the first part of this thesis, we study BMI related topics. At first, we develop a computational method to predict BMI information from face images automatically. We formulate the BMI prediction from facial features as a machine vision problem. Three regression methods, including least square estimation, Gaussian processes for regression, and support vector regression are employed to predict the BMI value. Our preliminary results show that it is feasible to develop a computational system for BMI prediction from face images. Secondly, we address the influence of BMI changes on face identity. Both synthesized and real face images are assembled as the databases to facilitate our study. Empirically, we found that large BMI alterations can significantly reduce the matching accuracy of the face recognition system. Then we study if the influence of BMI changes can be reduced to improve the face recognition performance. The partial least squares (PLS) method is applied for this purpose. Experimental results show the feasibility to develop algorithms to address the influence of facial adiposity variations on face recognition, caused by BMI changes.;Makeup can affect facial appearance obviously. In the second part of this thesis, we deal with makeup influence on face identity. It is principal to perform makeup detection at first to address makeup influence. Four categories of features are proposed to characterize facial makeup cues in our study, including skin color tone, skin smoothness, texture, and highlight. A patch selection scheme and discriminative mapping are presented to enhance the performance of makeup detection. Secondly, we study dual attributes from makeup and non-makeup faces separately to reflect facial appearance changes caused by makeup in a semantic level. Cross-makeup attribute classification and accuracy change analysis is operated to divide dual attributes into four categories according to different makeup effects. To develop a face recognition system that is robust to facial makeup, PLS method is proposed on features extracted from local patches. We also propose a dual-attributes based method for face verification. Shared dual attributes can be used to measure facial similarity, rather than a direct matching with low-level features. Experimental results demonstrate the feasibility to eliminate the influence of makeup on face recognition.;In summary, contributions of this dissertation center in developing facial image analysis systems to deal with newly emerged topics effectively, i.e., BMI prediction, makeup detection, and the rcognition of face identity with makeup and BMI changes. In particular,to the best of our knowledge, BMI related topics, i.e., BMI prediction; the influence of BMI changes on face recognition; and face recognition robust to BMI changes are first explorations to the biometrics society

    Effect of in vitro gastrointestinal digestion on the chemical composition and antioxidant properties of Ginkgo biloba leaves decoction and commercial capsules

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    In this study Ginkgo biloba leaves (GBL) decoction and commercial capsules were digested using an in vitro model. Thirty-six active compounds were identified and quantified by HPLC-ESI-MS analysis based on the MS/MS patterns (precursor ions and product ions) and retention times, in comparison with reference standards. Most compounds in GBL showed a significant decrease during intestinal digestion, with an exception of vanillic acid and biflavonoids. Bioaccessibility values of chemical compositions varied between decoction and capsules samples. Also, significant reductions of total flavonoids and total phenolic content was observed after in vitro digestion. Both, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging capacity decreased after gastric digestion, but increased during intestinal digestion. Nevertheless, different behaviour was observed in reducing antioxidant power (FRAP) assay. Compared to the pH of digestion, the influence of digestive enzymes on the chemical composition and antioxidant activity of GBL was relatively minor. Overall, these results may help provide a valid foundation for further investigations on bioactive compounds and the pharmacodynamics of GBL

    Human performance analysis of processes for retrieving Beidou satellite navigation system during breakdown

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    Satellite navigation systems provide continuous, timely, and accurate signals of location, speed, and time to users all over the world. Although the running of these systems has become highly automated, the human operator is still vital for its continued operation, especially when certain equipment failures occur. In this paper, we examined 180 incidents of one particular type of equipment failure and the whole recovery process as recorded in the log files from a ground control center of the Beidou satellite navigation system. We extracted the information, including the technical description of the failure, the time when the fault occurred, the full recovery time, and the demographic information of the team members on the shift responsible for responding to the failure. We then transformed these information into the cognitive complexity of the task, time of day, shift handover period, and team skill composition. Multiple regression analysis showed that task complexity and shift handover were key predictors of recovery time. Time of day also influenced the recovery time, during midnight to 4 a.m., operators made longer responses. We also found that the fault handling processes could be improved if the team’s most adept member is more skillful at that role than in other teams. We discussed the theoretical and practical implication of this study

    Potentials of neuron-specific enolase as a biomarker for gastric cancer

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    Purpose: To investigate the potentials of neuron-specific enolase (NSE) as a biomarker for gastric cancer (GC). Methods: Gastric cancer (GC) patients (n = 412) who underwent gastrectomy were recruited over a 3- year period for this study. Their clinicopathological data such as age, sex, histological type, depth, tumor invasion, lymph node metastasis, and distant metastasis were analyzed. The patients were followed up for four years and the outcomes were also assessed. Histological changes in biopsies and levels of expression of NSE in biopsies and serum of patients were determined using immunohistochemical staining, western blotting and enzyme-linked immunosorbent assay (ELISA), respectively. Results: Immunohistochemical staining showed that NSE was differentially expressed in the cytoplasm of GC cells. Histological changes in biopsies of patients in the overexpression group were not significantly different from those of patients in under-expression group (p > 0.05). In NSE overexpression group, the number of patients in early stage GC subgroup (n = 186, 86.10 %, T1) were significantly higher than that in advanced GC subgroup (n = 124, 62.20 % T2–T4) (p < 0.05). However, in NSE under-expression group, there were more patients in advanced GC subgroup (n = 72, 37.70 %) than in early GC subgroup (n = 30, 13.80 %) (p < 0.05). Patients in NSE overexpression group survived longer than those in NSE under-expression group (p < 0.05). The level of expression of NSE significantly decreased with increase in TNM stage (p < 0.05). There was no significant difference in serum NSE level between GC patients and healthy control (p > 0.05). The results of the correlation analysis indicated that NSE levels were positively associated with GC. Conclusion: The results obtained in this study suggest that NSE could serve as a potential biomarker for GC. Keywords: Biomarker, Gastric cancer, Neuron-specific enolase, Overexpression, TNM stagin

    Studies on MEMS vacuum sensor based on field emission of silicon tips array

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    In this paper, we present our recent works on the fabrication and testing of a novel MEMS (micro electro mechanical systems) vacuum sensor based on field emission of silicon tips array. The prototype vacuum sensor had been fabricated and tested under some conditions. It worked as a diode, having the voltage as the input and field emission current as output, with threshold voltage of approximate 7V and breakdown voltage of about 265V. When the pressure fell from 0.037Pa to 0.0077Pa, the field emission current increased from 80.3 mu A to 96.3 mu A. This work suggests a potential application of field emission to vacuum sensor

    Plasma microRNA Profiles as a Potential Biomarker in Differentiating Adult-Onset Still's Disease From Sepsis

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    Adult-onset Still's disease (AOSD) is a systemic inflammatory disease characterized by cytokine storm. However, a diagnostic test for AOSD in clinical use is yet to be validated. The aim of our study was to identify non-invasive biomarkers with high specificity and sensitivity to diagnosis of AOSD. MicroRNA (miRNA) profiles in PBMC from new-onset AOSD patients without any treatment and healthy controls (HCs) were analyzed by miRNA deep sequencing. Plasma samples from 100 AOSD patients and 60 HCs were used to validated the expression levels of miRNA by qRT-PCR. The correlations between expression levels of miRNAs and clinical manifestations were analyzed using advanced statistical models. We found that plasma samples from AOSD patients showed a distinct miRNA expression profile. Five miRNAs (miR-142-5p, miR-101-3p, miR-29a-3p, miR-29c-3p, and miR-141-3p) were significantly upregulated in plasma of AOSD patients compared with HCs both in training and validation sets. We discovered a panel including 3 miRNAs (miR-142-5p, miR-101-3p, and miR-29a-3p) that can predict the probability of AOSD with an area under the receiver operating characteristic (ROC) curve of 0.8250 in training and validation sets. Moreover, the expression levels of 5 miRNAs were significantly higher in active AOSD patients compared with those in inactive patients. In addition, elevated level of miR-101-3p was found in AOSD patients with fever, sore throat and arthralgia symptoms; the miR-101-3p was also positively correlated with the levels of IL-6 and TNF-α in serum. Furthermore, five miRNAs (miR-142-5p, miR-101-3p, miR-29c-3p, miR-29a-3p, and miR-141-3p) expressed in plasma were significantly higher in AOSD patients than in sepsis patients (P < 0.05). The AUC value of 4-miRNA panel (miR-142-5p, miR-101-3p, miR-29c-3p, and miR-141-3p) for AOSD diagnosis from sepsis was 0.8448, revealing the potentially diagnostic value to distinguish AOSD patients from sepsis patients. Our results have identified a specific plasma miRNA signature that may serve as a potential non-invasive biomarker for diagnosis of AOSD and monitoring disease activity

    Chromosome-level reference genome assembly provides insights into the evolution of Pennisetum alopecuroides

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    Pennisetum alopecuroides is an important forage grass resource, which plays a vital role in ecological environment improvement. Therefore, the acquisition of P. alopecuroides genome resources is conducive to the study of the adaptability of Pennisetum species in ecological remediation and forage breeding development. Here we assembled a P. alopecuroides cv. 'Liqiu' genome at the chromosome level with a size of approximately 845.71 Mb, contig N50 of 84.83Mb, and genome integrity of 99.13% as assessed by CEGMA. A total of 833.41-Mb sequences were mounted on nine chromosomes by Hi-C technology. In total, 60.66% of the repetitive sequences and 34,312 genes were predicted. The genomic evolution analysis showed that P. alopecuroides cv. 'Liqiu' was isolated from Setaria 7.53–13.80 million years ago and from Cenchrus 5.33–8.99 million years ago, respectively. The whole-genome event analysis showed that P. alopecuroides cv. 'Liqiu' underwent two whole-genome duplication (WGD) events in the evolution process, and the duplication events occurred at a similar time to that of Oryza sativa and Setaria viridis. The completion of the genome sequencing of P. alopecuroides cv. 'Liqiu' provides data support for mining high-quality genetic resources of P. alopecuroides and provides a theoretical basis for the origin and evolutionary characteristics of Pennisetum
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