Binocular camera calibration based on timing correction.

Camera calibration is crucial to the application of binocular measurement. However, many of the calibrations are carried out manually, so shaking of the calibration plate cannot be avoided. When the cameras are not synchronized or the exposure time is inconsistent, the image acquisition time of different cameras does not correspond strictly, which will introduce inevitable calibration errors. In this paper, two consecutive frames are collected instead of one frame, and the calibration data are corrected by the image acquisition time value returned by the camera. Experiments show that the proposed method can greatly reduce the re-projection error of calibration, and achieve higher calibration accuracy and less image quantity dependence.

Semantic speckle: an auto-located speckle pattern for DIC measurement.

Digital image correlation (DIC) has been widely used in both experimental mechanics and engineering fields. The matching algorithm of the DIC method usually requires surfaces containing a random speckle pattern as a deformation information carrier. The speckle pattern plays an irreplaceable role in DIC, which has led to extensive research on it. However, most previous research had always focused on the fabrication and computational performance of the speckle, ignoring the value of intentionally defining the meaning of speckle in design. In this study, we describe a novel, to the best of our knowledge, speckle pattern named semantic speckle. It is a digital speckle composed of several different speckle patterns with similar characteristics. Based on the deep-learning method and matching algorithm, the central location of the semantic part in the overall speckle image can be obtained automatically. Through the intentional definition of the semantic part, it can be possible to calibrate the camera parameters and correct the external parameters of the DIC systems.

Screening and evaluation of Monascus purpureus FJMR24 for enhancing the raw material utilization rate in rice wine brewing.

BACKGROUND: The rapid development of the rice wine industry has increased the demand for raw materials worldwide. A fungal strain with good adaptability to rice wine brewing conditions, which can also enhance the utilization rate of raw materials (URRM), thus increasing the production efficiency, was sought in the present research. RESULTS: The strain FJMR24 was successfully isolated and screened from 35 fermentation starters and exhibited high amylase activity (2200.9 ± 18.5 U g-1 ) and high glucoamylase activity (2330.4 ± 31.9 U g-1 ). Based on a morphological examination and a sequence analysis of the internal transcribed spacer (ITS) gene and ß-tubulin gene, FJMR24 was identified as Monascus purpureus, which is an edible and versatile fungus that plays a dominant role in the processing of Hong Qu. A moderate pH of 5-6 under incubation at 35 °C for 5-6 days was favorable for the growth and enzyme production of FJMR24. The strain could also tolerate the extreme conditions of 15-45 °C, 18% ethanol (v/v), and an acidity of pH 2. The excellent fermentation adaptability of FJMR24 might enable it to retain high enzyme activity during rice wine brewing. As a result of the action of FJMR24, the URRM of the base liquor increased by around 26% due to increased starch hydrolysis efficiency, which was mainly due to the high unit enzyme activity of FJMR24. CONCLUSION: This study provides perspectives for the application of a M. purpureus strain with high starch hydrolysis activity for enhancing the URRM in traditional rice wine brewing. © 2020 Society of Chemical Industry.

Amino acid and microbial community dynamics during the fermentation of Hong Qu glutinous rice wine.

Hong Qu glutinous rice wine (HQGRW) is typically very bitter after fermentation due to the presence of bitter amino acids (BAA). The amino acids are considered to primarily derive from the hydrolysis of protein from the raw material by microbial populations during fermentation, and temperature also has an important effect on bitter tastes. Here, the dynamics of fungal and bacterial communities during the traditional fermentation of HQGRW were investigated using high-throughput sequencing and RNA-based rRNA gene sequencing. Both principal component analysis (PCA) and hierarchical clustering analysis (HCA) revealed significant differences between the fungal and bacterial communities during fermentation at 20 °C and those performed at 25 °C and 30 °C. The growth of Saccharomyces and some LAB apparently inhibited the growth of several pernicious bacterial taxa including acetic acid bacteria. The amino acid contents of the samples all increased continuously under the different temperature conditions. Moreover, higher temperatures were associated with higher perceptual intensity of bitterness and contents of amino acids including bitter, sweet, umami, and astringent type amino acids as well as the total amino acid content during fermentation. Furthermore, the total BAA content was strongly and positively correlated with Pediococcus, Saccharomyces, Lactobacillus, Monascus, and Halomonas relative abundances, with correlations identified by |r| > 0.6 with P adjusted P < 0.05. In conclusion, these results contribute to a better understanding of the mechanisms underlying BAA production during the traditional fermentation of HQGRW and will help improve the quality and safety of these wines.

Analysis of Key Genes Responsible for Low Urea Production in Saccharomyces cerevisiae JH301.

There is a potential safety risk with ethyl carbamate (EC) in Hongqu Huangjiu production; 90% of the EC in rice wine is produced by the reaction of the urea with the alcohol of Saccharomyces cerevisiae. In our previous experiments, we screened and obtained a S. cerevisiae strain JH301 that offered low urea production. However, the key genes responsible for low urea production of strain JH301 remain unclear. Here, the whole genome sequencing of S. cerevisiae strain JH301 was accomplished via a next-generation high-throughput sequencing and long-read sequencing technology. There are six main pathways related to the urea metabolism of strain JH301 based on KEGG pathway mapping. Three species-specific genes are related to the urea metabolism pathways and were found in comparative genome analysis between strains JH301 and S288c during Hongqu Huangjiu production for the first time. Finally, the ARG80 gene was found to be likely a key gene responsible for low urea production of S. cerevisiae strain JH301, as determined by PCR and qRT-PCR check analyses from DNA and RNA levers. In conclusion, the results are useful for a scientific understanding of the mechanism of low urea production by Saccharomyces cerevisiae during Hongqu Huangjiu fermentation. It also is important to control the urea and EC contents in Hongqu Huangjiu production.

Fungal community diversity and fermentation characteristics in regional varieties of traditional fermentation starters for Hong Qu glutinous rice wine.

Hong Qu glutinous rice wine (HQ wine) is a traditional alcoholic beverage produced in China by fermenting cooked rice using a fermentation starter prepared with the fungus Monascus purpureus. This starter (Hong Qu, HQ) is made empirically by open spontaneous fermentation that is hard to control and standardize, resulting in inconsistent wine quality. This study investigates representative HQ samples from a large geographic region. It explores fungal microbiome compositions, identifies characteristic differences important for the production of various HQ wine styles, and reveals the key fungi responsible for HQ wine fermentation characteristics. The source of the HQ inoculum was found to be the main factor influencing fungal community composition and diversity, followed by processing technology and geographical distribution. Linear discriminant analysis effect size (LEfSe) uncovered 14 genera as potential biomarkers to distinguish regional varieties of HQ. Significant differences were also found in fermentation characteristics such as liquefying power (LP), saccharifying power (SP), fermenting power (FP), total acid content (TA) and liquor-producing power (LPP). The key fungi responsible for LP (5 genera), SP (3 genera), FP (1 genera), LPP (4 genera), and TA (4 genera) were determined using redundancy correlation analysis. Finally, Spearman's correlation analysis indicated that LPP shows a strong positive correlation with FP and LP, while TA displays a strong negative correlation with FP. The results of this study may be utilized to prepare consistently high quality, next-generation HQ by better controlling fungal community structures, and to design fermentation processes for HQ wines with desirable oenological characteristics.

Changes in Cold and Hot Syndrome and Gastrointestinal Bacterial Community Structure in Mice by Intervention with Food of Different Nature.

OBJECTIVE: To reveal the effect of foods with different natures on cold or hot syndrome and gastrointestinal bacterial community structure in mice. METHODS: Forty-five 6-week-old male ICR Kunming mice of clean grade were divided into 5 groups, 9 per group, including the control (CK), hot nature herbs (HM), Hong Qu glutinous rice wine (RW), tea rice wine (TW), and cold nature herbs (CM) groups. Distilled water or corresponding herbs were administered to mice (0.01 mL/g body weight) in the 5 groups by gastric infusion respectively, once daily for 28 d. Appearance, behavior, and serum biochemical indicators, including 5-hydroxytryptamine (5-HT), thyroid stimulating hormone (TSH), noradrenaline (NE), cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), the hot nature index, as well as the gastrointestinal bacterial community structure were analyzed in all groups after treatment. RESULTS: After supplementation for 28 d, CM and TW mice showed different degrees of cold syndrome, and HM and RW mice showed different degrees of hot syndrome. Compared with the HM and RW mice, the TSH, NE, cAMP levels and hot nature indices in the CM and TW mice were significantly decreased and 5-HT and cGMP levels were significantly increased (P<0.05). There was no obvious change in appearance or behavior in CK mice. Results of clustering analysis showed that the gastrointestinal bacterial community structures were highly similar in TW and CM mice as well as in RW and HM mice, and that they were from the same branch, respectively, when the distance was 0.02. The key microbes associated with cold syndrome were Lachnospiraceae uncultured, Lactococcus, etc., and the key microbes associated with hot syndrome were S24-7 norank, Ruminococcaceae uncultured, etc. CONCLUSION: The interventions with different nature foods could change cold or hot syndrome in mice, leading to changes in gastrointestinal bacterial community structure.

Development of a novel robotic platform with controllable stiffness manipulation arms for laparoendoscopic single-site surgery (LESS).

BACKGROUND: For current LESS robotic systems, the trade-off between dexterity and payload capability is always present. This paper presents a novel LESS robotic platform equipped with controllable stiffness manipulation arms. METHODS: Each manipulation arm with an articulated section and a controllable stiffness continuum section (CSCS) can be switched between a 7-DoF compliant status and 5-DoF rigid status according to the operation requirement. Screw theory and product exponential formula are used to quantify the kinematic performance. RESULTS: The stiffness of the manipulation arm promotes 3.03 to 4.12 times from compliant to rigid CSCS with maximum payload of 10 N in rigid status. The shortest rigid/compliant switching time is 5 s. The precision of a tracking test and an ex vivo procedure verified the accuracy and effectiveness of the controllable stiffness manipulation arms. CONCLUSIONS: This robot could potentially improve the surgical performance and further expand robotic LESS procedures.

Land-use type affects N2O production pathways in subtropical acidic soils.

The change in land-use from woodland to crop production leads to increased nitrous oxide (N2O) emissions. An understanding of the main N2O sources in soils under a particular land can be a useful tool in developing mitigation strategies. To better understand the effect of land-use on N2O emissions, soils were collected from 5 different land-uses in southeast China: shrub land (SB), eucalyptus plantation (ET), sweet potato farmland (SP), citrus orchard (CO) and vegetable growing farmland (VE). A stable isotope experiment was conducted incubating soils from the different land use types at 60% water holding capacity (WHC), using 15NH4NO3 and NH415NO3 to determine the dominant N2O production pathway for the different land-uses. The average N2O emission rates for VE, CO and SP were 5.30, 4.23 and 3.36 µg N kg-1 dry soil d-1, greater than for SB and ET at 0.98 and 1.10 µg N kg-1 dry soil d-1, respectively. N2O production was dominated by heterotrophic nitrification for SB and ET, accounting for 51 and 50% of N2O emissions, respectively. However, heterotrophic nitrification was negligible (<8%) in SP, CO and VE, where autotrophic nitrification was a primary driver of N2O production, accounting for 44, 45 and 66% for SP, CO and VE, respectively. Denitrification was also an important pathway of N2O production across all land-uses, accounting for 35, 35, 49, 52 and 32% for SB, ET, SP, CO and VE respectively. Average N2O emission rates via autotrophic nitrification, denitrification and heterotrophic nitrification increased significantly with gross nitrification rates, NO3- contents and C:N ratios respectively, indicating that these were important factors in the N2O production pathways for these soils. These results contribute to our understanding and ability to predict N2O emissions from different land-uses in subtropical acidic soils and in developing potential mitigation strategies.

Design and evaluation of a variable stiffness manual operating platform for laparoendoscopic single site surgery (LESS).

BACKGROUND: Most of the existing robotic platforms for LESS have workspace and load capacity weaknesses, because of the limitation of one single incision. We have developed a LESS manual operating platform of which the stiffness of the insertion tube is controllable. METHODS: The system included two dexterous tool manipulators, a stereo-vision module and a variable stiffness insertion tube (VSIT), which was designed using phase-change material (mixed indium, gallium and stannum). Experiments to evaluate the effectiveness of the VSIT were set up. Peg transfer tasks and trajectory tracking tasks were conducted to assess the initial performance of the overall system. RESULTS: The experimental results for stiffness characteristic suggested that the rigidity of the VSIT with a straight-forward pose was considerably increased by about four times in the rigid mode. Peg transfer tasks and trajectory tracking tasks were performed successfully with an average time of 97 s and 52 s, respectively. CONCLUSIONS: The experimental results for stiffness characteristic showed that the manual operating platform had great promise for solving large workspace, high manipulation force and stability problems in LESS. The tool manipulators had the ability to achieve basic operations.

Dynamic changes of total acid and bacterial communities during the traditional fermentation of Hong Qu glutinous rice wine

Background: Hong Qu glutinous rice wine (HQGRW) is brewed under non-aseptic fermentation conditions, so it usually has a relatively high total acid content. The aim of this study was to investigate the dynamics of the bacterial communities and total acid during the fermentation of HQGRW and elucidate the correlation between total acid and bacterial communities. Results: The results showed that the period of rapid acid increase during fermentation occurred at the early stage of fermentation. There was a negative response between total acid increase and the rate of increase in alcohol during the early fermentation stage. Bacterial community analysis using high-throughput sequencing technology was found that the dominant bacterial communities changed during the traditional fermentation of HQGRW. Both principal component analysis (PCA) and hierarchical clustering analysis revealed that there was a great difference between the bacterial communities of Hong Qu starter and those identified during the fermentation process. Furthermore, the key bacteria likely to be associated with total acid were identified by Spearman's correlation analysis. Lactobacillus, unclassified Lactobacillaceae, and Pediococcus were found, which can make significant contributions to the total acid development (| r| N 0.6 with FDR adjusted P b 0.05), establishing that these bacteria can associate closely with the total acid of rice wine. Conclusions: This was the first study to investigate the correlation between bacterial communities and total acid during the fermentation of HQGRW. These findings may be helpful in the development of a set of fermentation techniques for controlling total acid.