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Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Stem expansion and contraction are closely related to the plant water status. It is of great significance to real-time monitor the stem expansion and contraction, in order to improve the utilization rate of agricultural water resources in irrigation systems. Therefore, the sensors have been mainly used to monitor the expansion and contraction of plant stems at present. The linear micro-displacement can be measured to assess the plant water status. However, it is still limited to the high cost and inconvenient installation. In this study, a flexible and wearable sensor was designed and developed using the piezoresistive effect. A flexible pressure electrode was used as the sensing element to monitor the pressure variation, which was attached to the surface of plant stems. Different from the linear micro-displacement sensor, the developed sensor was used to assess the pressure variation caused by the expansion and contraction of the stem. The pressure signal detection and data collection were also designed to convert the pressure into electrical signals for storage. A series of experiments were conducted to evaluate the performance of the pressure sensor. Firstly, the performance test and sensor calibration were conducted under laboratory conditions. Then, the pressure sensor was installed on a tomato stem in a greenhouse, in order to observe the pressure variation. A comparison was made with the linear micro-displacement sensor. Finally, the variations in the expansion and contraction of tomato stems were observed under sufficient irrigation and water deficit using the two types of sensors. The results show that the average relative change rate of the stability test for flexible pressure sensors was 0.109%; There was negligible output variation caused by bending; The determination coefficient of calibration was greater than 0.99, and the most suitable working range was 2-100 kPa; The determination coefficient of the measurements between the two types of sensors was 0.955 1, compared with the linear micro displacement sensors. The greenhouse experiments show that the determination coefficients of the measurements using the two types of sensors were 0.767 2 and 0.851 9, respectively, for full irrigation and deficient irrigation. The flexible and wearable pressure sensor can be expected to monitor the variations in the expansion and contraction of tomato stems. The water deficit stress of the tomato can also be diagnosed as well. The pressure sensor achieved better performance during the experiment, such as the low cost and easy installation, compared with the linear micro-displacement sensors. [ABSTRACT FROM AUTHOR]

A root is one of the most important vegetative organs of plants. It is of great significance to explore the growth status of root under different water stress in modern agriculture. However, the existing observation of plant root are cumbersome, laborious and time-consuming. It is the high demand to meet the requirements of precision irrigation and water-saving under field conditions. In this study, a pipeline robot system was developed for the synchronous, in-situ and the high-throughput monitoring of plant root and root soil water using STM32. The system consisted of pipeline robot, data base station and PVC transparent pipeline. The pipeline robot system was embedded in the soil, where the macro camera and soil moisture sensor were carried by the robot. The root images were captured to obtain the soil moisture data while the robot cruising. Meanwhile, the robot shared the functions of autonomous timing cruise, wireless communication using command data and active return after encountering obstacles. The distorted correction, registered on plane, identified and segmented images were obtained for the parameters of the root area, length and density of the plants in the direction of the pipeline. The results of laboratory test show that: 1) The pipeline robot was clearly captured the root images, indicating the excellent performance on distortion correction and plane registration. The true length and area corresponding to a single pixel were 44 μm and 0.002 mm², respectively, whereas, the shooting range of a single root image was 14.17×10.60 mm. The characteristic information of root was obtained using MATLAB, where the images taken by the automatic cruise of pipeline robot. The image processing operations included the image distortion correction, image preprocessing, root region recognition and segmentation, and root feature extraction. Compared with the root characteristic parameters measured by the excavation, the relative errors of the root image processing program were 12.29%, 3.40% and 12.50%, respectively; 2) There was an excellent linear relationship between the output voltage of the soil moisture sensor that carried by the pipeline robot and the soil volumetric moisture content, where the coefficient of determination was 0.990; 3) The pipeline robot presented a high accuracy of autonomous cruise positioning, with a mean relative error of 1.47%. The field experiment show that: 1) The pipeline robot system was captured the plant root images with high-throughput in the field environment. Root growth dynamics was obtained to further extract the parameters of root length, area, average diameter and density from the images; 2) The pipeline robot was accurately monitor the soil moisture in the root zone, where the mean relative error of the measured was 2.23%, compared with the drying measurement; 3) Once the system was initially fully charged, the pipeline robot system operated independently for no less than 7 days, where the maximum cruise monitoring distance was about 48m. The pipeline robot system can be expected to realize insitu and high-throughput measurement of plant root and soil moisture in the root zone under field environment. The growth of root can be extracted after image recognition and segmentation. The finding can also provide the technical support to monitor the growth status of root in water-saving irrigation. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Yellow River is the property of Editorial Board of Yellow River and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Soil saturated hydraulic conductivity is an important parameter to calculate the water flux of soil profile in the irrigation and drainage system for agricultural production and resource utilization. An accurate and rapid measurement directly determines the prediction accuracy of various hydrological and hydrodynamic models. However, there are great differences in the saturated hydraulic conductivity in space, due to the different soil texture, structure, as well as physical and chemical properties. The current measurement approaches are time-consuming and laborious for the soil saturated hydraulic conductivity in the soil hydrodynamics. In this study, a rapid measurement was proposed for the soil saturated hydraulic conductivity combining the linear source inflow method and mobile phone image processing. Soil saturated hydraulic conductivity refers to the water flux per unit area of soil perpendicular to the water flow direction under the action of unit water potential gradient, when all pores of soil are filled with water. Soil infiltration rate refers to the rate at which water penetrates into the ground at any given time. The soil infiltration rate is close to a fixed value when the soil water is close to or reaches saturation in the process of infiltration. Therefore, this value is usually considered to be close to the actual soil saturated hydraulic conductivity. The specific procedure was taken as the core idea. Firstly, the soil infiltration rate was measured to consider the infiltration rate, when the water was saturated as the soil saturated hydraulic conductivity. The diffusion process of linear water flow on the soil surface was recorded by a mobile phone. The wetted area of the soil surface and the change curve with time were calculated, after the image processing operations, such as cutting, distortion correction, binarization, and count the number of target pixels in the binarized image. The water balance principle was selected to estimate the change process of soil steady-state infiltration rate using the linear source inflow method. The stable infiltration rate was taken as the soil saturated hydraulic conductivity, and then compared with the saturated hydraulic conductivity measured by the traditional constant head method. The results show that after the distortion correction and image processing, the surface wetted area of Quercus variabilis BL. forest soil, Pinus tabulaeformis Carr. forest soil and sandy loam presented an excellent power exponential relationship with the time, where the determination coefficients R2 were 0.994, 0.995, and 0.998 respectively. The steady-state infiltration rates (i.e. soil saturated hydraulic conductivity) of Quercus variabilis BL. forest soil, Pinus tabulaeformis Carr. forest soil, and sandy loam measured by the linear source inflow method were 23.40±1.21, 23.86±1.83, and 22.99±2.26 mm/h, respectively. At the same time, the values of saturated hydraulic conductivity for the three soil samples measured by the constant head standard method were 24.41±1.53, 24.26±0.37, and 23.81±0.10 mm/h respectively. The relative errors of the two methods were 4.14% 1.64% and 3.42%, respectively. It can be seen that the measurement was reasonable, simple, and accurate under the condition of sufficient water supply. The new measurement method can be widely expected to quickly acquire the soil saturated hydraulic conductivity. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of CT Theory & Applications is the property of Editorial Department of CT Theory & Applications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective To observe the expression changes of microRNA-155 (miR-155) in the peripheral blood mono-nuclear cells (PBMC) of patients with dilated cardiomyopathy (DCM) and to explore the relationship between miR-155 level and heart function. Methods Thirty patients with DCM (observation group) and 30 healthy volunteers (control group) were selected. In the observation group, 10 cases were grade Ⅱof NYHA functional classification, 11 cases were grade Ⅲand 9 cases were grade Ⅳ. PBMC in the two groups were separated by Ficoll-Hypaque density gradient centrifugation, and the relative expression of miR-155 was detected by real-time fluorescence quantitative PCR. The miR-155 levels were compared between the observation group and the control group and among DCM patients with different NYHA functional classification. In the observation group, the left ventricular ejection fraction (LVEF) and left ventricular end diastolic diameter (LVEDd) were recorded by color Doppler ultrasound. The relationships between miR-155 levels and LVEF, LVEDd were analyzed in DCM patients. Results The relative expression levels of miR-155 in the observation group and control group were (0.50 ±0.24) and (1.00 ±0.23), which showed a significant difference (P<0.01). The relative expression levels of miR-155 in NYHA functional classification Ⅱ,Ⅲ, ⅣDCM patients were (0.77 ±0.10), (0.47 ± 0.10) and (0.23 ±0.08), respectively.There were significant differences between each two groups (all P<0.01).In the observation group , the LVEF was 28%±10%, and the LVEDd was (70 ±7) mm. The miR-155 level was negatively correlated with NYHA functional classification , LVEF and LVEDd in DCM patients (r=-0.94, -0.67 and -0.53, P<0.05 or P<0.01). Conclusions The expression level of miR-155 is down-regulated in PBMC of DCM patients and is correlated with the severity of impaired cardiac function. [ABSTRACT FROM AUTHOR]