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•A new training algorithm is proposed for agricultural color classification problems.•The proposed method selects the optimal color space and channels for each scenario.•Applied to ...estimate accurately and efficiently the percentage of green cover (PGC).•Developed an application called ACPS (Automatic Classification of Plants and Soil).
Color analysis techniques in agriculture should be able to deal with non-trivial capture conditions such as shadows, noise, pixel saturation, low lighting, different varieties of crops and intrinsic parameters of the cameras. Previous studies have shown the importance of selecting the optimum color space for each application domain. This paper presents a new probabilistic approach to color processing capable not only to create optimum color models for the plant/soil segmentation, but also to select the most adequate color space for each problem. The system evaluates all the possible alternatives, producing color models in the optimum space and channels. Thereby, the dependences on the kind of crop, camera and capture conditions are avoided, since the method is adapted to the training conditions. The basis of the proposal is the use of non-parametric models for the probability density functions of plant/soil colors. The proposed method has been implemented and validated in a new software tool, called ACPS (Automatic Classification of Plants and Soil), thus proving its practical feasibility. The final purpose of this system is the analysis of the vegetal ground cover, in order to obtain the PGC (percentage of green cover) parameter. The ACPS software has been developed to be used by professionals, researchers, technicians and anyone working in the agricultural area. Furthermore, the models created can be exported to a defined file format which can be used in applications in the cloud, mobile devices and compact controllers that are currently being developed.
The coronavirus infectious disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has been spreading rapidly worldwide, creating a pandemic. This ...article describes the evaluation of the antiviral activity of nordihydroguaiaretic acid (NDGA), a molecule found in Creosote bush (
) leaves, against SARS-CoV-2 in vitro. A 35 µM concentration of NDGA was not toxic to Vero cells and exhibited a remarkable inhibitory effect on the SARS-CoV-2 cytopathic effect, viral plaque formation, RNA replication, and expression of the SARS-CoV-2 spike glycoprotein. The 50% effective concentration for NDGA was as low as 16.97 µM. Our results show that NDGA could be a promising therapeutic candidate against SARS-CoV-2.
•Low cost camera modules have been designed for continuous crop monitoring.•They are connected to a cloud computing server using client-server architecture.•The server contains functionality for ...image analysis and a web user interface.•The main objective is water balance estimation and precise irrigation scheduling.
The use of low cost cameras has been extended in all fields of technology in general, and agricultural applications in particular. Images provide useful information on the growing state of horticultural crops, which allow an accurate estimation of water balance and, hence, precise irrigation scheduling. In all of these cases, the temporary images of a crop can provide the percentage of green cover (PCG). This data is calibrated with the irrigation water amount that the crop needs for growing. Therefore, the use of visual monitoring systems in agriculture may reduce water consumption and increase productivity. In this paper, a novel system is presented using low cost cameras and a client-server architecture. It is composed of a set of inexpensive camera modules which communicate with a cloud computing server. Camera modules have been developed using open standard Arduino components; they are able to work independently, with their own connectivity, storage and power supply. On the other hand, the server is responsible for configuring these modules, performing computer vision algorithms and water balance estimation, storing all data in a secure database, and interacting with the user interface using the web. The final result is a complete and inexpensive system that allows continuous monitoring of the state of the crops, providing the user with valuable information about water balance for irrigation management. The proposed method achieves a high accuracy in the estimation of PGC, with an average error below 5%, requiring less than 2s of processing time per image in the server. This is transformed into an error in the computation of the crop coefficient below 1%. Technical details on the hardware and software components of the system are presented. Finally, advantages and weaknesses of the proposed solution are discussed, drawing new lines for future research.
•Measurements of two soil moisture sensor devices are compared (a commercial device and a low-cost prototype).•Soil temperature is seen to increase the measured capacitance, whilst electronics ...temperature effectively decreases the measured capacitance.•The calibration of these phenomena is included.
Frequency Domain Analysis is a well established technique in soil moisture determination, using the change in electrical capacitance of probes inserted into the soil caused by the presence of water. However it is known that temperature affects the determination of this capacitance. Here two different techniques are used, the first passing a fixed frequency through the soil via insulated probes, then measuring the amplitude of the resultant signal. The second uses the soil capacitance as the controlling component in a variable frequency oscillator, measuring the resultant times to charge and discharge. The measured capacitance is seen to be affected both by the temperature of the soil and, due to the sensitive nature of the monitoring electronics, also the temperature of critical components in the measurement circuits. Results from these experiments show that these two effects are complementary, soil temperature adding to the measured capacitance, whilst electronics temperature effectively decreases the measured capacitance. The daily profiles of the soil and electronics temperatures, whilst both rising during the day, and falling at night, show significant phase difference and therefore do not simply cancel out. Further, the strength of temperature compensation required is shown to vary with technique and moisture level. This paper explores these phenomena using results from a recently developed, four probe Frequency Domain capacitance based sensor costing around 12 Euros. These measurements are compared to those achieved by a commercial soil moisture system costing over 250 times this price. Preliminary results are presented from temperature compensation algorithms intended to minimize these effects.
•An AC of 50Hz was found to be suitable for characterizing the MI of olives.•An ADC of 10bits was sufficient for measuring the conductivity properly.•The conductivity increased while the hardness ...decreased during maturation.•Olive varieties have an average value of conductivity from ripening to maturation.•Electrical conductivity can be easily applied in the olive groves.
Measurement of the electrical conductivity of various agrifood products is used to determine different parameters of foods, such as the moisture content and germinability of seeds or the resistance of fruits to frost. Recent studies have established the measurement of electrical impedance asa technique for assessing the maturity stage and fruit quality. In this study, we developed an experimental conductivity meter of alternating current (AC) at 50Hz frequency, controlled by a microprocessor PIC18F2550 linked to aPC via a USB port. This device was used to measure the electrical conductivity in the mesocarp of olives (Olea europaea L.), which are used in oil production, at different stages of maturity. The measurements of electrical conductivity (expressed in % of full scale) were then used to establish an objective fruit maturity index and to determine the optimal timing of collection based on parameters such as oil yield and quality. The evolution of electrical conductivity in the mesocarp of the fruit was measured in four different cultivars, ‘Picual’, ‘Manzanilla de Sevilla’, ‘Hojiblanca’, and ‘Gordal Sevillana’. Our findings showed that the conductivity increased according to the stage of ripeness. Similarly, each variety had a characteristic average value for the latter stages of ripening and maturation.
•Performance automation indicators in pressurized collective irrigation pipeline networks.•Comparison of several irrigation networks in water user associations.•Water and energy savings for several ...case studies.
Water and energy in the agricultural sector must be used efficiently to obtain sustainable agriculture, which also leads to economical savings. This also has a positive influence on the conservation of fossil resources and the reduction of contamination. Automation in irrigation systems permits the control of water and energy resources. Therefore, several parameters related to water and energy efficiency, both in the pump station and in the collective irrigation network, can be controlled. In this study, several performance indicators are proposed to assess the implementation of automation in water user associations. Both the indicators and the methodology used for data gathering are detailed in the study, and the results of a case study in southeast Spain are presented. The results demonstrate that automation is a low-cost investment (1.24–6.72% of the total costs) compared to the large benefits and advantages (2.05–8.21% energy saving and 0.71–6.46% water saving). Moreover, the amortization periods are very short and are less than 1.5 years in the majority of cases.
The role of re-treatment with rituximab in aggressive B-cell lymphomas still needs to be defined. This study evaluated the influence of prior exposure to rituximab on response rates and survival in ...patients with diffuse large B-cell lymphoma treated with rituximab plus etoposide, cytarabine, cisplatinum and methylprednisolone (R-ESHAP).
We retrospectively analyzed 163 patients with relapsed or refractory diffuse large B-cell lymphoma who received R-ESHAP as salvage therapy with a curative purpose. Patients were divided into two groups according to whether rituximab had been administered (n=94, "R+" group) or not (n=69, "R-" group) prior to R-ESHAP.
Response rates were significantly higher in the R- group in the univariate but not in the multivariate analysis. In the analysis restricted to the R+ group, we observed very low complete remission and overall response rates in patients with primary refractory disease (8% and 33%, respectively), as compared to those in patients who were in first partial remission (41% and 86%) or who had relapsed disease (50% and 75%) (p<0.01 in both cases). Overall, 60% and 65% of patients in the R+ and R- groups, respectively, underwent stem-cell transplantation after the salvage therapy. With a median follow-up of 29 months (range, 6-84), patients in the R+ group had significantly worse progression-free survival (17% vs. 57% at 3 years, p<0.0001) and overall survival (38% v 67% at 3 years, p=0.0005) than patients in the R- group. Prior exposure to rituximab was also an independent adverse prognostic factor for both progression-free survival (RR: 2.0; 95% CI: 1.2-3.3, p=0.008) and overall survival (RR: 2.2; 95% CI: 1.3-3.9, p=0.004).
R-ESHAP was associated with a high response rate in patients who were not refractory to upfront rituximab-based chemotherapy. However, the survival outcome was poor for patients previously exposed to rituximab, as compared to in those who had not previously been treated with rituximab.
•A minimal cost, temperature compensated soil moisture measurement system for determining irrigation water requirements in real time.•Local data-logging incorporated to provide resilience against ...communications network failures.•Design for cost effective deployment in micro-managed irrigation environments and geographical areas where water is a critically scarce resource.•Capable of low cost expansion to provide a range of additional data and services.•The calibration of the device and the conditions of use in a variety of soil types are demonstrated.
Measurement of soil moisture is a fundamental parameter for irrigation scheduling. In order to determine this parameter, many types of sensors are employed. Some of these sensors for soil moisture measurements are based on electric resistivity. Measurements are affected by many factors including soil temperature, length of probes, amongst others, that can cause incorrect determination of soil moisture levels. Consequently, this can lead to inappropriate or unnecessary irrigation. The main objective of this paper is the presentation of results of several experiments focused on determining adequate temperature compensation for a simple soil moisture measurement and registration system based on resistivity measurements (Wenner compensation). Moreover, a comparison between the data obtained by this device and a reference sensor is included. The device was calibrated in a plot with potted vineyards (Vitis vinifera L. cv Bobal on 110R) under drip irrigation and additional conditions. Results are adequate and include a method of compensation of measured values based in a rolling average model of soil temperature with a good agreement. A simple weighed combination of box temperature of the device and 14cm deeper temperatures can provide a useful level of Wenner compensation. Additionally, this device has a competitive price and is adequate for water management in crops.
► Portable and easy-to-use solution to detect possible failures at a PV installation. ► Calculation of solar and photovoltaic parameters by using a mobile device with GPS. ► No software which confers ...this utility to a mobile device can be found in the market.
The application of the Information and Communication Technologies (ICTs) to the photovoltaic (PV) energy sector has increased notably in the last years. This paper presents a new mobile software application for maintenance tasks in PV installations by determining the PV output power of the system, the daily energy production, the clear-sky global solar radiation and other parameters associated with solar position from Global Position Data in handheld devices endowed with Android or Windows Mobile operating systems. The calculation of these parameters permits a technician to know if the PV plant is working properly, since the difference between the PV output power supplied by the installation in a clear-sky day for a determined hourly period and the values estimated by the application should be minimal. In case of fixed installations, the application also permits to determine if the PV module support structures of the installation are correctly oriented. Some comparisons between data supplied by four real PV installations and data calculated by the proposed application were performed for evaluation purposes.
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