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•α-Amylase-responsive carrier was fabricated using HMS and α-CD as shell materials.•The release of AVM from AVM-CRF was specifically triggered via α-amylase.•AVM-CRF was more stable ...under UV irradiation than AVM technical.•Toxicity of AVM-CRF to P. xylostella is significant stronger than that of AVM-CF.
α-Amylase-responsive carrier for controlled release of avermectin (AVM) was prepared based on α-cyclodextrin (α-CD) anchored hollow mesoporous silica (HMS) using α-CD as a capping molecule. The release of AVM was studied at different temperatures, pH values and in the presence or absence of α-amylase. The results revealed that the AVM-encapsulated controlled release formulation (AVM-CRF) has a drastic enzymatic dependence, an excellent encapsulation efficacy reaching 38%, and outstanding UV and thermal shielding ability. The AVM-CRF biological activity survey shows excellent toxicological properties against Plutella xylostella larvae, which confirms that α-CD caps could be uncapped enzymatically in vivo and release AVM, inducing P. xylostella larval death. AVM-CRF has a notable capability to keep 0.6 mg L−1 AVM biologically active until 14th day with 83.33% mortality of the target insect, which was 40% higher than that of treated with AVM commercial formulation. The study provides a theoretical basis for the application of pesticide reduction.
In the present study, enzymatic responsive controlled release formulations (CRFs) were fabricated. The CRFs were achieved by anchoring mechanically interlocked molecules using α-cyclodextrin onto the ...surface pore rims of hollow mesoporous silica (HMS). The CRFs were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis. The results showed that the CRFs had extraordinary loading ability for chlorantraniliprole (42% w/w) and could effectively preserve chlorantraniliprole against degradation under thermal conditions and UV radiation. The CRFs have been proven to be enzyme-sensitive. The release ratio of chlorantraniliprole from CRFs can be accelerated observably when external α-amylase was introduced. The persistence of CRFs was evaluated by regular sampling feeding experiment using Plutella xylostella as the target insect. The results showed that the larval mortality of P. xylostella was much higher than that of Coragen under all concentrations after 14 days, which proved that CRFs had remarkable persistence.
Teleoperating robotic manipulators can be complicated and cognitively demanding for the human operator. Despite these difficulties, teleoperated robotic systems are still popular in several ...industrial applications, e.g., remote handling of hazardous material. In this context, we present a novel haptic shared control method for minimising the manipulator torque effort during remote manipulative actions in which an operator is assisted in selecting a suitable grasping pose for then displacing an object along a desired trajectory. Minimising torque is important because it reduces the system operating cost and extends the range of objects that can be manipulated. We demonstrate the effectiveness of the proposed approach in a series of representative real-world pick-and-place experiments as well as in a human subjects study. The reported results prove the effectiveness of our shared control vs. a standard teleoperation approach. We also find that haptic-only guidance performs better than visual-only guidance, although combining them together leads to the best overall results.
Abstract
Challenges in strawberry picking made selective harvesting robotic technology very demanding. However, the selective harvesting of strawberries is a complicated robotic task forming a few ...scientific research questions. Most available solutions only deal with a specific picking scenario, for example, picking only a single variety of fruit in isolation. Nonetheless, most economically viable (e.g., high‐yielding and/or disease‐resistant) varieties of strawberry are grown in dense clusters. The current perception technology in such use cases is inefficient. In this work, we developed a novel system capable of harvesting strawberries with several unique features. These features allow the system to deal with very complex picking scenarios, for example, dense clusters. Our concept of a modular system makes our system reconfigurable to adapt to different picking scenarios. We designed, manufactured, and tested a patented picking head with 2.5‐degrees of freedom (two independent mechanisms and one dependent cutting system) capable of removing possible occlusions and harvesting the targeted strawberry without any contact with the fruit flesh to avoid damage and bruising. In addition, we developed a novel perception system to localize strawberries and detect their key points, picking points, and determine their ripeness. For this purpose, we introduced two new data sets. Finally, we tested the system in a commercial strawberry growing field and our research farm with three different strawberry varieties. The results show the effectiveness and reliability of the proposed system. The designed picking head was able to remove occlusions and harvest strawberries effectively. The perception system was able to detect and determine the ripeness of strawberries with 95% accuracy. In total, the system was able to harvest 87% of all detected strawberries with a success rate of 83% for all pluckable fruits. We also discuss a series of open research questions in the discussion section.
Unlike Newtonian dynamics which is linear and obeys the strong equivalence principle, in any non-linear gravitation such as Milgromian dynamics (MOND), the strong version of the equivalence principle ...is violated and the gravitational dynamics of a system is influenced by the external gravitational field in which it is embedded. This so called external field effect (EFE) is one of the important implications of MOND and provides a special context to test Milgromian dynamics. Here, we study the rotation curves (RCs) of 18 spiral galaxies and find that their shapes constrain the EFE. We show that the EFE can successfully remedy the overestimation of rotation velocities in 80 per cent of the sample galaxies in Milgromian dynamics fits by decreasing the velocity in the outer part of the RCs. We compare the implied external field with the gravitational field for non-negligible nearby sources of each individual galaxy and find that in many cases it is compatible with the EFE within the uncertainties. We therefore argue that in the framework of Milgromian dynamics, one can constrain the gravitational field induced from the environment of galaxies using their RCs. We finally show that taking into account the EFE yields more realistic values for the stellar mass-to-light ratio in terms of stellar population synthesis than the ones implied without the EFE.
Understanding the lethal effects of pesticides nano formulations on the targeted organisms (pathogens) and the non-targeted organisms (fish, earthworms, etc) is essential in assessing the probable ...impact of new technologies on agriculture and environment. Here we evaluated the bioactivity and the biotoxicity of new type of fungicide smart-delivery formulation based on conjugating carboxymethylated-β-glucans on the mesoporous silica nanoparticles (MSNs) surface after loading chlorothalonil (CHT) fungicide in the MSNs pores. The obtained formulation has been characterized with FE-SEM, and HR-TEM. The CHT loading efficiency has been measured with TGA. The bioactivity of the obtained formulation (CHT@MSNs-β-glucans) has been tested against four pathogens, fusarium head blight (Fusarium graminearum), sheath rot (Sarocladium oryzae), rice sheath blight (Rhizoctonia solani), and soyabean anthracnose (Colletotrichum truncatum) compared with CHT WP 75% commercial formulation (CHT-WP) and technical CHT. The environmental biotoxicity of CHT@MSNs-β-glucans compared with CHT-WP has been tested toward earthworm (Eisenia fetida) and zebra fish (Danio rerio). The results showed that CHT@MSNs-β-glucans has an excellent bioactivity against the subjected pathogens with better inhabiting effects than CHT-WP. CHT@MSNs-β-glucans toxicity to Eisenia fetida was found 2.25 times lower than CHT-WP toxicity. The LC50 of CHT@MSNs-β-glucans to zebra fish after the first 24h was 2.93 times higher than CHT-WP. After 96h of treatment, the LC50 of CHT@MSNs-β-glucans was 2.66 times higher than CHT-WP. This work highlighted the necessity to increase the mandatory bioassays of nano formulations with the major non-target organisms in the environmental risk assessment of new pesticide formulations.
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•In vitro bioassays used to assess toxicity of CHT-WP vs. CHT@MSNs-β-glucans.•CHT@MSNs-β-glucans bioactivity against pathogens is better than CHT-WP.•CHT@MSNs-β-glucans has lower toxicity to Eisenia fetida than CHT-WP.•CHT@MSNs-β-glucans has lower toxicity to zebra fish.•CHT@MSNs-β-glucans possessed good biocompatibility and biosafety.
We apply machine-learning techniques to construct nonlinear nonparametric forecasting models of consumer credit risk. By combining customer transactions and credit bureau data from January 2005 to ...April 2009 for a sample of a major commercial bank’s customers, we are able to construct out-of-sample forecasts that significantly improve the classification rates of credit-card-holder delinquencies and defaults, with linear regression
R
2’s of forecasted/realized delinquencies of 85%. Using conservative assumptions for the costs and benefits of cutting credit lines based on machine-learning forecasts, we estimate the cost savings to range from 6% to 25% of total losses. Moreover, the time-series patterns of estimated delinquency rates from this model over the course of the recent financial crisis suggest that aggregated consumer credit-risk analytics may have important applications in forecasting systemic risk.
Fosthiazate is a widely used chiral organophosphorous nematicide with four stereoisomers. The present study systemically assessed the stereoselectivity of fosthiazate for the first time, including ...absolute configuration confirmation, stereoselective bioactivity toward nematode and aphid, toxicity to honeybees, and stereoselective degradation in cucumber and pepper under field conditions. The absolute configurations of the four stereoisomers that eluted on the Superchiral IG-3 column were confirmed as (1S,3R)-(−)-fosthiazate, (1S,3S)-(−)-fosthiazate, (1R,3S)-(+)-fosthiazate, and (1R,3R)-(+)-fosthiazate. In comparison to the other two stereoisomers, (1S,3R)-fosthiazate and (1S,3S)-fosthiazate possess more than 100 times bioactivity and 10 times toxicity toward the target and non-target organisms, respectively. The molecular docking found that (1S,3R)-fosthiazate and (1S,3S)-fosthiazate had shorter binding distances and lower energies with acetylcholinesterase (AChE), which illuminated the mechanism of the experimental results. In addition, both of the high-bioactive stereoisomers had faster degradation rates in cucumber and pepper. On the basis of the results of bioactivity, toxicity, and degradation behavior, the stereoisomer mixture with (1S,3R)-fosthiazate and (1S,3S)-fosthiazate will be a better option than racemic fosthiazate to increase the bioactivity and reduce application rates.
Controlled release formulation of pesticides is a highly desirable way to increase the efficiency of the pesticide as well as help reduce environmental pollution issues. In the present study, a novel ...adhesive organic-inorganic hybrid material with a uniform size and morphology was fabricated employing hollow mesoporous silica (HMS) as an inlayer material and poly(diacetone acrylamide) (PDAAM) as an outer layer material. HMS was fabricated using polystyrene (PS) spheres as a hard template. Then, HMS was functionalized with 3-aminopropyltriethoxysilane and 2-bromoisobutyryl bromide after removal of PS. Finally, PDAAM was grafted onto HMS using surface-initiated atom transfer radical polymerization. Cyantraniliprole (CNAP) utilized as a model pesticide was incorporated into hybrid material to prepare controlled release formulation. The results showed that both CNAP−loaded HMS and HMS−PDAAM had extraordinary loading efficiencies (approximately 50% w/w). Kinetic studies of CNAP release demonstrated that CNAP−loaded HMS−PDAAM exhibited a sustained release property for at least 25 days. The stability test identified that CNAP−loaded HMS and HMS−PDAAM were much more stable under UV irradiation and thermal conditions than CNAP technical. Tests of the adhesive properties showed that the adhesive property of HMS−PDAAM was far stronger than that of HMS on rice leaves. Given the advantages of HMS−PDAAM, this hybrid material may be applied to other photosensitive pesticides, especially those used for foliar spraying.
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•A novel hybrid material was fabricated employing HMS and PDAAM as shell materials.•CNAP-loaded HMS@PDAAM exhibited a sustained release property.•CNAP-loaded HMS@PDAAM was more stable under UV irradiation than CNAP technical.•HMS@PDAAM showed far stronger adhesive property than that of HMS on rice leaves.
In this study, pH-responsive LC@O-CMCS/PU nanoparticles were prepared by encapsulating λ-cyhalothrin (LC) with O-carboxymethyl chitosan (O-CMCS) to form LC/O-CMCS and then covering it with ...polyurethane (PU). Characterization and performance test results demonstrate that LC@O-CMCS/PU had good alkaline release properties and pesticide loading performance. Compared to commercial formulations containing large amounts of emulsifiers (e.g., emulsifiable concentrate, EC), LC@O-CMCS/PU showed better leaf-surface adhesion. On the dried pesticide-applied surfaces, the acute contact toxicity of LC@O-CMCS/PU to Harmonia axyridis (H. axyridis) was nearly 20 times lower than that of LC EC. Due to the slow-releasing property of LC@O-CMCS/PU, only 16.38 % of LC was released at 48 h in dew and effectively reduced the toxicity of dew. On the pesticide-applied leaves with dew, exposure to the LC (EC) caused 86.66 % mortality of H. axyridis larvae significantly higher than the LC@O-CMCS/PU, which was only 16.66 % lethality. Additionally, quantitative analysis demonstrated 11.33 mg/kg of λ-cyhalothrin in the dew on LC@O-CMCS/PU lower than LC (EC) with 4.54 mg/kg. In summary, LC@O-CMCS/PU effectively improves the safety of λ-cyhalothrin to H. axyridis and has great potential to be used in pest control combining natural enemies and chemical pesticides.
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