Observation of two-dimensional yttrium oxide nanoparticles in mealworm beetles (Tenebrio molitor)

Nanomaterials are being used in medicine, manufacturing and consumer products, but their effects on organisms and the environment are not well understood because of the difficulty in detecting them. Here dual-energy X-ray K-edge subtraction was used to track two-dimensional yttrium oxide nanoparticles (which can be found in such household objects as color televisions) in adult mealworms (Tenebrio molitor). The insects ingested nanoparticle-infused feed for different time periods, up to 24 h, and the nanoparticles could then be identified at several locations in the insects’ head, thorax and abdomen, mostly within the digestive tract. In time, all particles were excreted.From Journal of Synchrotron Radiation, Volume 23, Issue 5 Pages 1056–1272. Published by John Wiley & Sons Ltd. Available online: http://dx.doi.org/10.1107/S1600577516009942. © 2016 International Union of Crystallography.Publisher version: https://doi.org/10.1107/S160057751600994

Observation of two-dimensional yttrium oxide nanoparticles in mealworm beetles ( Tenebrio molitor )

Nanomaterials are being used in medicine, manufacturing and consumer products, but their effects on organisms and the environment are not well understood because of the difficulty in detecting them. Here dual-energy X-rayK-edge subtraction was used to track two-dimensional yttrium oxide nanoparticles (which can be found in such household objects as color televisions) in adult mealworms (Tenebrio molitor). The insects ingested nanoparticle-infused feed for different time periods, up to 24 h, and the nanoparticles could then be identified at several locations in the insects' head, thorax and abdomen, mostly within the digestive tract. In time, all particles were excreted.</jats:p

Observation of two-dimensional Yttrium-oxide nanoparticles in mealworm beetles

Presented at the Advance Light Source’s (ALS) annual user meeting at the Lawrence Berkeley National Laboratory in Berkeley, CA. October 5-7, 2015. (The student Y. Chen, as first author, received the Neville B. Smith Student Poster Award.

An alternative novel tool for DNA editing without target sequence limitation: the structure-guided nuclease

Engineered endonucleases are a powerful tool for editing DNA. However, sequence preferences may limit their application. We engineer a structure-guided endonuclease (SGN) composed of flap endonuclease-1 (FEN-1), which recognizes the 3′ flap structure, and the cleavage domain of Fok I (Fn1), which cleaves DNA strands. The SGN recognizes the target DNA on the basis of the 3′ flap structure formed between the target and the guide DNA (gDNA) and cut the target through its Fn1 dimerization. Our results show that the SGN, guided by a pair of gDNAs, cleaves transgenic reporter gene and endogenous genes in zebrafish embryonic genome. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13059-016-1038-5) contains supplementary material, which is available to authorized users

Observation of yttrium oxide nanoparticles in cabbage (Brassica oleracea) through dual energy K-edge subtraction imaging

BACKGROUND: The potential transfer of engineered nanoparticles (ENPs) from plants into the food chain has raised widespread concerns. In order to investigate the effects of ENPs on plants, young cabbage plants (Brassica oleracea) were exposed to a hydroponic system containing yttrium oxide (yttria) ENPs. The objective of this study was to reveal the impacts of NPs on plants by using K-edge subtraction imaging technique. RESULTS: Using synchrotron dual-energy X-ray micro-tomography with K-edge subtraction technique, we studied the uptake, accumulation, distribution and concentration mapping of yttria ENPs in cabbage plants. It was found that yttria ENPs were uptaken by the cabbage roots but did not effectively transferred and mobilized through the cabbage stem and leaves. This could be due to the accumulation of yttria ENPs blocked at primary-lateral-root junction. Instead, non-yttria minerals were found in the xylem vessels of roots and stem. CONCLUSIONS: Synchrotron dual-energy X-ray micro-tomography is an effective method to observe yttria NPs inside the cabbage plants in both whole body and microscale level. Furthermore, the blockage of a plant’s roots by nanoparticles is likely the first and potentially fatal environmental effect of such type of nanoparticles

Heterogeneity Impacts of Farmers’ Participation in Payment for Ecosystem Services Based on the Collective Action Framework

Payments for ecosystem services (PES) are designed to reduce the impact of human activities on eco-sensitive areas. PES programs often adopt economic-incentive and command-control strategies. Increasing the enthusiasm of farmers’ participation is crucial for the sustainability of PES programs and ecosystem restoration. The watershed ecological compensation in Xin’an River Basin is the first horizontal ecological compensation pilot in China. In this study, economic-incentive strategy and command-control strategies in living and farming are implemented simultaneously to improve water quality. Under the collective action framework, we analyze the drivers of farmers’ participation in three concurrent strategies using hierarchical linear models (HLM). The results show: (1) Overall, 81.79%, 76.26%, and 79.11% of farmers are willing to participate in economic-incentive strategy, command-control strategy in living, and command-control strategy in farming, respectively, while 18.21%, 23.74%, and 20.89% are from the village level. (2) Among statistically significant (p < 0.01) factors at the farmer level, social trust (β = 0.305), and social participation (β = 0.134) have positive effects on the economic-incentive strategy; the number of communication and entertainment equipment has a positive effect on the willingness to participate in command-control strategy in living (β = 0.287) and command-control strategy in farming (β = 0.336). (3) At the village level, village characteristics have a direct impact on the farmers’ willingness to participate in strategies. Village woodland area is positively correlated with strategies participation. In addition, village characteristics play a moderating role by influencing farmers’ sustainable livelihood capital. We conclude that different concurrent strategies and collective actions need to be considered in the design of PES programs, particularly in ecologically sensitive areas, which can enrich the theory of collective action and the connotation of PES

Learning-based Nonlinear Model Predictive Control

© 2017 This paper presents stabilizing Model Predictive Controllers (MPC) in which prediction models are inferred from experimental data of the inputs and outputs of the plant. Using a nonparametric machine learning technique called LACKI, the estimated (possibly nonlinear) model function together with an estimation of Holder constant is provided. Based on these, a number of predictive controllers with stability guaranteed by design are proposed. Firstly, the case when the prediction model is estimated offline is considered and robust stability and recursive feasibility is ensured by using tightened constraints in the optimisation problem. This controller has been extended to the more interesting and complex case: the online learning of the model, where the new data collected from feedback is added to enhance the prediction model. An on-line learning MPC based on a double sequence of predictions is proposed.Spanish MINECO Grant PRX15-00300 and projects DPI2013-48243-C2-2-R and DPI2016-76493-C3-1-R. UK Engineering and Physical Research Council, grant no.EP/J012300/1

Amine-responsive bilayer films with improved illumination stability and electrochemical writing property for visual monitoring of meat spoilage

Amine-responsive bilayer films were developed by using agar (AG), anthocyanins (AN), gellan gum (GG) and TiO2 nanoparticles for visual monitoring of meat spoilage. The AG-AN layer worked as the sensing layer to volatile amines, while GG-TiO2 layer served as the light barrier layer and simultaneously the conducting layer to improve the illumination stability and electrochemical writing ability of the AG-AN layer, respectively. The Scanning electron microscopy (SEM) images and X-ray diffraction (XRD) spectra indicated the successful fabrication of bilayer films. Illumination experiments showed that the incorporation of TiO2 in the GG-TiO2 layer significantly improved the illumination stability of AN in the AG-AN layer. Meanwhile, electrochemical writing process could be easily conducted on the AG-AN layer in the presence of GG-TiO2 layer, indicating the feasibility of ink-free printing on bilayer biopolymer films. The AG-AN/GG-2%TiO2 film presented a limit of detection of 0.018 mM to trimethylamine (TMA), a typical basic gas generated during meat spoilage. Based on its good illumination stability and sensing ability to basic gases, the AG-AN/GG-2%TiO2 film exhibited rose red-to-green color changes along with the spoilage of pork and silver carp, indicating its great potential for monitoring meat spoilage in intelligent food packaging