Gapless topological Fulde-Ferrell superfluidity induced by in-plane Zeeman field

Topological superfluids are recently discovered quantum matters that host topologically protected gapless edge states known as Majorana fermions - exotic quantum particles that act as their own anti-particles and obey non-Abelian statistics. Their realizations are believed to lie at the heart of future technologies such as fault-tolerant quantum computation. To date, the most efficient scheme to create topological superfluids and Majorana fermions is based on the Sau-Lutchyn-Tewari-Das Sarma model with a Rashba-type spin-orbit coupling on the }\textbf{\textit{x-y}}\textbf{ plane and a large out-of-plane (perpendicular) Zeeman field along the }\textbf{\textit{z}}\textbf{-direction. Here we propose an alternative setup, where the topological superfluid phase is driven by applying an in-plane Zeeman field. This scheme offers a number of new features, notably Cooper pairings at finite centre-of-mass momentum (i.e., Fulde-Ferrell pairing) and gapless excitations in the bulk. As a result, a novel gapless topological quantum matter with inhomogeneous pairing order parameter appears. It features unidirected Majorana surface states at boundaries, which propagate in the same direction and connect two Weyl nodes in the bulk. We demonstrate the emergence of such an exotic topological matter and the associated Majorana fermions in spin-orbit coupled atomic Fermi gases and determine its parameter space. The implementation of our scheme in semiconductor/superconductor heterostructures is briefly discussed.Comment: 8 pages, 5 figure

Cross-Layer Adaptive Feedback Scheduling of Wireless Control Systems

There is a trend towards using wireless technologies in networked control systems. However, the adverse properties of the radio channels make it difficult to design and implement control systems in wireless environments. To attack the uncertainty in available communication resources in wireless control systems closed over WLAN, a cross-layer adaptive feedback scheduling (CLAFS) scheme is developed, which takes advantage of the co-design of control and wireless communications. By exploiting cross-layer design, CLAFS adjusts the sampling periods of control systems at the application layer based on information about deadline miss ratio and transmission rate from the physical layer. Within the framework of feedback scheduling, the control performance is maximized through controlling the deadline miss ratio. Key design parameters of the feedback scheduler are adapted to dynamic changes in the channel condition. An event-driven invocation mechanism for the feedback scheduler is also developed. Simulation results show that the proposed approach is efficient in dealing with channel capacity variations and noise interference, thus providing an enabling technology for control over WLAN.Comment: 17 pages, 12 figures; Open Access at http://www.mdpi.org/sensors/papers/s8074265.pd

End-to-End Adversarial Shape Learning for Abdomen Organ Deep Segmentation

Automatic segmentation of abdomen organs using medical imaging has many potential applications in clinical workflows. Recently, the state-of-the-art performance for organ segmentation has been achieved by deep learning models, i.e., convolutional neural network (CNN). However, it is challenging to train the conventional CNN-based segmentation models that aware of the shape and topology of organs. In this work, we tackle this problem by introducing a novel end-to-end shape learning architecture -- organ point-network. It takes deep learning features as inputs and generates organ shape representations as points that located on organ surface. We later present a novel adversarial shape learning objective function to optimize the point-network to capture shape information better. We train the point-network together with a CNN-based segmentation model in a multi-task fashion so that the shared network parameters can benefit from both shape learning and segmentation tasks. We demonstrate our method with three challenging abdomen organs including liver, spleen, and pancreas. The point-network generates surface points with fine-grained details and it is found critical for improving organ segmentation. Consequently, the deep segmentation model is improved by the introduced shape learning as significantly better Dice scores are observed for spleen and pancreas segmentation.Comment: Accepted to International Workshop on Machine Learning in Medical Imaging (MLMI2019

Near-infrared quantum cutting in Tm3+/Yb3+-doped phosphate glasses

Abstract A series of phosphate glasses with compositions of 30SrO-60P2O5-10Na2O-0.5Tm2O3-xYb2O3(x = 0, 1, 5, 9, 11 in mol%) were manufactured by melt-casting method, the quantum cutting between the Tm3+ and Yb3+ in the phosphate glasses is investigated, the energy transfer from Tm3+:1G4 to Yb3+:2F5/2 is proved. According to calculate, the highest quantum efficiency is up to 159.9%, the emission wavelength is at 1020 nm, matching the energy band gap of a silicon solar cell well, therefor, these phosphate glasses could potentially be used in silicon solar cells

Influence of Reducing Agents on Biosafety and Biocompatibility of Gold Nanoparticles

Extensive biomedical applications of nanoparticles are mainly determined by their safety and compatibility in biological systems. The aim of this study was to compare the biosafety and biocompatibility of gold nanoparticles (GNPs) prepared with HEPES buffer, which is popular for cell culture, and sodium citrate, a frequent reducing agent. From experimental results on the body weight and organ coefficients of acute oral toxicity tests, it could be observed that HEPES-prepared GNPs are biologically safer than citric-prepared GNPs at the same dose of 500 μg/kg. The in vitro cell viability was higher for HEPES-prepared GNPs than citric-prepared GNPs at 5.0- and 10.0-ug/mL concentrations. More reactive oxygen species (ROS) were generated in the cell suspension when supplemented with citric-prepared GNPs than HEPES-prepared GNPs when their concentrations were higher than 20 μg/mL. The results stated that HEPES-prepared GNPs had better biosafety and biocompatibility than citric-prepared GNPs. This study not only revealed the influence of reducing agent on biosafety and biocompatibility of nanomaterials but also provided accumulative evidence for nanomaterials in biomedical applications. [Figure: see text

Managing energy-water-carbon-food nexus for cleaner agricultural greenhouse production : a control system approach

DATA AVAILABILITY : Data will be made available on request.Poverty, food insecurity and climate change are global issues facing humanity, threatening social, economic and environmental sustainability. Greenhouse cultivation provides a potential solution to these challenges. However, some greenhouses operate inefficiently and need to be optimized for more economical and cleaner crop production. In this paper, an economic model predictive control (EMPC) method for a greenhouse is proposed. The goal is to manage the energy-water‑carbon-food nexus for cleaner production and sustainable development. First, an optimization model that minimizes the greenhouse's operating costs, including costs associated with greenhouse heating/cooling, ventilation, irrigation, carbon dioxide (CO2) supply and carbon emissions taking into account both the CO2 equivalent (CO2-eq) emissions caused by electrical energy consumption and the negative emissions caused by crop photosynthesis, is developed and solved. Then, a sensitivity analysis is carried out to study the impact of electricity price, supplied CO2 price and social cost of carbon (SCC) on the optimization results. Finally, a model predictive control (MPC) controller is designed to track the optimal temperature, relative humidity, CO2 concentration and incoming radiation power in presence of system disturbances. Simulation results show that the proposed approach increases the operating costs by R186 (R denotes the South African currency, Rand) but reduces the total cost by R827 and the carbon emissions by 1.16 tons when compared with a baseline method that minimizes operating costs only. The total cost is more sensitive to changes in SCC than that in electricity price and supplied CO2 price. The MPC controller has good tracking performance under different levels of system disturbances. Greenhouse environmental factors are kept within specified ranges suitable for crop growth, which increases crop yields. This study can provide effective guidance for growers' decision-making to achieve sustainable development goals.The Liaoning Province Educational Department and the National Natural Science Foundation of China.http://www.elsevier.com/locate/scitotenvhj2023Electrical, Electronic and Computer Engineerin

Release of moth pheromone compounds from Nicotiana benthamiana upon transient expression of heterologous biosynthetic genes

Background Using genetically modified plants as natural dispensers of insect pheromones may eventually become part of a novel strategy for integrated pest management. Results In the present study, we first characterized essential functional genes for sex pheromone biosynthesis in the rice stem borer Chilo suppressalis (Walker) by heterologous expression in Saccharomyces cerevisiae and Nicotiana benthamiana, including two desaturase genes CsupYPAQ and CsupKPSE and a reductase gene CsupFAR2. Subsequently, we co-expressed CsupYPAQ and CsupFAR2 together with the previously characterized moth desaturase Atr increment 11 in N. benthamiana. This resulted in the production of (Z)-11-hexadecenol together with (Z)-11-hexadecenal, the major pheromone component of C. suppressalis. Both compounds were collected from the transformed N. benthamiana headspace volatiles using solid-phase microextraction. We finally added the expression of a yeast acetyltransferase gene ATF1 and could then confirm also (Z)-11-hexadecenyl acetate release from the plant. Conclusions Our results pave the way for stable transformation of plants to be used as biological pheromone sources in different pest control strategies

Release of moth pheromone compounds from Nicotiana benthamiana upon transient expression of heterologous biosynthetic genes

Background: Using genetically modified plants as natural dispensers of insect pheromones may eventually become part of a novel strategy for integrated pest management. Results: In the present study, we first characterized essential functional genes for sex pheromone biosynthesis in the rice stem borer Chilo suppressalis (Walker) by heterologous expression in Saccharomyces cerevisiae and Nicotiana benthamiana, including two desaturase genes CsupYPAQ and CsupKPSE and a reductase gene CsupFAR2. Subsequently, we co-expressed CsupYPAQ and CsupFAR2 together with the previously characterized moth desaturase Atr∆11 in N. benthamiana. This resulted in the production of (Z)-11-hexadecenol together with (Z)-11-hexadecenal, the major pheromone component of C. suppressalis. Both compounds were collected from the transformed N. benthamiana headspace volatiles using solid-phase microextraction. We finally added the expression of a yeast acetyltransferase gene ATF1 and could then confirm also (Z)-11-hexadecenyl acetate release from the plant. Conclusions: Our results pave the way for stable transformation of plants to be used as biological pheromone sources in different pest control strategies