Optical rotation of heavy hole spins by non-Abelian geometrical means

A non-Abelian geometric method is proposed for rotating of heavy hole spins in a singly positive charged quantum dot in Voigt geometry. The key ingredient is the delay-dependent non-Abelian geometric phase, which is produced by the nonadiabatic transition between the two degenerate dark states. We demonstrate, by controlling the pump, the Stokes and the driving fields, that the rotations about $y$- and $z$-axes with arbitrary angles can be realized with high fidelity. Fast initialization and heavy hole spin state readout are also possible.Comment: 7 pages, 6 figure

Have human activities changed the frequencies of absolute extreme temperatures in eastern China?

Extreme temperatures affect populous regions, like eastern China, causing substantial socio-economic losses. It is beneficial to explore whether the frequencies of absolute or threshold-based extreme temperatures have been changed by human activities, such as anthropogenic emissions of greenhouse gases (GHGs). In this study, we compared observed and multi-model-simulated changes in the frequencies of summer days, tropical nights, icy days and frosty nights in eastern China for the years 1960–2012 by using an optimal fingerprinting method. The observed long-term trends in the regional mean frequencies of these four indices were +2.36, +1.62, −0.94, −3.02 days decade−1. The models performed better in simulating the observed frequency change in daytime extreme temperatures than nighttime ones. Anthropogenic influences are detectable in the observed frequency changes of these four temperature extreme indices. The influence of natural forcings could not be detected robustly in any indices. Further analysis found that the effects of GHGs changed the frequencies of summer days (tropical nights, icy days, frosty nights) by +3.48 ± 1.45 (+2.99 ± 1.35, −2.52 ± 1.28, −4.11 ± 1.48) days decade−1. Other anthropogenic forcing agents (dominated by anthropogenic aerosols) offset the GHG effect and changed the frequencies of these four indices by −1.53 ± 0.78, −1.49 ± 0.94, +1.84 ± 1.07, +1.45 ± 1.26 days decade−1, respectively. Little influence of natural forcings was found in the observed frequency changes of these four temperature extreme indices

Dense-Localizing Audio-Visual Events in Untrimmed Videos: A Large-Scale Benchmark and Baseline

Existing audio-visual event localization (AVE) handles manually trimmed videos with only a single instance in each of them. However, this setting is unrealistic as natural videos often contain numerous audio-visual events with different categories. To better adapt to real-life applications, in this paper we focus on the task of dense-localizing audio-visual events, which aims to jointly localize and recognize all audio-visual events occurring in an untrimmed video. The problem is challenging as it requires fine-grained audio-visual scene and context understanding. To tackle this problem, we introduce the first Untrimmed Audio-Visual (UnAV-100) dataset, which contains 10K untrimmed videos with over 30K audio-visual events. Each video has 2.8 audio-visual events on average, and the events are usually related to each other and might co-occur as in real-life scenes. Next, we formulate the task using a new learning-based framework, which is capable of fully integrating audio and visual modalities to localize audio-visual events with various lengths and capture dependencies between them in a single pass. Extensive experiments demonstrate the effectiveness of our method as well as the significance of multi-scale cross-modal perception and dependency modeling for this task.Comment: Accepted by CVPR202

Fabrication and characterization of controlled release poly(D,Llactide-co-glycolide) millirods

Abstract: A compression-heat molding procedure was developed to fabricate poly(D,L-lactide-co-glycolide) (PLGA) controlled release drug delivery devices for the local treatment of tumors. The drug delivery devices were designed in the shape of a cylindrical millirod (1.6-mm diameter, 10-mm length), which allows them to be implanted by a modified 14-gauge tissue biopsy needle into tumor tissues via imageguided interventional procedures. In this study, the prototype trypan blue-containing PLGA millirods were fabricated under a compression pressure of 4.6 × 10 6 Pa and different fabrication temperatures for 2 h. The scanning electron microscopy results showed complete polymer annealing for millirods fabricated at 80 and 90°C, while the cross sections of the 60 and 70°C millirods showed incompletely annealed PLGA microspheres and trypan blue powders. The density, flexural modulus, and release properties of the PLGA millirods were also characterized and compared. The average values of the density and flexural modulus of the millirods increased with an increase in fabrication temperature. The flexural modulus values of most PLGA millirods were above 1 × 10 8 Pa, which provides sufficient stiffness for implantation within the tumor tissue. In addition, a ⌬c p method was developed to determine the loading density of trypan blue in the PLGA millirods by differential scanning calorimetry. Results from the ⌬c p measurement showed that trypan blue was homogeneously distributed in the millirod. Release studies in phosphate-buffered saline showed that the release rate decreased for the millirods fabricated at higher temperatures. The times for the release of 50% trypan blue were 5, 25, 25, and 25 h for millirods fabricated at 60, 70, 80, and 90°C, respectively. Millirods fabricated at 90°C had the most reproducible release profiles. The results from this study established compression-heat molding as an effective method to fabricate controlled release PLGA millirods with sufficient mechanical strength and reproducible release profiles for local cancer therapy

Privacy-Preserving Joint Edge Association and Power Optimization for the Internet of Vehicles via Federated Multi-Agent Reinforcement Learning

Proactive edge association is capable of improving wireless connectivity at the cost of increased handover (HO) frequency and energy consumption, while relying on a large amount of private information sharing required for decision making. In order to improve the connectivity-cost trade-off without privacy leakage, we investigate the privacy-preserving joint edge association and power allocation (JEAPA) problem in the face of the environmental uncertainty and the infeasibility of individual learning. Upon modelling the problem by a decentralized partially observable Markov Decision Process (Dec-POMDP), it is solved by federated multi-agent reinforcement learning (FMARL) through only sharing encrypted training data for federatively learning the policy sought. Our simulation results show that the proposed solution strikes a compelling trade-off, while preserving a higher privacy level than the state-of-the-art solutions.Comment: 6 pages, 4 figures, IEEE Trans. on Veh. Techno

Membrane-encased polymer millirods for sustained release of 5-fluorouracil

Abstract: This article describes the design and development of a novel membrane-encased polymer millirod for the sustained release of an anticancer drug, 5-fluorouracil (5-FU). The millirod consists of two functional compartments: (1) an inner 5-FU-loaded monolithic millirod as the drug depot, and (2) an outer NaCl-impregnated polymer membrane to control the release rate of 5-FU. The inner millirod is fabricated by a compression-heat molding procedure to permit the entrapment of 5-FU particles in the poly(D,Llactide-co-glycolide) (PLGA) matrix. The drug loading density is controlled at 30 w/w% to achieve a burst release of 5-FU (>90% of the drug are released within 48 h) from the monolithic millirod. The NaCl-impregnated PLGA membrane is generated by solvent casting and is then wrapped over the monolithic millirod to produce the membraneencased millirod. Scanning electron microscopy shows that dissolution of NaCl particles produces a semipermeable polymer membrane to provide a sustained release of 5-FU. The membrane thickness and the density of NaCl particles inside the membrane are useful parameters to control the release kinetics of 5-FU. Under the experimental conditions in this study, sustained release of 5-FU [rates between 0.1 and 0.4 mg/(day и cm of millirod)] is achieved for 2 to 5 weeks in phosphate-buffered saline (pH 7.4) at 37°C. Results from this study demonstrate that membrane-encased polymer millirods provide controllable sustained release kinetics for applications in intratumoral drug delivery

Inhibition of Gsk3β activity improves β-cell function in c-Kit\u3csup\u3eWv/+\u3c/sup\u3e male mice

Previous studies have shown that the stem cell marker, c-Kit, is involved in glucose homeostasis. We recently reported that c-KitWv/+ male mice displayed the onset of diabetes at 8 weeks of age; however, the mechanisms by which c-Kit regulates β-cell proliferation and function are unknown. The purpose of this study is to examine if c-KitWv/+ mutation-induced β-cell dysfunction is associated with downregulation of the phospho-Akt/Gsk3β pathway in c-KitWv/+ male mice. Histology and cell signaling were examined in C57BL/6J/KitWv/+ (c-Kit Wv/+) and wild-type (c-Kit+/+) mice using immunofluorescence and western blotting approaches. The Gsk3β inhibitor, 1-azakenpaullone (1-AKP), was administered to c-KitWv/+ and c-Kit+/+ mice for 2 weeks, whereby alterations in glucose metabolism were examined and morphometric analyses were performed. A significant reduction in phosphorylated Akt was observed in the islets of c-KitWv/+ mice (P\u3c0.05) along with a decrease in phosphorylated Gsk3β (P\u3c0.05), and cyclin D1 protein level (P\u3c0.01) when compared with c-Kit+/+ mice. However, c-KitWv/+ mice that received 1-AKP treatment demonstrated normal fasting blood glucose with significantly improved glucose tolerance. 1-AKP-treated c-KitWv/+ mice also showed increased β-catenin, cyclin D1 and Pdx-1 levels in islets, demonstrating that inhibition of Gsk3β activity led to increased β-cell proliferation and insulin secretion. These data suggest that c-KitWv/+ male mice had alterations in the Akt/Gsk3β signaling pathway, which lead to β-cell dysfunction by decreasing Pdx-1 and cyclin D1 levels. Inhibition of Gsk3β could prevent the onset of diabetes by improving glucose tolerance and β-cell function. © 2012 USCAP, Inc All rights reserved