399 research outputs found

    Impacts of S1 and X2 Interfaces on eMBMS Handover Failure: Solution and Performance Analysis

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    In evolved Multimedia Broadcast/Multicast Service (eMBMS), service continuity enables users move from one cell to another without interrupting eMBMS service. Unlike traditional handover in unicast transmission, a UE can receive eMBMS service in either unicast or multicast mode. In this paper, we point out a new handover failure problem in eMBMS due to the miss of rekeying information. We first take a close look at the new handover scenarios. We then investigate the problem by using comprehensive mathematical models. Our models provide insights on the new handover problem and introduce theoretical guidelines for mobile operators to design and optimize their networks without wide deployment to save cost and time. Moreover, we propose a solution to combat against the handover failure. Both the simulation and analytical results demonstrate that the impacts of the eMBMS handover failure are reduced significantly. In this paper, we present a systematic way to investigate the handover failure problem in eMBMS

    TOXICOLOGICAL EVALUATION OF LEPISTA NUDA (BULL. EX FR.) COOKE MYCELIUM PRODUCED BY AN IN VITRO CULTURE METHODOLOGY

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    Objective: Considering the interest in L. nuda as a source of ingredients for the development of functional food and nutraceuticals has increased, the objective of this study was to evaluate its general toxicity and possible genotoxic effects in rats to assess its safety.Methods: This study evaluated the safety of L. nuda mycelium by using genotoxicity assays (reverse mutation, chromosomal aberration, and micronuclei tests) and a short-term toxicity test.Results: Our results have indicated that L. nuda mycelium did not significantly increase the number of revertant colonies and chromosomal aberration in both in vitro assays. Furthermore, it did not induce any increase in micronuclei formation in mouse bone marrow.Conclusion: In summary, no mutagenic effects and no evidence of systemic toxicity were found in this safety assessment, and the use of L. nuda mycelia is safe at a dose of 3 g/kg body weight in S-D rats. Using a safety factor of 100, the calculated acceptable daily intake in humans is 30 mg/kg body weight/d

    Design and Analysis of the Key Management Mechanism in Evolved Multimedia Broadcast/Multicast Service

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    3GPP introduced the key management mechanism (KMM) in evolved multimedia broadcast/multicast service (eMBMS) to provide forward security and backward security for multicast contents. In this paper, we point out that KMM may lead to frequent rekeying and re-authentication issues due to eMBMS's characteristics: 1) massive group members; 2) dynamic group topology; and 3) unexpected wireless disconnections. Such issues expose extra load for both user equipment (UE) terminals and mobile operators. It seems prolonging the rekeying interval is an intuitive solution to minimizing the impact of the issues. However, a long rekeying interval is not considered the best operational solution due to revenue loss of content providers. This paper quantifies the tradeoff between the load of the UEs and the operators as well as the revenue loss of the content providers. Moreover, we emphasize how essential this rekeying interval has impacts on the problems. Using our proposed tradeoff model, the operators can specify a suitable rekeying interval to best balance the interest between the above three parties. The tradeoff model is validated by extensive simulations and is demonstrated to be an effective approach for the tradeoff analysis and optimization on eMBMS

    Game Solving with Online Fine-Tuning

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    Game solving is a similar, yet more difficult task than mastering a game. Solving a game typically means to find the game-theoretic value (outcome given optimal play), and optionally a full strategy to follow in order to achieve that outcome. The AlphaZero algorithm has demonstrated super-human level play, and its powerful policy and value predictions have also served as heuristics in game solving. However, to solve a game and obtain a full strategy, a winning response must be found for all possible moves by the losing player. This includes very poor lines of play from the losing side, for which the AlphaZero self-play process will not encounter. AlphaZero-based heuristics can be highly inaccurate when evaluating these out-of-distribution positions, which occur throughout the entire search. To address this issue, this paper investigates applying online fine-tuning while searching and proposes two methods to learn tailor-designed heuristics for game solving. Our experiments show that using online fine-tuning can solve a series of challenging 7x7 Killall-Go problems, using only 23.54% of computation time compared to the baseline without online fine-tuning. Results suggest that the savings scale with problem size. Our method can further be extended to any tree search algorithm for problem solving. Our code is available at https://rlg.iis.sinica.edu.tw/papers/neurips2023-online-fine-tuning-solver.Comment: Accepted by the 37th Conference on Neural Information Processing Systems (NeurIPS 2023

    Improvement of n-butanol tolerance in Escherichia coli by membrane-targeted tilapia metallothionein

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    Background: Though n-butanol has been proposed as a potential transportation biofuel, its toxicity oftencauses oxidative stress in the host microorganism and is considered one of the bottlenecks preventing itsefficient mass production.Results: To relieve the oxidative stress in the host cell, metallothioneins (MTs), which are known as scavengersfor reactive oxygen species (ROS), were engineered in E. coli hosts for both cytosolic and outer-membrane-targeted (osmoregulatory membrane protein OmpC fused) expression. Metallothioneins from human (HMT),mouse (MMT), and tilapia fish (TMT) were tested. The host strain expressing membrane-targeted TMT showed thegreatest ability to reduce oxidative stresses induced by n-butanol, ethanol, furfural, hydroxymethylfurfural, andnickel. The same strain also allowed for an increased growth rate of recombinant E. coli under n-butanol stress.Further experiments indicated that the TMT-fused OmpC protein could not only function in ROS scavenging butalso regulate either glycine betaine (GB) or glucose uptake via osmosis, and the dual functional fusion proteincould contribute in an enhancement of the host microorganism’s growth rate.Conclusions: The abilities of scavenging intracellular or extracellular ROS by these engineering E. coli wereexamined, and TMT show the best ability among three MTs. Additionally, the membrane-targeted fusion protein,OmpC-TMT, improved host tolerance up to 1.5% n-butanol above that of TMT which is only 1%. These resultspresented indicate potential novel approaches for engineering stress tolerant microorganism strains

    Cyclosporine A Eye Drop-Induced Elongated Eyelashes: A Case Report

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    Purpose: The most common ocular adverse event following the use of cyclosporine A (CsA) 0.05% ophthalmic emulsion is ocular burning (17%). Other adverse effects that have been reported include conjunctival hyperemia (1–5%), discharge, epiphora, eye pain, foreign body sensation, pruritus, stinging and blurred vision. Here, we report a specific side effect of CsA, namely eye drop-induced eyelash elongation in a patient with refractory giant papillary conjunctivitis. Design: Observational case report. Methods: Case report and review of the literature. Results: A 32-year-old female with giant papillary conjunctivitis on the left eye, who had undergone papillectomy 3 years previously and was refractory to topical steroid therapy, was treated with CsA 0.05% ophthalmic emulsion (Restasis) 4 times a day, preservative-free artificial tears and gentamicin ophthalmic solution in the left eye. After 5 months of topical CsA treatment, elongated eyelashes of her left eye were observed without other adverse effects. Conclusion: Although hypertrichosis and trichomegaly have been documented in the literature as side effects of systemic CsA, topical CsA 0.05% eye drop-induced elongated eyelashes have not been reported, and we believe ophthalmologists should be mindful and inform patients about this specific side effect

    IGF-1/IGFBP-1 increases blastocyst formation and total blastocyst cell number in mouse embryo culture and facilitates the establishment of a stem-cell line

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    BACKGROUND: Apoptosis occurs frequently for blastocysts cultured in vitro, where conditions are suboptimal to those found in the natural environment. Insulin-like growth factor-1 (IGF-1) plays an important role in preventing apoptosis in the early development of the embryo, as well as in the progressive regulation of organ development. We hypothesize that IGF-1 and its dephosphorylated binding protein (IGFBP-1) may be able to improve embryo culture with an associated reduced cell death, and that the resultant increase in the total cell number of the embryo could increase the chances of establishing an embryonic stem-cell line. RESULTS: In vivo fertilized zygotes were cultured in medium containing supplementary IGF-1, or IGFBP-1/IGF-1. The stages of the resultant embryos were evaluated at noon on day five post-hCG injection. The extent of apoptosis and necrosis was evaluated using Annexin V and propidium iodine staining under fluorescent microscopy. The establishment of embryonic stem-cell lines was performed using the hatching blastocysts that were cultured in the presence of IGF-1 or IGFBP-1/IGF-1. The results show that the rate of blastocyst formation in a tissue-culture system in the presence of IGF-1 was 88.7% and IGFBP-1/IGF-1 it was 94.6%, respectively, and that it was significantly greater than the figure for the control group (81.9%). IGFBP-1/IGF-1 also resulted in a higher hatching rate than was the case for the control group (68.8% vs. 48.6% respectively). IGF-1 also increased the number of Annexin V-free and propidium iodine-free blastocysts in culture (86.8% vs. 75.9% respectively). Total cell number of blastocyst in culture was increased by 18.9% for those examples cultured with dephosphorylated IGFBP-1/IGF-1. For subsequent stem-cell culture, the chances of the successful establishment of a stem-cell line was increased for the IGF-1 and IGFBP-1/IGF-1 groups (IGF-1 vs. IGFBP-1/IGF-1 vs. control: 45.8% vs. 59.6% vs. 27.3% respectively). CONCLUSION: IGF-1 or dephosphorylated IGFBP-1/IGF-1 supplement does result in an anti-apoptotic effect for early embryo development in culture, with a subsequent increased total cell number resulting from cell culture. The effect is beneficial for the later establishment of a stem-cell line
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