The effect of particle-size distribution on the one-dimensional compressive behaviour of granular soil materials was investigated using the discrete-element method (DEM), and the results were ...compared with published experimental data with similar gradations. The particles used in this study were spherical, and their size range mimicked various power-law distributions. The contact formulation was calibrated such that the different compressibility and initial specific volume of non-uniform assemblies depended purely on the interaction of different particle sizes of the non-uniform gradations. This behaviour was visualised in the DEM simulations. As these particles rearranged themselves, these regions contributed to a higher volumetric compression. It was also found that the coordination number of DEM particles significantly increased with better gradations.
Federated Learning (FL) is a distributed learning framework that can deal with the distributed issue in machine learning and still guarantee high learning performance. However, it is impractical that ...all users will sacrifice their resources to join the FL algorithm. This motivates us to study the incentive mechanism design for FL. In this paper, we consider a FL system that involves one base station (BS) and multiple mobile users. The mobile users use their own data to train the local machine learning model, and then send the trained models to the BS, which generates the initial model, collects local models and constructs the global model. Then, we formulate the incentive mechanism between the BS and mobile users as an auction game where the BS is an auctioneer and the mobile users are the sellers. In the proposed game, each mobile user submits its bids according to the minimal energy cost that the mobile users experiences in participating in FL. To decide winners in the auction and maximize social welfare, we propose the primal-dual greedy auction mechanism. The proposed mechanism can guarantee three economic properties, namely, truthfulness, individual rationality and efficiency. Finally, numerical results are shown to demonstrate the performance effectiveness of our proposed mechanism.
Background. The optimal time to initiate antiretroviral therapy (ART) in human immunodeficiency virus (HIV)—associated tuberculous meningitis is unknown. Methods. We conducted a randomized, ...double-blind, placebo-controlled trial of immediate versus deferred ART in patients with HIV-associated tuberculous meningitis to determine whether immediate ART reduced the risk of death. Antiretroviral drugs (zidovudine, lamivudine, and efavirenz) were started either at study entry or 2 months after randomization. All patients were treated with standard antituberculosis treatment, adjunctive dexamethasone, and prophylactic co-trimoxazole and were followed up for 12 months. We conducted intention-to-treat, perprotocol, and prespecified subgroup analyses. Results. A total of 253 patients were randomized, 127 in the immediate ART group and 126 in the deferred ART group; 76 and 70 patients died within 9 months in the immediate and deferred ART groups, respectively. Immediate ART was not significantly associated with 9-month mortality (hazard ratio HR, 1.12; 95% confidence interval CI,.81-1.55; P = .50) or the time to new AIDS events or death (HR, 1.16; 95% CI,.87-1.55; P = .31). The percentage of patients with severe (grade 3 or 4) adverse events was high in both arms (90% in the immediate ART group and 89% in the deferred ART group; P = .84), but there were significantly more grade 4 adverse events in the immediate ART arm (102 in the immediate ART group vs 87 in the deferred ART group; P = .04). Conclusions. Immediate ART initiation does not improve outcome in patients presenting with HIV-associated tuberculous meningitis. There were significantly more grade 4 adverse events in the immediate ART arm, supporting delayed initiation of ART in HIV-associated tuberculous meningitis.
Network slicing is considered to be a crucial feature of fifth generation cellular systems. By dividing the network infrastructure into multiple logical segments, network slicing can support parallel ...services with different requirements. While technology developments focus on slicing the core networks, there are limited studies in network slicing for radio access networks (RAN). Hence, in this letter, we study the RAN slicing and slice coordination, which is formulated as a bi-convex problem. Even though there are complicated couplings between the RAN resource allocation for each slice and the coordination of the slices that share the same resources, we design two algorithms addressing these couplings of this bi-convex problem. Simulation results validate the efficacy of our proposed algorithms.
In Asian developing countries, large amounts of municipal wastes are dumped daily in open dumping sites without proper management. This practice may cause several adverse environmental consequences ...and increased health risk to local communities. To elucidate contamination by persistent organic pollutants (POPs)--including dichloro-diphenyl-trichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), chlordanes, hexachlorobenzene (HCB), and polychlorinated biphenyls (PCBs)--in such dumping sites, soil samples were collected from open dumping sites and respective control sites in Cambodia, India, and Vietnam from 1999 through 2001. Our results demonstrated that DDTs, PCBs, and HCHs were dominant contaminants in the dumping sites. However, the contamination pattern was not consistent, showing higher HCHs in India than in Cambodia and Vietnam. Interestingly, in all of the countries, extremely higher levels of POPs were observed in the dumping sites compared with those in the respective control sites, suggesting significant amplification of POP contamination in the dumping sites of Asian developing countries. Mean concentrations of DDTs and PCBs were 350 and 140 ng/g dry weight, respectively, in the dumping sites of Cambodia and 26 and 210 ng/g, respectively, in India. These residue levels were hundreds to thousands times higher than those in general soils, implying possible risk to human health of the local communities, especially to the rag pickers, including children who work in these sites to collect recyclable materials. Composition of DDT compounds suggested their recent use in populated areas, which in turn might have caused increased levels of DDTs in the open dumping sites. In addition, composition of HCH isomers revealed their different use pattern in different countries.
Purpose
IVM preceded by a prematuration step (capacitation CAPA-IVM) improves the acquisition of oocyte developmental competence and can enhance embryo quality. There is currently no follow-up data ...on babies born from CAPA-IVM. This study investigated developmental outcomes in children born after CAPA-IVM versus natural conception.
Methods
This prospective cohort study was conducted at a fertility clinic in Vietnam in August/September 2019. Children born after CAPA-IVM were propensity score-matched with those born after natural conception. All parents were asked to complete the Developmental Red Flags and Ages & Stages Third Edition (ASQ-3) questionnaires.
Results
A total of 46 parents (23 in each group) of 55 babies (31 CAPA-IVM and 24 natural conception) were included in the study. Baseline characteristics, including mother’s age and body mass index, gestational age at delivery, and birth weight, were comparable. The mean age of children at the end of follow-up was 15 months. The overall proportion of children with any abnormal ASQ-3 score was 6.5% in the CAPA-IVM group and 20.8% in the natural conception group (
p
= 0.24). The proportion of children with a developmental red flag did not differ significantly between the CAPA-IVM and natural conception groups (9.7% vs. 4.2%;
p
= 0.80).
Conclusions
The use of CAPA-IVM did not have any significant impact on childhood physical and mental development compared with children born as a result of natural conception.
Emerging cross-device artificial intelligence (AI) applications require a transition from conventional centralized learning systems toward large-scale distributed AI systems that can collaboratively ...perform complex learning tasks. In this regard, democratized learning (Dem-AI) lays out a holistic philosophy with underlying principles for building large-scale distributed and democratized machine learning systems. The outlined principles are meant to study a generalization in distributed learning systems that go beyond existing mechanisms such as federated learning (FL). Moreover, such learning systems rely on hierarchical self-organization of well-connected distributed learning agents who have limited and highly personalized data and can evolve and regulate themselves based on the underlying duality of specialized and generalized processes. Inspired by Dem-AI philosophy, a novel distributed learning approach is proposed in this article. The approach consists of a self-organizing hierarchical structuring mechanism based on agglomerative clustering, hierarchical generalization, and corresponding learning mechanism. Subsequently, hierarchical generalized learning problems in recursive forms are formulated and shown to be approximately solved using the solutions of distributed personalized learning problems and hierarchical update mechanisms. To that end, a distributed learning algorithm, namely DemLearn, is proposed. Extensive experiments on benchmark MNIST, Fashion-MNIST, FE-MNIST, and CIFAR-10 datasets show that the proposed algorithm demonstrates better results in the generalization performance of learning models in agents compared to the conventional FL algorithms. The detailed analysis provides useful observations to further handle both the generalization and specialization performance of the learning models in Dem-AI systems.
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•A green and cost-effective method to convert sugarcane bagasse into aerogel has been developed.•Sugarcane bagasse aerogel is a promising candidate for heat insulation ...applications.•Sugarcane bagasse aerogel is a promising candidate for oil-spill cleaning applications.•Sugarcane bagasse aerogel is highly flexible, and can be bent without breaking.
A promising and economic material for various applications, such as thermal insulation in construction building and oil clean-up in marine ecosystems, is successfully developed from the by-product of the sugarcane industry. Biodegradable sugarcane bagasse aerogels are produced using polyvinyl alcohol (PVA) binder, followed by a freeze-drying method. This environmental-friendly recycled aerogel has an ultra-low density (0.016-0.112 g/cm3), a high porosity (91.9–98.9%), and a very low thermal conductivity (0.031-0.042 W/mK). Its superhydrophobicity properties and its maximum oil absorption capacity (up to 25 g/g) are measured after coating aerogel samples with methyltrimethoxysilane (MTMS). The biodegradable aerogel has a Young's modulus of 88 K Pa and can be bent without breaking, demonstrating its high flexibility.
Abstract
STUDY QUESTION
Does use of medium containing amphiregulin improve meiotic maturation efficiency in oocytes of women with polycystic ovary syndrome (PCOS) undergoing in vitro maturation (IVM) ...preceded by a capacitation culture step capacitation IVM (CAPA-IVM)?
SUMMARY ANSWER
Use of medium containing amphiregulin significantly increased the maturation rate from oocytes retrieved from follicles with diameters <6 or ≥6 mm pre-cultured in capacitation medium.
WHAT IS KNOWN ALREADY
Amphiregulin concentration in follicular fluid is correlated with human oocyte developmental competence. Amphiregulin added to the meiotic trigger has been shown to improve outcomes of IVM in a range of mammalian species.
STUDY DESIGN, SIZE, DURATION
This prospective, randomized cohort study included 30 patients and was conducted at an academic infertility centre in Vietnam from April to December 2019. Patients with PCOS were included.
PARTICIPANTS/MATERIALS, SETTING, METHODS
In the first stage, sibling oocytes from each patient (671 in total) were allocated in equal numbers to maturation in medium with (CAPA-AREG) or without (CAPA-Control) amphiregulin 100 ng/ml. After a maturation check and fertilization using intracytoplasmic sperm injection (ICSI), all good quality Day 3 embryos were vitrified. Cumulus cells (CCs) from both groups were collected at the moment of ICSI denudation and underwent a molecular analysis to quantify key transcripts of oocyte maturation and to relate these to early embryo development. On return for frozen embryo transfer (second stage), patients were randomized to have either CAPA-AREG or CAPA-Control embryo(s) implanted. Where no embryo(s) from the randomized group were available, embryo(s) from the other group were transferred. The primary endpoint of the study was meiotic maturation efficiency (proportion of metaphase II MII oocytes; maturation rate).
MAIN RESULTS AND THE ROLE OF CHANCE
In the per-patient analysis, the number of MII oocytes was significantly higher in the CAPA-AREG group versus the CAPA-Control group (median interquartile range 7.0 5.3, 8.0 versus 6.0 4.0, 7.0; P = 0.01). When each oocyte was evaluated, the maturation rate was also significantly higher in the CAPA-AREG group versus the CAPA-Control group (67.6% versus 55.2%; relative risk RR 1.22 95% confidence interval (CI) 1.08–1.38; P = 0.001). No other IVM or embryology outcomes differed significantly between the two groups. Rates of clinical pregnancy (66.7% versus 42.9%; RR 1.56 95% CI 0.77–3.14), ongoing pregnancy (53.3% versus 28.6%; RR 1.87 95% CI 0.72–4.85) and live birth (46.7% versus 28.6%; RR 1.63 95% CI 0.61–4.39) were numerically higher in the patients who had CAPA-AREG versus CAPA-Control embryos implanted, but each fertility and obstetric outcome did not differ significantly between the groups. In the CAPA-AREG group, there were significant shifts in CC expression of genes involved in steroidogenesis (STAR, 3BHSD), the ovulatory cascade (DUSP16, EGFR, HAS2, PTGR2, PTGS2, RPS6KA2), redox and glucose metabolism (CAT, GPX1, SOD2, SLC2A1, LDHA) and transcription (NRF2). The expression of three genes (TRPM7, VCAN and JUN) in CCs showed a significant correlation with embryo quality.
LIMITATIONS, REASONS FOR CAUTION
This study included only Vietnamese women with PCOS, limiting the generalizability. Although 100 ng/ml amphiregulin addition to the maturation culture step significantly improved the MII rate, the sample size in this study was small, meaning that these findings should be considered as exploratory. Therefore, a larger patient cohort is needed to confirm whether the positive effects of amphiregulin translate into improved fertility outcomes in patients undergoing IVM.
WIDER IMPLICATIONS OF THE FINDINGS
Data from this study confirm the beneficial effects of amphiregulin during IVM with respect to the trigger of oocyte maturation. The gene expression findings in cumulus indicate that multiple pathways might contribute to these beneficial effects and confirm the key role of the epidermal growth factor system in the stepwise acquisition of human oocyte competence.
STUDY FUNDING/COMPETING INTEREST(S)
This work was funded by the Vietnam National Foundation for Science and Technology Development (NAFOSTED; grant number FWO.106-YS.2017.02) and by the Fund for Research Flanders (FWO; grant number G.OD97.18N). L.N.V. has received speaker and conference fees from Merck, grants, speaker and conference fees from Merck Sharpe and Dohme, and speaker, conference and scientific board fees from Ferring. T.M.H. has received speaker fees from Merck, Merck Sharp and Dohme and Ferring. J.S. reports speaker fees from Ferring Pharmaceuticals and Biomérieux Diagnostics and grants from FWO Flanders, is co-inventor on granted patents on CAPA-IVM methodologies in USA (US10392601B2), Europe (EP3234112B1) and Japan (JP 6806683 registered 08-12-2020) and is a co-shareholder of Lavima Fertility Inc., a spin-off company of the Vrije Universiteit Brussel (VUB, Brussels, Belgium). NA, TDP, AHL, MNHN, SR, FS, EA and UDTH report no financial relationships with any organizations that might have an interest in the submitted work in the previous three years, and no other relationships or activities that could appear to have influenced the submitted work.
TRIAL REGISTRATION NUMBER
NCT03915054.
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