2,159 research outputs found

    Influence of culture age on exopolymeric substances from common laboratory bacterial strains: a study on yield, profile and Cu(II) biosorption

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    Extracellular polymeric substances (EPS) produced by laboratory strains Bacillus cereus and Pseudomonas aeruginosa were extracted from cultures incubated at various incubation periods (24, 48, 72, 96 and 120 h). At each sampling time, the EPS were analysed for yield, quality, functional groups present, and their efficacies in copper (Cu(II)) biosorption (using 30 and 50 ppm EPS). Results revealed that EPS yield was influenced by incubation period, with 48-h culture of B. cereus and 96-h culture of P. aeruginosa producing the highest yield of EPS at 8.30 mg and 6.95 mg, respectively. The EPS produced at various incubation periods have similar characteristics in solubility, quality and major functional groups (C-O, CH3, C=C, O-H) present. Efficacy of Cu(II) biosorption was influenced by the amount of EPS used and the EPS-metal incubation time. Although Cu(II) removal was higher for EPS from 24-h B. cereus (18.96%) and 48-h P. aeruginosa (19.19%) when 30 ppm was used, application of 50 ppm EPS demonstrated no distinct differences in amount of Cu(II) removed. This suggested that higher biomass of EPS used and longer EPS-metal incubation period, superseded the efficacy of EPS from various incubation periods

    Supervised Collective Classification for Crowdsourcing

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    Crowdsourcing utilizes the wisdom of crowds for collective classification via information (e.g., labels of an item) provided by labelers. Current crowdsourcing algorithms are mainly unsupervised methods that are unaware of the quality of crowdsourced data. In this paper, we propose a supervised collective classification algorithm that aims to identify reliable labelers from the training data (e.g., items with known labels). The reliability (i.e., weighting factor) of each labeler is determined via a saddle point algorithm. The results on several crowdsourced data show that supervised methods can achieve better classification accuracy than unsupervised methods, and our proposed method outperforms other algorithms.Comment: to appear in IEEE Global Communications Conference (GLOBECOM) Workshop on Networking and Collaboration Issues for the Internet of Everythin

    Effects of System Characteristics on Adopting Web-Based Advanced Traveller Information System: Evidence from Taiwan

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    This study proposes a behavioural intention model that integrates information quality, response time, and system accessibility into the original technology acceptance model (TAM) to investigate whether system characteristics affect the adoption of Web-based advanced traveller information systems (ATIS). This study empirically tests the proposed model using data collected from an online survey of Web-based advanced traveller information system users. Con­firmatory factor analysis (CFA) was performed to examine the reliability and validity of the measurement model, and structural equation modelling (SEM) was used to evaluate the structural model. The results indicate that three system characteristics had indirect effects on the intention to use through perceived usefulness, perceived ease of use, and attitude toward using. Information quality was the most im­portant system characteristic factor, followed by response time and system accessibility. This study presents implica­tions for practitioners and researchers, and suggests direc­tions for future research.</p

    3D-PL: Domain Adaptive Depth Estimation with 3D-aware Pseudo-Labeling

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    For monocular depth estimation, acquiring ground truths for real data is not easy, and thus domain adaptation methods are commonly adopted using the supervised synthetic data. However, this may still incur a large domain gap due to the lack of supervision from the real data. In this paper, we develop a domain adaptation framework via generating reliable pseudo ground truths of depth from real data to provide direct supervisions. Specifically, we propose two mechanisms for pseudo-labeling: 1) 2D-based pseudo-labels via measuring the consistency of depth predictions when images are with the same content but different styles; 2) 3D-aware pseudo-labels via a point cloud completion network that learns to complete the depth values in the 3D space, thus providing more structural information in a scene to refine and generate more reliable pseudo-labels. In experiments, we show that our pseudo-labeling methods improve depth estimation in various settings, including the usage of stereo pairs during training. Furthermore, the proposed method performs favorably against several state-of-the-art unsupervised domain adaptation approaches in real-world datasets.Comment: Accepted in ECCV 2022. Project page: https://ccc870206.github.io/3D-PL

    Interference-Aware Deployment for Maximizing User Satisfaction in Multi-UAV Wireless Networks

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    In this letter, we study the deployment of Unmanned Aerial Vehicle mounted Base Stations (UAV-BSs) in multi-UAV cellular networks. We model the multi-UAV deployment problem as a user satisfaction maximization problem, that is, maximizing the proportion of served ground users (GUs) that meet a given minimum data rate requirement. We propose an interference-aware deployment (IAD) algorithm for serving arbitrarily distributed outdoor GUs. The proposed algorithm can alleviate the problem of overlapping coverage between adjacent UAV-BSs to minimize inter-cell interference. Therefore, reducing co-channel interference between UAV-BSs will improve user satisfaction and ensure that most GUs can achieve the minimum data rate requirement. Simulation results show that our proposed IAD outperforms comparative methods by more than 10% in user satisfaction in high-density environments.Comment: 5 pages, 3 figures, to appear in IEEE Wireless Communications Letter

    FGF Induces New Feather Buds From Developing Avian Skin

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    Induction of skin appendages involves a cascade of molecular events. The fibroblast growth factor (FGF) family of peptide growth factors is involved in cell proliferation and morphogenesis. We explored the role of the FGFs during skin appendage induction using developing chicken feather buds as a model. FGF-1, FGF-2, or FGF-4 was added directly to the culture medium or was released from pre-soaked Affigel blue beads. Near the midline, FGFs led to fusion of developing feather buds, representing FGFs' ability to expand feather bud domains in developing skin. In lateral regions of the explant where feather placodes have not formed, FGF treatment produces a zone of condensation and a region with an increased number of feather buds. In ventral epidermis that is normally apteric (without feathers), FGFs can also induce new feather buds. Like normal feather buds, the newly induced buds express Shh. The expression of Grb, Ras, Raf, and Erk, intracellular signaling molecules known to be downstream to tyrosine kinase receptors such as the FGF receptor, was enriched in feather bud domains. Genistein, an inhibitor of tyrosine kinase, suppressed feather bud formation and the effect of FGF. These results indicate that there are varied responses to FGFs depending on epithelial competence. All the phenotypic responses, however, show that FGFs facilitate the formation of skin appendage domains
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