541 research outputs found

    Thermal fluctuations in viscous cosmology

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    In this paper we investigate the power spectrum of thermal fluctuations in very early stage of viscous cosmology. When the state parameter as well as the viscous coefficient of a barotropic fluid is properly chosen, a scale invariant spectrum with large non-Gaussianity can be obtained. In contrast to the results previously obtained in string gas cosmology and holographic cosmology, we find the non-Gaussianity in this context can be k-independent such that it is not suppressed at large scale, which is expected to be testified in future observation.Comment: 13 pages, no figure, typos corrected, references adde

    Deep Q‐network implementation for simulated autonomous vehicle control

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    Deep reinforcement learning is poised to be a revolutionised step towards newer possibilities in solving navigation and autonomous vehicle control tasks. Deep Q‐network (DQN) is one of the more popular methods of deep reinforcement learning that allows the agent that controls the vehicle to learn through its mistakes based on its actions and interactions with the environment. This paper presents the implementation of DQN to an autonomous self‐driving vehicle control in two different simulated environments; first environment is in Python which is a simple 2D environment and then advanced to Unity software separately which is a 3D environment. Based on the scores and pixel inputs, the agent in the vehicle learns and adapts to its surrounding. It develops the best solution strategy to direct itself in the environment where its task is to manoeuvre the vehicle from point to point on a simulated highway scenario. The implemented DQN technique approximates the action value function with convolutional neural network. This evaluates the Q‐function for the Q‐learning architecture and updates the action value function. This paper shows that DQN is an effective learning method for the agent of an autonomous vehicle. In both simulated environments, the autonomous vehicle gradually learnt the manoeuvre operations and progressively gained the ability to successfully navigate itself and avoid obstacles without prior information of the surrounding

    Augmenting recombinant antibody production in HEK293E cells: Optimizing transfection and culture parameters

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    Background: Optimizing recombinant antibody production is important for cost-effective therapeutics and diagnostics. With impact on commercialization, higher productivity beyond laboratory scales is highly sought, where efficient production can also accelerate antibody characterizations and investigations. Methods: Investigating HEK293E cells for mammalian antibody production, various transfection and culture parameters were systematically analyzed for antibody light chain production before evaluating them for whole antibody production. Transfection parameters investigated include seeding cell density, the concentration of the transfection reagent and DNA, complexation time, temperature, and volume, as well as culture parameters such as medium replacement, serum deprivation, use of cell maintenance antibiotic, incubation temperature, medium volume, post-transfection harvest day, and common nutrient supplements. Results: Using 2 mL adherent HEK293E cell culture transfections with 25 kDa linear polyethylenimine in the most optimized parameters, we demonstrated a ~2-fold production increase for light chain alone and for whole antibody production reaching 536 and 49 μg, respectively, in a cost-effective manner. With the addition of peptone, κ light chain increased by ~4-fold to 1032 μg, whereas whole antibody increased to a lesser extent by ~2.5-fold to 51 μg, with benefits potentially for antibodies limited by their light chains in production. Conclusions: Our optimized findings show promise for a more efficient and convenient antibody production method through transfection and culture optimizations that can be incorporated to scale-up processes and with potential transferability to other mammalian-based recombinant protein production using HEK293E

    Over-the-Counter Medicine Attitudes and Knowledge among University and College Students in Brunei Darussalam:Findings from the First National Survey

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    Over-the-counter (OTC) medicine is defined as safe and effective for the general public to use, without seeking therapy from a health professional. As primary social media and internet users, university and college students are more likely to be exposed to unverified sources of health information. This study aims to assess the knowledge, attitudes, and behaviour of students at institutions of higher learning in Brunei with regard to the safe use of OTC medicines. A cross-sectional study was performed using a self-administered online questionnaire, adapted from the literature with additional information from the United States Food and Drug Administration (FDA) on the educational resources in understanding OTC medicine for consumers. The questionnaire consisted of 4 sections: demographic information, knowledge of OTC medicines, attitudes, and practice. Descriptive and inferential statistics were used for data analysis. A total of 335 students returned a completed questionnaire. The students had a mean knowledge score of 7.1 out of 9, with more than half (53.4%) having good knowledge (knowledge score > 7), and only a small percentage (5.7%) with poor knowledge. Almost all of the students (99.7%) had a positive attitude toward OTC medicine use. Few of the students practiced improper habits in terms of OTC medicine use, such as not reading the instructions or taking more than the recommended dose. Awareness of proper OTC medicine use among students in institutions of higher learning is necessary to prevent the rise of inappropriate user practices

    Japanese Encephalitis, Singapore

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    10.3201/eid1203.051251Emerging Infectious Diseases123525-52

    Do English and Chinese EQ-5D versions demonstrate measurement equivalence? an exploratory study

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    BACKGROUND: Although multiple language versions of health-related quality of life instruments are often used interchangeably in clinical research, the measurement equivalence of these versions (especially using alphabet vs pictogram-based languages) has rarely been assessed. We therefore investigated the measurement equivalence of English and Chinese versions of the EQ-5D, a widely used utility-based outcome instrument. METHODS: In a cross-sectional study, either EQ-5D version was administered to consecutive outpatients with rheumatic diseases. Measurement equivalence of EQ-5D item responses and utility and visual analog scale (EQ-VAS) scores between these versions was assessed using multiple regression models (with and without adjusting for potential confounding variables), by comparing the 95% confidence interval (95%CI) of score differences between these versions with pre-defined equivalence margins. An equivalence margin defined a magnitude of score differences (10% and 5% of entire score ranges for item responses and utility/EQ-VAS scores, respectively) which was felt to be clinically unimportant. RESULTS: Sixty-six subjects completed the English and 48 subjects the Chinese EQ-5D. The 95%CI of the score differences between these versions overlapped with but did not fall completely within pre-defined equivalence margins for 4 EQ-5D items, utility and EQ-VAS scores. For example, the 95%CI of the adjusted score difference between these EQ-5D versions was -0.14 to +0.03 points for utility scores and -11.6 to +3.3 points for EQ-VAS scores (equivalence margins of -0.05 to +0.05 and -5.0 to +5.0 respectively). CONCLUSION: These data provide promising evidence for the measurement equivalence of English and Chinese EQ-5D versions

    Noncommutative Geometry Inspired Entropic Inflation

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    Recently Verlinde proposed that gravity can be described as an emergent phenomena arising from changes in the information associated with the positions of material bodies. By using noncommutative geometry as a way to describe the microscopic, microstructure of quantum spacetime, we derive modified Friedmann equation in this setup and study the entropic force modifications to the inflationary dynamics of early universe.Comment: 14 pages, 5 figuers, Accepted for Publication in Phys. Lett.

    Thermal non-Gaussianity in holographic cosmology

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    Recently it has been shown that the thermal holographic fluctuations can give rise to an almost scale invariant spectrum of metric perturbations since in this scenario the energy is proportional to the area of the boundary rather than the volume. Here we calculate the non-Gaussianity of the spectrum of cosmological fluctuations in holographic phase, which can imprint on the radiation dominated universe by an abrupt transition. We find that if the matter is phantom-like, the non-Gaussianity fNLequilf_{NL}^{equil} can reach O(1){\cal O}(1) or even be larger than O(1){\cal O}(1). Especially in the limit ω5/3\omega\to -5/3, the non-Gaussianity is very large and negative. Furthermore, since the energy is proportional to the area, the thermal holographic non-Gaussianity depends linearly on kk if we neglect the variation in TT during the transition (fixed temperature).Comment: 13 pages, Minor corrections and one reference added;v3,minor correction

    Development of Eggshell-Based Orange Peel Activated Carbon Film for Synergetic Adsorption of Cadmium (II) Ion

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    Heavy metal contamination has spread around the world, particularly in emerging countries. This study aimed to assess the effectiveness of starch/eggshell/orange peel-activated carbon-based composite films in removing cadmium (II) ions from water samples. X-ray diffraction and scanning electron microscopy were used to characterize the composite films. The effect of Cd2+ was studied using a UV-Vis spectrophotometer and atomic absorption spectroscopy. The morphology of the composite film reveals a highly porous and rough surface with more open channels and a non-uniform honeycomb, indicating that the film has a high potential to adsorb Cd2+. The diffraction peaks for this film were found to be at 13.74°, 17.45°, 18.4°, and 23.6°, indicating a typical crystalline A-type packing arrangement within the starch granules. The results indicate that crystalline structure was unaffected by the addition of eggshell powder and orange peel-activated carbon. In 0.5 mg L−1 and 1.0 mg L−1 Cd2+ ions, the composite film removed 100% and 99.7% of the Cd2+, respectively, while the maximum removal efficiency for methylene blue was 93.75%. Thus, the current study shows that starch/eggshell/orange peel activated carbon film has a high potential for commercial activated carbon as a low-cost adsorbent
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