211 research outputs found

    Purifacation of Wild Type EcoRI Endonuclease and EcoRI Endonuclease RS187Crystal Growth of WT EcoRI Endonuclease-DNA comlex and EcoRI Endonuclease

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    EcoRI endonuclease is a very useful tool to study the structural mechanism of protein-DNA recognition. In this work, wild type EcoRI Endonuclease and EcoRI Endonuclease mutant RS187 were purified to high purity. Crystals of wild type EcoRI Endonuclease-DNA 13mer complex have been obtained with good size and shape. Some small crystals of EcoRI Endonuclease RS187-DNA 13mer complex were also grown

    Assessment of Liberia's Beer Industry Effluent Discharge Parameters in the Context of Urban Sustainability

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    Due to untreated brewery effluent and increasing industrial growth, most of Liberia's rivers have considerable water body pollution. The nature and extent of pollution caused by wastewater effluent discharged into these environments have not been thoroughly examined. This study looked into the effects of such effluents on the beer industry in Montserrado, Liberia. It assesses discharged effluent parameters, sustainable management practices, and potential wastewater reuse options within the context of urban sustainability. The findings highlight the need for immediate and substantial intervention to mitigate escalating pollution and associated health risks. The research also noted for the development of practical national industrial discharge standards, regulatory and management framework, tailored to local contexts, rather than a uniform application of stringent regulations that may hinder sectoral growth and intensify public health issues in under-resourced areas. Furthermore, the effectiveness of some treatment technologies. Technology consideration such as onsite treatment and irrigation that enable water reuse options (cooling, agriculture, and resource recovery) which can significantly reduce the environmental footprint of breweries were recommended. However, the implementation of these technologies may face challenges due to infrastructure deficiencies, financial constraints, and public perception regarding the safety and quality of reused wastewater. The analysis concludes that enhancing wastewater discharge effluents management is key for promoting sustainable industrial growth, improving water conservation, and gaining public trust and acceptance. Achieving these goals requires a concerted effort to strengthen policy, enhance technical capacity, and invest in community engagement to foster a sustainable and economically viable brewery sector.&nbsp

    Outer Channel of DNA-Based Data Storage: Capacity and Efficient Coding Schemes

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    In this paper, we consider the outer channel for DNA-based data storage, where each DNA string is either correctly transmitted, or being erased, or being corrupted by uniformly distributed random substitution errors, and all strings are randomly shuffled with each other. We first derive the capacity of the outer channel, which surprisingly implies that the uniformly distributed random substitution errors are only as harmful as the erasure errors. Next, we propose efficient coding schemes which encode the bits at the same position of different strings into a codeword. We compute the soft/hard information of each bit, which allows us to independently decode the bits within a codeword, leading to an independent decoding scheme. To improve the decoding performance, we measure the reliability of each string based on the independent decoding result, and perform a further step of decoding over the most reliable strings, leading to a joint decoding scheme. Simulations with low-density parity-check codes confirm that the joint decoding scheme can reduce the frame error rate by more than 3 orders of magnitude compared to the independent decoding scheme, and it can outperform the state-of-the-art decoding scheme in the literature in a wide parameter regions.Comment: This paper has been submitted to IEEE Trans. Inf. Theor

    Assessment of heterotrophic growth supported by soluble microbial products in anammox biofilm using multidimensional modeling

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    Anaerobic ammonium oxidation (anammox) is known to autotrophically convert ammonium to dinitrogen gas with nitrite as the electron acceptor, but little is known about their released microbial products and how these are relative to heterotrophic growth in anammox system. In this work, we applied a mathematical model to assess the heterotrophic growth supported by three key microbial products produced by bacteria in anammox biofilm (utilization associated products (UAP), biomass associated products (BAP), and decay released substrate). Both One-dimensional and two-dimensional numerical biofilm models were developed to describe the development of anammox biofilm as a function of the multiple bacteria-substrate interactions. Model simulations show that UAP of anammox is the main organic carbon source for heterotrophs. Heterotrophs are mainly dominant at the surface of the anammox biofilm with small fraction inside the biofilm. 1-D model is sufficient to describe the main substrate concentrations/fluxes within the anammox biofilm, while the 2-D model can give a more detailed biomass distribution. The heterotrophic growth on UAP is mainly present at the outside of anammox biofilm, their growth on BAP (HetB) are present throughout the biofilm, while the growth on decay released substrate (HetD) is mainly located in the inner layers of the biofilm

    DEM-based analysis of water inrush process of underground engineering face with intermittent joints in karst region

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    Water inrush disaster of karst tunnel often lead to significant economic losses and serious casualties, which is an urgent engineering roadblock to be solved in the construction of tunnel in karst area. In this paper, three-dimensional discrete element method considering fluid-solid coupling effect and structural characteristics of water-mud resistant rock mass is adopted to systematically study the evolution law of displacement field and seepage field of intermittent joint type water-mud resistant rock mass of tunnel face and its water inrush critical characteristics during the process of sequential excavation of karst tunnel close to the frontal high-pressure water-rich karst cavity. The results show that: With the tunnel face gradually approaching the front-concealed high-pressure water-rich karst cavity, the stability of water-mud resistant rock mass is increasingly affected by high-pressure karst water, and karst water pressure gradually becomes the main control factor. The closer the tunnel face is to the front-concealed high-pressure water-rich karst cavity, the greater the extrusion displacement of karst tunnel face and its increase amplitude, the higher damage degree of water-mud resistant rock mass of face. With the advance of tunnel excavation, the intermittent cracks in the water-mud resistant rock mass of face gradually connect and form a stable hydraulic connection. The flow velocity and seepage pressure of karst water rise significantly at the moment of overall instability of face and the formation of water inrush channel, showing obvious precursor characteristics. The research achievements provide a reference for early warning and prevention and control of water inrush disaster of karst tunnel face
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