170 research outputs found

    A Family of Scalable Polynomial Multiplier Architectures for Ring-LWE Based Cryptosystems

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    Many lattice based cryptosystems are based on the Ring learning with errors (Ring-LWE) problem. The most critical and computationally intensive operation of these Ring-LWE based cryptosystems is polynomial multiplication over rings. In this paper, we exploit the number theoretic transform (NTT) to build a family of scalable polynomial multiplier architectures, which provide designers with a trade-off choice of speed vs. area. Our polynomial multipliers are capable to calculate the product of two nn-degree polynomials in about (1.5nlgn+1.5n)/b(1.5n\lg n + 1.5n)/b clock cycles, where bb is the number of the butterfly operators. In addition, we exploit the cancellation lemma to reduce the required ROM storage. The experimental results on a Spartan-6 FPGA show that the proposed polynomial multiplier architectures achieve a speedup of 3 times on average and consume less Block RAMs and slices when compared with the compact design. Compared with the state of the art of high-speed design, the proposed hardware architectures save up to 46.64\% clock cycles and improve the utilization rate of the main data processing units by 42.27\%. Meanwhile, our designs can save up to 29.41\% block RAMs

    The influence of X-ray wavelength and the simulative human skin and muscle obstruction on the detection of human body-hidden drugs by non-intrusive X-ray diffraction method

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    AbstractIn order to detect the body-hidden drugs non-intrusively and rapidly, the influence of the X-ray wavelength and covering of the simulative skin and muscle on the detection of methamphetamine sample by synchrotron radiation X-ray diffraction (SR-XRD) technique have been investigated. Synchrotron radiation based X-ray with three different wavelengths (1.29 Å, 1.54 Å, 1.80 Å) has been chosen as the X-ray source. The results indicate that the intensities as well as the number of the diffraction peaks of methamphetamine sample covered by simulative muscle decreased with the increasing of the X-ray wavelength from 1.29 Åto 1.80 Å. In addition, the intensities of the diffraction peaks for methamphetamine will be seriously affected by the covered simulative skin or muscle due to the X-ray absorption. Furthermore, the absorption of X-ray by the simulative muscle seems much stronger than that of the simulative skin. Moreover, the specific molecular structure of the methamphetamine sample has been obtained by X-ray diffraction method

    Impacts of Human Activities on the Composition and Abundance of Sulfate-Reducing and Sulfur-Oxidizing Microorganisms in Polluted River Sediments

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    Water system degradation has a severe impact on daily life, especially in developing countries. However, microbial changes associated with this degradation, especially changes in microbes related to sulfur (S) cycling, are poorly understood. In this study, the abundance, structure, and diversity of sulfate-reducing microorganisms (SRM) and sulfur-oxidizing microorganisms (SOM) in the sediments from the Ziya River Basin, which is polluted by various human interventions (urban and agricultural activities), were investigated. Quantitative real-time PCR showed that the S cycling-related (SCR) genes (dsrB and soxB) were significantly elevated, reaching 2.60 × 107 and 1.81 × 108 copies per gram of dry sediment, respectively, in the region polluted by human urban activities (RU), and the ratio of dsrB to soxB abundance was significantly elevated in the region polluted by human agricultural activities (RA) compared with those in the protected wildlife reserve (RP), indicating that the mechanisms underlying water system degradation differ between RU and RA. Based on a 16S rRNA gene analysis, human interventions had substantial effects on microbial communities, particularly for microbes involved in S cycling. Some SCR genera (i.e., Desulfatiglans and Geothermobacter) were enriched in the sediments from both RA and RU, while others (i.e., Desulfofustis and Desulfonatronobacter) were only enriched in the sediments from RA. A redundancy analysis indicated that NH4+-N and total organic carbon significantly influenced the abundance of SRM and SOM, and sulfate significantly influenced only the abundance of SRM. A network analysis showed high correlation between SCR microorganisms and other microbial groups for both RU and RA, including those involved in carbon and metal cycling. These findings indicated the different effects of different human interventions on the microbial community composition and water quality degradation

    Mitigating Nitrous Oxide Emissions from Tea Field Soil Using Bioaugmentation with a Trichoderma viride

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    Land-use conversion from woodlands to tea fields in subtropical areas of central China leads to increased nitrous oxide (N2O) emissions, partly due to increased nitrogen fertilizer use. A field investigation of N2O using a static closed chamber-gas chromatography revealed that the average N2O fluxes in tea fields with 225 kg N ha−1 yr−1 fertilizer application were 9.4 ± 6.2 times higher than those of woodlands. Accordingly, it is urgent to develop practices for mitigating N2O emissions from tea fields. By liquid-state fermentation of sweet potato starch wastewater and solid-state fermentation of paddy straw with application of Trichoderma viride, we provided the tea plantation with biofertilizer containing 2.4 t C ha−1 and 58.7 kg N ha−1. Compared to use of synthetic N fertilizer, use of biofertilizer at 225 kg N ha−1 yr−1 significantly reduced N2O emissions by 33.3%–71.8% and increased the tea yield by 16.2%–62.2%. Therefore, the process of bioconversion/bioaugmentation tested in this study was found to be a cost-effective and feasible approach to reducing N2O emissions and can be considered the best management practice for tea fields

    Correlation Between Protein Primary Structure and Soluble Expression Level of HSA dAb in Escherichia coli

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    Izoelektrična točka, duljina molekule, molekularna masa i slijed aminokiselina bitno utječu na topljivost proteina. U ovom smo se radu fokusirali na sastav aminokiselina i ispitali one koje najviše utječu na razinu ekspresije topljivog protutijela albumina iz ljudskog seruma (HSA dAb). Grupiranjem i primjenom linearnog modela analizirana je topljivost 65 varijanti proteina. Bitan utjecaj na ekspresiju topljivog protutijela dAb imale su specifične kombinacije aminokiselina, i to (S, R, N, D, Q) u supernatantu, (G, R, C, N, S) u lizatu peleta i (R, S, G) u ukupnom topljivom protutijelu dAb. Od 20 aminokiselina, arginin je imao negativan, a glicin i serin su imale pozitivan učinak na razinu ekspresije topljivog proteina. Preciznost linearnog modela predviđanja topljivosti proteina bila je 80 %. Zaključeno je da se povećanjem udjela polarnih aminokiselina, osobito glicina i serina, te smanjenjem udjela arginina bitno povećala ekspresija topljivog proteina HSA dAb.It is widely accepted that features such as pI, length, molecular mass and amino acid (AA) sequence have a significant influence on protein solubility. Here, we mainly focused on AA composition and explored those that most affected the soluble expression level of human serum albumin (HSA) domain antibody (dAb). The soluble expression and sequence of 65 dAb variants were analysed using clustering and linear modelling. Certain AAs significantly affected the soluble expression level of dAb, with the specific AA combinations being (S, R, N, D, Q), (G, R, C, N, S) and (R, S, G); these combinations respectively affected the dAb expression level in the broth supernatant, the level in the pellet lysate and total soluble dAb. Among the 20 AAs, R displayed a negative influence on the soluble expression level, whereas G and S showed positive effects. A linear model was built to predict the soluble expression level from the sequence; this model had a prediction accuracy of 80 %. In summary, increasing the content of polar AAs, especially G and S, and decreasing the content of R, was helpful to improve the soluble expression level of HSA dAb

    Comparison of Bacterial Communities in Two Partial Nitrification Systems for High-ammonia Wastewater and Sewage Treatment

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    ABSTRACT Partial nitritation is an important part of the biological nitrogen removal processes; it saves half of the aeration energy, since only half of NH 4 + -N need to be oxidized to nitrite. The performance of the process was determined by the microbial community structure. In this study, we measured the microbial diversity in terms of the quantity of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) that were present. The results revealed that the amount of aerobic bacteria did not change significantly in high-ammonia wastewater, but decreased significantly with running time in sewage. The abundance of AOB and NOB in high-ammonia wastewater ranged from 1.23 × 10 7 to 8.95 × 10

    Mudskipper genomes provide insights into the terrestrial adaptation of amphibious fishes

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    Mudskippers are amphibious fishes that have developed morphological and physiological adaptations to match their unique lifestyles. Here we perform whole-genome sequencing of four representative mudskippers to elucidate the molecular mechanisms underlying these adaptations. We discover an expansion of innate immune system genes in the mudskippers that may provide defence against terrestrial pathogens. Several genes of the ammonia excretion pathway in the gills have experienced positive selection, suggesting their important roles in mudskippers’ tolerance to environmental ammonia. Some vision-related genes are differentially lost or mutated, illustrating genomic changes associated with aerial vision. Transcriptomic analyses of mudskippers exposed to air highlight regulatory pathways that are up- or down-regulated in response to hypoxia. The present study provides a valuable resource for understanding the molecular mechanisms underlying water-to-land transition of vertebrates
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