36 research outputs found

    Cryptanalysis of some self-synchronous chaotic stream ciphers and their improved schemes

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    In this paper, a cryptanalysis method that combines a chosen-ciphertext attack with a divide-and-conquer attack by traversing multiple non-zero component initial conditions (DCA- TMNCIC) is proposed. The method is used for security analysis of n-D (n=3,4,5,6,7,8) self- synchronous chaotic stream ciphers that employ a product of two chaotic variables and three chaotic variables (n-D SCSC-2 and n-D SCSC-3), taking 3-D SCSC-2 as a typical example for cryptanalysis. For resisting the combinational effect of the chosen-ciphertext attack and DCA- TMNCIC, several improved chaotic cipher schemes are designed, including 3-D SCSC based on a nonlinear nominal system (3-D SCSC-NNS) and n-D SCSC based on sinusoidal modulation (n-D SCSC-SM (n=3,4,5,6,7,8)). Theoretical security analysis validates the improved schemes

    Design and smartphone implementation of chaotic duplex H.264-codec video communications

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    In this paper, a chaotic duplex H.264-codec-based secure video communication scheme is designed and its smartphone implementation is also carried out. First, an improved self- synchronous chaotic stream cipher algorithm equipped with a sinusoidal modulation, a multipli- cation, a modulo operation and a round down operation (SCSCA-SMMR) is developed. Using the sinusoidal modulation and multiplication, the improved algorithm can resist the divide-and- conquer attack by traversing multiple nonzero component initial conditions (DCA-TMNCIC). Meanwhile, also by means of the round down operation and modulo operation, on the premise that the DCA-TMNCIC does not work, the original keys cannot be further deciphered only by the known-plaintext attack, the chosen-plaintext attack and the chosen-ciphertext attack, respectively. Then, the Android low-level multimedia support infrastructure MediaCodec class is used to access low-level media encoder/decoder components and the H.264 hardware encod- ing/decoding is performed on real-time videos, so the chaotic video encryption and decryption can be realized in real-time by smartphones. Security analysis and smartphone experimental results verify the effectiveness of the proposed method

    Effects of Dietary Supplementation of Alpha-Ketoglutarate in a Low-Protein Diet on Fatty Acid Composition and Lipid Metabolism Related Gene Expression in Muscles of Growing Pigs

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    The aim of the current study was to investigate whether dietary supplementation with alpha-ketoglutarate (AKG) in a reduced crude protein (CP) diet would affect fatty acid composition and lipid metabolism related gene expression in the muscles of growing pigs. A total of 27 Large White × Landrace growing pigs at 44 ± 1 d of age (11.96 ± 0.18 kg) were randomly allocated to three treatments (n = 9). Dietary treatments included: (1) normal protein diet with 20% crude protein (CP) (NP); (2) a low crude protein diet formulated to contain approximately 17% CP (LP); and (3) a low crude protein diet with 17% CP supplemented with 1% AKG at the expense of regular corn components (ALP). The experimental trial lasted 35 d. The results showed that compared with the NP and LP diets, supplementation with AKG in a low-protein diet increased the intramuscular fat (IMF), oleic acid (C18:1n-9), and monounsaturated fatty acid (MUFA) contents (p < 0.05), and tended to increase the percentage of palmitoleic acid (C16:1) and stearic acid (C18:0) (p < 0.10) in the biceps femoris and longissimus dorsi muscles of growing pigs. These effects may be associated with increased relative mRNA expression levels of fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), adipocyte determination and differentiation factor 1 (ADD1), fatty acid binding protein 4 (FABP4), and stearoyl-CoA desaturase (SCD) in skeletal muscle, indicating that AKG might be involved in the differential regulation of some key lipogenic genes in skeletal muscles of pigs

    Data from: Study on expression modes and cleavage role of miR156b/c/d and its target gene Vv-SPL9 during the whole growth stage of grapevine

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    miR156 regulates the expression of its target SPL (PROMOTER BINDING-LIKE) genes during flower and fruit development, diverse developmental stage transitions, especially from vegetative to reproductive growth phases, by cleaving the target mRNA SPL of one plant-specific transcription factor. However, systematic reports on grapevine have yet to be presented. Here, the precise sequence of miR156 (vvi-miR156b/c/d) in grapevine “Takatsuma” was cloned with a previously cloned grapevine SPL (Vv-SPL9). Expression profiles in 18 grapevine tissues were identified through stem-loop RT-PCR. The interaction mode between vvi-miR156b/c/d and Vv-SPL9 was further validated by detecting the cleavage site and cleavage products of 3′- and 5′-ends via an integrated approach of 5′-RLM-RACE (RNA ligase-mediated 5′-rapid amplification of cDNA ends), 3′-PPM-RACE (poly(A) polymerase-mediated 3′-rapid amplification of cDNA ends), and qRT-PCR (real time reverse transcriptase-polymerase chain reaction). The variation in their cleavage roles in the whole growth stage of grapevine was also systematically investigated. Results showed that vvi-miR156b/c/d exhibited typical temporal–spatial-specific expression levels. The expression levels were higher in vegetative organs, such as leaf, than in reproductive organs, such as tendrils, flowers, and berries. A significant variation was observed during vegetative-to-reproductive transition. The expression patterns of Vv-SPL9 showed the opposite trends with those of vvi-miR156b. We confirmed that the cleavage site was at the 10th site of vvi-miR156b/c/d complementary to Vv-SPL9 in “Takatsuma” grapevine. We also identified the temporal–spatial variation of the cleavage products. This variation can indicate the regulatory function of miR156 on SPL in grapevines. Our findings provide further insights into the functions of vvi-miR156b/c/d and its target Vv-SPL9, and also help enrich our knowledge of small RNA-mediated regulation in grapevine

    Effect of Dietary Niacin Supplementation on Growth Performance, Nutrient Digestibility, Hematology, and Lipoprotein Concentrations of Young Turkeys, Meleagris gallopavo

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    The growth performance, nutrient digestibility, hematology, serum chemistry, and lipoprotein concentrations of turkey (Meleagris gallopavo) poults fed diets supplemented with high or recommended concentrations of niacin were investigated in this study. A total of 120 four-week-old turkey poults were randomly divided into three treatment groups with five replicates of eight birds in each group. The poult diets were supplemented with 0.0, 60, and 180 mg/kg niacin in the three treatments, termed control, recommended niacin supplementation (RNS), and high niacin supplementation (HNS), respectively. The study lasted for four weeks. The results showed that the HNS treatment reduced the feed intake and increased the body weight gain of poults. The apparent, nitrogen-corrected, and true metabolizable energy contents were the highest in the HNS-group turkey poults (P<0.05). The red and white blood cell counts and hemoglobin concentration of the turkeys improved with increasing niacin supplementation (P<0.01). The serum constituents, including the serum protein and globulin, were significantly increased (P<0.05), while the uric acid and creatinine contents were significantly reduced in the HNS-group turkeys. Similarly, the HNS-group turkeys exhibited significantly reduced alanine aminotransferase (ALT) and alkaline phosphatase (ALP) contents, while the RNS-group turkeys had the least aspartate aminotransferase (AST) content. In addition, the HNS-group turkeys had the least serum low-density lipoprotein (LDL), triglyceride, and total cholesterol concentrations and the highest serum high-density lipoprotein (HDL) (P<0.01) concentrations. In conclusion, the supplementation of 180 mg/kg niacin in the diet reduced the feed intake and serum ALT, ALP, LDL, triglyceride, and cholesterol contents and increased the body weight gain, metabolizable energy, and HDL concentration in turkeys. This study showed that niacin supplementation could reduce the fat content without compromising the body weight gain and increase stress resistance in turkey poults

    An Improved Method for Quantification of Viable Fusarium Cells in Infected Soil Products by Propidium Monoazide Coupled with Real-Time PCR

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    Fusarium is a soil-borne pathogen that causes root rot disease in cucumber. To date, quantitative real-time PCR (qPCR) is a common tool to detect the content of Fusarium in soil. However, qPCR cannot distinguish between viable and nonviable cells. The aim of this study was to develop a detection technique to pretreat tissue fluid with propidium monoazide (PMA) followed by extract DNA, and then to quantify viable Fusarium cells in contaminated soil. In this work, the specific primer pair F8-1/F8-2 was designed based on the translation elongation factor (EF) gene and a PMA-qPCR assay was established to amplify and quantify soils of viable Fusarium cells. The PMA pretreatment test was optimized, which indicated that the optimal PMA concentration and light exposure time were 50 mmol L−1 and 15 min, respectively. The lowest limit of viable cells in suspension detected and soil by PMA-qPCR were 82 spore mL−1 and 91.24 spore g−1, respectively. For naturally contaminated soil, viable Fusarium cells were detected in eight of the 18 samples, and the Fusarium amount ranged from 104 to 106 spore g−1. In conclusion, the PMA-qPCR method has the characteristics of high sensitivity, efficiency, and time saving, which could support nursery plants to avoid Fusarium infection and agro-industry losses

    Multifeature Short-Term Power Load Forecasting Based on GCN-LSTM

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    With the construction of a new-type power system under the China “double carbon” target and the increasing diversification of the energy demand on the user side, the short-term load forecasting of the power system is facing new challenges. To fully exploit the massive information contained in data, based on the graph convolutional network (GCN) and long short-term memory network (LSTM), this paper presents a new short-term load forecasting method for power systems considering multiple factors. The Spearman rank correlation coefficient was used to analyse the correlation between load and meteorological factors, and a model including meteorology, dates, and regions was established. Secondly, GCN and LSTM are jointly used to extract the spatial and temporal characteristics of massive data, respectively, and finally achieve short-term power load prediction. Historical electrical load data from 2020 to 2022 public data of a real industrial park in southern China were selected to verify the validity of the proposed method from the aspects of forecasting accuracy, feature dimension, and training time

    Dynamic Structure of Yeast Septin by Fast Fluctuation-Enhanced Structured Illumination Microscopy

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    When Saccharomyces cerevisiae divides, a structure composed of different septin proteins arranged according to a certain rule is formed at the cell division site. The structure undergoes multiple remodeling stages during the cell cycle, thus guiding the yeast cells to complete the entire division process. Although the higher-order structure of septins can be determined using electron microscopy, the septin’s dynamic processes are poorly understood because of limitations in living cell super-resolution imaging technology. Herein, we describe a high lateral resolution and temporal resolution technique, known as fast fluctuation-enhanced structured illumination microscopy (fFE-SIM), which more than doubles the SIM resolution at a frame rate of 38 Hz in living cells. This allows a highly dynamic and sparse septin structure to be observed in Saccharomyces cerevisiae
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