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Torin 1, TOR Inhibitor Enhances Cellular Proliferation in NT-1 Tobacco Suspension Cell Cultures
No full textTorin 1 is an ATP-competitive TOR inhibitor which inhibits the signaling of TOR and S6K kinase in mammals and plants. The objective of this research is to determine the effect of Torin 1 in a relatively simple and homogeneous plant system such as the NT-1 tobacco suspension cell cultures. Cultures of NT-1 cells were tested with 5, 50, 150 and 250 nM of Torin 1. During kinetics growth of NT-1 tobacco suspension cell cultures, 150 and 250 nM Torin 1 inhibits the early growth and later enhanced the cellular proliferation during exponential growth by means of an increased expression of E2F1 and cyclin B. Furthermore, Torin 1 stimulates the growth of NT-1 cells during log phase with small shaped cell, characteristic of tobacco suspension cell cultures with high mitotic activity
Green Synthesis of Bimetallic Nanoparticles From Prosopis juliflora (Sw) DC., and Its Effect Against Cotton Mealybug, Phenacoccus solenopsis (Hemiptera: Pseudococcidae)
No full textPhenacoccus solenopsis has been recognized as an aggressively invasive species on cotton plants in different countries. This study was conducted to investigate the effect of green synthesized Cu/Zn-nanoparticles using aqueous leaf extract of Prosopis juliflora (mezquite) against P. solenopsis. The scanning electron microscope (SEM) showed bimetallic nanoparticles of Cu/Zn-NPs with spherical shape with varying size of 74.33 nm to 59.46 nm. More than 30% mortality of P. solenopsis was observed with Cu/Zn-nanoparticles (100 ppm) at 96 hours after treatment. Negligible mortality of P. solenopsis was recorded with Cu/Zn solution (100 ppm) and aqueous P. juliflora extracts. The results of the viability test for Cu/Zn-nanoparticles of P. juliflora showed a significant reduction of the cell viability by 50% in insect exposed to Cu/Zn-nanoparticles-P.juliflora. Therefore studies about nanotoxicity of Cu/Zn-NPs of P.juliflora are needed to reveal the mechanism of toxicity this phytonanoparticles in P.solenopsis
The Origin and Identity of the Calyculus in Loranthaceae: Inferred From the Floral Organogenesis of Loranthus tanakae Franch. & Sav.
No full textThe flowers of the hemiparasitic family Loranthaceae are always subtended by a rimmed structure known as the calyculus. The origin and identity of the calyculus have been disputed for more than a century. Various hypotheses have been proposed, for example, an outgrowth of the axis, a reduced calyx, and a bracteolar (prophyllar) origin, but controversies remain. To obtain a plausible explanation of the origin of the calyculus, we investigated the flowers of Loranthus tanakae using scanning electron microscopy and light microscopy to observe the entire developmental process of the floral parts. Our results show that bracts are not present in L. tanakae. The calyculus, which lacks serving vascular bundles, initiates as a semicircular primordium and then develops into a circular structure by an adnation at both sides. The flower primordium usually cleaves into six petals from its centre along a whorled pattern in two series with three petals each, before or after the calyculus closed. Isomerous stamen primordia probably follow the same initiation pattern as petals do. Several carpels of different sizes initiate simultaneously as a united primordium. We support the hypotheses that the calyculus is of bract or bracteole origin due to its independent initiation from the inflorescence rachis, its similar morphology and positioning as the bract or bracteole, and that having no developmental relationship with the petals. We suggest keeping the usage of the term “calyculus”. Loranthus flowers should be considered monochlamydeous with three whorls of floral parts, namely petal, androecium, and gynoecium
Keyphrase Generation Based on Self-Attention Mechanism
No full textKeyphrase greatly provides summarized and valuable information. This information can help us not only understand text semantics, but also organize and retrieve text content effectively. The task of automatically generating it has received considerable attention in recent decades. From the previous studies, we can see many workable solutions for obtaining keyphrases. One method is to divide the content to be summarized into multiple blocks of text, then we rank and select the most important content. The disadvantage of this method is that it cannot identify keyphrase that does not include in the text, let alone get the real semantic meaning hidden in the text. Another approach uses recurrent neural networks to generate keyphrases from the semantic aspects of the text, but the inherently sequential nature precludes parallelization within training examples, and distances have limitations on context dependencies. Previous works have demonstrated the benefits of the self-attention mechanism, which can learn global text dependency features and can be parallelized. Inspired by the above observation, we propose a keyphrase generation model, which is based entirely on the self-attention mechanism. It is an encoder-decoder model that can make up the above disadvantage effectively. In addition, we also consider the semantic similarity between keyphrases, and add semantic similarity processing module into the model. This proposed model, which is demonstrated by empirical analysis on five datasets, can achieve competitive performance compared to baseline methods
ICVSS: A New Method for Vulnerability Quantitative Grading
No full textVulnerability technology is the basic of network security technology, vulnerability quantitative grading methods, such as CVSS, WIVSS, ICVSS, provide a reference to vulnerability management, but the problems of ignoring the risk elevation caused by a group of vulnerabilities and low accuracy of exploitable level evaluation exist in current vulnerability quantitative grading methods. To solve problems above in current network security quantitative evaluation methods, this paper verified the high relevance degree between type and exploitable score of vulnerability, proposed a new vulnerability quantitative grading method ICVSS, ICVSS can explore attack path using continuity level defined by privilege, add vulnerability type to measure indexes of exploitable metrics and use Analytic Hierarchy Process (AHP) to quantify the influence of vulnerability type on exploitable level. Compared with CVSS and WIVSS, ICVSS is proved that it can discover attack path consist of a sequence of vulnerabilities for network security situation evaluation, and has more accuracy and stability
Achieving Privacy-Preserving Iris Identification Via El Gamal
No full textCurrently, many biometric systems maintain the user’s biometrics and templates in plaintext format, which brings great privacy risk to uses’ biometric information. Biometrics are unique and almost unchangeable, which means it is a great concern for users on whether their biometric information would be leaked. To address this issue, this paper proposes a confidential comparison algorithm for iris feature vectors with masks, and develops a privacy-preserving iris verification scheme based on the El Gamal encryption scheme. In our scheme, the multiplicative homomorphism of encrypted features is used to compare of iris features and their mask information. Also, this paper improves the Hamming distance of iris features, which makes the similarity matching work better than existing ones. Experimental results confirm the practicality of our proposed schemes in real world applications, that is, for the iris feature vectors and masks of 2048 bits, nearly 12 comparisons can be performed per second
Novel DDoS Feature Representation Model Combining Deep Belief Network and Canonical Correlation Analysis
No full textDistributed denial of service (DDoS) attacks launch more and more frequently and are more destructive. Feature representation as an important part of DDoS defense technology directly affects the efficiency of defense. Most DDoS feature extraction methods cannot fully utilize the information of the original data, resulting in the extracted features losing useful features. In this paper, a DDoS feature representation method based on deep belief network (DBN) is proposed. We quantify the original data by the size of the network flows, the distribution of IP addresses and ports, and the diversity of packet sizes of different protocols and train the DBN in an unsupervised manner by these quantified values. Two feedforward neural networks (FFNN) are initialized by the trained deep belief network, and one of the feedforward neural networks continues to be trained in a supervised manner. The canonical correlation analysis (CCA) method is used to fuse the features extracted by two feedforward neural networks per layer. Experiments show that compared with other methods, the proposed method can extract better features
Experimental Characterization of MCF-10A Normal Cells Using AFM: Comparison with MCF-7 Cancer Cells
Get PDFThe mechanical properties of single cells have been recently identified as the basis of an emerging approach in medical applications since they are closely related to the biological processes of cells and human health conditions. The problem in hand is how to measure mechanical properties in order to obtain them more accurately and applicably. Some of the cell’s properties such as elasticity module and adhesion have been measured before using various methods; nevertheless, comprehensive tests for two healthy and cancerous cells have not been performed simultaneously. As a Nanoscale device, AFM has been used for some biological cells, however for breast cells, it has been utilized just to measure elasticity module. To provide a more accurate comparison for the healthy and the malignant cancer cells of breast, mechanical properties of MCF-10A cells such as topography, elasticity module, adhesion force, viscoelastic characteristics, bending and axial rigidity were determined and compared to the MCF-7 cells results obtained in previous works. Results revealed that the healthy breast cells are stiffer and less adhesive in comparison with the cancerous ones. Topography images revealed that cancerous cells have bigger radii. These results can help with the diagnosis of malignant cancer cells and even the level of the disease
Microfibrillated Cellulose from Sugarcane Bagasse as a Biorefinery Product for Ethanol Production
Get PDFResearch involving the preparation of microfibrillated cellulose (MFC) from sugarcane bagasse is a relevant topic to the production of new nanomaterials and more accessible cellulose substrates for the production of second generation ethanol. Regarding the transformation of cellulose into glucose, the precursor of second generation ethanol, this nanosized cellulosic substrate represents a more appropriate material for the chemical hydrolysis process. The high aspect ratio of MFC improves hydrolysis, requiring mild conditions and decreasing the generation of by-products. Here, MFC was prepared from sugarcane bagasse by ultrasound defibrillation. This material was oxidized with 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) to produce negatively charged high defibrillated MFC. The MFC was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and viscosity measurements
Enzymatic Conversion of Sugarcane Lignocellulosic Biomass as a Platform for the Production of Ethanol, Enzymes and Nanocellulose
Get PDFThe conversion of sugarcane lignocellulosic biomass into fuels, chemicals and high-value materials using the biochemical pathway is considered the most sustainable alternative for the implementation of future biorefineries. Actually, the first large-scale cellulosic ethanol plants that have started operating worldwide apply the enzymatic hydrolysis process to convert biomass into simple sugars that are fermented to ethanol by yeasts. However, several technological challenges still need to be addressed in order to obtain commercially competitive products. This review describes current challenges and perspectives regarding the enzymatic hydrolysis step for processing sugarcane lignocellulosic biomass within the biorefinery. Recent developments in terms of process configuration strategies and opportunities for the implementation of a sugarcane biorefinery, in which the production of ethanol is integrated into the production of high-value products such as enzymes and nanocellulose, are discussed in view of the demands of the current bioeconomy