Studies on a Nicotiana hybrid infected with a plant rhabdovirus

The morphology of Sonchus yellow net virus (SYNV) has been studied by electron microscopy in both negative stained and ultrathin sectioned samples. Depending on the stain, bullet-shaped or bacilliform particles could be observed. However, the incubation of grids containing the samples with anti-SYNV antiserum prior to negative staining preserved the integral bacilliform morphology of the virus particles. The yield of the virus during the purification-steps was estimated by enzyme-linked immunosorbent assay (ELISA). The loss of the virus, using the standard procedure for purification was about 24%. Systemic movement of SYNV to leaves and roots was first detected by protein immunoblotting and ELISA 24 h after mechanical inoculation. Virus levels rose to a maximum ten days after inoculation: the highest levels, between 4.0 and 7.3 mug/g tissue, were in leaves which were not yet fully expanded. Electron microscopy of tissue sections revealed that when the virus content of tissues was greatest, virtually all leaf and root cells were infected. Most of the virions were in the perinuclear space, with only a few scattered particles in the cytoplasm. Nuclei contained large viroplasms associated with viral nucleocapsids, the matrix of these viroplasms reacted strongly to anti-SYNV antiserum in immunogold labelling experiments. Between 10 and 20 days after inoculation, levels of virus antigen and viral RNA fell to about 20% of their maximum. By 20 days after inoculation, no more than 10% of cells contained virus particles and almost all the virions were within the cytoplasm. Virions were almost never observed in most tissues of plants infected for longer than 60 days. These results suggest that SYNV spreads systemically until most or all cells are infected. The plants then undergo a recovery phase during which virions disappear from the nuclei of infected cells and vesiculate into the cytoplasm. The effects of SYNV on the nucleus, chloroplasts, mitochondria, endoplasmic reticulum, plasma membranes and the cell walls in mechanically inoculated N. edwardsonii were studied at various times after inoculation. Immunogold labelling was used to localize the viral protein(s) in infected cells. During the acute phase of the virus infection, nuclei showed obvious abnormalities, most strikingly, the development of nuclear viroplasms containing viral nucleocapsids and granular or fibrillar matrix. The association of the nucleocapsids with viroplasms and the strong reaction, in immunogold labelling experiments, of gold particles to these viroplasms suggest that viroplasms are the sites of nucleocapsid assembly. Chloroplasts of infected cells exhibited a number of ultrastructural abnormalities. In immunogold labelling experiments, antiserum to purified SYNV bound extensively to the thylakoids and stroma of chloroplasts from infected cells at all stages of infection, but not to the vesicles or inclusion bodies. Mitochondria of infected cells also exhibited a number of ultrastructural abnormalities. Neither nucleocapsids nor virus particles were observed in association with diseased mitochondria and in immunogold labelling experiments, no label was bound to mitochondria. Changes in the endoplasmic reticulum (ER) network were observed. Nucleocapsids and virus particle were associated with this ER. Infected cells showed alteration in the plasma membranes including the formation of piasmalemmasomes, multivesiculated plasmalemmasomes and piasmalemmasome-like structures. Tubular channels interconnecting adjacent cells and often containing virions developed. Similar channels containing nucleocapsids were observed within the nucleus and interconnecting the nucleus and the cell wall. Immunogold labelling indicated the presence of viral proteins associated with the cell wall or associated structures. These channels may be involved in movement of virus from cell to cell. Virus particles were not detectable by electron microscopy in chronically infected plants. However, virus proteins G & N plus a novel immunologically cross-reacting polypeptide of 41 KD (p41) were detectable in immunoblots. Immunogold labelling experiments revealed the presence of considerable quantities of free virus protein in the nucleus and cytoplasm. In leaf discs labelled with 35S-methionine, synthesis, in vivo, of all four virus structural proteins was detectable. Proteins N, M1 & M2 were detected in the in vitro translation products of poly(A)+mRNA from these plants. Thus proteins G & N accumulate in leaves but M1 & M2 fail to do so, presumably as a result of rapid turnover or specific degradation. The origin of protein p41 is not clear. It may be an additional non-structural viral protein, a modified form of one of the other structural proteins or a cross-reacting host protein induced by chronic infection. Plants were examined by electron microscopy 5 months after inoculation with SYNV. Mo virions were observed in leaf or root cells, but cells in sections of calyx contained large numbers of virus particles. Most particles were only 73-86% of the length of standard SYNV but reacted with anti-SYNV antiserum in immunogold labelling. Plants inoculated with sap extracted from calyx became systemically infected but exhibited chlorotic mottling, instead of the normal vein-clearing symptoms. Most virus particles in these plants were short, and when purified, sedimented more slowly than standard SYNV. Purified short particles were not infective, but plants inoculated with a mixture of short and standard particles developed mottling symptoms and yielded predominantly short particles. Proteins from short particles were electrophoretically and antigenically identical to those from standard virus. RNA from short particles was about 77% the size of RNA from standard SYNV and hybridized to cloned SYNV cDNA. These short particles have all the characteristics of defective-interfering particles. When plants were infected using inocula derived from chronically infected plants, nucleocapsids were observed within chloroplasts. Western blots of protein from chloroplasts isolated from these plants revealed the presence of the virus nucleocapsid protein N and possibly protein L

An improved genetic algorithm for solving the multiprocessor scheduling problem

Multiprocessor Scheduling Problem (MSP) is an NP-complete optimization problem. The applications of this problem are numerous, but are, as suggested by the name of the problem, most strongly associated with the scheduling of computational tasks in a multiprocessor environment. Many methods and algorithms were suggested to solve this problem due to its importance. Genetic algorithms were among the suggested methods. In this research, sound improvements were done on one of the known papers [3]. Results show very good improvements in increasing the percentage of getting the exact solution as well as decreasing the number of generations needed to converge

A novel secret key generation based on image link

One of the main problems with symmetric encryption is key distribution especially when involving large number of users i.e to generate identical keys at different locations. To address this challenge, we proposed a novel algorithm of secret key infusion protocol (SKIP) to generate an identical secret key. While, the key is generated based on a provided image link, starting pattern and string length which must be kept in secret as the algorithm is publicly known. The image from website must be a static image and used as the input of random bits to produce string of hexadecimal values. In a case where image link is compromised, the adversary has to guess other layers of parameters in starting pattern and string length. The generated secret keys were identical at two different locations. In other observation, different secret keys were generated even with the same image link and pattern length but different starting pattern

Hybrid feature selection based on principal component analysis and grey wolf optimizer algorithm for Arabic news article classification

The rapid growth of electronic documents has resulted from the expansion and development of internet technologies. Text-documents classification is a key task in natural language processing that converts unstructured data into structured form and then extract knowledge from it. This conversion generates a high dimensional data that needs further analusis using data mining techniques like feature extraction, feature selection, and classification to derive meaningful insights from the data. Feature selection is a technique used for reducing dimensionality in order to prune the feature space and, as a result, lowering the computational cost and enhancing classification accuracy. This work presents a hybrid filter-wrapper method based on Principal Component Analysis (PCA) as a filter approach to select an appropriate and informative subset of features and Grey Wolf Optimizer (GWO) as wrapper approach (PCA-GWO) to select further informative features. Logistic Regression (LR) is used as an elevator to test the classification accuracy of candidate feature subsets produced by GWO. Three Arabic datasets, namely Alkhaleej, Akhbarona, and Arabiya, are used to assess the efficiency of the proposed method. The experimental results confirm that the proposed method based on PCA-GWO outperforms the baseline classifiers with/without feature selection and other feature selection approaches in terms of classification accuracy

Effects of trade facilitation on trade costs in developed and developing countries: PPML analysis

Trade facilitation reduces trade costs and eases the movement of goods and services. Studies have shown that trade flows increased by improving the trade facilitation process and reducing trade costs. The study aims to estimate the effects of trade facilitation enhancement on trade costs in 111 developed and developing countries over the 2008 to 2014 period using the Poisson-Pseudo Maximum Likelihood (PPML) estimator. The findings show that trade facilitation components such as border administration, business environment and transport and communication infrastructure reduce trade costs. This trade facilitation should have helped alleviate the effects of the financial recession and eased world trade recovery. On the other hand, the study finds that additional market access increases trade costs. The most important finding is that the effectiveness of trade facilitation is higher when more countries engage in trade and when those countries are together participating in trade facilitation

Step by step preparation of urine samples for in-Solution, gel-free proteomic studies, suitable for MALDI TOF MS and LCMS QTOF MS

Two-dimensional electrophoresis is an established method for isolating and separating proteins for proteomic analysis and identification of proteins. However, it requires a lot of optimization and it suffers from some ongoing concerns regarding quantitative reproducibility and limitations on its ability to study certain class of proteins. We propose a simpler method in preparing urine samples from acute melioidosis patients for in-solution proteomics using liquid chromatography coupled with mass spectrometry quadrupole time of flight (LCMS-QTOF MS) or matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). This method is relatively easier than 2-dimensional electrophoresis, affordable, reproducible, can be performed in less equipped laboratories for transport to specialized centers for proteomic studies and bioinformatic analysis

The expression of virulence genes in Group B Streptococcus isolated from symptomatic pregnant women with term and preterm delivery.

During pregnancy, group B streptococcus (GBS) colonization is one of the risk factors for preterm delivery and neonatal infections. Previous studies have revealed the crucial roles of GBS virulence factors including hemolytic pigment (CylE), hyaluronidase (HylB), serine rich protein (Srr) and bacterial surface adhesion of GBS (BsaB) in mediating GBS colonization and intrauterine ascending infection, that triggers preterm delivery. The aim of this study is to investigate the association between mRNA expression of virulence genes in GBS isolates obtained from symptomatic pregnant women and preterm delivery. GBS isolates were obtained from high vaginal swabs of pregnant women (n=40) with gestational age less than 37 weeks and symptoms including preterm labour, preterm premature rupture of membrane (pPROM), vaginal discharge and vaginal bleeding. RNA was extracted from these GBS isolates and RT-qPCR was performed to determine the relative mRNA expression of GBS virulence genes including CylE, HylB, Srr and BsaB. Women with preterm labour and pPROM who delivered prematurely were demonstrated with higher expression of CylE gene and a trend towards an increased expression of HylB gene, in comparison to women with term delivery. The expression of Srr and BsaB genes were both similar between symptomatic pregnant women who delivered at term and prematurely. These results suggest that following vaginal colonization, both CylE and HylB genes possibly contribute to intrauterine ascending infection and inflammation, causing preterm delivery in humans. These virulence factors may be targeted for the pre-clinical stages of vaccine development or therapeutic intervention

Pellet diameter of Ganoderma lucidum in a repeated-batch fermentation for the trio total production of biomass-exopolysaccharide-endopolysaccharide and its anti-oral cancer beta-glucan response

The pellet morphology and diameter range (DR) of Ganoderma lucidum were observed in a repeated-batch fermentation (RBF) for the trio total production of biomass, exopolysaccharide (EPS) and endopolysaccharide (ENS). Two factors were involved in RBF; broth replacement ratio (BRR: 60%, 75% and 90%) and broth replacement time point (BRTP: log, transition and stationary phase) in days. In RBF, 34.31 g/L of biomass favoured small-compact pellets with DR of 20.67 μm< d < 24.00 μm (75% BRR, day 11 of BRTP). EPS production of 4.34 g/L was prone to ovoid-starburst pellets with DR of 34.33 μm< d <35.67 μm (75% BRR, day 13 of BRTP). Meanwhile, the highest 2.43 g/L of ENS production favoured large-hollow pellets with DR of 34.00 μm< d < 38.67 μm (90% BRR, day 13 of BRTP). In addition, RBF successfully shortened the biomass-EPS–ENS fermentation period (31, 33 and 35 days) from batch to 5 days, in seven consecutive cycles of RBF. In a FTIR detection, β- 380 AIMS Microbiology Volume 6, Issue 4, 379–400. glucan (BG) from EPS and ENS extracts were associated with β-glycosidic linkages (2925 cm-1, 1635 cm-1, 1077 cm-1,920 cm-1 and 800 cm-1 wavelengths) with similar 1H NMR spectral behaviour (4.58, 3.87 and 3.81). Meanwhile, 4 mg/L of BG gave negative cytotoxic effects on normal gingival cell line (hGF) but induced antiproliferation (IC50 = 0.23 mg/mL) against cancerous oral Asian cellosaurus cell line (ORL-48). Together, this study proved that G. lucidum mycelial pellets could withstand seven cycles of long fermentation condition and possessed anti-oral cancer beta-glucan, which suits large-scale natural drug fermentation