Surface Modification of Basalt Fibers by Nanostructured Silica Aerogel

Basalt fibers were surface modified by a new method using nanostructured porous silica aerogel via sol-gel process followed by ambient pressure drying method. FTIR, FE-SEM, and nitrogen adsorption analysis were used for characterization of silica aerogel particles which proved their mesoporous structure with pore size of 7 nm, high porosity and low density. FTIR spectra indicated the formation of silica aerogel on the basalt fibers surface. SEM analysis proved the surface modification of basalt fibers and quantitative measurement showed an increase of 2-fold in the surface roughness compared to unmodified surface fibers. A decrease of 42 % in the density of the surface modified basalt fibers was observed. Also, acoustical properties measurement showed that sound absorption coefficient was increased by 25 %. The obtained results show that silica aerogel structure can affect the physical properties of surface modified basalt fibers. Two silica aerogels with different density and porosity were used in this work.     

Effect of Heavy Metals on Silencing of Engineered Long Interspersed Element-1 Retrotransposon in Nondividing Neuroblastoma Cell Line

Background: L1 retrotransposons are the most active mobile DNA elements in human genome. Unregulated L1 retrotransposition may have deleterious effect by disrupting vital genes and inducing genomic instabilities. Therefore, human cells control L1 elements by silencing their activities through epigenetic mechanisms. It has been shown that cell division and heavy metals stimulate the frequency of L1 activities. Removal of silencing by L1 motivators may restart L1 element functions. Here, we have proposed that weather neurotoxic environmental heavy metals (as L1 stimulating factors) have a role in removing L1 silencing and restating its activities in nondividing neuronal cells. Methods: L1-RP green fluorescent protein (GFP)-tagged knock-in human neuroblastoma clones were prepared. Single-cell clone was treated with mitomycin-c combined with nontoxic and toxic concentrations of iron (Fe), copper (Cu), and mercury (Hg). Silencing status of engineered L1 elements in dividing and nondividing cells was determined through measuring the amount of GFP expressing cells with flow cytometry. The cytotoxic effect of mitomycin-c combined with metals was measured by MTT assay. Results: Hg in nondividing cells and Fe, Cu, and Hg in dividing neuroblastoma cells could significantly remove L1 silencing. Also, mitomycin-c treatment did not have any effect on metal toxicity status in neuroblastoma cells. Conclusion: Totally, our findings have shown that cell division has a role in removing L1 silencing as well as L1 retrotransposition induced by environmental heavy metals. It has been also indicated that Hg at all concentrations could remove silencing of engineered L1 element regardless of cell cycle state. Key Words: Cell division, Heavy metals, L1 retrotransposon     

Rabies Infection: An Overview of Lyssavirus-Host Protein Interactions

Viruses are obligatory intracellular parasites that use cell proteins to take the control of the cell functions in order to accomplish their life cycle. Studying the viral-host interactions would increase our knowledge of the viral biology and mechanisms of pathogenesis. Studies on pathogenesis mechanisms of lyssaviruses, which are the causative agents of rabies, have revealed some important host protein partners for viral proteins, especially for most studied species, i.e. RABV. In this review article, the key physical lyssavirus-host protein interactions, their contributions to rabies infection, and their exploitation are discussed to improve the knowledge about rabies pathogenesis. Key Words: Host-Pathogen Interactions, Lyssavirus, Rabies     

Compatibility of insecticides and Elachertus inunctus Nees (Hymenoptera: Eulophidae) for controlling Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) in greenhouse condition

Journal of Plant Diseases and Protection - South American Tomato Pinworm (SATP), Tuta absoluta Meyrick (Lepidoptera: Gelechiidae), is one of the most devastating pests in tomato greenhouses....     

Genotypic-specific responses caused by prolonged drought stress in smooth bromegrass (Bromus inermis): Interactions with mating systems

The consequences of recurrent drought events compared with a single drought, and drought's interaction with deliberate selfing compared with open-pollination on postdrought recovery and persistence of smooth bromegrass, are not clear. This research was conducted to investigate the effects of recurrent drought stresses compared with a single drought on stress response, poststress recovery and persistence of full-sib and half-sib progenies of smooth bromegrass. During this study, 25 selfed (S1) and 25 open-pollinated (OP) progenies of smooth bromegrass created in 2012 were evaluated in the field under normal and recurrent drought stress during 2013–2016. After the first harvest of above-ground biomass in 2016, irrigation was withheld in both environments for 2 months; plants were subsequently re-watered and evaluated. Recurrent drought stress changed the relationships between different traits. Moreover, prolonged drought stress resulted in increased plant productivity (recovery aerial biomass; RABI) of S1 and OP populations in recurrent drought stress compared with normal environment. Mandatory selfing increased persistence of smooth bromegrass genotypes but did not affect recovery after prolonged drought stress. Results revealed that, selecting among S1 families would be more effective than OP ones.     

A multiple criteria analysis of factors affecting markets of engineered wood products with respect to customer preferences: a case study of particleboard and MDF

Of considerable importance and a principal goal in business is the creation of customer satisfaction. Evalu- ation of end user preferences for producers of particleboard and medium density fiberboard (MDF) requires indices for the assessment of markets and modification of product quality. However, only sporadic research has been carried out in this field. Therefore, the goal of this survey was to identify indices with respect to the points of view of: 1) consumers in order to select particleboard and MDF, 2) suppliers in order to consider production strategies, improve product quality, improve competitive ability of domestic producers in the market and help industry to be more customer oriented. This survey consisted of two stages. In the first stage, factors affecting customer preferences in the selection of particleboard and MDF were determined using a Delphi method, with the help of experts and a group of principal users of these prod- ucts. Then these factors were categorized in three groups: qualitative, technical and technological and marketing factors. Furthermore, questionnaires were prepared and distributed among consumers and responses evaluated and weighted by using an analytic hierarchy process (AHP) using expert choice software. Our results show that at both stages, the consistency ratio was less than 0.1, indicating that all results and judgments were stable and acceptable. The results obtained from questionnaires about particleboard rank the priorities for factors in the selection by consumers as follows: nail and screw holding ability, homogeneity in structure, edge strength of panel, durability and bending strength. The most important factors for MDF were machinability of panels, homogeneity in structure, nail and screw holding ability, edge strength of panel, durability and bending strength.     

Genetic variation,heritability and correlations of agro-morphological traits in tall fescue (<Emphasis Type="Italic">Festuca arundinacea</Emphasis> Schreb.)

To study the genetic variation, heritability and genetic correlations of some agro-morphological traits in tall fescue, 25 parents from a genetically broad-base germplasm were polycrossed and their respective half-sib families were generated. Clonally propagated parents and their half-sib families were grown as spaced single plants using a randomized complete-block design with three replications, and observed for seven traits in 2006 and 2007. The estimates of broad-sense heritability were moderate to high for the traits studied. Narrow-sense heritability estimates from analyses of progenies and from regression of half-sib (HS) progenies on parents suggested that genetic variation for these traits was largely controlled by additive gene action. Association of dry matter yield (DMY) with plant height, number of fertile shoot, curbs width and spring growth was positive and significant. With the exception of number of days to pollination, correlation coefficients of the traits between the parents and offspring were not significant. Based on parent-offspring regression, genetic gain from selection for DMY was high, demonstrating genetic potential for improving this trait. Overall, there was high genetic variation and moderate heritability for most traits in the tall fescue populations evaluated. In conclusion, to improve herbage yield, selection would be more effective based on forage yield components.     

Large-scale high throughput screening of sugar beet germplasm using a nanobiosensor and its comparison with ELISA method for resistance to Polymyxabetae

Identification of resistance resources of sugar beet germplasm against Polymyxa betae has always been a critical concern among sugar beet breeders. In the present study, two different methods including the DAS-enzyme-linked immunosorbent assay (ELISA) test and a nanobiosensor method based on florescent resonance transfer energy (FRET) were compared in order to achieve resistant germplasm. More specifically, 58 sugar beet germplasm as well as two negative and two positive controls were cultivated in infested soil under greenhouse conditions. The contamination level or in another words sensitivity and specificity observed based on the ELISA readings was inaccurately lower in comparison with the investigated nanobiosensor. Moreover, the nanobiosensor was 70 folds less time consuming compared to the ELISA method, for the immuno-reaction was much faster and no sample treatment steps were required. As a result, the quantum dots-FRET-based nanobiosensor investigated herein could well suit the task of everyday screening of resistance resource and could be efficiently used in breeding programs.