Transcriptomic profiling of the extremophile eutrema salsugineum response to environmental stressors

Plants are sessile organisms that are constantly exposed to a variety of abiotic and biotic environmental stresses. Some plants are known to be more tolerant to those environmental stressors than others; those are the extremophilic plants. Studying the stress response pathways in such plants is extremely important in developing transgenic crop plants with enhanced tolerance to environmental stresses. Eutrema salsugineum is an extremophilic plant that is known to be resistant to many abiotic stress factors such as drought, cold, salt, and nitrogen deficiency. Experiments were carried out in KAUST by exposing the extremophilic plant to heat stress and exogenous ABA stress. RNA sequencing was done in order to get the transcriptome profile of the plant in response to the stresses. De novo transcriptome assembly was done followed by transcript abundance quantification and normalization using Kallisto. Differential expression analaysis was done to identify the differentially expressed transcripts in response to the different treatments in the shoot and root using the R bioconductor package EdgeR. The transcripts were annotated using EggNOG. The protein coding transcripts were identified by aligning them to the nr protein database using tblastx. Functional analysis of the DE transcripts to get the enriched terms was carried out using DAVID. Trinity de novo assembly produced 49857 genes and 134493 transcripts. Out of the 134493 transcripts, 114692 (85.28%) transcripts had tblastx hits (protein coding). Thus, 19801 potentially non coding or novel transcripts have been identified. A large variety of proteins were found to be differentially expressed depending on the pair-wise comparison. The genes were mainly involved in plant heat and ABA stress, ROS signaling pathway, ROS scavenging, secondary metabolite production, and lipid transfer. Further investigation of the role of secondary metabolites such as flavonoids, and nitrogen and sulfur containing compounds in the abiotic stress response of E. salsugineum is needed since it appears to be a major mechanism used by the plant. The results of this research offer a wide variety of stress related protein in E.salsugineum. Investigation of the over-expression of some of these genes in stress sensitive plants will help in further understanding their functions and mechanisms of action

Primary User Emulation Attacks: A Detection Technique Based on Kalman Filter

Cognitive radio technology addresses the problem of spectrum scarcity by allowing secondary users to use the vacant spectrum bands without causing interference to the primary users. However, several attacks could disturb the normal functioning of the cognitive radio network. Primary user emulation attacks are one of the most severe attacks in which a malicious user emulates the primary user signal characteristics to either prevent other legitimate secondary users from accessing the idle channels or causing harmful interference to the primary users. There are several proposed approaches to detect the primary user emulation attackers. However, most of these techniques assume that the primary user location is fixed, which does not make them valid when the primary user is mobile. In this paper, we propose a new approach based on the Kalman filter framework for detecting the primary user emulation attacks with a non-stationary primary user. Several experiments have been conducted and the advantages of the proposed approach are demonstrated through the simulation results.Comment: 14 pages, 9 figure

The flavonoid constituents of Leucaena Leucocephala growning in Egypt, and their biological activity

Background: Leucaena leucocephala is native to Southern Mexico and Northern Central America, but is now naturalized throughout the tropics. The phyto-chemical data of L. leucocephala revealed the presence of terpenes, flavonoids, coumarins and sterols. Various parts of L. leucocephala have been reported to have medicinal properties.Materials and Methods: Flavonoids were isolated from the aerial parts of L. leucocephala. Antioxidant activity of the extracts and the isolated compounds was evaluated using (DPPH), as well as their cytotoxic activity using a single tumor [Ehrlish ascites carcinoma cells].Results: The flavonoidal constituents isolated from chloroform, ethyl acetate and n-butanol fractions of the aqueous alcoholic extract of aerial parts of Leucaena leucocephala were identified as Caffeic acid, Isorhamnetin, Chrysoeriol, Isorhamnetin 3-O-galactoside, Kaempferol-3-O-rubinoside, Quercetin-3-O-rhamnoside and Luteolin-7-glucoside. Chemical structures of the isolated compounds were identified by TLC, PC and spectral techniques (UV, 1H -NMR and MS). The ethyl acetate fraction and the isolated flavonoidal compounds showed high antioxidant activity compared to Trolox (standard antioxidant compound). The different fractions and isolated compounds of Leucaena leucocephala exhibited no cytotoxic activity against Ehrlich- ascitis carcinoma cell line at the tested concentrations.Conclusion: This is the first record of the flavonoids in the aerial parts of Leucaena leucocephala (L.) except Quercetin-3-O-rhamnoside.Key words: Leucaena leucocephala., Flavonoids, Antioxidant, cytotoxic activity

Elements of nuclear safety – Research reactors

This publication gives a global overview of the diversity and complementarity of research reactors, some of which have been or are still being used to conduct experiments that are essential for the development and operation of nuclear power reactors, including in relation to safety issues. This work highlights the many uses of these reactors, which have very different designs, use highly varied quantities of radioactive substances with varying levels of risk for safety and radiation protection, and which — in many cases because they are old or have been shut down — require appropriate measures to control the ageing or obsolescence of some of their equipment, as well as, on an organisational and human level, to ensure that they continue to be operated safely. For some research reactors, safety and radiation protection aspects must be considered, taking into account that two types of operators are present at the same time within these reactors: reactor operating personnel and operators in charge of experimental devices using neutrons from the reactor for fundamental or applied research purposes. There are two specific chapters on the safety standards established under the aegis of the IAEA for research reactors and on serious accidents, notably those involving criticality and reactivity, in research reactors. The second part of the work focuses on French research reactors, including the regulations and official documents applicable to these reactors, on lessons learned in France from significant events and accidents — as well as abroad, such as the Fukushima Daiichi nuclear power plant accident in 2011 — on the consideration of reactivity accidents in the design of French research reactors, and on the ten-yearly safety reviews carried out in France

Fast Fashion Assessment Tool: A Case Study of a Moroccan Apparel Supply Chain

In order to increase their profit margins and international expansion, many international fashion brands implemented a new supply chain strategy named fast fashion. It is a strategy that aims to rapidly get the trendiest fashion clothes in the stores. Several Moroccan fashion retailers tried to copy the fast fashion business model in order to get a responsive supply chain and a high profit margin. Thus, they need a practical tool to ensure that the fast fashion elements are properly implemented. This paper develops an assessment tool using a maturity evaluation model. This maturity assessment tool has been tested at a Moroccan fast fashion retailer. This pilot test adopted a qualitative research methodology with data collected using semi-structured interviews from a single retailer case operating in Moroccan apparel industry. The fast fashion assessment tool enables fashion retailers managers to have a view of the implementation progression and to eventually locate problems and mobilise other tools and mechanisms to explore them