Evaluation of a cocktail of three bacteriophages for the biocontrol of Salmonella of wastewater

Salmonella serovars are increasing in importance as significant pathogens of both human and animals. Although water and wastewater are treated to eliminate pathogenic microorganisms, they still play an important role in the transmission of Salmonella spp. In this study, bacteriophages infecting Salmonella spp. were isolated from wastewater and evaluated; for their potential to lyse environmental Salmonella strains in vitro at different MOIs and temperatures; and to control the wastewater bacterial community. Three distinct phages designated sww65, sww275, and sww297; as defined by plaque morphology, electron microscopy and host range; were obtained from wastewater. Challenge tests were performed at 37, and 30 °C with the infection of the Salmonella cultures with individual phage, a mixture of two phages, and cocktail of three phages at MOIs of 10⁰, 10², and 10⁴ PFU/CFU. At 30, and 37 °C, a cocktail of three phages reduced all of the Salmonella cultures tested. These results required a high multiplicity of infection. However, when infected with only one phage or a mixture of two phages at MOIs of 10⁰ or 10 ² PFU/CFU, an emergence of bacterial resistance was observed. The dynamic monitoring of wastewater enterobacterial community was conducted using Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR). The number of bands decreased gradually with the use of individual phage or phage cocktails. Moreover, the dynamic monitoring of Salmonella community during wastewater treatment was performed using PCR detection of virulence gene invA. The results correlated with the ERIC-PCR fingerprints, and suggested that Salmonella community was affected by the phage treatment. Indeed, in wastewater, bacteriophages are reducing Salmonella and other members of the Enterobacteriaceae. These results indicated that dynamic changes are closely related with the process of treatment. The introduction of wide host range bacteriophages in wastewater can have a potential impact on the dynamics of the microbial communities, manifested by the reduction or the elimination of microbial species.     

A dual‐band case‐printed planar inverted‐F antenna design with independent resonance control for wearable short range telemetric systems

In this article, a novel 3D meandered planar inverted‐F antenna (PIFA) is proposed for dual band application targeting Wireless Body Area Network (WBAN). The proposed antenna is printed on the casing of a 3D‐base‐station model having a size of 88 × 95 × 10.2 mm³. The proposed PIFA covers two bands including medical implant communication service (MICS) (402‐405 MHz), as well as the industrial, scientific, and medical (ISM) (2.4‐2.48 GHz) bands. Each of the two bands can be controlled independently. The 3D configuration contains two linked meandered resonators to downsize the structure. Due to its conformal shape, omnidirectional radiation pattern, and low‐profile nature, the proposed PIFA is a potential candidate for targeting the WBAN applications. The proposed antenna, covering the MICS and ISM bands, works with an optimally matching (VSWR<2) at the aforementioned bands. The design concept was validated by fabricating the antenna prototype and measuring its characteristics.     

Hash key-based image encryption using crossover operator and chaos

This paper proposes a color image encryption scheme using one-time keys based on crossover operator, chaos and the Secure Hash Algorithm(SHA-2). The (SHA-2) is employed to generate a 256-bit hash value from both the plain-image and the secret hash keys to make the key stream change in each encryption process. The SHA-2 value is employed to generate three initial values of the chaotic system. The permutation-diffusion process is based on the crossover operator and XOR operator, respectively. Experimental results and security analysis show that the scheme can achieve good encryption result through only one round encryption process, the key space is large enough to resist against common attacks,so the scheme is reliable to be applied in image encryption and secure communication.     

Bacillus cereus adhesion: an investigation of the physicochemical characteristics of surface and effect of bio adhesion on the properties of silicone

The initial microorganism adhesion on substrate is an important step for biofilm formation. The surface properties of the silicone and Bacillus cereus were characterized by the sessile drop technique. Moreover, the physicochemical properties (hydrophobicity; electron donor/electron acceptor) of surface adhesion and the impact of bio adhesion on the silicone were determined at different time of contact (3, 7, and 24?h). The results showed that the strain was hydrophilic (Giwi?=?3.37?mJ/m²), whereas the silicone has hydrophobic character (Giwi?=??68.28?mJ/m²). Silicone surface presents a weak electron-donor character (γ ^??=?2.2?mJ/m²) conversely to B. cereus that presents an important electron donor-parameter (γ ^??=?31.6?mJ/m²). The adhesion of B. cereus to silicone was investigated using environmental scanning electron microscope and image analysis was assessed with the Matlab^® program. After 3?h of contact, the data analysis, confirmed the bio adhesion with an amount of 9.610⁵?cfu/cm² adhered cells. After 24?h, the percentage of silicone covered reached 93%. Furthermore, despite the difference in hydrophohbicity, the interaction between B. cereus and substrata was favoured by the thermodynamic model of adhesion (ΔG _adhesion ?<?0). The real time investigation of the effect of B. cereus adhesion on the physicochemical properties of silicone has revealed that the substrata becomes hydrophilic (θ°?=?47.3, ΔGiwi?=?23.7?mJ/m²), after 7?h of contact. This bio adhesion had also favoured the increase of electron donor/acceptor character of silicone (γ ^??=?53.1?mJ/m² and γ ⁺?=?5.3?mJ/m²).     

Equal Size Clusters to Reduce Congestion in Wireless Multimedia Sensor Networks

Wireless Multimedia Sensor Networks (WMSNs) are a particular instance of Wireless Sensor Networks that support the transmission of multimedia data such as video, image or sound. Those multimedia data should be delivered with a variety of predefined levels of Quality of Service swhich imposes the development of specific routing protocols. In this paper, we propose a new routing protocol based on clustering, that balances the number of nodes in clusters, called Equal Size Clusters to reduce Congestion in WMSNs. We seek to balance the number of members in each cluster in order to reduce intra-cluster congestion and reduce the number of congested cluster-heads. Therefore, we propose a novel metric called Maximum Cluster-heads Utilization Ratio (MCUR) that indicates the largest number of members assigned to a cluster-head to ensure a reliable transmission of multimedia data. Simulation results indicate that our proposed scheme outperforms other protocols proposed in the literature in terms of MCUR, number of cluster-heads and energy consumed.     

Remote monitoring of cardiac activity using a flexible loop antenna

In this paper, a meandered loop antenna, useful for medical cardiac monitoring application, more specifically, for heart beating close scrutiny is designed and experimentally tested. The proposed antenna is operating at the MICS band displays a high flexibility which allowing it to be curved easily around the heart's wall. In both, Simulation and measured results the antenna shows a sensitive nature any change introduced in heart's model size and would certainly bring about a noticeable shift in the antenna's resonant frequency. Linking the frequency variations taking place in concord with the heart movement turns out to stand as an effective key that provides extremely valuable information about the heart's activities. A correspondence between the obtained frequency variation linking with the change in size of the heart. In addition to the frequency response evaluation, the antenna characteristically displays an omni‐directional radiation pattern, which necessarily fits it for in‐body operation.     

Production of bioactive peptides from tomato seed isolate by Lactobacillus plantarum fermentation and enhancement of antioxidant activity

Tomato seed contains proteins of high nutritional value and nutraceutical properties, which can be recovered for application as food additives. In this study, we investigated the use of a Lactobacillus plantarum strain to obtain high-added-value peptides from the fermentation process using tomato seed meal extract as the substrate. Potentially tomato seed meal extract have antioxidant activity which is correlated to the amino acid structures, compositions and sequences. After 24 h of fermentation, the radical scavenging activity of the isolated extract was increased by 87%. The increase of antioxidant activity is potentially attributed to the production of different bioactive peptides bio transformed during fermentation. L. plantarum growth on tomato seed meal extract as substrate reduced content of crude and soluble proteins by 18.44% and 68.99%, respectively, after 24 h of fermentation. Gel filtration chromatography showed a depolymerization of high molecular weight of polymers. HPLC analysis showed a significant decrease in the concentration of total amino acids, especially glutamic acid and aspartic acid. FTIR results showed that the fermentation favors the production of new amides and aromatic compounds. The production of protease by L. plantarum was investigated and results showed that highest activity (401.45 U/ml) were obtained after 20 h of fermentation. Results confirmed that L. plantarum could degrade and convert tomato seed proteins into bioactive peptides that contributed positively to the improvement of antioxidant activity of the protein isolate.     

Insights into the use of landfill leachate to grow Chlorella sp. for lipid and fatty acids production

Clean Technologies and Environmental Policy - Microalgae provide a potential alternative for high-value products. Integrating microalgae into the landfill leachate valorization process gives the...     

An Improved Energy Efficient Clustering Protocol for Increasing the Life Time of Wireless Sensor Networks

The intention behind this article is to devise a fresh clustering algorithm for Wireless Sensor Networks. The major aspiration is to curtail the energy utilization at the cluster building and data transmission levels to the Base Station. The algorithms offered are not dedicated to a particular type of sensor network or a specific application. We consider several parameters when choosing Cluster Head such as energy, degree and distance. These parameters have been studied separately or in combination in several literature works and their efficiency in terms of energy utilization and structural stability have been shown. The proposed approach is termed as the Distance Energy Evaluated (DEE) Approach. The DEE approach has lower intricacy in message size. The proposed approach is tested by running various MATLAB simulations. The results illustrate that our proposed protocol has shown significant improvement as compared to other approaches in terms of the lifespan of the network and energy usage.