Contribution of anthropic activities to the seawater pollution at the Port of Tenes

The port of Ténès, located at West of Algiers, is a medium of intense anthropic activities. Its pollution was monitored using a sampling technique. The analysis of the parameters: pH, temperature, electrical conductivity and dissolved oxygen (D.O) was carried out in situ. The concentration of heavy metals has been carried out by the atomic absorption while scanning the wavelengths varying from 217.0 nm at 228.8 nm. The evolution of the nitrate and nitrite content was obtained by spectrophotometer. Their spatio-temporal profiles were obtained by the Geographic Information System (GIS) software. The high toxicity of seawater is due to the presence of lead and cadmium with concentrations exceeding 60 times the normal value (0.015 mg/l). Moreover, the deficit in D.O announces strong biological activities. This wild aggression is related to the industrial discharges in the port area.Keywords: marine pollution; heavy metals, sampling, physiochemical analysis, toxicit

Mechanical properties, microstructure and crystallographic texture of magnesium AZ91-D alloy welded by Friction Stir Welding (FSW)

The objective of the study was to characterize the properties of a magnesium alloy welded by friction stir welding (FSW). The results led to a better understanding of the relationship between this process and the microstructure and anisotropic properties of alloy materials. Welding principally leads to a large reduction in grain size in welded zones due to the phenomenon of dynamic recrystallization. The most remarkable observation was that crystallographic textures appeared from a base metal without texture in two zones: the thermo-mechanically affected and stir welded zones. The latter zone has the peculiarity of possessing a marked texture with two components on the basal plane and the pyramidal plane. These characteristics disappeared in the TMAZ, which had only one component following the basal plane. These modifications have been explained by the nature of the plastic deformation in these zones, which occurs at a moderate temperature in the TMAZ and high temperature in the SWZ

In vitro Antibacterial and Antifungal Activities of the Saudi Lawsonia inermis Extracts Against Some Nosocomial Infection Pathogens

The increasing prevalence of antibiotic-resistant pathogens has drawn the attention of the researchers in the pharmaceutical field towards studies on the potential antimicrobial activity of plant-derived substances. This study was conducted to investigate the antibacterial and antifungal activity of leaf extracts of Lawsonia inermis (Henna) on some nosocomial infection pathogens. Leaf samples of the plant were collected from Yanbu city, Saudi Arabia. Methanol, ethanol, and hexane extracts were obtained by maceration method. The pathogens were isolated from the hospital environment and identified based on cultural, morphological and biochemical characteristics as Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa, Staphyloccocus aureus, Staphylococcus epidermidis, Enterococcus faecalis, and the yeast Candida albicans. The methanol extract was shown high antibacterial and antifungal activity compared with Hexane and Chloroform extracts. Methanol extract expressed highest and broad- spectrum antibacterial activity against pathogenic strains. It exhibited high activity against Gram- positive and Gram- negative bacteria and fungi. The results of this study support the use of Lawsonia inermis plant in traditional medicine to treat bacterial and fungal diseases and this plant could be a source of new antibiotic compounds

Antimicrobial activity of Streptomyces sp. isolated from the gulf of Aqaba-Jordan and screening for NRPS, PKS-I, and PKS-II genes

Forty-nine Streptomyces isolates were recovered from sediment samples in the gulf of Aqaba/Jordan. All isolates were tested for antimicrobial activity against Gram positive bacteria, Gram negative bacteria, and yeast. Twenty eight Streptomyces isolates were active against at least one of the tested strains. The majority of the isolates showed activity against Gram positive bacteria: Streptomyces aureus (89%), Streptomyces epidermidis (64%) and Bacillus Subtilis (50 %). Lower activity was observed toward Gram negative bacteria with only 25% active against Pseudomonas aeruginosa, whereas only 17% were active against the yeast Candida albicans. Isolate S34 showed best activity. It produced heat stable antimicrobial activity at both acidic and alkaline pH (5 to 5.5 and 8 to 9.5). S34 was found to be related to Streptomyces rochei. Forty-nine Streptomyces isolates were screened for genes encoding non ribosomal peptide synthetases (NRPS) and polyketides synthases (PKS; types I and II). NRPS sequences were widely distributed and detected in 81% of Streptomyces isolates. PKS types I and II were detected in 63.2 and 65.3% of isolates, respectively. Additionally, the relationship between the occurrences of biosynthetic gene sequences (NPRS and PKS sequences) and the production of antimicrobial activities was determined. The above results reveal that the marine Streptomycetes are a promising source of novel and unique products.Keywords: Marine Streptomyces, antimicrobial activity, non ribosomal peptide synthetases (NRPS), polyketides synthases (PKS), enzymes, gulf of Aqaba, JordanAfrican Journal of Biotechnology, Vol 13(31) 3505-351

Clustering and Discernment of Bee Pollen Using an Image Analysis System

In this paper, we suggest a framework for multi-focal image classification and identification, the methodology being demonstrated on microscope pollen images (image processing and classification techniques). The framework is intended to be generic and based on a brute force-like approach aimed to be efficient not only on any kind, and any number, of pollen images (regardless of the pollen type), but also on any kind of multi-focal images. Both stages of the framework's pipeline are planned to be used in an automated Fashion. First, the optimum focus is chosen using the absolute gradient method. Then, pollen grains are collected using a coarse-to-fine method involving both clustering and morphological techniques. Finally, features are extracted and selected using a generalized method, and their classification is checked using hierarchical cluster analysis (HCA). Our findings indicate that HCA meets the demands for automatic pollen detection making it an alternative method for research concerning pollen