Rafidain Journal of Science

The PCR-based technique of randomly amplified polymorphic DNA (RAPD) was used to fingerprint and assess the genetic relatedness among nine species of the fungus Alternaria isolated from various crop plants showing the leaf spot disease in Mosul, Iraq. Genomic DNA of each species was extracted at a final concentration of 300 - 400 µg / 2-3 g of wet mycelium , and at a purity of 1.6-1.8. Each DNA sample was amplified with each of 22 primers and the products were resolved electrophoretically on 1.2% agarose gel, stained with ethidium bromide and photographed under UV. One Primer failed to support amplification but the remaining 21 (95.5%) primers produced a total of 112 bands (2-10 per primer) across the nine species. Of these bands, 100 (1-10 per primer ) were polymorphic. The least efficient primer was OP-H01 (1.79%), while the most efficient one weas OP-M05 (8.93 %). Primers OP-C05, OP-E20 and OP-T20 had the lowest (0.1%) discriminatory power while primer OP-M05 had the highest (10 %) power and identified all 9 species through unique patterns of banding. RAPD analysis fingerprinted eight of the nine isolates through marker bands with one or more of the 21 primers. Cluster analysis based on the genetic distances split the nine species into three distinct clusters with no obvious association between the pattern of clustering of the species and their host specificities.

The present work aimed to examine the efficacy of Peganum harmala Linn. alkaloids as potential antilieshmanial agents in vitro, and to determine their toxicity in mice.
The study included extraction and isolation of Peganum harmala crude alkaloids from seeds. The isolated fraction that contains alkaloids was detected, using Myer`s and modified Dragendorff`s reagents. Then, the crude alkaloids were tested for their antileishmanial activity against Leishmania tropica promastigotes in vitro including their effects on parasite growth and metabolism.
It was found that the studied alkaloids inhibited growth of the parasite remarkably. The inhibitory concentration of 50% of the promastigotes (IC50) at the log phase (96) hrs was 50 µg of the alkaloids/ ml of culture.
Furthermore, the extracted alkaloidal fraction from Peganum harmala seeds, resulted in decline of RNA, DNA, and protein content of the parasite and reduced specific activity of dihydrofolate reductase and thymidine phosphorelase enzymes. It also had obvious inhibitory effects on energy metabolism of the parasite.
Oral median lethal dose (oral LD50) of the extracted alkaloids was 1070 mg / kg body weight in Balb/c mice, using the up-and-down method.
It can be concluded that Peganum harmala alkaloids show promising antilieshmaneal activity and may have potential role in the search for novel antilieshmaneal drugs, as they affect metabolism of proteins, nucleic acids and energy of the parasite (in vitro) with a slight toxicity in mice (in vivo).

In this study, the analysis of 48 qualitative macroinvertebrate samples were taken from four sites in the lower reach of Greater Zab river near Guwer subdistrict- Erbil from May 2008- April 2009. Sixteen taxa belong to Ephemeroptera, Diptera, Plecoptera, Hemiptera, in addition to one taxa belong to class Arachnides were identified. Site 1 is characterized by more identified taxa (12 taxa) than the other sites. Most abundant taxa were Tanypus spp. during studied period which followed by Hydrachna spp., with highest F index percentage reached to 75% and 58.3% respectively. According to Sorenson index, sites 2 and 3 were the most similar sites with values reached to 75%.

Investigations were carried out on the gill tissues of common carp Cyprinus carpio L. exposed to high levels 31oC, and low levels 18oC of temperature for a total period of successive of 10 days. The histological study of the gill sections of this fish species showed marked histological lesions, include hyperplasia and hypertrophy of the respiratory epithelium, bloody congestion with hemorrhage and abundance of mucous substance, this at high temperature, while at low temperature also showed hyperplasia, shrinkage of blood vessels, fusion of secondary lamellae, cellular atrophy, damage and lamellar disorganization. Lesions were comparatively most severity at low temperature.

A simple spectrophotometric method for the trace determination of barbituric acid (BA) has been established. The method is based on the coupling reaction of barbituric acid with diazotized nitroaniline in basic medium to form an intense yellow-water soluble and stable mono azodyes which shows maximum absorption at 418, 380, and 370 nm with diazotized o-, m- and p-nitroanilines, (DONA, DMNA, and DPNA), respectively. A plot of absorbance versus BA concentration was linear to a certain limit, indicating that Beer's law was adhered to over the range 5-300 g of BA/25 ml final volume (i.e., 0.2-12 ppm) with a molar absorptivity of 1.998×104, 2.328×104, and 2.184×104 l mol–1 cm–1 for DONA, DMNA, and DPNA, respectively. Sandell sensitivity indexes were 0.0064, 0.0055, and 0.0059 µg cm–2, while the relative errors were -3.365 to 0.904%, -3.325 to 0.138%, and -2.053 to 2.679% for DONA, DMNA, and DPNA, respectively. The relative standard deviation (RSD) were 0.489 to 3.330, 0.897 to 2.209 and 0.059 to 3.689 for DONA, DMNA and DPNA, respectively. The optimum conditions for the color reaction, nature of dye, stability constant and the interference of variety of organic compounds had been investigated. The method has been successfully applied to the determination of barbituric acid in Tigris water river. The proposed method for the determination of barbituric acid is simple, sensitive, very low cost, has a wide analytical range and without the need for heating or solvent extraction techniques.

The analysis of solar cell performance in terms of material and microscopic device parameters is the key to understanding device performance and efficiency. The purpose of this paper is to study and analysis the (n+ p) homojunction silicon solar cell, and study for regions of solar cell which the base, depletion and emitter region after determent the parameters such a sample. And finding the quantum efficiency for this cell, and studying the effect of the recombination velocity of minority carriers and different diffusion lengths on the performance of the solar cell.