Biological activities (antibacterial, antifungal and cytotoxic) of secondary metabolites of Ircinia spp.

Sponges are the most primitive of the multicellular, These organisms don’t have any mechanical defense system, so their early appearance in evolution has given them a lot of time for the development of advanced secondary metabolites as chemical defense system. Sponges have the potential to provide drugs from chemical components against diseases. In this investigation the sponge samples, which it is Ircina spp., were collected at depth of 15- 24 meter, from locations on the coastline of Island Kish in Persian Gulf of Iran. For identifying natural components, methanolic and diethyletter were used as extraction solvents, after removal of the solvents, the GC/MS spectra of the fraction were obtained. Then in vitro cytotoxic, antimicrobial and antifungal were identified. In vitro cytotoxity screening, by XTT assay, against KB/ C359 and HUT-56/ C365 cell line, was conducted in this study in 1 - 544 μg/ml. IC54 for winter diethyletter extract was 325 μg/ml, winter methanolic extract was 364 μg/ml, IC54 for summer diethyletter extract was 544 μg/ml, and summer methanolic extract was 454 μg/ml in HUT-56. IC54 for winter diethyletter extract was 454 μg/ml, winter methanolic extract was 444 μg/ml, IC54 for summer diethyletter extract was 344 μg/ml, and summer methanolic extract was 424 μg/ml in KB. In vitro antimicrobial activity by Broth Dilution Methods against clinical gram-positives and gram negatives (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis). The results conducted that the MIC values of winter diethyletter extract for Escherichia coli 24mg/ml, the MIC values of winter diethyletter extract for Escherichia coli 24mg/ml, the MIC and MBC values of winter diethyletter extract for Staphylococcus aureus was 2mg/ml and 24mg/ml. The MIC and MBC values of winter diethyletter extract for Bacillus subtilis was 1.5 mg/ml and 2mg/ml. In vitro antifungal activity by Broth Dilution Methods against clinical pathogens; Candida albicans and Aspergillus fumigatus. The results conducted that the aqueous extracts didn’t have any antifungal activities on pathogens, the MFC of the summer and winter diethyletter extract was 30 mg/ml and 2 mg/ml A. fumigates, the summer and winter methanolic extract was 0722 mg/ml and 2 mg/ml A. fumigates, the summer and winter methanolic was 4/75mg/ml, MFC 5 mg/ml on C. albicans.

Investigation into the meteorological aspects of the variations in the level of Lake Victoria

The level of Lake Victoria has, since 1961, reached a height which caused serious flood damage. Already the financial implications are considerable for Kenya, Tanzania and Uganda. If further rises can be anticipated, expenditure on flood control measures to the tune of several million pounds sterling must be envisaged. If such rises should lead to uncontrolled discharge at the Owen Falls Dam site because of overshooting, downstream districts of Uganda and the Sudan may be seriously flooded. All this merits a thorough study, and any indication of the future behaviour of lake levels, even when associated with a low probability, must be taken into account. In these circumstances the Water Development Department of Kenya approached the East African Meteorological Department in November, 1964, on behalf of all parties concerned with the request to study the meteorological background of the Iake level variation, with a view to forecasting future behaviour.

Investigation and prediction of sea level variations in the northern coasts of Persian Gulf using artificial neural network

Sea- level variations have a significant impact on coastal areas. Prediction of sea level variations expected from the pre most critical information needs associated with the sea environment. For this, various methods exist. In this study, on the northern coast of the Persian Gulf have been studied relation to the effectiveness of parameters such as pressure, temperature and wind speed on sea leve and associated with global parameters such as the North Atlantic Oscillation index and NAO index and present statistic models for prediction of sea level. In the next step by using artificial neural network predict sea level for first in this region. Then compared results of the models. Prediction using statistical models estimated in terms correlation coefficient R = 0.84 and root mean square error (RMS) 21.9 cm for the Bushehr station, and R = 0.85 and root mean square error (RMS) 48.4 cm for Rajai station, While neural network used to have 4 layers and each middle layer six neurons is best for prediction and produces the results reliably in terms of correlation coefficient with R = 0.90126 and the root mean square error (RMS) 13.7 cm for the Bushehr station, and R = 0.93916 and the root mean square error (RMS) 22.6 cm for Rajai station. Therefore, the proposed methodology could be successfully used in the study area.

A survey on prevalence rate of aflatoxigenic species of Aspergillus and residues of aflatoxins by ELISA method in cold-water cultural fish (rainbow trout) feeds in Tehran and West Azarbayjan provinces-Iran

Aflatoxins are one kind of fungal toxins produced by species of toxigenic Aspergillus (A. flavus and A. parasiticus) and in other words they are secondary metabolites which are considered as one of the threatening factors of food consumer's health. In this research 96 samples of cold-water cultural fish feed, rainbow trout, during the seasons of spring and summer of 2007 (every fifteenth of the month) were randomized (by simple and stratified random) to determine: 1. The prevalence rate of aflatoxigenic species of Aspergillus in stored feed of cold-water cultural fish in West Azarbayjan cultural fish farms in both seasons (spring and summer); 2. The residues of total aflatoxin in stored feed of fish in cultural fish farms of West Azarbayjan in both seasons by ELISA method; and 3. The residues of that toxin in feed produced in aquatic feed factories in Tehran and West Azarbyjan provinces with the same method. In order to study prevalence rate of toxigenic species of Aspergillus, pour-plate culture method by general medium such as Malt Extract Agar (M.E.A.) and Sabouraud-Dextrose Agar (S.D.A.) and by standard No.997 of Iranian Standard Institute were used. The produced colonies were examined microscopically. To determine the aflatoxins residues, ELISA method using Agra-Quant kit of Romer Lab company, were applied. The results of this survey indicated that only 8.3% of the samples were infected by A. flavus. A. parasiticus was not observed. There were no significant differences between the prevalence rate of AFT and seasons/months, either (P<0.05). Evaluating mean of aflatoxin rate showed that the rates of this variable are lower than the tolerance levels designated by the joint FAO/WHO expert committee (The mean of AFT in all data was lower than 11 ppb). Furthermore, mean of total AFT residues rates of stored feed of various cultural center of West Azarbayjan and Tehran factories were comparable in spring and summer, and no significant differences were observed (P<0.05). But there were significant differences between the total aflatoxin rates in the feed of West Azarbayjan factory and spring and summer (P<0.05), and AFT residues in spring (8.6 ppb) were higher than summer (6.1 ppb). Prevalence rates of AFT in Tehran feed factories (9.2 ppb) are higher than W. Azarbayjan (7.4 ppb). In other words, location was considered as a decisive factor in total AFT rates of samples. Moreover, the results indicated that there was significant difference between total aflatoxin rates of feed and cultural centers (P<0.05). The mean of AFT rates in embankment dam cultural fish farms (6.75 ppb) and multi-functions cultural fish farms (6.25 ppb) was higher than individual cultural pond (4.67 ppb). In conclusion, the finally results of this survey indicated that the lower rates of Aspergillus is not effective on the presence of total aflatoxin rates in trout feed. Due to low levels of aflatoxin rates (lower than 20 ppb), the produced feed of cold-cultural fishes, Rainbow Trout, in Tehran and West Azarbayjan provinces, in spring and summer of 2007, were safe and healthy both for fish and their consumers.