غزال یزدان پناه

The presence of medicines in the environment is considered as a serious threat to the human health. The entrance of these substances into the water sources causes soil pollution, which eventually leads to the environmental pollution and it creates some problems for the public health. Also, increasing antibiotic resistant bacteria has attracted the attention of researchers to the use of natural resources such as marine products, for producing new antibiotics. The aim of this study was to evaluate antimicrobial activities of powdered cuttlebone against Klebsiella oxytoca, Staphylococcus aureus, and Aspergillus flavus.
At first, cuttlebones were washed, dried, and powdered. Then, the powdered cuttlebone was characterized. In the next step, its antimicrobial activities were evaluated using agar well diffusion technique, and minimum inhibitory concentration (MIC) was calculated.
The powdered cuttlebone was found to be effective against K. oxytoca (24 mm, MIC: 10-1 mg/mL), but no antimicrobial response was found against S. aureus. Also, the powdered cuttlebone antifungal activity and MIC against A. flavus were recorded 23 mm and 10-1 mg/mL, respectively.
The obtained results suggest antimicrobial activities of powdered cuttlebone, which are concentration dependent. Furthermore, cuttlebone can be used as an accessible natural source to provide novel, low cost, and safe antimicrobial agents.

Changes in temperature and precipitation pattern seriously affect the amount of river runoff coming into Dam Lake. These changes could influence the operating conditions of reservoir systems such as Jor hydropower reservoir system (Malaysia) with the total capacity of 150 MW. So, it is necessary to analyze the effect of changes in weather parameters on the river runoff and consequently, the hydropower production. In this research, LARS-WG was used to downscale the weather parameters such as daily minimum temperature, maximum temperature, and precipitation based on one of the general circulation sub-model (HADCM3) under three emission scenarios, namely, A1B, A2, and B1 for the next 50 years. Then, the artificial neural network (ANN) was constructed, while rainfall and evapotranspiration were used as input data and river runoff as output data to discover the relationship between climate parameters and runoff at the present and in the future time. It was revealed that the monthly mean temperature will increase approximately between 0.3-0.7°C, while the mean monthly precipitation will vary from -22% to +22% in the next 50 years. These changes could shift the dry and wet seasons and consequently, change the river runoff volume. In most months, the results of models integration showed reductions in river runoff. It can be concluded that the output of hydropower reservoir system is highly dependent on the river runoff. So, the impacts of climate changes should be considered by the reservoir operators/managers to reduce these impacts and secure water supplies.

The aim of this study was to evaluate the physical and chemical quality of groundwater in the villages of Qom province during summer 2014, and to compare the results with Iran’s Standard No. 1053.
This research is a descriptive sectional study. During the investigation, one step sampling with the necessary repetitions (if necessary) was performed of each well for evaluation of physical and chemical quality of groundwater in the villages of Qom province. SPSS version 16 and ARCGIS software were employed for data analysis and data zoning respectively.
The average concentration of magnesium, sulfate and ammonia in wells water were higher than standard. The average concentration of fluoride was lower than the standard limit. pH and turbidity in all wells were within the standard limit but sulfate in 33.33%, ammonia in 13.33%, magnesium in 10.66%, sodium in 40%, calcium in 5.33%, nitrate in 17.33%, total dissolved solids (TDS) in 14.66% and electrical conductivity (EC) in 24% of wells were higher than the standard limit, and fluorine in 98.66% of wells was lower than the standard limit. The results of zoning in the villages of Qom province revealed that measured values at most wells were in the maximum amount in central and northeastern areas and minimum amount in southern and western areas.
This study indicated that most of the physicochemical parameters such as fluoride in almost all villages, and sulfates, chloride, magnesium, sodium, calcium, nitrate, TDS and EC in some of the wells did not fall within the permissible limit.