نشریه علوم دانشگاه خوارزمی
سال دوازدهم شماره 3 (پاییز 1391)

In this study، gammaruses were collected from southern coast of Caspian Sea in Bandar Anzali. Samples were divided into three groups; control، dried and frozen. These treatments were examined with several experiments such as protein، fat، sah and moisture in three time; after a week، two weeks and a month in three replications. The results showed that the Analyze- Variance among the groups had significant differences in the average amount of protein، ash and moisture، but for fat no significant difference interaction between time and maintenance. In additional، by comparing of these factors by the Duncan test، in the dried samples greatest amount of protein (43/13%)، fat (5/78%) and ash (23/25 %) were higher than those of in control samples، (protein: 12/36%، fat: 0/41%، ash: 5/82% and moisture: 75/67%) while control samples had higher moisture than dried samples. In all samples، control treatment had lowest fat (0/41%) and protein (12/36%)، while dried samples had lowest moisture.

Citrus fruits are tropical and sub-tropical crops. The main problem in sub-tropical area is chilling and frost damage. Regarding the sensitivity of citrus fruit to low temperature and the conjunction of the fruit harvest season with low temperature، the investigation of the physiological impacts of low temperature treatments are very important. In this study، flavedo tissue of five cultivars of citrus fruit was examined to compare some enzymatic antioxidants activities including Superoxide dismutase (SOD)، Ascorbate peroxidase (APX)، peroxidase (POD) and Catalase (CAT) under various cold treatments، i. e. control (~15)، 3، 0، -3 and -6 °C in two stages of before and after ripening of the fruits. The high activity of SOD enzyme in the flavedo tissue of the examined cultivars indicated that this tissue is the first defensive line of the fruits facing low temperatures treatments. The activity of CAT enzyme in the flavedo tissue of Sanguinello before and after ripening stages was higher in all low temperature treatments compared with other cultivars. Unshiu and Local Orange had maximum and minimum activity of APX enzyme، respectively in both stages. Also، Unshiu، Sanguinello and Local lemon showed increasing activity of POD enzyme by decreasing temperature

There are many reports on the effects of magnetic fields on the plants، but the exact mechanisms of these effects are poorly understood. In this study we compared the effects of different magnetic fields on the germination and early growth of wheat seeds. The seeds of wheat (Triticum aestivum L.) in two groups، dry and imbibed، were treated with static magnetic field (SMF 30mT) and electromagnetic field (EMF 10KHz) for 4 days and 5 hour for a day. After treatment، seed water uptake، the percent and speed of germination، early growth characteristics and electrolyte leakage of seeds coat and seedlings root membrane were estimated. The results showed that treatment with SMF and EMF had not significant effect on the germination percent of imbibed wheat seeds، but accelerated the speed of germination، fresh and dry weight and vigor index II، compared to control groups. In dry wheat group only positive effect of magnetic field had seen on the length of seedlings. Magnetic field treatment decreased the electrolyte leakage of seeds coat and seedlings root membranes; however had not increased the water uptake of seeds. So elevated speed of germination and growth of seedlings probably was due to increase of membrane integrity، content or activity of the germination enzymes or antioxidant enzymes. In general، effects of magnetic field on the imbibed seeds is better than dry seeds and SMF had better effect than EMF on the germination and early growth of wheat seedlings.

Light is one of the most important environmental factors in fish life. The effect of photoperiod on the growth performances and survival of rainbow trout (Oncorhynchus mykiss) larvae and fingerlings was investigated in two consecutive experiments. In both experiments fish were exposed to four treatments (light: dark، L: D) (24L/0D، 16L/8D، 8L/16D، 0L/24D) in three replicates. The results of the first experiment indicated that photoperiod affected the growth performances in larval stage of rainbow trout. The best weight gain and specific growth rate was observed in 24L: 0D and 16L: 8D without significant differences between them and the lowest rates was achieved in 0L: 24D. Also in second experiment، the effect of photoperiod on the growth performances had significant difference and the highest growth rate and specific growth rate was observed in 8L: 16D and the lowest in 24L: 0D and 0L: 24D. Results showed that the effect of photoperiod on rainbow trout، depends on developmental stage and larvae unlike fingerlings have better growth in longer light phases.

Oil pollutions as a consequence of increasing consumption of petroleum، have a tremendous effect on water and soil ecosystems and their microflora. In this study the diversity in physiological parameters، including growth rate، photosynthesis، chlorophyll-a and phycobiliproteins content، between cyanobacterial strains flora isolated from oil-polluted and non-polluted areas، were assessed. To this end، strains were isolated and purified. The experiments were carried out on logarithmic phase cultures of the isolates in suitable liquid media. The chlorophyll and phycobiliproteins contents were determined using a colorimetric method. Photosynthesis was measured by Oxyview apparatus. Growth rates were calculated based on dry weights. Under laboratory conditions، the photosynthesis activity and the chlorophyll content of isolates from oil-polluted sites were significantly lower than non-polluted isolates. On the other hand، the growth rate average of strains from oil-polluted sites was significantly higher than non-polluted strains. Also despite the higher phycobiliproteins content in non-polluted isolates، there was no significant difference in any of these pigments between the two groups. Altogether the results showed that in response to petroleum stress، the cyanobacteria restore the decrease in their chlorophyll content and photosynthesis activity by increasing their biomass. In fact the response is the reflects of restructuring cyanobacterial flora from sensitive autotrophic species to oil-pollution resistant mixotrophic species in the polluted ecosystems that in addition to photosynthesis are able to use crude oil as an energy source for their growth requirements، hence overcome the energy loss due to reduction of photosynthesis and even increase growth rate than non-oil-pollution isolates.

Salvia L. is one of the important genera of the Lamiaceae family، that most of its species have nutritious and medicinal values. This study aimed to examine the total phenol and flavonoid contents and the antioxidant activities of S. aethiopis using spectrophotometric method. The essential oil of this species was analyzed using GC and GC/MS methods. In addition، antibacterial activities of the essential oil and methanolic extract were evaluated against six gram positive and negative bacteria، respectively. Results showed that the extract has high content of phenolic compounds with high antioxidant activity. From GC analysis، 11 different compounds were indentified in which α-copaene was the most abundant compound with 33. 48%. The extract of the species showed a high antibacterial activity against Proteus vulgaris. However، the essential oil of S. aethiopis had no effect on examined bacteria.

Umbilical cord (UC) is an important source of multipotential mesenchymal stem cells (MSCs). MSCs can be differentiated into different types of cells if they cultured under specific conditions. It has been proved that vitamin D3 can cause differentiation of stem cells in to osteoblast. Also، it has been observed that bee venom (BV) is effective in differentiation of cancerous cells. In this study differentiating potential of BV and vitamin D3 on MSCs to osteoblast was examined. Furthermore، our hypothesis was that BV could increase differentiating potential of vitamin D3. The cells obtained from UC tissues of 10-12 mouse embryos which were digested enzymatically and suspended in DMEM medium. For approving of stem cells، embryonic Oct4 marker was checked and the mesenchymal character of these cells was proven by surface markers including CD73، CD29، CD44. The flowcytometric analysis revealed high levels of these markers. After the second passage، in order to induce osteogenic differentiation، cells were cultured for 21days in DMEM medium containing different concentrations of BV، vitamin D3 separately and BV/vitamin D3 together. At first، cytotoxic effects of BV on MSCs were tested by MTT assay، which were shown that BV inhibited MSCs growth at higher concentrations than 6μg/ml. Following the treatment، calcium’s level in the cells was determined by Alizarin red staining. Also، as an osteogenic marker، alkalin phosphatase level was measured in treated and non-treated cells. By Alizarin red staining and alkalin phosphatase assay، we found that BV With non-toxic concentrations (2µgr/ml، 4µgr/ml and 6µgr/ml) can cause a few osteogenic differentiation of MSCs. Whereas، usage of BV/vitamin D3 together، caused increasing the differential effects of vitamin D3. In conclusion we suggest that if MSCs were treated with bee venom and vitamin 3 at the same time، these components able to differentiate MSCs to osteoblast، therefore، they could be useful in cell therapy.

In the present study، the effects of indole acetic acid (IAA) on certain physiological and biochemical parameters in Glycine max (L.) Merr under aluminum chloride (AlCl3) stress were studied. Seeds were sterilized and cultured in petri-dishes. Six days old seedlings were transferred to pots، and then they were irrigated with Hoagland solution in a growth chamber (with 16 h light period per 24 h، with day / night temperatures of 25/18 ºC respectively). Twenty days old plants were treated with different concentrations of AlCl3 (0، 50، 100، 200 and 300 µM) and IAA (0، 50 and 100 µM). Plants were harvested 15 days after treatment. The plants exhibited decline in the relative water content (RWC)، protein، soluble sugars، the chlorophylls a and b، carotenoids contents and photosynthetic rate with increase of aluminum chloride concentration، but the respiration rate and CO2 compensation concentration were increased. With addition of IAA to culture solutions containing aluminum، the plants showed further decrease in the amount of soluble sugars، chlorophylls a and b، carotenoids and photosynthetic rate and further increase in other parameters. With ncreasing of aluminum concentration to culture solutions with and without IAA unsoluble sugars، proline and lipid peroxidation increased.