جستجوی مقالات مرتبط با کلیدواژه "گرگان" در نشریات گروه "زیست شناسی"

Effective treatment of domestic sewage and industrial effluent to maintain the quality of the utmost importance. Quality wastewater treatment, usually with parameters such as PH, dissolved oxygen, chemical oxygen, biochemical oxygen demand, total organic carbon, total dissolved solids, total suspended solids, concentration of some special compounds and other parameters can be expressed. There are several methods for determining toxicity, including bioluminescence, respiration, nitrification, denitrification, molecular-based tests and sensors, and bioassay. Toxicity testing for aquatic life is a method in which the reactions of aquatic organisms are used to detect or measure the presence or effect of one or more toxic substances, wastewater, or environmental factors alone or in combination. This method has many deficiencies, including lack of recognition synchronized effects and toxicity index them. Even the most comprehensive physico-chemical properties wastewater effluent adverse effects on ecosystems will not show the effects of bio-waste only determined by bioassay tests. One of the standard methods for determining the toxicity of wastewater is the toxicity test or bioassay. Although all bioassay tests are very similar in principle, this study focuses more on bioassay with the help of microorganisms, because bioassays focus on microorganisms in addition to their specificity in controlling water pollution. There are many types for bioassay. The two most commonly used types are chronic and acute toxicity. Many organisms such as fish, algae, bacteria and freshwater and sea creatures are used in the bioassay. One of these indicators is a hard skin called Daphnia Magna. The results of research on a variety of laboratory organisms show that bioassay with Daphnia Magna compared to some organisms with high sensitivity, short reproduction, simplicity of testing and low laboratory costs and most importantly due to fertilization. They have a genetic similarity, which is one of the most important factors in the validity of the results of bio-experiments, in infants born of the same sex. It also has a special place in water pollution control measures. Today, the use of Daphnia Magna is accepted in different countries due to its high sensitivity and easier use to monitor the effluent and determine the efficiency of the treatment plant in reducing toxicity.The aim of this study was to evaluate the toxicity of effluent from wastewater treatment plants, industrial city of Gorgan in Golestan Province Using the biology test.

The accuracy of a biological test is limited to a number of reasons, which are due to natural differences between members of a species. Study with accidentally selected species does not provide accurate information about the toxicity of a compound compared to other species and life stages. Experiments with one species, provide an accurate estimate of toxicity only to other similar species in terms of size, age, and physiological conditions in water with similar characteristics and conditions. Daphnia Magna is the largest daphnia, measuring 5 mm in size. Many of them can be grown in a relatively small space. Daphnia Magna babies are 0.8 to 1 mm long and can be seen with the naked eye. Daphnia magna is very important in biological experiments at this stage of the life cycle. The female genus Daphnia magna can survive for up to 4 months at 20 ° C. They grow in natural waters and dechlorinated tap water. Their diet consists of bacteria, algae and yeasts along with soil extracts and organic matter. Daphnia magna is grown individually in small containers and in large aquariums. According to the sensitivity of Daphnia and the reports that Daphnia magna is the most sensitive invertebrate to various organic compounds; To determine the effectiveness of the processes used in this study, Daphnia Magna was used as a bioindicator of bioassay experiments. First, the test materials, diluent water, and toxic solutions are prepared, and the test and control solutions are introduced in 100 ml volumes into wide-mouthed glass or similar containers. Necessary tests such as pH, DO, TSS, temperature, BOD, COD, EC were performed on the effluent sample. After preparing the test solutions, 10 Daphnia infants were placed in each test container and control container; then observation is performed regularly. Observation is usually done after 1, 2, 4, 6, 12 hours and then daily for up to four days (96 hours). The number of moving animals in each test vessel should be recorded. Mortality in control samples should not be more than 10% and preferably more than 5%, which indicates a sick organism in the group of 10 to 20. Then using Daphnia magna Bioandicator acute toxicity unit and LC50 at 12, 24, 48, 72 and 96 hours with probit test in SPSS version 22 was used. Composite samples of raw sewage and industrial wastewater treatment plant of the city of Gorgan were refined. It should be noted that all toxicity tests determined in the Health college laboratory of Medical Sciences university was conducted. In this study, LC50 and toxicity unit (TU) were determined.

To determine the toxicity of raw and treated effluents during different treatment times by COP method with experimental method, the results related to Magna and LC50 mortality and toxicity unit (TU) are presented in Figures 1 to 7. BOD5 and COD parameters treated wastewater Industrial Town BandarGaz, respectively 44 ± 4 and 28 ± 2 mg with 0.8% and 47% by volume of input and output LC50-96h with the TU respectively 12773 and 214 for Agh Ghala Industrial Town COD 50 ±25 mg LC50-96h with the input and output, respectively 0.8% and 39.9%, respectively 12159 and 251 were measured by the TU.

The results showed that the removal of toxic wastewater treatment LC50-96h Aq Qala and Bandar Gaz respectively from 0.8% to 39.9% and from 0.8% to 47% by volume, respectively. The acute toxicity of waste water treatment plants Aqqala from 12159 to 251and acute toxicity of the wastewater treatment plant Bandargaz after 96 hours measure fell from 12 773 to 214. Considering that the toxicity of Aqqala water treatment plant effluent is approximately 1.1 times than Bandar-e-Gaz treatment plant, according to the classification of toxic compounds based on the toxicity unit, the effluent from both treatment plants is extremely toxic. Therefore, necessary measures to monitor and reduce toxicity, in addition to observing the parameters of the standard index of wastewater treatment plants are necessary.

Iodine is one of the most important essential micronutrients throughout life. Salt is the most important and inexpensive iodized foods in Iran. This study aims to investigate the concentration of iodine of salt in Gorgan and compare it with standards. This study was descriptive-analytical. The sampling was performed on 11 brands of iodized salt in Gorgan,s stores. The iodine content was measured by titration with three replications. The data were analyzed using SPSS software. In this study, the lowest average iodine concentration was observed in the K brand (15.05 µg/g). It did not meet the Ministry of Health standards (30-60 µg/g and 20-50µg/g). It met the WHO, UNICEF, ICCDD standards(15-55µg/g). Also, the brand of J (21.68 µg/g), F (24.62 µg/g), I (28.23 µg/g), and E (23.62 µg/g) did not meet the new standards of the Ministry of Health. The amount of iodine in the salt can be due to its quality in the production stage (e.g. purity) and the time interval from production to consumption. Therefore, continuous monitoring is very important in the chain of production and distribution timely.

In general, the testes in the Hynobiidae Family are slender. In urodeles, the testis is organized in lobes of increasing maturity throughout the cephalocaudal axis. The anuran testis is organized in tubules. Spermatogenesis occurs in cysts composed by Sertoli cells enveloping germ cells at synchronous stages. Moreover, in numerous species germ cell progression lasts a year which defines the sexual cycle. Due to the above quoted features, research on factors regulating germ cell progression in amphibians may reach greater insight as compared with mammalian animal models .In the present research for the first time identification and structural description of stage in spermatogenesis in Paradactylodon. In order to fulfill this purpose 16 specimens of Paradactylodon gorganensis were captured and transferred to laboratory. In species is only found in the Shir-Abad Cave and the stream flowing from it, 60 km east of Gorgan (36 57' N, 55 01' E), in the eastern part of the Elburz Mountains, in the  Golestan  Province, northern Iran. After macroscopic analyses and obtainment of the testicular fragments, the material was submitted to the histological routine to inclusion in paraffin and coloration with haematoxylin/eosin. Anatomical studies showed that, in this species testis is slender and milk-white and average length and diameter of active testis were 32.76 mm and 4.77 mm. In microscopic analyses studies showed that ,in this species testis is ampular and spermatogenesis occurs in cysts which develop within seminiferous lobules and  each one of these units clusters cells in the same stage of differentiation and with a synchronism development, common characteristic in the amphibians .In the germ tissue the primary spermatocyte (mean 5.511 ± 0.537 μm) are biggest spermatogenetic cells. With the cellular differentiation and proliferation, succeeded the other cellular types (spermatogonia, spermatocytes II, spermatids I and II, and spermatooza) with a cystic organization, that is, groups of cells associated with Sertoli cells, forming the spermatogenetic cysts or spermatocysts. The spermatogenetic lineage cells were differentiated and identified according to the cellular and cystic morphology.

Bees are the major pollinators of angiosperms (flowering plants) in most ecosystems. Halictidae is second most diverse bee family in the world that pollinates rangeland plants, field crops, fodder and some horticultural plants. Regarding the importance of bees on pollination of flowering plants, collecting of the bees was conducted in Gorgan County (Golestan province, Iran) during flowering seasons in 2014-2015. Because of daylight activity, all bees were collected by sweep nets while they were searching for nectar and pollen. The halictid bee specimens were killed in glass or propylene jars containing chopped cork and ethyl acetate and then pinned. In the present study, descriptions of 21 halictid bee species belong to three subfamilies Rophitinae, Nomiinae, Halictinae, four genera Rophites, Pseudapis, Halictus, Lasioglossum and nine subgenera Rophitiodes, Nomiapis, Halictus, Hexataenites, Vestitohalictus, Seladonia, Lasioglossum, Evylaeus and Dialictus with photos of the most important characters of each species are provided for first time in Iran.

Persian salamander Paradactylodon gorganensis is endemic, unique and valuable genetic pool of Iranian Amphibians that exists in forests of Golestsn province. In this research, for the investigation of biological aspects of this species, for the first time natural habitats include Odaneh, Req and Gorgloo springs have been recognized in forested area of Ziarat village in south of Gorgan in 1250-1600m elevation above the sea level. We studied these localities 12 times from August 2009 to September 2010. Also, geographical position, climate, substrate, fauna, flora were investigated. In every time characters of larvae were studied. Results, shows that larvae are active at all time of the year, even when the habitat covered with snow and air temperature is -3°C. The larvae were seen with different sizes and ages in a same time, Therefore, it seems that they don’t transform during the first year. There was cannibalism relationship in larvae. Also some of larvae may be eaten by crabs (Potamon sp). Although larvae have 4 fingers and toes in the limbs but some specimens were seen without, 3 and 5 fingers and toes. It seems that the air and water temperature do not have serious effect on growth and metamorphosis in larvae. Habitat destruction by farmers and animals, pH changes, water shortage are the most important and threating factors for population of this endemic species that live in specific habitats with limited distribution.