105 research outputs found

    A study on length frequency, length-weight relationship, distribution and biomass of shrimp (Palaemon adspersus) in the south east Caspian Sea, Golestan Province

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    Assessment of length frequency, length-weight relationship, distribution and biomass of the shrimp P. adspersus was done four times in the summer of the year 2002 in the Gorgan Bay and south east of the Caspian Sea. Results indicated that the mean carapace length (CL) was 13.55±1.79mm, and minimum and maximum CL was 8.7 and 18.7mm respectively. We determined the length weight 123 relationship as W=0.0035CL^2.3123 In the south east region of the sampling area the mean carapace length was 12.67±2.23mm and minimum and maximum CL was 5.2 and 17.5mm Respectively. For this region, we found the length weight relationship as W=0.0072CL^2.0956 P. adspersus were found in all depths. Parallel with the air temperature increase, the shrimp density showed an increase at the depth of 2-10m. The estimated biomass of this species in the Gorgan Bay was 1999kg and in the south east region was 1160kg

    Study of possibilities of aquaculture activities in the Gorgan Bay

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    The Gorgan Bay has situated in the South east of the Caspian Sea and water entersthe Bay from the Sea .it covers an area about 450 squar kilometers that is connected to the sea only by the passage of Ashouradeh in the north east of the bay . The water balance is almost constant and is not tidal. In this study, a model made for the bay on the basis of its water quality and quantity. Its reactions evaluated under different qualified scenarios and its surrounding water quality survey during next 29 years. Mike 21 software was used for 2 dimensional modeling . At first hydrodynamic modeling of the bay was done .one of the important factor was water depth which calculated by hydrography method of the bay. Then, a model made for the salinity of the bay. Since, salinity is a stable parameter, a sub-program TM (Mike 21) which has the ability to make a model from the process of advection – dispersion was used. The amount of Manning (0.025) and Dispersion (50) coefficient calculated simultaneously with calibration of salinity model (D:square meter / second). Results from data verification of salinity model indicated about 3 percent mean error. The pollution dispersion type in the bay evaluated at six points of the bay using the method of dot constant source of pollution. Results showed that around 99.9 percent of pollution decreases under the effect of dilution process till the 100 m distance. Then modeling of dissolved oxygen, Ammonia, nitrite and nitrate was done by using of subprogram ECOLAB at the Mike software To make these models, first the sensitivity analysis of these parameters was done. Important parameters chose for model calibration and then data verified and also the model calibrated. The result of data verification test showed the mean error of oxygen, ammonia, nitrite and nitrate were respectively about 3, 4, 6.3 and 37 percent. Then modeling made according to four different scenarios which defined on the basis of pollutions originated from aquaculture in the bay (scenario 1: aquaculture at the first half year. Scenario 2: aquaculture at the 2nd half year. Scenario 3: aquaculture at the whole of year. Scenario 4: cultivation of bluga for 3 years). Water quality of the bay and also different amount of aquaculture production surveyed during next 29 years under different scenarios of aquacultures. The places under pollution were included the appropriate places for aquacultures in each scenario that was already determined at the bay .Then the reaction of the Gorgan bay was determined under each scenario. The curves of pollution fluctuations were drawn along with amount of cultivation at the each scenario. At last, appropriate amount of cultivation was calculated at each scenario with considering of self-purification of the bay that does not tend to pollution of the bay. On the other hand, the farms arrange, distances between farms and the number of cultivation ponds at the each farm was calculated. Finally, results showed that the aquaculture capacity of the bay is less than 300 tons per year

    Characterization of air velocities near greenhouse internal mobile screens using 3D sonic anemometry

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    In Dutch greenhouses, different screen types are used for different purposes (shading, energy saving, black-out, light emission, etc.). In order to quantify the energy and mass transfers through screens, characterization of air permeability through the screens is required. In the case of energy-saving screens, it is an essential parameter to estimate the energy saving of each screen. Air permeability can be measured under defined conditions in a laboratory. In order to select the appropriate equipment for air velocity measurements, the air velocity vector near screens in a practical situation in a greenhouse needs to be identified by measurements. Sonic anemometry techniques have been used extensively in different types of greenhouses: a) to study natural ventilation, with and without insect screens, and in different positions; b) to study airflow patterns in greenhouses with mechanical ventilation/pad and fan systems; c) to study airflow patterns induced by different types of heating systems, and d) for the estimation of crop evapotranspiration (i.e., eddy covariance). However, to the best of our knowledge, no research has been carried out to study the airflow near different types of screens in a greenhouse. Many Dutch growers are increasingly using various types of fans with different positions in the greenhouse for dehumidification and improved climate uniformity purposes. The effect of such fans on the air velocity near screens, and therefore the effect on energy and mass transfer, is unknown. For this purpose, air velocities near different types of screens in commercial greenhouses were measured using ultrasonic 3D anemometers. The results show that, in the absence of fans, air velocity near the screens is affected by vent opening. With vents closed, air velocities are hardly ever above 0.2 m s-1. Therefore, a simple air-suction device can be used to characterize permeability of screens at a very low Reynolds range.</p

    Evaluation of central auditory processing of azeri-persian bilinguals using dichotic listening tasks in first and second languages

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    Objectives Sometimes there is no hearing impairment, but it is possible to have an auditory disorder. This is known as a central auditory processing disorder (CAPD). Speech dichotic tasks are useful tools to evaluate CAPD, but there is almost no tool to assess this for Azeri people in their native language. The aim of this study was to evaluate central auditory processing of Azeri participants by Azeri dichotic digit test (ADDT). Materials & Methods Participants were 52 normal Iranian Azeri students (mean age 23.27± 4.71; 26 females, 26 males) in the Department of Audiology, School of Rehabilitation Sciences, Iran University of Medical Science, Tehran, Iran in 2016. They were chosen by convenient sampling. ADDT was constructed and administered in free recall conditions along with a Persian dichotic digit test (PDDT). After two to four weeks, reliability was performed. Results The mean of the right ear score of PDDT and ADDT was 98.90 and 99.09, respectively. ADDT was reliable in almost all scores. There was no significant difference in performance between men and women in any score of both tests (P>0.05). The results showed a significant difference between both ears� scores in PDDT (P<0.02) as well as in ADDT (P=0.00). The right ear advantage was seen in both tests. Conclusion All participants performed significantly better on digits presented in the right ear than the left ear in both tests. Central auditory processing of Azeri participants for Azeri is similar to that for Persian. © 2019, Iranian Child Neurology Society. All rights reserved

    The study of pollution in the Gorgan bay

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    From an environmental standpoint bays around the world are very important ecosystems including the Gulf of Gorgan Bay and thus are important. Which has a relatively low depth, a little flow, temperature appropriate, biogenic materials and abundant food in the sea suitable for children sometimes place (Nursery ground) and also the perfect place for power (Fattening ground) is an early sea fish. In this research effort will be the initial studies on the impact of environmental pollutants on the ecosystem of the Gulf of Gorgan and the quality and quantity of pollution, especially pollution, agricultural pesticides and entering the Gulf of Gorgan and the impact on the ecosystem's the initial assessment and the monitoring of changes in them over the years. The user in the Gulf of Gorgan, agriculture. Pollution from agricultural fields related to pesticides and fertilizers are used in the fields. According to consumer research, and the remaining amount of pesticides in water and sediments of the Gulf of measured, indicated that most of the remains of chlorinated pesticides in sediments of the pesticides used in the agricultural sector In addition, all the toxins in the summer and spring peak. In addition, the DDE concentration compared to other poisons. In the case of other contaminants in the area is now threatened by the Gulf of Gorgan, although not serious, but it seems that the increase in organic matter and reduce the amount of oxygen of the water. The near future to Eutrofication risks in the ecosystem

    The study of aquaculture potential of Bojnord and Jajarm cities (Northern Khorasan province)

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    This study investigates the potential of Bojnord and Jarjam cities (Northern Khorasan province) for developments of Aquaculture. First of all, the current condition of Aquacture and fish farms were montiroed and recorde. Then, the information on geology, weather and climate as well as water resources data were gathered and evaluated. Climatology, geology and distribution of water reseources (i.e. reviers, springs, wells, and aqueducts) were prepared using GIS software. Evaluation of selected water resources in study area revealed suitability for culture of cold water fishes. Potentialities of the water resources for aquacture production were determined according to the latest guidline of Shilat organization. The maps of production potentialities were prepared for each water resources

    Prevalence of Cannabis Lifetime Use in Iranian High School and College Students: A Systematic Review, Meta-Analyses,and Meta-Regression

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    Cannabis is the most widely used substance in the world. This study aimed to estimate the prevalence of cannabis lifetime use (CLU) in high school and college students of Iran and also to determine factors related to changes in prevalence. A systematic review of literature on cannabis use in Iran was conducted according to MOOSE guideline. Domestic scientific databases, PubMed/Medline, ISI Web of Knowledge, and Google Scholar, relevant reference lists, and relevant journals were searched up to April, 2014. Prevalences were calculated using the variance stabilizing double arcsine transformation and confidence intervals (CIs) estimated using the Wilson method. Heterogeneity was assessed by Cochran's Q statistic and I-2 index and causes of heterogeneity were evaluated using meta-regression model. In electronic database search, 4,000 citations were retrieved, producing a total of 33 studies. CLU was reported with a random effects pooled prevalence of 4.0 (95 CI = 3.0 to 5.0). In subgroups of high school and college students, prevalences were 5.0 (95 CI = 3.0 to -7.0) and 2.0 (95 CI = 2.0 to -3.0), respectively. Meta-regression model indicated that prevalence is higher in college students (beta = 0.089, p < .001), male gender (beta = 0.017, p < .001), and is lower in studies with sampling versus census studies (beta = -0.096, p < .001). This study reported that prevalence of CLU in Iranian students are lower than industrialized countries. In addition, gender, level of education, and methods of sampling are highly associated with changes in the prevalence of CLU across provinces

    Study on ecological capacity of the release sites of the fingerlings of sturgeon and bony fishes in order to regulate the restocking program at the Gorganrud River

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    This review is started from April 2002 in Gorgan River and continued for one year. Three sampling stations along the river to the mouth of the estuary were 4000 meters away from the bridge to the village Charqly all samples were collected in this area. Four million sturgeon larvae with average weight of 3/2 grams were obtained from martyr Marjani and Vushmgir Dam farms. Over 40 days released at release stations, and 316 million bony fish fingerlings are being release that 282 million were whitefish, 25 million carp and 9 million bream from Vushmgir Dam and Syjval Bream Center within two months at the release stations in Gorgan River. At sampling stations, especially estuaries to determine the shelf life of fry in the river and to determining migration into the river as well as physical - chemical and assess the frequency and biomass of feeding materials (phytoplankton, zooplankton, and benthos) at the sampling stations in Gorgan River were studied. The entire estuary to the sea makes itself. Maximum migration happened at sunset. Average Debbi for 20-year was at the rate of 14.95 cubic meters per second. In 2002, the annual average was 20.8 cubic meters per second, respectively. Evaluation of abundance and biomass of feeding materials (phytoplankton, zooplankton, and benthos) indicates the status of the average biomass of phytoplankton in the river at the release station was 23/75 mg per liter that was highest in September and was lowest in December. Mean primary production based on a 145 mg chlorophyll cubic meters. 6 orders of benthic invertebrates were observed. Benthic including 9 families and 11 genera have been identified including groups of insects, worms, low-tar and Polychaetes, crustaceans, bivalve and gastropod. But at the release station (S2) the highest levels of benthic biomass (18/18 grams per square meter) degree of diversity of benthic organisms (12) species have largely been seen as a maximum in April and minimum in December. Also zooplankton condition, zooplankton total of 27 genera belonging to five categories, Rotatoria, Kladvsra, Coupe Pvda, Balanvs, and protozoa were identified. In general, in September zooplankton has the greatest diversity and abundance and in September and March, the lowest number is observed

    Hereditary risk factors for the development of gastric cancer in younger patients

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    BACKGROUND: It is believed that the development of gastric cancer (GC) before the age of 50 has a hereditary basis. Blood group A and history of gastric cancer in first-degree relatives have been shown to be risk factors for GC. METHODS: In this case-control study, we enrolled patients with GC who were diagnosed before the age of 50. Patients who were diagnosed as having GC were selected. A total of 534 cases were found; of these, 44 diagnosed before the age of 50 were included in the case group. For the control group, 22 males and 22 females were randomly selected from the remaining subjects, who had diagnoses of GC after the age of 50. All the surviving patients and family members of the dead patients were interviewed about the history of cancer in the family and the age at which other family members developed cancer. The blood group of each subject was also obtained. RESULTS: forty-four cases under 50 years old (mean age: 36.2 years) and forty-four controls (mean age: 67.1 years) were enrolled in the study. At the time of the study, 59.1% of the study group and 50% of the control group were alive (P value = NS). In the study group, 68.1%, 13.6%, 13.6% and 4.5% had blood groups O, A, B and AB, respectively. In the control group the corresponding figures were 27.7%, 63.6%, 6.8% and 4.5%. First or second-degree relatives with cancer, including gastric (the most frequent), breast, lung, gynecological and hematological malignancies, were noted in 54.5% of the cases and 11.4% of the controls (p < 0.01). Family histories of cancer were accepted as valid provided that they were based on valid medical documents. CONCLUSIONS: It seems that the development of GC before the age of 50 is likely to be accompanied by familial susceptibility. Interestingly, our study showed a significant correlation between blood group O and the development of gastric cancer under the age of 50
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