Poređenje gustine nasda nereis diversicolor u prirodnim i uzgojnim (anzali lagona) uslovima

Nereis diversicolor is regarded as a live food and is significantly effective in increasing stocks, enhancing tolerance in sturgeons and also increasing survival of sturgeon fry. Research conducted indicates that N. diversicolor is more abundant in May as compared to other months of the year. In February, only breeders of this species are found in the environment. N. diversicolor was found in four different weight classes from March 2009 to February 2010. They showed decrease in density with increase in temperature and reached the lowest numbers in February. In years 2009 and 2010, 200 sampling conducted monthly at the point where Caspian Sea mixes with the Anzali lagoon. Sampling was performed by Van Veen sampler with 400 cm2 cross section. Sediments were washed through a sieve with 0.5 mm mesh size. The residue along with Nereis was transferred to a dish, worms separated and transferred to lab. The density of worms per m2 was calculated according to the density formula. Two experiments were conducted to determine the best stocking density for the culture of N. diversicolor. Stocking density of 381-6350 worms m-2 were used in 6 trials initially and best growth was recorded in trial with density of 381 worms m-2. In the second experiment using 381-3175 worms m-2 in 7 trials, trial with 381 worms m-2 again showed better growth as compared to other trials. These results obtained were almost similar to those obtained for N. diversicolor is in its natural environment (447 worms m-2)

Feeding habits of sturgeon fishes in shallow coastal waters of Guilan Province, southern Caspian Sea

We collected sturgeon specimens from seven fishing stations operating 30 to 35 Km away from each other in Guilan province over the years 1999 MD 2000. Trawl nets six meters long were drawn using motorboats at each station, repeated three times for each season. Among the studied premature sturgeons, 121 Acipenser persicus specimens with an average age of less than two years and a length of 10 to 49.9 ± 0.77 cm showed full stomachs (57.17 % fullness). Among the mature specimens with an average age of 11 years and a length range of 90 to 194 cm, only three showed full stomachs (11.54 % fullness). The highest gut index in this study belonged to premature A. persicus. A one-way analysis of variance showed no significant difference in condition factor and gastro-somatic index among the different length groups (P<0.05). We found that the food consumed by premature A. persicus was comprised of eight genera of benthic invertebrates Hypania sp., Hypaniola sp., Pterocuma sp., Stenocuma sp., Abra ovata, Paramysis sp., Gammarus sp. and Nereis sp. Adult sturgeons were found feeding mainly on fish species belonging to Gobidae, Atherinidae and Clupeidae families. The main preys of premature A. persicus were polychaet worms Hypania sp. and Hypaniola sp. belonging to the class Sedantaria. Crustaceans Stenocuma sp. and Pterocuma sp. of the class Cumacea were also seen in the diet of the premature sturgeons. The main preys of adult A. persicus were fishes belonging to the family Gobiidae and secondary prey were fishes of the family Atherinidae

Efekat tri različite hrane na rast i preživljavanje larvi persijske jesetre (acipenser persicus)

A feeding experiment was conducted to evaluate growth and survival of Persian sturgeon larvae fed with live food (Nereis diversicolor and Daphnia spp.) and artificial diet. Diets were included: Diet 1: Dafnia (Dafnia magna), Diet 2: Nereis diversicolor worm; Diet 3: Mix of Daphnia (Daphnia spp.) (50%) and Nereis diversicolor (50%), Diet 4: Mix of Nereis diversicolor (50%) and concentrate food (50%) and Nereis diversicolor (50%); Diet 5: Mix of Daphnia spp. (33.33%) and Nereis diversicolor (33.33%) and concentrate food (33.33%). Persian sturgeon larvae were distinctly transferred to 15 tanks and fed for 15 days. For each treatment, 60 larvae were stocked into tanks. The total length and body weight of the fish were determined once before initiation of the experiment and at the end of the experimental period to assess their growth performance. Water quality parameters were recorded two times a day. There was significant difference (P0.05) were not found between diets 2 and 3 and also between diets 4 and 5. The value for BWI, PBWI, GR, DGI, SGR was higher in larvae fed mix of Nereis diversicolor and Daphnia spp. (diet 3) (p<0.05) and there was significant difference between all of groups. Except diet 3 there was no significant difference in the CF of fish fed the survey diets

The effects of temperature, salinity and photoperiod on sexual maturity and concomitant reproduction behavior in Nereis diversicolor

Nereis diversicolor worms were collected from the Anzali lagoon during the years 2004-2006 using Van Veen grab sampler with a surface area of 400cm ^(2). Water salinity, temperature and total organic matter (TOM) of sediments in the sampling region was determined. The worms were maintained in 0.5 tons (1x1m ^(2)) tanks until they reached a weight of 200-300mg. Sexual maturity in the samples was attained at 4-6C and spawning occurred at approximately 16°C. The first gametes were observed after the temperature increased from 6 to 16C. Sexual maturity was studied at various salinities (0.5, 5, 12, and 15 ppt). Results indicated that the worm attains sexual maturity at salinity 15ppt in a shorter period as compared to other salinities. No significant differences were observed between sexual maturity attained at salinities 12 and 15ppt (P>0.05). The effect of light and photoperiod in synchronizing reproduction in male and female N. diversicolor was also studied. We observed that reproduction behavior in adult worms increased for a period of one week at the end of each month after they were exposed to a prolonged photoperiod (L:D 16:8) followed by a period of dim light. Mature males crawled around outside the tubes in search of a female. In the presence of a mature female, the males released sperm directly in front of the female tube. Soon after, there was an increase in the activity of the females which showed intense ventilation movements. The female worms with their eggs already released began to carry the sperm into their tube. The ripe females nearby which had not yet laid eggs in their tubes released their gametes a few minutes after the male and began to carry sperm into their tubes. The fertilized eggs remained inside the tube protected by the female. The benthic larvae developed fast, feeding on the mucus and microbial film on the tube wall. After 10 to 14 days, larvae began to leave the tube. A few days later the females died

Observation of psi (3686) -&gt; n(n)over-bar and improved measurement of psi (3686) -&gt; p(p)over-bar

We observe the decay psi (3686) -> n (n) over bar for the first time and measure psi (3686) -> p (p) over bar with improved accuracy by using 1.07 x 10(8) psi (3686) events collected with the BESIII detector. The measured branching fractions are B(psi(3686) -> n (n) over bar) = (3.06 +/- 0.06 +/- 0.14) x 10(-4) and B(psi(3686) -> p (p) over bar) = (3.05 +/- 0.02 +/- 0.12) x 10(-4). Here, the first uncertainties are statistical, and the second ones are systematic. With the hypothesis that the polar angular distributions of the neutron and proton in the center-of-mass system obey 1 + alpha cos(2) theta, we determine the a parameters to be alpha(n (n) over bar) = 0.68 +/- 0.12 +/- 0.11 and alpha(p (p) over bar) = 1.03 +/- 0.06 +/- 0.03 for psi(3686) -> n (n) over bar and psi(3686) -> p (p) over bar, respectively

Observation of the Singly Cabibbo-Suppressed Decay D+ -&gt; omega pi(+) and Evidence for D-0 -&gt; omega pi(0)

Based on 2.93 fb(-1) e(+)e(-) collision data taken at center-of-mass energy of 3.773 GeV by the BESIII detector, we report searches for the singly Cabibbo-suppressed decays D+ -> omega pi(+) and D-0 -> omega pi(0). A double tag technique is used to measure the absolute branching fractions B(D+ -> omega pi(+)) = (2.79 +/- 0.57 +/- 0.16) x 10(-4) and B(D-0 +/- omega pi(0)) = (1.17 +/- 0.34 +/- 0.07) x 10(-4), with statistical significances of 5.5 sigma and 4.1 sigma, where the first and second uncertainties are statistical and systematic, respectively

Prirodna hrana acipenser persicus gajenog u ribnjačkim jezerima

A study on live food in Acipenser persicus rearing ponds was carried out In four rearing ponds; two in the Shahid Beheshti hatchery and two ponds in the Yousefpour hatchery. Samples were collected from three points in each pond on a weekly basis. Samples were collected using plankton nets (mesh size 50 µm), Ruthner sampler and Ekman grab. Zooplankton and benthic samples were fixed in 4 % formalin solution for later analysis. Zooplankton species identified in water samples collected at all four ponds belonged mainly to two phyla; Arthropoda and Rotifera. Total abundance of zooplankton species was estimated 87576 individuals L-1 in the Yousefpour hatchery and 136626 individuals L-1 in the Shahid Beheshti hatchery. Insect larvae, oligochaeta worms and mollusks were found in the sediment samples collected from the Yousefpour hatchery while sediment samples collected from the Shahid Beheshti hatchery contained only insect larvae and oligochaeta worms. The total abundance of benthic organisms was 0.343 g m-2 in the Yousefpour hatchery and 1.28 g m-2 in the Shahid Beheshti hatchery. Condition factor in fishes ranged from 0.29-0.54 in the Yousefpour hatchery and from 0.30-0.47 in the Shahid Beheshti hatchery

Epidemiological study of hospitalized road traffic injuries in Iran 2011

Background: In Iran, Road Traffic Injuries (RTIs) is the second-leading cause of deaths, and the first leading cause of disabilityadjusted life year, and has one of the highest rates of death (32.1 per 100 000 population) all over the world. This study's aim was to investigate the epidemiological pattern and underlying components of hospitalized RTIs in 31 provinces of Iran in 2011. Methods: This study conducted on all hospitalized RTIs during one-year period (March 21, 2011 to March 21, 2012). Data extracted from a hospital-based traffic injury registration system. According to a national law passed in 2005, all hospital expenses of traffic injuries should be covered by ministry of health based on governmental tariffs. The medical costs of eligible patients will be paid to the hospitals only if the patient data are sent to the above mentioned database. Statistical analysis was performed using SPSS v.16 (SPSS Inc., Chicago, USA), and spatial maps are provided using GIS 10.2. Descriptive statistics and t-test were used to compare means. World (WHO 2000-2025) standard population used to calculate age-adjusted incidence rate. All statistical tests were performed at the 5 level of statistical significance. Results: There were 322,064 injured cases recorded in the registration system during the study period. The national age-adjusted incidence rate of RTIs was 405 per 100,000 population. The highest incidence rates were in the age group of 15-29 years (643 per 100,000 population), followed by 30-44 year age groups (401 per 100,000 population). The incidence rate in men was 3.36 times more than women. Motorcyclist were the most frequent type of road users (39.2) who involved in RTIs, followed by passengers (28.9) and pedestrians (20.0). Head injuries were among the most affected part of the body which occurred in 27.2 of the patients. The proportion of urban crashes was 60.7. Conclusion: The results of this study indicated that the majority of RTI occurred on motorcyclists and head injuries was the most commonly affected body part. Therefore, in order to reduce motorcycle accidents and avoiding head injury among them, stricter law enforcement is urgently needed for helmet use and promotion of safety behaviors among motorcycle riders. © Iran University of Medical Sciences

Three-Dimensional Dirac Electrons at the Fermi Energy in Cubic Inverse Perovskites: Ca_3PbO and its Family

The band structure of cubic inverse perovskites, Ca_3PbO and its family, are investigated with the first-principles method. A close observation of the band structure reveals that six equivalent Dirac electrons with a very small mass exist on the line connecting the Gamma- and X-points, and at the symmetrically equivalent points in the Brillouin zone. The discovered Dirac electrons are three-dimensional and remarkably located exactly at the Fermi energy. A tight-binding model describing the low-energy band structure is also constructed and used to discuss the origin of the Dirac electrons in this material. Materials related to Ca_3PbO are also studied, and some design principles for the Dirac electrons in this series of materials are proposed.Comment: 4.2 pages, refined versio