1,059 research outputs found

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

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    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

    Population of sand goby (Neogobious fluviatilis pallasi) in southwest coasts of the Caspian Sea using morphological characteristics

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    Caspian sand goby, Neogobius fluviatilis pallasi belongs to Gobiidae family. Because of their abundance in Caspian Sea, they have important role in the sea food chain in this area. This study was conducted from October 2005 to September 2006 in southwest coasts of the Caspian Sea in Guilan province. Samples were collected monthly from four stations (Astara, Anzali, Chamkhaleh and Chaboksar coasts) from coastal areas to waters l5 meters deep using bottom trawl. Result of differential function analyses on corrected morphometric statistic showed three functions 51.3%, 28.4% and 20.3%, respectively, and sum of differentiative function percentage was 80% which proved difference among groups. The functions showed that samples in Astara station were completely different from other regions while they were similar to Anzali station only in some sampling points. Chamkhaleh and Astara stations were the same but Chaboksar station was a separated group. Analysis of differential functions for studied characteristics included on average 86.3% of the population with most of it belonging to Astara station (93.3%) and Anzali (90%). The minimum amount belonged to Chamkhaleh with 79.3%. The results showed that Neogobius fluviatilis pallasi probably has three different populations in Astara, Anzali, Chamkhaleh and Chaboksar populations

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

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    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

    Clinical presentation of coronary arteriovenous fistula according to age and anatomic orientation

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    Background: Coronary arteriovenous fistulas (CAVFs) are direct connections from one or more coronary arteries to cardiac chambers or a large vessel. They are mostly of congenital origin. The aim of this study was to describe clinical presentation and also delineate the course and management of CAVF. Methods: Clinical data, chest x-rays, echocardiographic and angiographic evaluation of 40 patients with congenital CAVF during 1990 to 2008 were reviewed retrospectively. Results: Seventeen patients were �20 years old (42.5) were mostly asymptomatic, and twenty tree cases were older than 20 years old (57.5), mostly symptomatic (P < 0.05). Twenty one (52.5) patients had pure CAVF and nineteen (47.5) patients with associated intarcardiac congenital heart disease (15) or acquired valvular and coronary arteries diseases (32.5). CAVFs mostly originated from left anterior descending artery (LAD) (42.5) and mostly drained into the main pulmonary artery (MPA) (35 ). Twenty-four patients underwent CAVF surgical ligation. From twenty-one patients with pure CAVF, eight (38) patients were complicated by congestive heart failure and aneurism formation of fistula. Conclusion: Unlike some previous reports, in our study, the most prevalent origin site for CAVFs was the left anterior descending (LAD). Most patients with CAVFs especially those who went first diagnosed before 20 years old were asymptomatic. On the other hand, as the continuous murmur is not always detected in children or infants, consequently, cases of spontaneous closure may remain undetected. All symptomatic and asymptomatic patients with moderate to severe shunting should be operated on and minimal morbidity and good surgical results could be expected

    The Effect of Dust Storm on the Microbial Quality of Ambient Air in Sanandaj: A City Located in the West of Iran.

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    BACKGROUND & AIMS: The presence of pathogenic microorganisms in the dust storm can cause diseases such as Asthma, Pneumonia, and respiratory infections. The aim of this study was to determine the relationship between air-borne particles with airborne microorganisms in normal and dusty days in Sanandaj, a city located in the west of Iran. MATERIALS & METHODS: Air sampling was conducted during the normal and dusty days through Andersen single-stage impactor (28.3 L/min) for 2.5 min. Air particles concentration (PM10) was measured daily and microbial sampling was also conducted on every six days and on the dusty days. Finally, the data was analyzed by SPSS-16 (ANOVA and paired T-tests). RESULTS: The concentration of airborne microorganisms (bacteria and fungi) was increased by an increase of the airborne particles. Particles concentration in May, June and July (twice per month) was more than of the standard value. The predominant species of bacteria and fungi during the occurrence of Dust storm was Bacillus spp. (56.2% of total bacteria) and Mycosporium spp. (28.6% of total fungi), respectively. DISCUSSION AND CONCLUSION: The results showed that the number of airborne microorganisms (bacteria and fungi) increased during the dust storm. Therefore, the microorganisms in the dust storm can cause biological harmful effects on human health

    Growth-related quantitative trait loci in domestic and wild rainbow trout (Oncorhynchus mykiss)

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    Background: Somatic growth is a complex process that involves the action and interaction of genes and environment. A number of quantitative trait loci (QTL) previously identified for body weight and condition factor in rainbow trout (Oncorhynchus mykiss), and two other salmonid species, were used to further investigate the genetic architecture of growth-influencing genes in this species. Relationships among previously mapped candidate genes for growth and their co-localization to identified QTL regions are reported. Furthermore, using a comparative genomic analysis of syntenic rainbow trout linkage group clusters to their homologous regions within model teleost species such as zebrafish, stickleback and medaka, inferences were made regarding additional possible candidate genes underlying identified QTL regions.Results: Body weight (BW) QTL were detected on the majority of rainbow trout linkage groups across 10 parents from 3 strains. However, only 10 linkage groups (i.e., RT-3, -6, -8, -9, -10, -12, -13, -22, -24, -27) possessed QTL regions with chromosome-wide or genome-wide effects across multiple parents. Fewer QTL for condition factor (K) were identified and only six instances of co-localization across families were detected (i.e. RT-9, -15, -16, -23, -27, -31 and RT-2/9 homeologs). Of note, both BW and K QTL co-localize on RT-9 and RT-27. The incidence of epistatic interaction across genomic regions within different female backgrounds was also examined, and although evidence for interaction effects within certain QTL regions were evident, these interactions were few in number and statistically weak. Of interest, however, was the fact that these predominantly occurred within K QTL regions. Currently mapped growth candidate genes are largely congruent with the identified QTL regions. More QTL were detected in male, compared to female parents, with the greatest number evident in an F 1male parent derived from an intercross between domesticated and wild strain of rainbow trout which differed strongly in growth rate.Conclusions: Strain background influences the degree to which QTL effects are evident for growth-related genes. The process of domestication (which primarily selects faster growing fish) may largely reduce the genetic influences on growth-specific phenotypic variation. Although heritabilities have been reported to be relatively high for both BW and K growth traits, the genetic architecture of K phenotypic variation appears less defined (i.e., fewer major contributing QTL regions were identified compared with BW QTL regions)

    Antifungal susceptibility testing of <i>Candida </i>species isolated from the immunocompromised patients admitted to ten university hospitals in Iran

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    Abstract Background Antifungal susceptibility testing is a subject of interest in the field of medical mycology. The aim of the present study were the distributions and antifungal susceptibility patterns of various Candida species isolated from colonized and infected immunocompromised patients admitted to ten university hospitals in Iran. Methods In totally, 846 Candida species were isolated from more than 4000 clinical samples and identified by the API 20 C AUX system. Antifungal susceptibility testing was performed by broth microdilution method according to CLSI. Results The most frequent Candida species isolated from all patients was Candida albicans (510/846). The epidemiological cutoff value and percentage of wild-type species for amphotericin B and fluconazole in Candida albicans, Candida tropicalis, Candida glabrata and Candida krusei were 0.5 μg/ml (95%) and 4 μg/ml (96%); 1 μg/ml (95%) and 8 μg/ml (95%); 0.5 μg/ml (99%) and 19 μg/ml (98%); and 4 μg/ml (95%) and 64 μg/ml (95%), respectively. The MIC90 and epidemiological cutoff values to posaconazole in Candida krusei were 0.5 μg/ml. There were significant differences between infecting and colonizing isolates of Candida tropicalis in MIC 90 values of amphotericin B, and isolates of Candida glabrata in values of amphotericin B, caspofungin, and voriconazole (P < 0.05). Conclusions Our findings suggest that the susceptibility patterns of Candida species (colonizing and infecting isolates) in immunocompromised patients are not the same and acquired resistance was seen in some species
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