Morphometric and meristic variations in bream (Abramis brama orientalis, Berg, 1949) during larval development

This study was conducted to examine morphometric and meristic characteristics alongside pigmentation patterns of bream larvae, Abramis brama orientalis, in four stages of larval development. Morphological characters including total length (TL), standard length (SL), notochord length (NL), head length (HL), head depth (HD), eye diameter (ED) and mouth width (MW) were examined from hatching time through 30 days after hatching (DAH). The results showed morphometric variations in the different larval stages. Growth and development of fins occurred mainly at the Post Flexion stage with the completion of caudal fin at 9 mm TL and pelvic fin at 13.33 mm TL. At all larval stages, the highest concentration of pigments was seen on dorsal, ventral and somewhat on the lateral sides of body in descending order. The highest density of melanophores at larvae yolk sac stage was observed on the yolk sac and the back of head zone, while at preflexion and flexion stages melanophores were dominant on the back of head and on the skin folds which resulted from yolk absorption. At post flexion stage, high density of melanophores was found on the back of the head, bases of fins and caudal fin, while less concentrations of these cells were evident on the lateral sides of fish' body. In conclusion, a clear change in the growth and main morphological characters were observed in postflexion stage. This may be due to the main development of fins, which would suggest enhanced swimming capabilities and also prey capture efficiencies

Morphometric and meristic variations in bream (Abramis brama orientalis, Berg, 1949) during larval development

This study was conducted to examine morphometric and meristic characteristics alongside pigmentation patterns of bream larvae, Abramis brama orientalis, in four stages of larval development. Morphological characters including total length (TL), standard length (SL), notochord length (NL), head length (HL), head depth (HD), eye diameter (ED) and mouth width (MW) were examined from hatching time through 30 days after hatching (DAH). The results showed morphometric variations in the different larval stages. Growth and development of fins occurred mainly at the Post Flexion stage with the completion of caudal fin at 9 mm TL and pelvic fin at 13.33 mm TL. At all larval stages, the highest concentration of pigments was seen on dorsal, ventral and somewhat on the lateral sides of body in descending order. The highest density of melanophores at larvae yolk sac stage was observed on the yolk sac and the back of head zone, while at preflexion and flexion stages melanophores were dominant on the back of head and on the skin folds which resulted from yolk absorption. At post flexion stage, high density of melanophores was found on the back of the head, bases of fins and caudal fin, while less concentrations of these cells were evident on the lateral sides of fish' body. In conclusion, a clear change in the growth and main morphological characters were observed in postflexion stage. This may be due to the main development of fins, which would suggest enhanced swimming capabilities and also prey capture efficiencies.Publishe

Relationship between root and yield morphological characters in rainfed low land rice ( Oryza sativa L.)

Understanding the relationship between root system and yield related traits is an important objective in crop breeding programs. Canonical correlation analysis has been adopted to study the strength of association between the root morphological traits and grain yield components under low-moisture stress and well-watered conditions and to find the root morphological characters that have the largest influence on grain yield and its components under the two conditions. This study revealed that root to shoot length and weight ratios and root dry weight were had the largest effect on plant height, shoot dry weight and grain yield under well-watered condition. Under low moisture stress, maximum root length and root number were also important for improving grain yield and panicle length. The interrelationships clearly identified the importance of root to shoot length and weight ratios and root dry weight under well-watered condition. While, maximum root length and root number are a better combination under low moisture stress condition

Seroprevalence of hepatitis C and risk factors in haemodialysis patients in Guilan, Islamic Republic of Iran

ABSTRACT We assessed the prevalence of hepatitis C virus (HCV) infection and associated risk factors for all 298 haemodialysis patients in 7 dialysis units in Guilan province. Serum samples were screened for anti-HCV antibodies using a second generation enzyme-linked immunosorbent assay. Positive samples were confirmed by immunoblot assay. Overall prevalence was 24.8% (range: 9%-40%; 95% CI: 19.9-29.7): 80 patients tested positive and 74 were confirmed positive by immunoblot assay. Length of time on dialysis and history of rejected kidney transplant were statistically significantly associated with HCV infection. Age, sex and previous blood transfusion were not associated. Nosocomial transmission may play a role in the spread of HCV in haemodialysis units. A separate dialysis system should be used for seropositive HCV patients

Effect of Plant Density on Growth and Yield of Three Sunflower Hybrids (Helianthus annuus L.) as a Second Crop

In order to study the effects of plant density on growth, yield and oil percentage of three sunflower hybrids (Azargol, Alistar, Eroflor) an experiment was conducted at Agriculture Research Station of Myandoab in 2004. These hybrids were sown at four densities of 6, 8, 10 and 12 plants m-2 as factorial based on randomized complete block design with three replications. The results showed that dry matter accumulation (DM), crop growth rate (CGR) and relative growth rate (RGR) were increased with increasing plant density. By increment plant density, leaf area index (LAI) was slowly increased in early stages of growth but with beginning of plant rapid growth, increased dramatically. DM and CGR in Azargol and Eroflor were greater than Alistar. Analysis of variance showed that all traits were significantly affected by plant density. Yield per unit area, oil percentage and oil yield per unit area were increased, with increasing plant density. Although seed yield per plant at low densities was greater than that of high densities, but this increment was not enough for compensating the reduction of yield due to low density