16 research outputs found
Growth, survival and stress resistance of tiger barb (Puntius tetrazona) larvae fed on linseed oil-enriched Artemia franciscana nauplii
Effect of feeding on linseed oil (LO)-enriched Artemia was investigated on growth, survival and stress resistance of tiger barb (Puntius tetrazona) larvae. Larvae were fed by LO-enriched (2.5, 5 and 7.5%) as well as non-enriched Artemia nauplii for 14 d, followed by 14 d feeding on non-enriched Artemia. Fish fed on enriched nauplii showed significant increase in growth performance at both 14th and 28th d. Also, fish fed on enriched Artemia, especially those fed on 7.5% LO, showed greater resistance in response to osmotic and hypoxia stress at 28th d. The results suggest that LO enriched Artemia nauplii are capable to promote growth and stress response in tiger barb larvae
Evaluation of effects of physico-chemical factors on chlorophyll-a in Shadegan International Wetland - Khouzestan Province - Iran
Measurement of chlorophyll-a can be considered important to investigate the primary production of an ecosystem. This study aimed to investigate chlorophyll-a concentration, primary production and the factors affecting them in Shadegan Wetland located in Khouzestan Province - Iran. Sampling for measuring (NO3, PO4, BOD5, DO, pH, EC, salinity, temperature) was performed seasonally at five sampling stations of the wetland (Canal, Ragbeh, Khoroosi, Mahshahr and Atish), from March 2013 – through February 2014. Results showed that chlorophyll-a concentrations in Canal station were significantly higher than that in the other stations; however, there were no significant differences among the other sampling stations (p>0.05). The maximum and minimum primary production (and chlorophyll-a) (62, 1.14 mg/m^3) were observed at Canal and Ragbeh stations, respectively. Annual average chlorophyll-a concentration was 10.28 mg/m^3, and there was no significant seasonal difference (p>0.05). The maximum value of chlorophyll-a was observed in the fall (29.63 mg/m^3), whereas, the minimum value was related to the spring (4.07 mg/m^3). Among the water physicochemical parameters, nitrate had a significant effect on chlorophyll-a concentrations. According to trophic state index (TSI), Shadegan Wetland is mesotrophic in the spring and winter, whereas it is eutrophic in the summer and fall. Overall, the lake is suitable for warm water species
Production of soybean meal-based feed and its effect on growth performance of western white shrimp (Litopenaeus vannamei) in earthen pond
The effects of two diets, a control diet (commercial feed with 39% crude protein) and an experimental diet (prepared based on 42% soybean meal with 38% crude protein), on growth performance of western white shrimp (Litopenaeus vannamei) in six 0.4-ha-earthen ponds (three replications per treatment) with 25 per m^2 density, were investigated. There was no significant difference in final weight (mean final weights were 15.7±0.88 and 15.6±0.52 g for the experimental and control treatments, respectively) between the treatments during the 115 days rearing period. There were no difference in FCR: 1.80±0.08 and 1.76±0.06, protein efficiency: 1.46±0.01 and 1.45±0.05, SGR: 2.38±0.04 and 2.38±0.03, final production: 2853.58±64.14 and 2864.83±168.57 kg/ha and survival rate: 91±1.78, 92±2.41% between experimental and control treatments, respectively (p>0.05) but net protein utilization in experimental treatment (17.05±0.38 g) and in the control (11.80±0.26 g) revealed significant differences (p<0.05). It is concluded that the experimental feed with 42% soybean meal was more efficient than the commercial feed on some growth parameters of western white shrimp
Production of artificial diets and determination of their effects as alone and combination with natural wet diet on female western white shrimp broodstock maturation (Litopenaeus vannamei)
Due to the usefulness of shrimp broodstock pelleted diets, from aspects of, easier maintenance, transportation, broodstock feeding, and cheaper as compared to natural wet diets, the use of natural wet foods, include sand worm (Perinereis nuntica), cattle fish )Sepia pharaonis) and veal livier decreased and the quantity of pelleted diet increased. Survey was conducted, in tankes with a volume of 300 liters. Tanks were filled with 150 liters of water. 10 broodstock in each tank was left, with an average weight of 37±2 grams. Daily feeding rate, was twenty-five percent of their biomass. The survey was include, 9 treatments with 3 replicates in each tank as described below. Control treatment: broodstock feeding only with, sand worm (33%), cattle fish (34%) and bull livier (33%). Exprimental treatment 1: broodstock feeding with pelleted diet contain 50 percent crude protein and 8 percent crude fat (50%)+sand worm (16 %)+cattle fish (18%)+veal livier (16%). Treatment 2: broodstock feeding with pelleted diet contain 50 percent crude protein and 10 percent crude fat (50 %)+sand worm (16 %)+cattle fish (18%) and veal livier (16%). Treatment 3: broodstock feeding with pelleted diet contain 40 percent crude protein and 10 percent crude fat (50%)+sand worm (16 %)+cattle fish (18 %) and veal livier (16 %). Treatment 4: broodstock feeding with pelleted diet contain 40 percent crude protein and 8 percent crude fat (50 %)+sand worm (16 %)+cattle fish (18 %) and veal livier (16 %). Treatment 5: broodstock feeding with pelleted diet contain 50 percent crude protein and 10 percent crude fat (100 %). Treatment 6: broodstock feeding with pelleted diet contain 50 percent crude protein and 8 percent crude fat (100 %). Treatment 7: broodstock feeding with pelleted diet contain 40 percent crude protein and 10 percent crude fat (100 %). Treatment 8: broodstock feeding with pelleted diet contain 40 percent crude protein and 8 percent crude fat (100%). The results showed that, Gonadosomatic index (GSI) in treatments 3: control and 6, was significantly more than others treatments (p0.05). From the aspect of mean weight of broodstock, wasn’t significant difference in treatments (p>0.05). From the aspect of mean length of carapac, wasn’t significant difference in treatments (p>0.05). From the aspect of mean body length, wasn’t significant difference in often treatments (p>0.05), and in treatments 5 and 6 was significantly less than others (p0.05). In the determination of, correlation between weight (g) and total length(cm), (r=0.71), weight and carapace length (cm) (r=0.70), the correlation was strong. Between GSI, HIS, carapace length and total length the correlation was intermediate (r=0.54). The correlation between absolutely fecundity and total length (r=0.20), absolutely fecundity and carapace length (r=0.28), absolutely fecundity and weight (r=0.35) was weak. The results showed that, the use of combination of pelleted diet and natural wet diets can increase female maturation indexes. Totally we can noted that, GSI, HIS and absolute fecundity of broodstock, that fed with pelleted diet contain 40 percent crude protein and 10 percent crude fat (50 %)+sand worm (16 %)+cattle fish (18 %) and veal livier (16 %) (treatment 3) was better than the other treatments. Positive effects of this treatnent on sexual indexes, was due to provide part of nutritional requirement of shrimp broodstock from pelleted diet
Small Corrections to the Tunneling Phase Time Formulation
After reexamining the above barrier diffusion problem where we notice that
the wave packet collision implies the existence of {\em multiple} reflected and
transmitted wave packets, we analyze the way of obtaining phase times for
tunneling/reflecting particles in a particular colliding configuration where
the idea of multiple peak decomposition is recovered. To partially overcome the
analytical incongruities which frequently rise up when the stationary phase
method is adopted for computing the (tunneling) phase time expressions, we
present a theoretical exercise involving a symmetrical collision between two
identical wave packets and a unidimensional squared potential barrier where the
scattered wave packets can be recomposed by summing the amplitudes of
simultaneously reflected and transmitted wave components so that the conditions
for applying the stationary phase principle are totally recovered. Lessons
concerning the use of the stationary phase method are drawn.Comment: 14 pages, 3 figure
Increased expression of DCLK1, a novel putative CSC maker, is associated with tumor aggressiveness and worse disease-specific survival in patients with bladder carcinomas
Doublecortin-like kinase 1 (DCLK1) has been characterized as a novel potential cancer stem cell (CSC) marker in several types of cancer. It is considered as one of the most specific markers for distinguishing colorectal CSCs from normal stem cells. Yet, there are limited reports on the role of DCLK1 as a putative CSC marker in bladder cancer. Using immunohistochemistry, DCLK1 expression was examined in a well-defined tissue microarray series of 472 bladder cancer tissues. The association between DCLK1 protein expression and clinicopathological features, as well as survival outcomes, was assessed. Our findings showed strong, moderate, and weak DCLK1 expression in 123 (26.1), 230 (48.7), and 119 (25.2) of the bladder cancer specimens, respectively. Higher expression of DCLK1 was significantly associated with increase in histological grade (P � .001), pT stage (P = .014), lamina propria (P = .006), and lamina propria/muscularis (L/M) involvement (P = .014). On multivariate analysis, pT stage (P < .001), histological grade (P = .021), and lamina propria involvement (P = .001) were independent prognostic factors in DCLK1 expression. Moreover, the expression of DCLK1 was found to be an independent marker of poor prognosis for disease- specific survival (DSS) (P = .048) in bladder carcinomas. Our observations showed that DCLK1 expression was associated with more aggressive tumor behavior, more advanced disease, and poorer DSS in patients with bladder carcinomas. However, any potential clinical applications of DCLK1 as a novel target molecule in bladder cancer patients would require further investigations. © 201