Evaluation of some biofilter substrates in freshwater recirculation system

The nitrifying bacteria acting on various biofilter substrates including: scoria, P.V.C., marble and zeolite were evaluated. The experiment started with manufacture of a recirculation system with 130 liter fresh water volume in 7 l.min-1 flow rate in 3 replicate for every treatment. The volume of each biofilter was 60×40×30cm and after achievement to stable environmental conditions the nitrifying bacteria at a concentration of 105 ml-1were inoculated in each biofilters. Daily 3-10mg.l-1 of NH4Cl was added to biofilters. The procedure was conducted by exposure of Ammonium and Nitrate concentrations and pH in biofilters. The results showed that the Scoria can be reliable substrate as biofilter, in which provide the best substrate for the growth and attachment of the nitrifying bacteria which can reduce the retention time of a biofilter from 40-60 to 15 days

The effect of anaerobic fermentation of cow manure on culture of Rutilus frisii Kutum and comparison of survival and growth factors versus traditional feeding

Rutilus firisii kutum is one of the important fish in Caspian Sea that has significant economical role to the region. The overall objective of the project is to compare the growth and survival of Rutilus frisii Kutum larvae under conventional conditions and conditions under use of organic fertilizer by anaerobic fermentation or slurry. This study was conducted in nine 1.7 hec pounds with 3 treatments with stocking densities of 1.7 million fish larva at Dr Yousefpoor Center at Siakal Village, 32km far from city of Rasht in North of Iran. The first treatment considered as control using concentrated food and grinded kilka fish. In the second treatment, the pound was supplied only by slurry for 13 days followed by concentrated fish food. The third treatment started with slurry for 13 days followed by slurry and concentrated food together. The physical and chemical parameters of water, plankton, biometry of fish, growth indices were monitored weekly. The result indicated that production was 1.7 to 2 times higher in slurry than traditional treatment also the survival rate was 1.7 times higher in slurry treatment. Slurry with several active substances is more effective and can promote the growth of zooplanktons that is the food for larval stage of Rutilus frisi kutum. Nutritional contents of phosphorous, nitrogen, calcium, magnesium, potassium, protein and lipid after anaerobic fermentation were higher in slurry treatment than control. The blue-green algae density in slurry pounds was less than control

Pastoral Traditional Ecological Knowledge Dynamicity: A Global Review

There is a significant knowledge gap concerning the extent to which pastoral traditional ecological knowledge (TEK) has changed. We conducted a systematic review of 152 papers on pastoral TEK, focusing specifically on 63 papers that explicitly mentioned types of knowledge transitions (retention, erosion, adaptation or hybridization). Studies on pastoral TEK represent less than 3% of all the scholarly literature on TEK. Geographical distribution of the case studies was largely biased. Knowledge domains of pastoral TEK such as herd and livestock management, forage and medicinal plants, and landscape and wildlife were relatively equally covered, however, climate-related knowledge was less studied. Out of the 63 papers explicitly mentioning transition of pastoral TEK, 83% reported erosion, and only 11 studies documented explicitly knowledge retention, adaptation or hybridization. We conclude that future research should focus more on the diverse dynamics of pastoral traditional knowledge, be more careful in distinguishing the four knowledge transition types

Time-averaged heat transfer and vortex shedding of a singular and twin heated bluff bodies in cross flow

Flow characteristics in the onset of vortex shedding and heat transfer pattern over a single and two same-sized square prisms placed in tandem are studied numerically. All simulations are carried out for Reynolds numbers range varying from 1 to 200 and spacing between the prisms in the order of five widths of prism for in tandem configuration. The calculations are done employing a finite volume in-house computer program according to semi-implicit method for pressure linked equations-consistent (SIMPLEC) numerical procedure and nonstaggered mesh in 2-dimensional, steady/unsteady and incompressible flow regimes. The instantaneous and time-averaged streamlines as well as iso-therm pattern for different Reynolds numbers are analysed. Furthermore, the influence of Reynolds number and the onset of vortex shedding on the flow pattern are studied in detail. Three distinct patterns namely fully-attached, trailing-edge separation and leading-edge separation were observed

The effect of optimum dosage of Ovaprim injection on artificial spawning of Esox lucius

This project was conducted to explore the effect of optimum dosage of Ovaprim injection on the artificial spawning of Esox lucius. The research implemented by 4 treatments with 3 replicates for each one. Three female and six male brooders were injected in each replicate. The animals in 1, 2 and 3 treatments were injected by 10, 20 and 30 µg/kg BW, respectively, and 4 the treatment was considered as the control being injected with 4 mg/kg BW pituitary gland extract. Average (±SE) weights were 1361±521, 1376±954, 1009±160 and 1100 ±422 g in 1, 2, 3 and 4 treatments in females, respectively. In addition, positive response percent to hormone injection were measured as 77.8 ±19.24, 88.9 ± 19.24, 55.5 ±50.91 and 55.5 ± 19.24 % in 1, 2, 3 and 4 treatments in female and 94.4 ± 9.58, 88.9 ±19.26, 83.3±28.86 and 88.9 ± 19.26 % in male brooders, respectively. However, there was no significant different between all treatments. Fertilization content (±SE) in one to four treatments measured as 87.1±10, 88.04±7.7, 83.9±5.2 and 72.4±19.7 %, respectively. No significant differences were found among pairwise treatments. Average (±SE) percentage of eyed eggs were 66.6±15.9 for treatment one, 61.2±22.3 in treatment two, 58.3±10.7 in treatment three, and 56.1±15.04 in treatment four, with no significant pairwise differences. The average (±SE) hatching eggs were measured as 27.41±19.8 in treatment one, 39.53±26.9 in treatment two, 95.18±5.6 in treatment three and 26.78±12.4 in treatment four, with no significant pairwise differences. Also, the best dosage injection of ovaprim hormone was 10 and 20 µg/kgBW

Shelf-life determination of tiger-toothed Croaker (Otolithes ruber) during flake ice storage

Quality of tiger-toothed croaker stored in flake ice was studied for 19 days by sensory, chemical (total volatile basic nitrogen (TVB-N)), (thiobarbituric values (TBA)), pH and microbial (total viable count, TVC) methods. Sensory scheme was modified according to the panelists perception and a specific schema was created for this fish. Sensory analyses showed that: "gills color and odor", "convexity of eyes", "peritoneum" and "elasticity of flesh" are the best sensory parameters. Results of sensory and microbial analyses had high correlation. Total viable count of flesh was 2.86 log cfu g-1 at first day and reached the limiting level of TVC (106) after 15 days of storage (P<0.05). TVB-N levels were 15.31mg/100 g tissue at the first day of storage and reached 36.52mg/100 g at the end of storage day (P<0.05). Measuring amounts of TVB-N showed that total volatile basic nitrogen is a good quality index for tiger-toothed croaker during ice storage. The initial level of TBA was 0.83mg of malondialdehyde per kg flesh (mg MDA/kg) and increased to 3.75mg MDA/kg at the end of storage. TBA levels were less than limiting level (5mg MDA/kg) over the period of storage. According to the results, shelf-life of tiger-toothed croaker was determined 15 days during ice storage

Expression profile of Wnt molecules in leukemic cells from Iranian patients with acute myeloblastic leukemia

Background: Wnt molecules play a key role in growth, proliferation and development of some embryonic and adult organs as well as hematopoietic stem cells. Wnt signaling pathways are aberrantly activated in many tumor types, including solid tumors and hematologic malignancies. Objective: To investigate the expression profile of a large number of Wnt genes in leukemic cells from Iranian patients with acute myeloblastic leukemia. Methods: RT-PCR method was used to determine the Wnt genes expression in bone marrow (BM) and/or peripheral blood (PB) samples from 16 patients with AML and PB samples of 36 normal subjects. Results: Among 14 Wnt molecules included in this study, Wnt-7A and Wnt-10A were significantly down-regulated (p = 0.002 and p < 0.0001, respectively) and Wnt-3 was significantly over-expressed (p < 0.02) in AML patients compared to normal subjects. No significant association was found between Wnt expression and FAB classification of the patients. Conclusion: Our results demonstrated for the first time aberrant expression of Wnt-7A, Wnt-10A and Wnt-3 genes in Iranian AML patients. This may be of relevance to the tumorigenesis process in this malignancy