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81.
This study evaluated the effects of diets containing 20, 40, 60, 80 and 100 mg kg?1 diet astaxanthin or canthaxanthin on Pethia conchonius (Hamilton, 1822) pigmentation. A completely randomized experimental design was developed with ten treatments and three replicates. Three hundred rosy barb with a mean weight of 0.92 ± 0.06 g were assigned to thirty aquaria for period of eight weeks. Carotenoid contents of fish fed canthaxanthin were always lower than those fed astaxanthin. Yellowness (b*) was not affected by pigments. While Luminosity (L*) decreased in fish fed astaxanthin diets, this parameter increased by feeding on canthaxanthin. The most pronounced effect was higher a* values in fish fed astaxanthin. Astaxanthin retention rate was higher than that of canthaxanthin. The present results demonstrate that canthaxanthin cannot be considered as a proper replacement with astaxanthin. Inclusion of 80 and 100 mg astaxanthin kg?1 diet can be suitable dietary levels to ensure pigmentation and this condition may improve market value of rosy barb.  相似文献   
82.
Despite efforts made, forage yield of smooth bromegrass has increased slowly over the last 50 years of breeding. It therefore seems necessary to investigate more on the genetic basis of agro-morphological traits in this cool-season, highly drought resistant grass. The present study was aimed at estimation of total genetic variance, narrow-sense heritability, general combining ability, phenotypic and genotypic correlation among different quantitative traits in half-sib (HS) families derived from polycross of 25 smooth bromegrass genotypes that were mainly originated from Iran. Families differed significantly for all of the agro-morphological and quality traits measured. Narrow sense heritability ( ${\text{h}}_{\text{n}}^{2}$ ) ranged from about 0.2 (plant height) to 0.7 (day to inflorescence emergence and day to anthesis). Moderate to high heritability for forage dry matter yield (0.42) indicates that phenotypic selection for this trait can be successful. A wide range of general combining ability was observed for most of the studied traits, especially those related to forage yield. Relatively low genetic variation and heritability for crude protein and also negative correlation of this trait with forage yield, indicates a low probability of improving forage yield and quality simultaneously.  相似文献   
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85.
This study, we synthesized graphite-nanoflakes (GNFs) by acid treatment and thermal shock and then using the ultrasonic irradiation technique to exfoliate flake-carbon. The SrFe12O19 nanoparticles (NPs) were coated by co-precipitate method on GNFs after by alkaline treatment. Finally nanocomposite (GNF/SrFe12O19/PTh) was prepared by in-situ oxidative polymerization method in presence of thiophene (Th) as monomer. The magnetic and electrical conducting properties of the resulting nanocomposites were measured by using vibrating sample magnetometer and standard four-point-probe method, respectively. The synthesized nanocomposites were characterized by X-ray diffraction (XRD) and fourier transform infrared spectra (FTIR). In addition, morphological analyses were investigated by scanning electron microscopy (SEM). A minimum reflection loss (RL) of GNFs/SrFe12O19/PTh with 50 % wt GNFs/SrFe12O19 as core were observed ?28 and ?39 dB at 9.7 and 12 GHz for a 1.5 mm thickness. The results indicated that we can perform good microwave shielding in X-band (8–12 GHz) by these nanocomposites.  相似文献   
86.
One of the features of the forest dwellers in the Zagros region of Iran is their dependence on non-timber forest products (NTFPs). These products can play an important role in the livelihood of households located in the forest. The present study aims to determine the most important sources of forest dwellers’ incomes in the northern Zagros in terms of three income groups (lower, middle, and higher), to assess how changes in income are related to types of NTFPs harvested, and to investigate the most significant socio-economic factors determining absolute and relative household revenue from NTFPs. Income in higher- and middle-income groups come predominantly from border trade between Iran and Iraq, comprising 50 and 44 % of relative income, respectively. The main source of income for the lower-income group is remittance and government interest (such as cash subsidies), comprising 31 % of total household annual income. The relative income from NTFPs depends on the income group, varying between 10 and 21 %. Relative income from NTFPs (such as oak acorns, firewood, Gazoo, and Mazooj) for lower-income households is significantly higher than in middle- and higher-income households (p < 0.05). Feed used for grazing livestock in the forest is the most important type of NTFPs in this area, and its benefit in the higher-income group is significantly higher than that for groups with middle and lower income. A similar result is achieved for tree fodder. Relative income from the NTFPs is positively related to number of household members and negatively related to the average education of adult members of the household, the relative income from border trade, and the relative income from agriculture. Our results support our hypothesis that if there is access to other sources of income for forest dwellers, their dependence on forests would be reduced.  相似文献   
87.
Fisheries Science - Illipe Shorea macrophylla is a riverine fruit naturally eaten by Malaysian mahseer Tor tambroides and other riverine cyprinids. The effects of crude illipe oil on the growth...  相似文献   
88.
Ramularia ranunculicola sp. nov. (Mycosphaerellaceae) is described from Iran on Ranunculus muricatus and compared with other species reported on Ranunculus spp. Ramularia carletonii on Lactuca tuberosa and R. nagornyi on Centaurea solstitialis are newly reported from Iran, and Picris strigosa is a new host for R. picridis (= R. inaequalis s. lat.).  相似文献   
89.
Zinc (Zn) desorption is an important process to determine Zn bioavailability in calcareous soils. An experiment was performed to assess the pattern of Zn release from 10 calcareous soils of orange orchards, southern Iran and the soil properties influencing it. For Zn desorption studies, soil samples were extracted with diethylene triamine penta-acetic acid solution at pH 7.3 for periods of 0.083–48 h. Suitability of seven kinetic models was also investigated to describe Zn release from soils. Generally, Zn desorption pattern was characterized by a rapid initial desorption up to 2 h of equilibration, followed by a slower release rate. The simple Elovich and two-constant rate kinetic models described Zn release the best, so it seems that Zn desorption is probably controlled by diffusion phenomena. The values of the rate constants for the superior models were significantly correlated with some soil properties such as soil organic matter (SOM) content, cation exchange capacity (CEC), and soil pH, whereas carbonate calcium equivalent and clay content had no significant influence on Zn desorption from soils. SOM had a positive effect on the magnitude of Zn release from soils, while soil pH showed a negative effect on Zn desorption. Furthermore, the initial release rate of soil Zn is probably controlled by CEC in the studied soils. Finally, it could be concluded that SOM, CEC, and soil pH are the most important factors controlling Zn desorption from calcareous soils of orange orchards, southern Iran.

Abbreviations: Soil organic matter (SOM); Cation exchange capacity (CEC); Calcium carbonate equivalent (CCE); Zinc (Zn).  相似文献   

90.
To study the genetic variation, heritability and genetic correlations of some agro-morphological traits in tall fescue, 25 parents from a genetically broad-base germplasm were polycrossed and their respective half-sib families were generated. Clonally propagated parents and their half-sib families were grown as spaced single plants using a randomized complete-block design with three replications, and observed for seven traits in 2006 and 2007. The estimates of broad-sense heritability were moderate to high for the traits studied. Narrow-sense heritability estimates from analyses of progenies and from regression of half-sib (HS) progenies on parents suggested that genetic variation for these traits was largely controlled by additive gene action. Association of dry matter yield (DMY) with plant height, number of fertile shoot, curbs width and spring growth was positive and significant. With the exception of number of days to pollination, correlation coefficients of the traits between the parents and offspring were not significant. Based on parent-offspring regression, genetic gain from selection for DMY was high, demonstrating genetic potential for improving this trait. Overall, there was high genetic variation and moderate heritability for most traits in the tall fescue populations evaluated. In conclusion, to improve herbage yield, selection would be more effective based on forage yield components.  相似文献   
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