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An experiment was conducted for 60 d in a recirculatory system consisting of 20 glass aquariums (each of size 41 × 41 × 46 cm) to evaluate meat and bone meal (MBM) as partial replacement for fish meal (FM) in Macrobrachium rosenbergii postlarvae (PLs) with a view to develop an inexpensive nursery diet. Three nursery diets were formulated to contain 32% protein and to be as isoenergetic as possible. FM in these diets was progressively replaced with MBM (Diet 1 contained 25% FM and 14% MBM, Diet 2 contained 20% FM and 20% MBM, and Diet 3 contained 15% FM and 26% MBM). Inclusion levels of mustard oilcake and sesame meal in diets were kept fixed at 10%. A commercial shrimp nursery diet (30% protein) from Saudi Bangla Fish Feed Ltd., Mymensingh, was used as the reference diet (Diet 4). Each treatment had three replicates. PLs of M. rosenbergii (26 ± 0.02 mg) were stocked at the rate of 60 PLs (1 PL/L) in each aquarium. At the beginning, PLs were fed three times daily at a rate of 20% of the body weight and it was gradually reduced to 10% at Day 30. The ranges of water quality parameters in the system were as follows: temperature, 27–29 C; dissolved oxygen, 6.5–8.4 mg/L; pH, 6.8–8.3; and total ammonia, 0.01–0.15 mg/L. The result of the study showed that there was no significant difference (P > 0.05) between the weight gains of PLs fed Diet 1 (containing 14% MBM) and Diet 4 (reference diet) but was significantly higher than other dietary groups containing higher levels of MBM. Diets 1 and 4 showed significantly lower (P < 0.05) apparent food conversion ratios (1.74 and 1.73, respectively). The survival (%) of PLs ranged between 62 and 76% with PLs fed Diets 1 and 4 showing significantly higher (P < 0.05) survival. The result of the study demonstrated that the MBM could be included at 14% level in a nursery diet, and a diet containing 25% FM, 14% MBM, 10% sesame meal, and 10% mustard oilcake may be recommended for profitable production of PLs of M. rosenbergii.  相似文献   
3.
Chemical and spectroscopic characteristics were determined on the organic matter in two Luvisolic soils from northwestern Alberta, Canada. One of these (the Debolt soil) is known to crust only slightly while the other (the Demmitt soil) exhibits severe crusting after heavy rainfalls. The Debolt top soil is richer in total C, total N, carbohydrates and proteinaceous materials than the Demmitt top soil. Humic acid extracted from the Debolt soil is more aliphatic, and contains fewer CO2H groups than does humic acid extracted from the Demmitt soil. The quality of the organic matter appears to play a role in soil crusting.  相似文献   
4.
Rhizobacteria were isolated from the rhizosphere of different Brassica species and assayed for their ability to produce auxins in vitro. The isolates varied greatly in their potential for auxin production (ranging from 0.33 to 11.40 µg ml-1). L-Tryptophan (an auxin precursor) addition to the media increased the auxin production by several fold. Based upon in vitro auxin production and growth promotion of B. juncea seedlings caused by various isolates under gnotobiotic conditions, promising isolates were selected and tested in pot trial to observe their effects on growth, yield and oil content of the same Brassica species. Results showed that seed inoculation with different isolates of rhizobacteria significantly increased plant height (up to 56.5%), stem diameter (up to 11.0%), number of branches (up to 35.7%), number of pods per plant (up to 26.7%), 1,000-grain weight (up to 33.9%), grain yield (up to 45.4%) and oil content (up to 5.6%) over the uninoculated control. Isolate S54 gave the most promising and consistent results. Highly significant correlations between L-TRP-derived auxin production by plant growth-promoting rhizobacteria (PGPR) in vitro and grain yield (r =0.77**), number of pods (r =0.78**) and number of branches per plant (r =0.77**) of B. juncea were found. It was hypothesized that these PGPR may influence the growth and yield of inoculated plants by production of auxins in the rhizosphere of inoculated plants from the L-TRP present in the root exudates, although other mechanisms of action might have also contributed.  相似文献   
5.
In western immunoblotting studies of canine sera using Malassezia pachydermatis extracts, the reported patterns of immunoreactivity vary between different laboratories. Because the duration of culture influences the antigenic composition of lipid-dependent Malassezia spp. when probed with human sera, we investigated whether the in vitro growth phase of M. pachydermatis influences immunoreactivity using canine sera. Extracts of M. pachydermatis CBS 1879 grown in Sabouraud's liquid medium at 37 degrees C for 2, 4, 6, 8 and 10 days were prepared by mechanical disruption, centrifugation, dialysis and lyophilization. Yeast growth phase was assessed by sequential colony counts and optical density measurements. Patterns of IgG immunoreactivity in high (n = 3) and low (n = 3) titre sera were compared using extracts prepared at each time point by sodium dodecyl sulphate polyacrylamide gel electrophoresis and western immunoblotting. Protein bands of 62 and 49 kDa were recognized by all sera, and 98 and 68 kDa bands were recognized by five sera. Proteins of 188, 66, 58, 57, 38, 28 and 17 kDa were only recognized by high titre sera. All high titre sera used recognized more bands in exponential phase (d2) extracts when compared with decline phase (d8-d10) extracts, and two of these sera showed most bands in stationary phase (d4-d6) extracts. Bands of 62 and 57 kDa were primarily detected in exponential and early stationary phase extracts. There is variation in antigenic expression in different growth phases of M. pachydermatis, which might explain discrepancies between previous laboratory studies of canine immunity to this yeast.  相似文献   
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Using Hsp70 as a biomarker, thermal stress impinges on reproductive organs, ovary and hepatopancreas were being analyzed by determining the expression of Hsp70 mRNA inside the organs after the adult inter‐molt females were subjected to thermal treatment at 35, 30 and 28°C (Control). Results showed the expression of Hsp70 mRNA under thermal treatment of 35°C after 2 hr recovery in ovary were upregulated at 2, 4, 6, 12, 24 hr and 30 days compared to control whereas in hepatopancreas under similar treatment, the expression of Hsp70 mRNA were significantly higher than control at 6, 24 hr and 30 days. Frequency of reproductive molt at 35°C showed the ovary of females were failed to develop and only entered common molt along three consecutive molt cycles. For 30°C thermal treatment, the expression of Hsp70 mRNA was significantly higher than control after 2 hr recovery but returned to normal afterwards until 30 days’ thermal treatment. Maternal heat shock for 2 hr at 35°C were found to give significantly lower frequency of reproductive molt and longer duration of ovarian development and incubation period whereas maternal heat shock for 2 hr at 30°C gave lower frequency of reproductive molt, slower development of embryo and lower hatching success compared to untreated control. This study suggests that short and long‐term thermal stress at 30 and 35°C were found to affect the induction of Hsp70 mRNA in reproductive organs of Macrobrachium rosenbergii and also influence their reproductive performance.  相似文献   
8.
The research work was carried out to synthesize a series of novel chitosan based water dispersible polyurethanes (CS-WDPUs). The three step synthesis involves the formation of end capped PU-prepolymer was formed through the reaction between polyethylene glycol (PEG) (Mn=600 g/mole, dimethylolpropionic acid (DMPA) and isophorone diisocyanate (IPDI) followed by the preparation of neutralized NCO terminated PU-prepolymer, which lead to the chain extension by using the chitosan. The dispersion of the obtained product was carried out by adding proper proportion of water. The synthesized CS-WDPUs were applied onto the different qualities of plain weave poly-cotton printed and dyed textile swatches by employing pad-dry-cure procedures. The textile assets of the treated and untreated textile swatches were assessed, as color fastness, pilling resistance, tear and tensile strength. The results showed that the chitosan incorporation into PU backbone has significant effect on the assets of treated textiles. These synthesized CS-WDPUs are eco-friendly bio-based finishes with potential applications for polyester/cotton textiles.  相似文献   
9.
Purpose

This study assesses the potential of two contrasted fragrant Pelargonium cultivars to induce pH and dissolved organic carbon (DOC) changes in the soil solution, Pb speciation, and their subsequent effects on rhizosphere phytoavailable Pb.

Materials and methods

Rooted plantlets were grown in special devices, floating on aerated nutrient solution in PVC tanks. This setup allows roots to be physically separated, through a mesh, from a 3-mm soil matrix layer that can be considered as rhizosphere soil. Two contrasted soils, each spiked with Pb-rich particles, emitted from a battery recycling industry, were used at total burdens of 500 and 1500 mg Pb kg?1 in addition to a control unspiked soil. Soil solution pH, phytoavailable Pb, DOC, Pb adsorption, precipitation on roots, and Pb phases in soil and plant were investigated.

Results and discussion

Attar of Roses (Attar) cultivar acidified its rhizosphere by 0.4 pH units in both spiked soils. Concolor Lace (Concolor) was unable to change soil solution pH on soil-1 and increased it by 0.7 units on soil 2. Concentrations of Pb in soil solution from Attar plants were always higher than those of Concolor ones. DOC contents of both unspiked soil-1 and soil-2 without plants were not significantly different. In the case of spiked samples, DOC contents in the rhizosphere soil were increased by three and two times for Attar and Concolor, respectively, compared to the unspiked soil without plant. Both cultivars were able to increase DOC contents, independent of soil type and level of contamination. Accumulation of Pb in shoots and roots was higher in Attar as compared to Concolor due to enhanced available Pb as a result of pH and DOC modifications of the rhizosphere soil. Significant amounts of Pb were adsorbed on roots of both cultivars. X-ray elemental analysis of precipitates on roots revealed the association of Pb with P in cylinder-like structures. Extended X-ray absorption fine structure (EXAFS) spectroscopy revealed that Pb was present, to a major extent in the inorganic form, mainly as PbSO4 in the soil, whereas it was complexed with organic species within plant tissues. The conversion of Pb into organic species could decrease toxicity, may enhance plant tolerance, and could increase translocation.

Conclusions

Plant-induced changes were responsible for the modification of lead phases within the soil. Immobile forms present in the source leaded particles as well as in the soils were converted into soluble species, ultimately improving the phytoavailable or soil solubilized Pb.

  相似文献   
10.
A total of 70 sheep and 330 goats were selected randomly. All the animals were kept under same housing and management conditions. Serum samples were collected from all the animals and tested for the presence of antibodies against Peste des petits ruminants (PPR) virus using competitive ELISA (cELISA). All the animals were found negative showing percentage inhibition (PI) values <50. The animals were vaccinated against PPR with Nig/75/1 strain vaccine of PPR Serum samples were collected from randomly selected 12 sheep and 30 goats at 10, 30 and 45 days post-vaccination. The samples were subjected to cELISA to determine the presence of antibodies against PPRV. The samples with PI >50 were considered as sero-positive. The sheep found positive at 10, 30 and 45 days post-vaccination were 1(8.3%), 7(58.3%) and 12(100%) respectively. In case of goats 3(10.0%), 29(96.6%) and 27(90.0%) animals gave positive results at 10, 30 and 45 days post-vaccination respectively. Mean PI values in sheep at 10, 30 and 45 days post-vaccination were recorded as 37, 65 and 91 respectively, whereas in goats these values were 43, 78 and 86 respectively.  相似文献   
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