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121.
The Australian freshwater fish, silver and golden perch, are increasingly being used for aquaculture. Addition of salt to water is commonly used in commercial aquaculture to reduce stress attributed to high ammonia concentrations. The activities in gill homogenates of ouabain-sensitive Na+/K+-ATPase and NEM-sensitive ATPases (as a measure of H+-ATPases) of silver and golden perch were measured after maintaining the fish in water containing different salt and ammonia concentrations. Six treatments were applied in a 2 × 3 factorial design: two salt treatments, low salt (LS) of 2.5 g l− 1 and high salt (HS) 5 g l− 1, and three ammonia treatments, no added ammonia (NA), low ammonia (LA), 3 mg total ammonia nitrogen (TAN) l− 1 and high ammonia (HA), 5 mg TAN l− 1. In both species, activity of Na+/K+-ATPase was lowest in fish kept in the LSNA treatment (7.4 ± 0.4 μmol Pi mg protein− 1 h− 1 for silver perch and 3.1 ± 0.6 for golden perch) and highest in the HSHA treatment (15.2 ± 1.0 μmol Pi mg− 1 protein h− 1 for silver and 8.4 ± 1.2 for golden perch). In both species there was a significant increase (P < 0.001) in Na+/K+-ATPase activity with increase in salt concentration and with an increase in ammonia concentrations. A significant interaction (P < 0.036) between salt and ammonia on Na+/K+-ATPase activity was observed in silver but not in golden perch. In contrast, the lowest activity for NEM-sensitive ATPase was observed in the HSNA treatment (1.0 ± 0.2 μmol Pi mg− 1 protein h− 1 for silver and 1.5 ± 0.4 for golden perch) and highest in LSHA treatment (2.9 ± 0.4 μmol Pi mg− 1 protein h− 1 for silver and 3.6 ± 1.2 for golden perch). In both species there was a significant decrease in NEM-sensitive ATPase activity with increase in salt concentration and an increase in activity with increase in ammonia (P < 0.003). In silver perch, a significant interaction between the treatments was observed (P < 0.02). The results suggest that in these species of freshwater fish the Na+/K+-ATPase has a role in salt and ammonia homeostasis and that the NEM-sensitive ATPases are more active in fish kept in water with a lower salt content. It is possible that the increase in ammonia resistance when salt is added to the environmental water in commercial aquaculture systems may be due to the effects of salt on gill Na+/K+-ATPase activity rather than the NEM-sensitive ATPases.  相似文献   
122.
Summary

The effects of ‘cash’ [a novel 2:5:1 (w/w/w) mixture of calcium sulphate, ground sunflower heads, and humic acid] as a soil amendment on the growth, fruit yield, and leaf nutrient status of tomato (Solanum lycopersicum L.) grown on reclaimed saline soil (EC = 9.4 dS m–1) were investigated. A glasshouse experiment was performed in a completely randomised design with six treatments (0, 10, 20, 30, 40, or 50 g ‘cash’ kg–1 soil) each with four replicates. The results indicated that ‘cash’ increased both the shoot dry weight (DW) plant–1 and the root DW plant–1, the free proline contents of leaves, and leaf chlorophyll contents. The use of ‘cash’ also increased the number of fruit plant–1, fruit yield pot–1, and fruit vitamin C contents, although total soluble solids (TSS) contents were not affected. The contents of nitrogen (N), potassium (K), and calcium (Ca), and the Ca:Na ratios of leaf tissues increased with all application rates of ‘cash’. Leaf phosphorus (P) contents showed no response to any applied level of ‘cash’. Leaf sodium (Na) contents declined gradually with an increase in the level of ‘cash’ applied to the soil. We concluded that ‘cash’ has a pronounced positive effect on the growth and fruit yield of tomato plants grown in reclaimed saline soil. ‘Cash’ therefore has the potential to be used as a soil amendment for vegetable crops such as tomato to overcome the adverse effects of salinity in newly-reclaimed soils.  相似文献   
123.
Since natural fiber/polymer composites are increasingly used, the development of safe and environmental friendly flame retarding bio-based composites is of great importance. But this issue must maintain the mechanical performance of these composites. To study these objectives, four levels of magnesium hydroxide Mg(OH)2 of (0, 10, 20, 30 phc) and two levels of nanoclay (0, 3 phc) were considered and incorporated into HDPE/wheat straw composites. Maleic anhydride grafted polyethylene (PE-g-MA) was also used as a compatibilizer at constant content. The samples were prepared by melt compounding and injection molding processes, respectively. The some properties of samples including burning rate and mechanical properties (tensile and impact strengths) were tested based on the ASTM standard. The results showed that the burning rate of samples decreased with increasing the nanoclay and Mg(OH)2 content. The tensile and impact strengths showed a marginal reduction by adding Mg(OH)2 from 10 phc to 30 phc and the tensile modulus and impact strength revealed an increase by increasing the amount of nanoclay up to 3 phc. Generally, these results confirmed that the fire retarding and mechanical properties of HDPE/wheat straw composites could be significantly improved with an appropriate combination of the nanoclay and Mg(OH)2 in the composites.  相似文献   
124.
This study was done to evaluate if nursing mothers of infants with rickets have vitamin D deficiency, and to evaluate the relationship between maternal vitamin D levels with hypocalcemic seizures in infants with rickets. We selected a cohort of breastfed infants with rickets. Infants were included in this study if they were breastfed and presented with any of the following clinical criteria: delayed motor milestones or delayed teething, were found to have specific rachitic bony signs, or presented with hypocalcemic seizures. We checked serum calcium (Ca), phosphorus (P), alkaline phosphatase, 25 hydroxy vitamin D [25(OH)D] and parathyroid hormone (PTH) levels in both infants and their mothers. Out of 32 children who met the clinical criteria for rickets, 23 (72%) had vitamin D level less than 20 ng mL(-1). Twenty two mothers (69%) had vitamin D deficiency (25 hydroxy vitamin D < 20 ng mL(-1)). Mothers of nine infants who presented with hypocalcemic seizures had severe vitamin D deficiency, (p = 0.005). We conclude that maternal vitamin D deficiency is common in nursing mothers of infants diagnosed with rickets. Invariably mothers of infants presenting with hypocalcemic seizures have severe vitamin D deficiency. Hypocalcemic seizures in infants secondary to maternal vitamin D deficiency might be prevented by supplementation of vitamin D.  相似文献   
125.
In this study, the effect of extracts of two herbs (Oliviera decumbens and Satureja khuzestanica) on immune response of carp was investigated. At the beginning of experiment, fish were divided to two groups including vaccinated (using vaccine developed against A. hydrophila) and non‐vaccinated. Fish in both groups were fed diets containing O. decumbens and S. khuzestanica and combination of two herbal extracts for 5 weeks. Control fish (negative control) and fish vaccinated only (positive control) were fed basal diets without supplements of herbal extracts. Lysozyme activity, antibody titre, complement activity and bactericidal activity in serum were measured. After 5 weeks feeding, fish were infected with A. hydrophila and mortalities were recorded. In both experimental groups, no significant differences were found in terms of alternative haemolytic complement (ACH50) activity and antibody titres of Serum. In non‐vaccinated fish group, lysozyme and bactericidal activity of fish fed S. khuzestanica or combination of O. decumbens and S. khuzestanica was higher compared with control and other experimental treatments. In vaccinated fish group, the lysozyme and bactericidal activity was not significant in all treatments compared with control group. The results of this study showed that feeding non‐vaccinated and vaccinated carp with only S. khuzestanica or in combination with O. decumbens enhance only some immunity indices including lysozyme and bactericidal activity in non‐vaccinated fish and these extracts have no immunological stimulatory role on vaccinated individuals.  相似文献   
126.
To confirm the diagnosis of the infectious pancreatic necrosis, the pancreas, liver, kidney and spleen specimens from 140 rainbow trout (Oncorhynchus mykiss) of weight ranges from 15 to 250?g were processed for routine histopathological and immunohistochemical (IHC) studies together with a nested-PCR using primers that amplify a 164-bp product. Of the 140 fish samples, 37 (26.4%) had a final diagnosis of IPN on the basis of hematoxylin and eosin staining (H&E), while 39/45 (86.6%) were positive by IHC method. With the nested-PCR, 59/140 (42.1%) fish samples were positive. The IHC and nested-PCR showed higher prevalence than histopathology (P?<?0.05). Based on the nested-PCR, as the fish weight increased, IPN positive results decreased (P?<?0.05). However, IHC method detected IPNV constantly in these weight ranges. Only IPNV serotype Sp was identified by nucleotide sequencing and immunohistochemistry, and antiserum to IPNV serotype Ab and IHNV showed negative results in IHC. This is the first comparative diagnostic study of IPN at different weight ranges in cultured salmonids.  相似文献   
127.
Background: A growing body of preclinical data indicates that statins may possess antineoplastic properties; however, some studies have raised the possibility that statins may also have carcinogenic potential. Methods: An air pouch model was used for angiogenesis. Single or multiple applications of croton oil on the back of Swiss albino mice with or without initiation by dimethylbenz(a)antheracene (DMBA) were used to evaluate the skin tumorgenesis, ultrastructural and histological alterations. Results: Atorvastatin (orally, 10 mg/kg/day) produced a significant (P<0.05) reduction in angiogenesis. Concurrent administration of mevalonate reversed the anti-angiogenic effect of atorvastatin. However, local injection of atorvastatin (200 µg) into the pouches induced a significant (P<0.5) increase in angiogenesis that was not reversed by co-administration of mevalonate. The disturbance of cell polarity, inflammatory response, thickness of epidermal layer, and mitotic index induced by croton oil were inhibited markedly and dose-dependently (P<0.001) by pre-treatment with atorvastatin. In spite of the strong anti-inflammatory and anti-proliferative effects of atorvastatin on epidermal cell proliferation, it was identified that the same doses of atorvastatin in DMBA-initiated and croton oil-promoted skin tumorgenesis in mice increased the incidence of tumors and their conversion into malignant carcinoma. Conclusion: The reasons for these discrepancies remain unclear, and could be related to ambivalent effects of atorvastatin on angiogenesis or to specific differences in the experimental conditions. It is suggested that the pro-angiogenic effect of the drug, which could be responsible for promotion of skin tumors, is independent of the 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibition that can be mediated directly by atorvastatin.Key Words: Atorvastatin, Angiogenesis, Cell Proliferation, Cancer  相似文献   
128.
In this study, the effects of spermiation time are investigated on milt quality of Russian sturgeon over the course of the spawning season. The milt samples were collected from three broodstock batches at three time points including: the beginning, middle and at the end of the spawning season. According to the results, the milt quality parameters including pH, sperm density, spermatocrit, duration of sperm motility and percentage of sperm motility were significantly low in the beginning and end of season than middle of season. The values of milt quality parameters in the middle of season were as follows: (motility percentage: 69.6 ± 3.5, motility duration: 460.3 ± 37.2 s, sperm density: 8.7 ± 0.4 × 109, milt volume: 86.3 ± 8.1 and milt pH: 8.3 ± 0.15). Significant positive correlations were also found between milt pH and sperm motility as well as between sperm density and spermatocrit. In conclusion, our study showed that the middle of season is the best time for collection of milt with appropriate quality in Russian sturgeon. Selection of milt with good quality is necessary aim to cryopreservation of spermatozoa in endangered fish species including Russian sturgeon.  相似文献   
129.
In an attempt to transfer the Lr56/Yr38 resistance loci from Aegilops sharonensis to wheat, a 6A‐6Ssh chromosome translocation was produced. It involves essentially the entire chromosome 6Ssh with a small terminal segment of 6AL. Induced homoeologous recombination of the translocated chromosome with 6A produced numerous recombinants including three recombined chromosomes carrying Lr56 that could not be precisely mapped for lack of suitable markers. This study aimed to determine the chromosomal locations of the translocation breakpoints in these three recombinants using various DNA markers as well as physical and genetic mapping. The three recombinants Lr56‐39, ‐157 and ‐175 carry small segments of Ae. sharonensis chromatin distally to the Xgpw4329 and IWA5416 loci near the 6AS telomere. The Ae. sharonensis chromatin that remains in each line includes a homoeolocus of the wheat marker locus Xdupw217 (on 6BS) and its characteristic amplification product can be used as a dominant marker for the presence of Lr56. Of the three recombined chromosomes, Lr56‐157 retained the least alien chromatin and appears to be the best candidate for use in wheat breeding.  相似文献   
130.
A well developed network of roads must exist as a necessary infrastructure system in modern forestry to facilitate forest operations. But forest roads have the potential to disrupt the drainage characteristics of watersheds and lead to negative impacts on the environment with increased erosion and sediment yields. Numerous factors affect surface erosion of roads and sediment production potential; determining and ranking them could be a guide for management decisions to erosion control. In this study, the CULSED model (as an extension of ArcGIS) was used to estimate sediment delivery and the distribution of a road network, given the existing culverts. Using the model, some culverts were added to the road network around places with high sediment delivery in order to minimize it. After a correlation analysis and adjustment between sediment production and the factors, i.e., road width, road gradient, age of road and vegetation cover, the trend of changes in sediment delivery with model changes in the input was investigated with a sensitivity analysis of the model. The results show that adding new culverts to the road resulted in a significant reduction of sediment delivery. The most important factor affecting sediment delivery was road width, followed by road gradient, vegetation cover and age of road. Road width and gradient were positively correlated with sediment delivery, while vegetation cover and age of road were negatively correlated. The best model to show the relation between sediment delivery and road width as well as with road gradient was a linear model, for vegetation cover a cubic equation and for road age a power model. The results of sensitivity analysis showed that sediment delivery had the greatest sensitivity to changes of road width and was least sensitive to changes in the age of the road. This model can help to estimate sediment delivery with its spatial distribution, which can be used for optimization of cross drain systems and strategies of sediment control. Application of the model requires field trials to acquire the necessary input data. The reliability of our results is a function of the accuracy of inputs, especially digital elevation model.  相似文献   
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