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11.
Johnsamuel Godwin Christopher Arunachalam Ganesan Murugesan Natarajapillai Sukumaran 《International Aquatic Research》2012,4(1):1-8
We studied the microdistribution of the artificial radionuclide 241Am in the components of Elodea canadensis - a submerged macrophyte of the Yenisei River. The alpha-track analysis showed that the microdistribution of 241Am within different components of the submerged plant E. canadensis was not uniform. 241Am distribution was found to be affected by the age of the leaf blades, state of the cells, and morphological features of the plant stem. The radionuclide 241Am penetrated into the plant cells through the cell wall of E. canadensis, but it was accumulated in the vacuoles rather than in the cell wall or cytoplasm. In this case, the integrity of the cell membranes was not damaged. 相似文献
12.
In this study, efficacy of three antigenic preparations from the fish pathogen Aeromonas hydrophila was evaluated as vaccine candidate in rohu Labeo rohita. The rabbit anti-rohu globulin conjugate was prepared in rabbit using sera obtained from healthy adult rohu. Three antigens, namely formalin inactivated A. hydrophila (FAH), FAH mixed with Freund’s incomplete adjuvant in a 1:1 (v/v) ratio (FAH + A), and extra cellular product were prepared. Protection of rohu against A. hydrophila infection was tested at days 10, 20, and 30 post-vaccination. At the end of the vaccination, fish were challenged with A. hydrophila (dose: 1 × 107 cfu ml?1) and relative per cent of survival was recorded up to 60th day of post-challenge. Study of cellular immunological parameters including antigen-specific leucocyte proliferation, antigen-specific nitric oxide production, and superoxide anion production exhibited significantly higher (p < 0.05) values on 10th and 20th day of post-vaccination compared with control. Among all the antigenic groups, FAH + A showed most significant responses compared with the other groups and produced maximum antibody on 30th day following vaccination. Among the humoral immune responses, lysozyme activity showed almost similar trend like cellular parameters. The result of the challenge study showed a higher level of survival in all the vaccinated groups, especially in FAH + A group. Our results suggest that vaccine FAH + A can effectively protect rohu against A. hydrophila infection and could offer an appropriate strategy to prevent this infection in rohu farms. 相似文献
13.
S. Nagarajan N. P. Sukumaran P. S. N. Sastry 《Journal of Agronomy and Crop Science》1994,172(5):352-357
In field experiments conducted for 2 consecutive years at Shimla (31°06'N, 77°10'E at 2202 m above mean sea level with potato ( Solarium tuberosum L.), weekly means of rainfall (P), potential evapotranspiration (PET), pan evaporation (PAN) and photosynthetically active radiation (PAR) were estimated during the crop season. It was evident that from April to end of June, the evaporative demand was more than the precipitation and that the crop suffered from water deficit from emergence to tuber initiation. Four different energy summation indices accumulated over important phenological stages of growth and energy-use efficiency in terms of biomass production at these stages were estimated for two seasons. Weekly cumulative biomass production showed a significant correlation with accumulated PET, PAN and PAR in the four genotypes tested in year 2. 相似文献
14.
Vrinda Sukumaran Douglas W Lowman Thavarool P Sajeevan Rosamma Philip 《Aquaculture Research》2010,41(12):1799-1805
The immunostimulatory property of glucan isolates from three marine yeasts (Debaryomyces hansenii S8, Debaryomyces hansenii S169 and Candida tropicalis S186) and one Baker's yeast (Saccharomyces cerevisiae S36) as examined for potential application as immunostimulants in Penaeus monodon postlarvae against White Spot Syndrome Virus (WSSV) infection. Structural characterization of the glucan component in the isolates by proton nuclear magnetic resonance (NMR) indicated similar structures containing (1‐3)‐linked anhydroglucose repeat units (AGRUs) in the backbone with (1‐6)‐linked AGRUs in side chains that are (1‐6)‐linked to the backbone AGRUs. Glucan from C. tropicalis (S186) with the highest molecular weight and the lowest level of branching supported maximum survival (69%) followed by the other two marine yeast (S169 and S8) glucans of 27% and 23% respectively while glucan from Baker's yeast, S. cerevisiae S36 with the lowest molecular weight and the highest level of branching exhibited poor survival (4%) in P. monodon post challenge WSSV. The present study showed that the glucan isolate from marine yeast with a higher molecular weight and a lower degree of branching acts as better immunostimulants in P. monodon postlarvae than did the glucan isolate from S. cerevisiae. 相似文献
15.
A feeding trial of 120 days was conducted to study the effect of graded levels of dietary phosphorus on haematology, serum
protein concentrations and HSP70 expression in fingerlings of the Indian major carp, Catla (Catla catla). Eight isonitrogenous and isoenergetic purified diets were formulated to contain graded levels of dietary phosphorus (dP),
i.e., T1, 0.1%; T2, 0.3%; T3, 0.5%; T4, 0.7%; T5, 0.9%; T6, 1.1%; T7, 1.3%; or T8, 1.5%. Four hundred and eighty fish (average weight 4.23 ± 0.016 g) were equally distributed into 24 tanks forming eight
treatments with three replicates each. The fish were fed daily at the rate of 3.5% body weight in two instalments. At the
end of feeding trial fish were sampled to study total RBC and WBC count, haemoglobin, serum lysozyme activity, serum total
protein, albumin (A), globulin (G) concentration and HSP70 expression. Total RBC count, haemoglobin concentration and serum
lysozyme activity did not vary significantly in response to different dietary phosphorus concentrations. Total WBC count was
found to be significantly (P < 0.05) higher in T1 relative to all other treatments. Serum albumin and A/G ratio was found to be significantly lower in fish of T1 and T2 in relation to T7 group (P < 0.05). Serum globulin and total protein levels remained unaffected by variations in dietary phosphorus. HSP70 expression
was observed in T1 group (0.1% dP) in gills and brain tissue, but not in liver and muscle tissues. No HSP70 expression was observed in fish
of T4 (0.7% dP) and T8 (1.5% dP) treatments. These prima facie results suggest that dietary phosphorus had only minor influence on the haemato-biochemical parameters studied; however dietary
phosphorus deficiency caused organ specific induction of HSP70 in catla fingerlings. 相似文献
16.
Everaers R Sukumaran SK Grest GS Svaneborg C Sivasubramanian A Kremer K 《Science (New York, N.Y.)》2004,303(5659):823-826
The viscoelastic properties of high molecular weight polymeric liquids are dominated by topological constraints on a molecular scale. In a manner similar to that of entangled ropes, polymer chains can slide past but not through each other. Tube models of polymer dynamics and rheology are based on the idea that entanglements confine a chain to small fluctuations around a primitive path that follows the coarse-grained chain contour. Here we provide a microscopic foundation for these highly successful phenomenological models. We analyze the topological state of polymeric liquids in terms of primitive paths and obtain parameter-free, quantitative predictions for the plateau modulus, which agree with experiment for all major classes of synthetic polymers. 相似文献
17.
Summary Diurnal changes in net photosynthetic rate were measured in a furrow-irrigated potato crop and in a riverbed crop where the
water table was always maintained at 20–28 cm from the soil surface. In the irrigated crop, the photosynthetic rate during
mid-afternoon was about half the peak rate observed at noon. This reduction was accompanied by a near tripling of stomatal
resistance, a 45% reduction in transpiration, and a 5-fold increase in the difference between leaf and air temperatures. No
such changes were observed in the riverbed crop where the photosynthetic rate remained nearly constant at about 0.9 mg m−2 s−1 between 9 a.m. and 4 p.m. Tuber yield in the riverbed crop was about 30% higher than in the irrigated crop. 相似文献
18.
The vulnerability of four prey species to predation by the freshwater prawn, Macrobrachium malcolmsonii, was found to be in order of decreasing vulnerability: tadpoles of frog (Rana cyanaphyctis) > minnow (Aplocheilus lineatus) > common carp fry (Cyprinus carpio) >Tilapia mossambica fry. The weight of the prey consumed per day was, respectively, 12.48 ± 1.45 g, 6.02 ± 1.15 g, 5.61 ± 0.40 and 2.89 ± 0.26 g; and the estimated 50% predation time was 1.25 ± 0.26 days, 1.66 ± 0.33 days, 2.0 ± 0.17 days, and 3.54 ± 0.72 days, respectively. 相似文献
19.
Krishna Sukumaran Asim Kumar Pal Narottam Prasad Sahu Dipesh Debnath & Biswamitra Patro 《Aquaculture Research》2009,40(2):139-147
A 120‐day feeding trial was conducted to determine the dietary requirement of phosphorus for Indian major carp, catla (Catla catla) fingerlings. Four hundred and eighty fingerlings (mean body weight: 4.23±0.87 g) were randomly distributed among eight treatment groups with three replicates each. Eight isonitrogenous and isocaloric semi‐purified diets (crude protein: 35% and crude lipid: 8.5%) were formulated with graded levels of phosphorus using KH2PO4 (T1: control, 0.1%; T2: 0.3%; T3: 0.5%; T4: 0.7%; T5: 0.9%; T6: 1.1%; T7: 1.3%; T8: 1.5%) and fed to the respective groups. Twenty fish were stocked in 150 L plastic tanks and fed to apparent satiation twice a day. Specific growth rate (SGR) significantly (P<0.05) increased with increasing dietary phosphorus concentration from 0.73% to 1.27%, after which there was a slight decline in growth at 1.1% available phosphorus (aP) and remained constant thereafter. The quadratic broken‐line model based on growth was Y=317.5?581(0.64?x) (0.64?x); R2=0.73. Moisture and crude protein contents of whole body were similar among all the treatments. However, the ether extract in T1 group was significantly (P<0.05) higher than all the other treatments. The whole‐body phosphorus content increased significantly (P<0.05) with an increase in phosphorus in the diets. The one‐slope broken‐line model based on whole‐body phosphorus concentration was Y=4.07?1.63 (0.71?x); R2=0.48. The one‐slope broken‐line model for non‐faecal phosphorus excretion as inorganic phosphorus (Pi) for 24 h revealed a trend of Y=12.67+73.96 (x?0.6); R2=0.81. Minimum aP requirements based on weight gain (%), whole‐body phosphorus content and phosphorus excretion were 0.64%, 0.71% and 0.6%, respectively. Hence, the dietary aP requirement of catla fingerlings ranges from 0.6% to 0.71%. 相似文献
20.
J. G. Christopher A. G. Murugesan N. Sukumaran 《Journal of the World Aquaculture Society》2014,45(5):558-566
This study reports the results on induced diploid androgenesis in the Indian catfish, Heteropneustes fossilis. Ultraviolet (UV) irradiation was used to inactivate maternal genome of H. fossilis. Complete inactivation of maternal genome was recorded at 12,500 ergs/mm2. These genome‐inactivated eggs of H. fossilis were inseminated with conspecific sperm. The sperm suspension was diluted to 1 × 107 sperm ml/L in Hank's Balanced Salt Solution. Egg viability was assessed for different exposure durations at fertilization, hatching, haploidy, and diploidization. Majority of the larvae derived from irradiated eggs had abnormal appearance. Complete inactivation of maternal genome was detected by haploid syndrome and confirmed by chromosome counting (n = 29). These eggs activated with sperm were subjected to heat shock at 40 and 41 C for different postactivation times and durations. Diploid androgens had a normal appearance as controls and confirmed by chromosome counting (n = 58). A maximum of 21 and 14% of diploidization was recorded at 30 min after activation, at 40 and 41 C, which corresponds to the first cleavage suppression time. 相似文献