Influence of chloride and sulphate ions on soil enzymes   总被引：1，自引：0，他引：1  

R. Dinesh    G. Ramanathan  Harjit  Singh 《Journal of Agronomy and Crop Science》1995,175(2):129-133

Ammonium chloride (AC) and ammonium sulphate (AS) are commonly used nitrogen fertilizers. But the effect of chloride and sulphate ions from these fertilizers on soil enzyme activity has received scant attention. Hence, we conducted a pot culture study to assess the influence of chloride (as AC) and sulphate (as AS) on the activities of urease, amidase, phosphatase and dehydrogenase in soil using rice as the test crop. Chloride and sulphate levels were fixed at 132, 264 and 396 kg ha⁻¹ respectively. Controls were also performed. The enzymes were assayed at three stages of the crop growth viz., active tillering, panicle initiation and harvest.
The enzyme activities decreased with increasing chloride and sulphate levels; however, the degree of inhibition varied among the enzymes assayed and the nature and amounts of salts added. The inhibition may be due to the specific effects of chloride and sulphate ions on microbial growth and subsequent enzyme synthesis, osmotic desiccation leading to microbial cell lysis, and a salting-out effect modifying the ionic conformation of the active site of the enzyme protein.  相似文献   

A visual health assessment of captive Asian elephants (Elephas maximus) housed in India     

Anand Ramanathan  Avanti Mallapur 《Journal of zoo and wildlife medicine》2008,39(2):148-154

A visual health assessment and survey questionnaire was conducted on 81 Asian elephants (Elephas maximus) housed in 10 animal facilities throughout India between November 2004 and February 2005. The survey questionnaire consisted of 10 questions that evaluated the health of the elephants, and they were completed after visually assessing each individual elephant. The information collected was ranked on a scale that was used to statistically compare the health among the study subjects. This study documented that 43.21% of the captive elephants surveyed exhibited hyperkeratosis. A significant proportion of the elephants owned by tourist camps had poor skin condition when compared with elephants from zoos and at a forest camp. Similarly, captive-born individuals were found to have better skin condition than animals that were caught from the wild. Sixty (74.1%) of the captive elephants that were observed during this study had fissures in their footpads, 20% of which were severe. The prevalence of foot fissures was significantly higher in females. A greater proportion of elephants owned by tourist camps displayed vertical and horizontal toenail cracks in comparison with the forest camp and zoo elephants. It was noted that 76.9% of the wounded animals and 80% of those having abscesses were housed at temples and tourist camps. Also, approximately 8.5% of the captive elephant population observed during this study had eye-related problems, and they were all housed at temples and tourist camps. In conclusion, it was evident that elephants housed at temples or tourist camps exhibited poor skin condition with wounds and abscesses. These findings suggest that the overall condition of the elephants housed at tourist camps was poor compared with elephants housed at zoos and at the forest camp.  相似文献   

Optimization of the stocking parameters for mud spiny lobster Panulirus polyphagus (Herbst, 1793) capture‐based aquaculture in tropical open sea floating net cages          下载免费PDF全文

Divu Damodaran  Kunnamangalam Mohammed Koya  Suresh Kumar Mojjada  Chauhan Devaji Lalaji  Gyanaranjan Dash  Vinay Kumar Vase  Kannanchery Ramanathan Sreenath 《Aquaculture Research》2018,49(2):1080-1086

Mud spiny lobsters, Panulirus polyphagus (Herbst, 1793), were reared at four different stocking sizes and stocking densities in open sea cages to evaluate their effects on growth performance. To evaluate the effect of stocking size on the growth performance, the lobsters were segregated into four different treatment groups according to size and were stocked at a density of 300 animals per cage. To evaluate the effect of stocking density on the growth performance, lobsters of 81–100 g were stocked in four different stocking densities, i.e. 16/m², 24/m², 32/m² and 40/m². The results showed that the growth rate of (60–80 g) size group, was significantly higher compared to the size groups, i.e. 101–120 g and 121–140 g comprising of larger individuals. The final body weight, though significantly higher in 81–100 g as compared to 60–80 g, the growth performance (i.e. weight gain percentage (WG %) and specific growth rate (SGR)) were not significantly different. The density‐dependent influence on growth performance was evident in this study. The WG % and SGR during 90 days’ culture period was significantly higher in 24/m² compared to other groups. This study provides crucial information about the appropriate stocking density and stocking size of lobsters at the field level, which would help to promote sustainable lobster cage farming by maximizing the production potential of the system.  相似文献   

Direct observation and quantification of CO₂ binding within an amine-functionalized nanoporous solid     

Vaidhyanathan R  Iremonger SS  Shimizu GK  Boyd PG  Alavi S  Woo TK 《Science (New York, N.Y.)》2010,330(6004):650-653

Understanding the molecular details of CO(2)-sorbent interactions is critical for the design of better carbon-capture systems. Here we report crystallographic resolution of CO(2) molecules and their binding domains in a metal-organic framework functionalized with amine groups. Accompanying computational studies that modeled the gas sorption isotherms, high heat of adsorption, and CO(2) lattice positions showed high agreement on all three fronts. The modeling apportioned specific binding interactions for each CO(2) molecule, including substantial cooperative binding effects among the guest molecules. The validation of the capacity of such simulations to accurately model molecular-scale binding bodes well for the theory-aided development of amine-based CO(2) sorbents. The analysis shows that the combination of appropriate pore size, strongly interacting amine functional groups, and the cooperative binding of CO(2) guest molecules is responsible for the low-pressure binding and large uptake of CO(2) in this sorbent material.  相似文献   

Hypoglycemic activity of Nymphaea stellata leaves ethanolic extract in alloxan induced diabetic rats     

Dhanabal SP  Raja MK  Ramanathan M  Suresh B 《Fitoterapia》2007,78(4):288-291

The ethanolic extract of leaves of Nymphaea stellata given by oral route to diabetic rats at dose of 100 and 200 mg/kg/day for seven days reduced significantly by 31.6 and 42.6 % the plasma glucose level increased by intraperitoneal injection of 120 mg/day of alloxan. Moreover, the treatment significantly affected the plasma level of cholesterol and triglyceride.  相似文献   

Persistence of serum antibodies to Sarcocystis neurona in horses moved from North America to India     

Brown CM  Morrow JK  Carleton CL  Ramanathan B  Reddy R  Vaidya V  Karthikeyan SM  Zulfikar AA  Kannadkar VS 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2006,20(4):994-997

BACKGROUND: The study reported here was undertaken to assess the presence of antibodies to Sarcocystis neurona in the serum of horses of North American origin that had been relocated for 1 year or more to India (ie, outside of the known endemic areas for S. neurona). HYPOTHESIS: The presence or absence of such antibodies should provide information concerning the persistence of such antibodies, or support the presence of chronic infection, or both. ANIMALS: A total of 228 Thoroughbred horses were sampled in India, of which 86 were of North American origin that had been in India between 1 and 13 years, 124 were Indian-born horses that had never been out of India, 8 were of Irish origin, 8 were of English origin, and 2 were originally from France. METHODS: Sera were tested using established western blot analysis. RESULTS: Of the Indian-born horses, 0.8% were test positive, and of the North American horses, 42% were test positive. All of the English and Irish horses were test negative, and the 2 French horses were test positive. CONCLUSIONS AND CLINICAL IMPORTANCE: These data indicate that antibodies against S. neurona can be detected for many years after horses have been removed from an endemic area and that this may be attributable to long half-life of the antibodies or to chronic infection and ongoing antibody production, or both.  相似文献   

Simultaneously mitigating near-term climate change and improving human health and food security   总被引：3，自引：0，他引：3  

Shindell D  Kuylenstierna JC  Vignati E  van Dingenen R  Amann M  Klimont Z  Anenberg SC  Muller N  Janssens-Maenhout G  Raes F  Schwartz J  Faluvegi G  Pozzoli L  Kupiainen K  Höglund-Isaksson L  Emberson L  Streets D  Ramanathan V  Hicks K  Oanh NT  Milly G  Williams M  Demkine V  Fowler D 《Science (New York, N.Y.)》2012,335(6065):183-189

Tropospheric ozone and black carbon (BC) contribute to both degraded air quality and global warming. We considered ~400 emission control measures to reduce these pollutants by using current technology and experience. We identified 14 measures targeting methane and BC emissions that reduce projected global mean warming ~0.5°C by 2050. This strategy avoids 0.7 to 4.7 million annual premature deaths from outdoor air pollution and increases annual crop yields by 30 to 135 million metric tons due to ozone reductions in 2030 and beyond. Benefits of methane emissions reductions are valued at $700 to $5000 per metric ton, which is well above typical marginal abatement costs (less than $250). The selected controls target different sources and influence climate on shorter time scales than those of carbon dioxide-reduction measures. Implementing both substantially reduces the risks of crossing the 2°C threshold.  相似文献   

Host-Specific Toxin Production by Rhizoctonia solani, the Rice Sheath Blight Pathogen     

Vidhyasekaran P  Ponmalar TR  Samiyappan R  Velazhahan R  Vimala R  Ramanathan A  Paranidharan V  Muthukrishnan S 《Phytopathology》1997,87(12):1258-1263

ABSTRACT Rhizoctonia solani, the rice sheath blight pathogen, produces a toxin that reproduces all symptoms of the disease. The toxin has been partially purified and it was found to be a carbohydrate containing glucose, mannose, N-acetylgalactosamine, and N-acetylglucosamine. The toxin was also detected in infected leaves. Highly virulent isolates produced more toxin than less virulent isolates. Several R. solani isolates from rice and one each from cotton and tomato produced a similar toxin. All rice cultivars tested were susceptible to the pathogen and sensitive to the toxin. Host specificity of the toxin has been demonstrated using hosts and nonhosts of the pathogen.  相似文献   

Factor analysis of fodder yield components in oats     

K. L. Mehra  Bhag Mal  P. R. Sreenath  M. L. Magoon  D. S. Katiyar 《Euphytica》1971,20(4):597-601

Summary The causative sources of common variation of seven components of fodder yield in oats were analysed, using the centroid method of factor analysis. Two factors together accounted for most of the inter-correlations of these characters. Factor 1 had different degrees of positive loading on all characters, the highest being on the fodder yield. Factor 2 affected negatively a few and positively the remaining characters. The plant height and fodder yield were affected positively by Factor 1 and negatively by Factor 2. Factor 1 and 2 were significantly negatively associated with each other. The fodder yield components in the material studied seem to be influenced by the two interacting hormonal systems. The implications of the findings, in selecting for high quality and high yielding varieties of fodder oats, are discussed.  相似文献   

Global air pollution crossroads over the Mediterranean   总被引：3，自引：0，他引：3  

Lelieveld J  Berresheim H  Borrmann S  Crutzen PJ  Dentener FJ  Fischer H  Feichter J  Flatau PJ  Heland J  Holzinger R  Korrmann R  Lawrence MG  Levin Z  Markowicz KM  Mihalopoulos N  Minikin A  Ramanathan V  De Reus M  Roelofs GJ  Scheeren HA  Sciare J  Schlager H  Schultz M  Siegmund P  Steil B  Stephanou EG  Stier P  Traub M  Warneke C  Williams J  Ziereis H 《Science (New York, N.Y.)》2002,298(5594):794-799

The Mediterranean Intensive Oxidant Study, performed in the summer of 2001, uncovered air pollution layers from the surface to an altitude of 15 kilometers. In the boundary layer, air pollution standards are exceeded throughout the region, caused by West and East European pollution from the north. Aerosol particles also reduce solar radiation penetration to the surface, which can suppress precipitation. In the middle troposphere, Asian and to a lesser extent North American pollution is transported from the west. Additional Asian pollution from the east, transported from the monsoon in the upper troposphere, crosses the Mediterranean tropopause, which pollutes the lower stratosphere at middle latitudes.  相似文献