Evidence for new sources of NOX in the lower atmosphere     

EC Zipf  SS Prasad 《Science (New York, N.Y.)》1998,279(5348):211-213

Laboratory studies show that the reaction of short-lived O2(B3Sigmau) molecules (lifetime approximately 10 picoseconds) with N2 and the photodissociation of the N2:O2 dimer produce NOx in the stratosphere at a rate comparable to the oxidation of N2O by O(1D). This finding implies the existence of unidentified NOX sinks in the stratosphere. The NO2 observed in this experiment is isotopically heavy with a large 15N/14N enhancement. However, photodissociation of this NO2 unexpectedly produced NO molecules with a low 15N/14N ratio. The diurnal odd-nitrogen cycle in the stratosphere will be marked by a complex isotope signature that will be imprinted on the halogen and HOX catalytic cycles.  相似文献   

Influence of leguminous cover crops on microbial and selected enzyme activities in soils of a plantation     

R. Dinesh  M. A. Suryanarayana  G. Shyam Prasad  A. K. Bandyopadhyay  A. K. Nair  T. V. R. S. Sharma 《植物养料与土壤学杂志》1999,162(1):57-60

A study dealing with ecological sustainability of plantation based land use initiated in 1991 in a 19 yr old coconut plantation consists of growing certain leguminous crops like Atylosia, Pueraria, Centrosema and Calopogonium as soil cover in separate plots with lemon grass as live bounds. These cover crops are grown during the rainy season and incorporated into the soil towards the end of the monsoon every year. The effect of such cover crops on soil microbial counts (total counts, fungi, actinomycetes and bacteria), biomass C, organic C, total N and on the activity of enzymes like urease, amidase, L-glutaminase, aryl sulphatase and dehydrogenase was determined in soils (Ap horizon) collected from these plots after 5 years. Soils with cover crops registered significantly higher microbial biomass, biomass C, organic C and total N compared to control. Consequently, all the enzymes were activated to different degrees in soils with cover crops. Significant and positive relationships of enzyme activities with organic C, mineral N and total N suggested that growing cover crops, increased C turnover and N availability and therefore, provided a conducive environment for microbial proliferation, enzyme synthesis and accumulation in the soil matrix.  相似文献   

Identification and characterization of SSRs in <Emphasis Type="Italic">Clarias batrachus</Emphasis> and their application in population study     

Shreya Srivastava  Basdeo Kushwaha  Jyoti Prakash  Manmohan Pandey  Suyash Agarwal  Ravindra Kumar  N. S. Nagpure  Mahender Singh  Paramananda Das  Chaitanya Joshi  Joy Krushna Jena 《Fisheries Science》2017,83(2):265-272

Magur Clarias batrachus is an indigenous catfish, commonly found in India, Nepal, Bhutan and Bangladesh. Presently, the populations of magur have declined rapidly in their natural habitat mainly due to overexploitation and habitat degradation. Understanding the population genetic structure of the species has significance in improvement of stocks and in conservation of the species. In the present study, simple sequence repeat (SSR) markers were used to differentiate the populations of magur, collected from three geographic locations. For this, a total of 31,814 SSRs were mined from the de novo assembled pooled of whole genome sequence data of C. batrachus. A bioinformatics pipeline with stringent criteria was applied to analyze the data which resulted in selection of 30,142 microsatellite loci falling in the intergenic region. Out of the 25 loci selected for primer development, 16 loci were successfully amplified and 9 loci were found to be polymorphic in this species. The average observed as well as expected heterozygosity in the loci across different stocks varied from 0.652 to 0.688 and 0.864 to 0.873, respectively. These three populations were further segregated into two clusters based on the NJ genetic distance. The Lucknow population formed one cluster, while the Bhubaneswar and Kolkata populations constituted another cluster. A comparable finding was also deduced from the STRUCTURE analyses. The results revealed significant variation among the populations of C. batrachus under study.  相似文献   

‘Damsel in distress’‐ The tale of Miss Kerala,Puntius denisonii (Day), an endemic and endangered cyprinid of the Western Ghats biodiversity hotspot (South India)     

Rajeev Raghavan  G. Prasad  Benno Pereira  P.H. Anvar Ali  L. Sujarittanonta 《水产资源保护:海洋与淡水生态系统》2009,19(1):67-74

• 1. Denison's Barb, Puntius denisonii (Day) is an endemic and endangered cyprinid fish of the Western Ghats biodiversity hotspot in peninsular India, which is the focus of an organized yet undocumented fishery targeting juveniles for the international aquarium trade.
• 2. Research on P. denisonii has been very limited and there has been no systematic effort to assess and monitor their abundance, distribution and populations.
• 3. Anecdotal and circumstantial evidence indicates a highly restricted distribution, low abundance, declining populations, low catch per unit effort and increasing market prices, providing evidence of an impending conservation crisis and the need for urgent management of wild stocks.
• 4. This paper reviews current knowledge, provides results from the authors' field study and suggests priorities for conservation and management actions for P. denisonii in the streams of Kerala.

Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

EFFECT OF NANOSCALE ZINC OXIDE PARTICLES ON THE GERMINATION,GROWTH AND YIELD OF PEANUT     

T. N. V. K. V. Prasad  P. Sudhakar  Y. Sreenivasulu  P. Latha  V. Munaswamy  K. Raja Reddy 《Journal of plant nutrition》2013,36(6):905-927

An investigation was initiated to examine the effects of nanoscale zinc oxide particles on plant growth and development. In view of the widespread cultivation of peanut in India and in other parts of the globe and in view of the potential influence of zinc on its growth, this plant was chosen as the model system. Peanut seeds were separately treated with different concentrations of nanoscale zinc oxide (ZnO) and chelated bulk zinc sulfate (ZnSO₄) suspensions (a common zinc supplement), respectively and the effect this treatment had on seed germination, seedling vigor, plant growth, flowering, chlorophyll content, pod yield and root growth were studied. Treatment of nanoscale ZnO (25 nm mean particle size) at 1000 ppm concentration promoted both seed germination and seedling vigor and in turn showed early establishment in soil manifested by early flowering and higher leaf chlorophyll content. These particles proved effective in increasing stem and root growth. Pod yield per plant was 34% higher compared to chelated bulk ZnSO₄. Consequently, a field experiment was conducted during Rabi seasons of 2008–2009 and 2009–2010 with the foliar application of nanoscale ZnO particles at 15 times lower dose compared to the chelated ZnSO₄ recommended and we recorded 29.5% and 26.3% higher pod yield, respectively, compared to chelated ZnSO₄. The inhibitory effect with higher nanoparticle concentration (2000 ppm) reveals the need for judicious usage of these particles in such applications. This is the first report on the effect of nanoscale particles on peanut growth and yield.  相似文献   

Stress mitigating and immunomodulatory effect of dietary pyridoxine in Labeo rohita (Hamilton) fingerlings     

Mohammad Shahbaz Akhtar  Asim Kumar Pal  Narottam Prasad Sahu  Ciji Alexander  Sanjay Kumar Gupta  Arup Kumar Choudhary  Ashish Kumar Jha  Mysore Govindrajan Rajan 《Aquaculture Research》2010,41(7):991-1002

A 60‐day experiment was carried out to delineate stress mitigating and immunomodulatory role of dietary pyridoxine (PN) in Labeo rohita fingerlings exposed to endosulfan. Two hundred and seventy fingerlings were randomly distributed into six treatments in triplicates. Five iso‐caloric and iso‐nitrogenous purified diets were prepared with graded levels of pyridoxine. Six treatment groups were T₀ (10 mg PN+without endosulfan), T₁ (0 mg PN+endosulfan), T₂ (10 mg PN+endosulfan), T₃ (50 mg PN+endosulfan), T₄ (100 mg PN+endosulfan) and T₅ (200 mg PN+endosulfan). The role of pyridoxine on stress mitigation and immunomodulation was assessed by biochemical and haemato‐immunological parameters like aspartate aminotransaminase, alanine aminotransaminase, lactate dehydrogenase, malate dehydrogenase, superoxide dismutase and catalase were significantly (P<0.05) lower while acetylcholinesterase was significantly (P<0.05) higher in pyridoxine‐fed groups. Erythrocytes count, haemoglobin content and total serum protein, albumin, globulin, nitroblue tetrazolium and lysozyme activity were significantly (P<0.05) higher while cortisol and blood glucose were decreased significantly (P<0.05) in pyridoxine‐fed groups. Percentage survival after challenge with Aeromonas hydrophila was highest in T₀ group. The results obtained in present study indicate that dietary pyridoxine supplementation at 100 mg PN kg^?1 diet reduces the endosulfan‐induced stress and triggers immune response in L. rohita fingerlings.  相似文献   

Optimum timing of insecticide applications against diamondback moth Plutella xylostella in cole crops using threshold catches in sex pheromone traps     

Gadi Venkata Prasad Reddy  Angel Guerrero 《Pest management science》2001,57(1):90-94

Field trials were conducted in cabbage (Brassica oleracea var capitata), cauliflower (B oleracea var botrytis) and knol khol (B oleracea gongylodes) crops at two different locations in Karnataka State (India) to optimize the timing of insecticide applications to control the diamondback moth, Plutella xylostella, using sex pheromone traps. Our results indicate that applications of cartap hydrochloride as insecticide during a 12–24 h period after the pheromone traps had caught on average 8, 12 and 16 males per trap per night in cabbage, cauliflower and knol khol, respectively, were significantly more effective than regular insecticide sprays at 7, 9, 12 or 15 days after transplantation. This was demonstrated by estimation of the mean number of eggs and larvae per plant, the percentage of holes produced, as well as the marketable yield of the three crops at each location. A good correlation between the immature stages, infestation level, the estimated crop yield and the number of moths caught in pheromone traps was also found, indicating the usefulness of pheromone‐based monitoring traps to predict population densities of the pest. © 2001 Society of Chemical Industry  相似文献   

Controlled-environment and field evaluation of heat stress induced genetic variability on translocation efficiency and grain filling traits in rice     

Ayyavu  Vinitha  Dhashnamurthi  Vijayalakshmi  Venugopal  Babu Rajendra Prasad 《Journal of Crop Science and Biotechnology》2022,25(5):535-545

Journal of Crop Science and Biotechnology - The grain filling of rice is gets weakened by heat stress due to reduced spike photosynthesis at high temperature stress. An alternate source of carbon...  相似文献