Nitrous oxide emissions from kharif and rabi legumes grown on an alluvial soil     

Sabyasachi Ghosh  Deepanjan Majumdar  M. Jain 《Biology and Fertility of Soils》2002,35(6):473-478

Nitrous oxide (N₂O) emissions were monitored for a period of 60 days in a pot culture study, from two kharif (June-September) and two rabi (October-March) season legumes, which were grown on a Typic Ustochrept, alluvial sandy loam soil. Black gram (Vigna mungo L. Hepper), var. T-9, and soybean (Glycine max L. Merril), var. Punjab 1, were taken up in kharif season whereas lentil (Lens esculenta Moench), var. JLS-1, and Bengal gram (Cicer arietinum L.), var. BGD-86, were grown in rabi season. All the crops were grown with and without urea and one pot (containing soil but with no fertilizer or crop) was used as a control. Nitrous oxide emissions were significantly higher in unfertilized cropped soil than in the control, while the addition of urea to the crops further increased the emissions. Significant emissions occurred during third and seventh week after sowing for all the treatments in both kharif and rabi seasons. In kharif, soil cropped with soybean had higher total N₂O-N emission than soil sown with black gram both under fertilized and unfertilized conditions; while in rabi, lentil had a higher total N₂O-N emission than Bengal gram under both fertilized and unfertilized conditions. In kharif, total N₂O-N emissions ranged from 0.53 (control) to 3.84 kg ha^-1 (soybean+urea), while in rabi it ranged from 0.45 (control) to 3.06 kg ha^-1 (lentil+urea). Higher N₂O-N emissions in kharif than in rabi was probably due to the favorable effect of temperature on nitrification and denitrification in the former season. The results of the study indicated that legume crops may lead to an increase in N₂O formation and emission from soils, the extent of which varies from crop to crop.  相似文献   

Pink body colour in Tilapia shows single gene inheritance     

K C Majumdar  K Nasaruddin  K Ravinder 《Aquaculture Research》1997,28(8):581-589

Segregation of a wide range of body colour in the progenies was observed in breeding experiments with the Taiwanese red tilapias. Homozygous stocks of pink, red and golden colour morph were selected from such a stock by brother-sister crossing for six generations. DNA fingerprinting analysis using multilocus M13 and Bkm 2(8) probe and HinfIenzyme combinations of pink individuals, showed homozygosity in their genome. Pink individuals when crossed to black Oreochromis mossambicus (Peters) resulted in all pink F1 progenies. F1 X F1 crosses resulted in segregation of pink and black in the F2 progenies in a 3 : 1 ratio. F1 pink individuals when backcrossed to O. mossambicus gave progeny in the ratio of 1: 1 of pink and black. Black individuals from the F2 generation, when crossed to O. mossambicus and pink separately, resulted in all black and all pink progenies, respectively. These results show that the pink colour is dominant over the black phenotype and is inherited as an autosomal locus with complete penetrance.  相似文献   

Toxico-kinetics, recovery, and metabolism of napropamide in goats following a single high-dose oral administration     

Pahari AK  Majumdar S  Mandal TK  Chakraborty AK  Bhattacharyya A  Chowdhury A 《Journal of agricultural and food chemistry》2001,49(4):1817-1824

Toxicokinetic behavior, recovery and metabolism of napropamide (a pre-emergent herbicide) and its effect on Cytochrome P(450) of liver microsomal pellet were studied following a single high-dose oral administration of 2.5 g kg(-1) and continuous (7 days) oral administration of 500 mg kg(-1) in black Bengal goat. Napropamide was detected in blood at 15 min and the maximum quantity was recovered at 3 h after administration. The absorption rate constant (Ka) value was low indicating poor absorption from the gastrointestinal tract. High elimination half-life (t(1/2) beta) and low body clearance (Cl(B)) values coupled with higher transfer of compound from tissue to central compartment (K(21)) suggest that napropamide persisted in the blood for a long time, i.e., after 72 h of oral administration. The recovery percentage of napropamide, including metabolites, from goats varied from 75.94 to 80.08 and excretion of the parent compound through feces varied from 18.86 to 21.59%, indicating that a major portion of the orally administered napropamide was absorbed from the gastrointestinal tract of goat. Napropamide significantly increased the Cytochrome P(450) content of liver microsomal pellet. The recovery of metabolites from feces, urine, and tissues ranged from 4.2--6.2, 40.81--49.42, and 2.7--11.6%, respectively, during a 4--7 day period. The material balance of napropamide (including metabolites) following a single high-dose oral administration at 2.5 g kg(-1) during 4--7 days after dosing was found to be in the range of 75--80%.  相似文献   

Potassium management in rice–maize systems in South Asia     

Jagadish Timsina  Vinod Kumar Singh  Kaushik Majumdar 《植物养料与土壤学杂志》2013,176(3):317-330

Potassium (K) availability in soils is largely governed by their mineralogical composition. The extent of weathering of primary K‐bearing minerals, the chemical pathways through which weathering takes place, as well as the dynamic equilibrium between various K fractions in soils are factors which determine different soil types of varying K‐supplying capacity. The marked variability of K availability in soils in South Asia needs to be taken into account when formulating K‐management strategies in intensive cereal‐based systems in response to K application. Evidence from long‐term fertilizer experiments in rice–rice (R‐R) or rice–wheat (R‐W) systems strongly indicates significant yield responses to K application and negative K balances where K application is either omitted or applied suboptimally. However, K‐fertilizer recommendations in South Asia are generalized over large areas while farmers neglect K application to crops and remove crop residues from fields. These practices may strongly affect yield and soil K‐fertility status in the emerging rice–maize (R‐M) systems in different locations of South Asia. The dry‐matter yield of the R‐M system is usually much higher than that of the R‐R or R‐W system causing high withdrawal of nutrients from the soil. The current review assesses various K forms and K availability in diverse soil types of South Asia supporting rice‐based systems. Aspects considered include: long‐term crop yield and its response to added nutrients, K balance for intensive rice‐based systems, and the role of crop residues in supplying K to crops. Emerging data from either completed or on‐going experiments on the R‐M systems in India and Bangladesh have revealed very high system productivity and variable responses and agronomic K‐use efficiency of maize and rice. Potassium responses of maize are extremely high and variable for soils in Bangladesh. Finally, a plant‐based strategy for field‐specific nutrient management is presented and the need for models and decision support systems for developing efficient K management of the R‐M system is also discussed.  相似文献   

Solid-state thermal rectifier   总被引：1，自引：0，他引：1  

Chang CW  Okawa D  Majumdar A  Zettl A 《Science (New York, N.Y.)》2006,314(5802):1121-1124

We demonstrated nanoscale solid-state thermal rectification. High-thermal-conductivity carbon and boron nitride nanotubes were mass-loaded externally and inhomogeneously with heavy molecules. The resulting nanoscale system yields asymmetric axial thermal conductance with greater heat flow in the direction of decreasing mass density. The effect cannot be explained by ordinary perturbative wave theories, and instead we suggest that solitons may be responsible for the phenomenon. Considering the important role of electrical rectifiers (diodes) in electronics, thermal rectifiers have substantial implications for diverse thermal management problems, ranging from nanoscale calorimeters to microelectronic processors to macroscopic refrigerators and energy-saving buildings.  相似文献   

Plasticity of animal genome architecture unmasked by rapid evolution of a pelagic tunicate     

Denoeud F  Henriet S  Mungpakdee S  Aury JM  Da Silva C  Brinkmann H  Mikhaleva J  Olsen LC  Jubin C  Cañestro C  Bouquet JM  Danks G  Poulain J  Campsteijn C  Adamski M  Cross I  Yadetie F  Muffato M  Louis A  Butcher S  Tsagkogeorga G  Konrad A  Singh S  Jensen MF  Cong EH  Eikeseth-Otteraa H  Noel B  Anthouard V  Porcel BM  Kachouri-Lafond R  Nishino A  Ugolini M  Chourrout P  Nishida H  Aasland R  Huzurbazar S  Westhof E  Delsuc F  Lehrach H  Reinhardt R  Weissenbach J  Roy SW  Artiguenave F  Postlethwait JH  Manak JR  Thompson EM 《Science (New York, N.Y.)》2010,330(6009):1381-1385

Genomes of animals as different as sponges and humans show conservation of global architecture. Here we show that multiple genomic features including transposon diversity, developmental gene repertoire, physical gene order, and intron-exon organization are shattered in the tunicate Oikopleura, belonging to the sister group of vertebrates and retaining chordate morphology. Ancestral architecture of animal genomes can be deeply modified and may therefore be largely nonadaptive. This rapidly evolving animal lineage thus offers unique perspectives on the level of genome plasticity. It also illuminates issues as fundamental as the mechanisms of intron gain.  相似文献   

Empirical modelling of tensile strength of woven fabrics     

Abhijit Majumdar  Anindya Ghosh  Shib Sankar Saha  Ayan Roy  Subir Barman  Dhrubajyoti Panigrahi  Anjan Biswas 《Fibers and Polymers》2008,9(2):240-245

Aesthetic properties of fabrics have been considered as the most important fabric attribute for years. However, recently there has been a paradigm shift in the domain of textile material applications and consequently more emphasis is now being given on the mechanical and functional properties of fabrics rather than its aesthetic appeal. Moreover, in certain woven fabrics used for technical applications, strength is a decisive quality parameter. In this work, tensile strength of plain woven fabrics has been predicted by using two empirical modelling methods namely artificial neural network (ANN) and linear regression. Warp yarn strength, warp yarn elongation, ends per inch (EPI), picks per inch (PPI) and weft count (Ne) were used as input parameters. Both the models were able to predict the fabric strength with reasonably good precision although ANN model demonstrated higher prediction accuracy and generalization ability than the regression model. The warp yarn strength and EPI were found to be the two most significant factors influencing fabric strength in warp direction.  相似文献   

Fidelity of a simple Liberty leaf-painting assay to validate transgenic maize plants expressing the selectable marker gene,bar     

K. Rajasekaran  R. Majumdar  C. Sickler  Q. Wei  J. Cary  D. Bhatnagar 《Journal of Crop Improvement》2017,31(4):628-636

Screening of gene manipulation events (transgenic, mutation/genome editing, etc.) is a cost/labor-intensive and time-consuming process in plant science research. While polymerase chain reaction (PCR) is the most commonly used method for screening, the process still requires efficient DNA extraction and subsequent confirmation. However, PCR cannot predict gene expression. To screen a larger number of transgenic plants, it would be ideal to develop a quick and reliable screening procedure. We have applied a Liberty^® leaf-painting method (against bar gene under 4x35S promoter) to screen transgenic maize (Zea mays L.) plants and validated the results through PCR and quantitative real-time PCR (qRT-PCR). Liberty leaf painting at 500 mg L^?1a.i. was > 95% accurate in identifying transgenic events that agreed with the PCR results. Further investigation of bar gene expression in sensitive lines that were PCR positive shows very low expression of the bar gene. We have provided a simple, and rapid assay to determine the transgene expression potential of maize plants expressing the bar gene. The herbicide can be applied to a fully expanded leaf and evaluated one week after application. Green or partially green leaf blades indicate high or moderately high expression of the bar gene and a total yellowing indicates absence or extremely low expression of the bar gene in the transgenic plants. A small volume of Liberty solution is adequate to test hundreds of maize plants, and the assay is reproducible with a high frequency (> 95%) and also displays good correlation with gene expression in planta.  相似文献   

Redescription of Neocamallanus singhi (Nematoda: Camallanidae) with a note on related species     

N C De  G Majumdar 《Folia parasitologica》1984,31(2):105-111

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The growth hormone-encoding gene isolated and characterized from Labeo rohita Hamilton is expressed in CHO cells under the control of constitutive promoters in ‘autotransgene’ constructs     

Rajesh R  Majumdar KC 《Fish physiology and biochemistry》2008,34(4):413-436

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