Indian Agricultural Statistics Research Institute

About: Indian Agricultural Statistics Research Institute is a facility organization based out in New Delhi, India. It is known for research contribution in the topics: Population & Small area estimation. The organization has 454 authors who have published 870 publications receiving 7987 citations.

von Bertalanffy stochastic differential equation growth model with multiplicative noise

Abstract: The well-known von Bertalanffy growth (VBG) model for estimating age-length relationship in fisheries is considered. Stochastic differential equation (SDE) approach is employed to take into account the effect of fluctuating environment. In this paper, the von Bertalanffy SDE (VBSDE) model with multiplicative noise is proposed. The resultant model is solved analytically. Relevant computer code for fitting the model is developed in SAS package and the same is added as an Appendix. Finally, as an illustration, superiority of our proposed model over VBSDE model with additive noise for fitting and forecasting purposes is shown for some fish data.

Did Tsunami tremor jolt microbial biomass and their activities in soils? A case study in Andaman Island, India

Abstract: The nature of selected soil-chemical and microbial properties influenced by tsunami affected and non-affected areas along the border areas of the alluvial Andaman Island in India were investigated. Soils of these areas have turned saline and saline-sodic due to the ingression of sea water. The electrical conductivity of the saturation extract of the surface soil varied from 11.2 to 23.8 dS m−1 in 2005, and it was decreased to 0.8–10.3 dS m−1 in 2006 due to the heavy rain in the following year after the tsunami. Soil quality indicators, like microbial biomass C, microbial metabolic quotient, microbial respiration quotient and fluorescein diacetate hydrolyzing activity, decreased in the tsunami affected soil in 2005, but slightly increased in 2006. All microbial parameters were significantly negatively correlated with the electrical conductivity, sodium absorption ratio and exchangeable sodium percentage. Suppression of microbial biomass and their activities in the soils due to the increased-salinity is of great agronomic significance and needs suitable intervention for sustainable crop production. Significant differences were found in soil-chemical and microbial characteristics between tsunami affected and non-affected areas. Hierarchical clustering algorithm on the basis of different soil-chemical and microbial characteristics revealed that there is significant difference in grouping between tsunami affected and non-affected zones. From this study, it can be concluded that the sea water ingression detrimentally influenced the microbial properties of tsunami affected soil.

Identification, characterization and expression analysis of ERF transcription factor VviERF073 and standardization of stable reference gene under salt stress in grape.

Abstract: Salinity is one of the several abiotic factors affecting grape productivity and quality. Transcription factors belonging to AP2/ERF family play an important role in abiotic stress response. Based on the in silico analysis of salt stress libraries of grape ESTs, a transcription factor VviERF073 , having a single AP2/ERF conserved domain was identified. The sequence of VviERF073 was analyzed in 'Thompson Seedless'. VviERF073 belonged to the B2 subfamily of ERF transcription factors. Under salt stress, the relative expression of VviERF073 increased 2.7 fold in the leaves of grafted grapevine within six hours of salt stress. The expression increased to 8.7 fold at 15 days of salt stress, thus indicating its role in early as well as late response to salt stress. However, expression of VviERF073 did not change significantly in grapevines raised on own roots. The expression varied in the roots of 'Thompson Seedless' but not in the roots of '110R'. Under salt stress conditions, GAPDH and EF1α for grafted vines and Actin and Tubulin for own root vines, were identified as the stable reference genes for qPCR data normalization.

On Some E-Optimal Block Designs.

Abstract: TheE-optimality of block designs is the concern of this paper. Bounds for the smallest positive eigenvalue of theC-matrix of block designs are obtained in some general classes of connected designs with equal or unequal block sizes. Use of these bounds is made to obtainE-optimal block designs in various classes.