Suresh Kumar

Assessing potential of MODIS derived temperature/vegetation condition index (TVDI) to infer soil moisture status

High‐resolution soil moisture holds the key to improving weather forecast, drought monitoring and hydrological modelling. Therefore, the present study investigates the potential of the temperature/vegetation dryness index (TVDI) from the MODIS to assess soil moisture status in sub‐humid parts of India (western Uttar Pradesh). The TVDI was calculated by parameterizing the normalized difference vegetation index–surface temperature space from 8 day MODIS reflectance and surface temperature products. Correlation and regression analysis was carried out to relate the TVDI against in‐situ measured soil moisture during early (April) and peak (October) stages of growth in sugarcane crop. Spatio‐temporal patterns in the TVDI shows that northern areas had more surface wetness compared to southern areas. The results further reveal that a significantly strong and negative relationship exists between the TVDI and in‐situ soil moisture, particularly when vegetation cover is sparse. The dryness index was also found satisfactory to capture the temporal variation in the surface moisture status in terms of antecedent precipitation index.

Modelling soil erosion risk based on RUSLE-3D using GIS in a Shivalik sub-watershed

The RUSLE-3D (Revised Universal Soil Loss Equation-3D) model was implemented in geographic information system (GIS) for predicting the soil loss and the spatial patterns of soil erosion risk required for soil conservation planning. High resolution remote sensing data (IKONOS and IRS LISS-IV) were used to prepare land use/land cover and soil maps to derive the vegetation cover and the soil erodibility factor whereas Digital Elevation Model (DEM) was used to generate spatial topographic factor. Soil erodibility (K) factor in the sub-watershed ranged from 0.30 to 0.48. The sub-watershed is dominated by natural forest in the hilly landform and agricultural land in the piedmont and alluvial plains. Average soil loss was predicted to be lowest in very dense forest and highest in the open forest in the hilly landform. Agricultural land-1 and agriculture land-2 to have moderately high and low soil erosion risk, respectively. The study predicted that 15% area has ‘moderate’ to ‘moderately high’ and 26% area has high to very high risk of soil erosion in the sub-watershed.

Medicinal chemistry of dihydropyran-based medium ring macrolides related to aspergillides: selective inhibition of PI3Kα.

A set of nine trans-disubstituted dihydropyran-based medium ring macrolides has been synthesized using d-glucal as chiral pool and evaluated against a panel of three human cancer cell lines and a normal cell line. The synthetic route to the targeted molecule is simple, concise, and high yielding compared to other reported methods. Bioevaluation studies have resulted in the identification of a potent cytotoxic molecule (10) exhibiting dose-dependent growth inhibition against HL-60 cell line with an IC50 value of 1.10 ± 0.075 μM, which is lower than that of naturally occurring molecules of this class and of comparable activity to the synthetic drug fludarubin. Compound 10 inhibits the PI3K/AKT signaling pathway by selectively targeting the p110α subunit of PI3Kα. This leads to mitochondrial stress that causes translocation of cytochrome c from mitochondria to cytosol, which in turn activates caspase-mediated apoptotic cell death. Further in silico docking simulations of four macrolides with p110α subunits have been carried out to visualize the orientation pattern.

Hyperspectral Satellite Data in Mapping Salt-Affected Soils Using Linear Spectral Unmixing Analysis

Development of salt-affected soils in the irrigated lands of arid and semi-arid region is major cause of land degradation. Hyperion hyperspectral remote sensing data (EO-1) was used in the present study for characterization and mapping of salt-affected soils in a part of irrigation command area of Indo-Gangetic alluvial plains. Linear spectral mixture analysis approach was used to map various categories of salt affected soils represented by spectral endmembers of slightly, moderately and highly salt-affected soils. These endmembers were related to surface expression of various categories of salt-affected soils in the area. The endmembers were selected by performing minimum noise fraction (MNF) transformation and pixel purity index (PPI) on Hyperion (EO-1) data with reference to high resolution LISS IV data and field data. The results showed that various severity classes of salt-affected soils could be reliably mapped using linear spectral unmixing analysis. A low RMSE value (0.0193) over the image was obtained that revealed a good fit of the model in identification and classification of endmembers of various severities of salt affected soils. The overall classification accuracies for slight, moderate and highly salt-affected soils were estimated of 78.57, 79.81 and 84.43% respectively.

Hyperspectral remote sensing data derived spectral indices in characterizing salt-affected soils: a case study of Indo-Gangetic plains of India

Hyperspectral remote sensing (Hyperion EO-1) data has emerged as most promising tool in quantifying severity of salt-affected soils. The study deals with identifying sensitive spectral bands (wavelength regions) for salinity parameters and thereafter used to compute spectral indices viz. Salinity index (SI), Brightness index (BI), Normalized Differential Salinity Index (NDSI), Combined Spectral Response Index (COSRI) and Coloration index (CI). Six sensitive hyperspectral bands (Band 9, 20, 22, 28, 29 and 46) of Hyperion-1 satellite data were identified to generate the spectral indices. The relationship between these spectral indices and salinity parameters of electrical conductivity (EC), sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP) were established to generate maps showing severity of salt-affected soils of the area. The severity maps were categorized into classes of normal, slight, moderate and highly showing the spatial distribution of severity of salt affected soils. Among these spectral indices, SI shown highest correlation coefficient (r2) with the parameters of ECe (r2xa0=xa00.777), SAR (r2xa0=xa00.801) and ESP (r2xa0=xa00.804) followed by BI, COSRI and CI. The Hyperion data has shown the potential to assess severity of salt-affected soils for large area which may very useful for identifying the area for carring out reclamation measures and management planning.

Spatial distribution of soil nutrients in a watershed of Himalayan landscape using terrain attributes and geostatistical methods

Terrain attributes derived from digital terrain model (DTM) were used to study spatial variation of total soil C, N and available P in surface soils of a watershed of Himalayan landscape. Terrain attributes elevation, slope gradient and upslope catchment area (UCA) and terrain indices [terrain wetness index (TWI), water power index (WPI) and sediment transport index (STI)] were derived from DTM and evaluated for their potential in soil nutrients mapping. These nutrients showed positive correlation with UCA, TWI, SPI and STP terrain indices. Among these terrain indices, TWI showed highest correlation coefficient for TC (r2xa0=xa00.71), N (r2xa0=xa00.67) and P (r2xa0=xa00.66) followed by WPI and STI. Geostatistical analyses used to map these nutrients, co-kriging with TWIxa0+xa0NDVI, TWI and slope as co-variables, had improved the spatial prediction to 60.46, 55.81, 44.18xa0% for TC and 33.63, 21.78, 17.82xa0% for N, respectively, contrary to ordinary kriging. The prediction accuracy for P was improved with co-variables of TWIxa0+xa0NDVI and TWI by 30.03 and 4.50xa0%, respectively. The study clearly revealed that by integrating NDVI as co-variable has significantly improved the accuracy for TC followed by N and P. TWI alone as co-variable has improved the spatial prediction significantly.

Synthesis and biological evaluation of novel peptide BF2 as an antibacterial agent against clinical isolates of vancomycin-resistant enterococci.

Enterococci are the leading cause of nosocomial infections worldwide and acquired resistance to a variety of antibiotics. Antimicrobial peptides represent a promising molecule against the antibiotic resistance in bacteria and an indispensable component of the innate immune system. The aim of the study was to develop an antimicrobial peptide against vancomycin-resistant enterococci (VRE). We have designed a series of peptides based on Sapecin B as template. An in vitro antibacterial study of synthetic peptide BF2 against the clinical isolates of vancomycin-resistant and control strains of enterococci showed rapid killing effect on enterococci by killing 99.9% of bacterial cells in 60 min and susceptibility at minimum inhibitory concentration (MIC) range of 6.25-12.5 μg/mL. Synergy of BF2 was observed in combination with vancomycin and teicoplanin. The peptide was bactericidal and nontoxic to mammalian cells. An in vivo study also revealed the antibacterial activity against enterococci-infected Wistar albino rats. BF2 may be used synergistically with antibiotics.

Mapping of plant-based medicine research in China and India

An analysis of 2,183 papers published by Chinese researchers and 1,034 papers published by Indian researchers in the field of plant-based medicine during 1990–2004 and indexed by Pub Med indicates that Chinas output is more than twice to Indias output. Medical universities and colleges mainly contribute to Chinas output, while academic institutions mainly contribute to the Indian output. The major focus of Chinese researchers was on chemical analysis including chromatographic and spectrometric investigations, followed by oncology/radiation protection. Indian researchers emphasized gastroenteritis/liver diseases and oncology/radiation protection. The investigations were mainly focused on native plants of respective countries. Chinese researchers preferred to publish their work in domestic journals; Indian researchers in journals published from the Western countries. The share of papers in journals covered by SCI for India was higher than that from China. However, the proportion of papers in high impact factor journals for China is higher than for India. Average rate of citation for Chinese and Indian papers was almost the same. Copyright , Beech Tree Publishing.

Antiproliferative potential of a novel parthenin analog P16 as evident by apoptosis accompanied by down-regulation of PI3K/AKT and ERK pathways in human acute lymphoblastic leukemia MOLT-4 cells

Leukemia is one of the deadliest types of cancer. Lack of effective treatment strategies has resulted in an extensive quest for new therapeutic molecules against it. This study explores the molecular mechanism of anticancer activity of P16, a semisynthetic analog of parthenin, against the human acute lymphoblastic leukemia MOLT-4 cells. P16 displayed antiproliferative activity in different cancer cell lines; however, MOLT-4 cells showed highest sensitivity for P16 with IC50 value of 0.6μM. Further studies revealed that P16 induced cell death by apoptosis. It caused mitochondrial stress, which was mediated by the translocation of Bax from cytosol to mitochondria and release of cytochrome c into the cytosol and consequent activation of caspase-9. However, P16 was also able to activate caspase-8, thus involving both extrinsic and intrinsic pathways of apoptosis. Further, activation of caspase-3 led to cleavage of its target proteins PARP-1 and ICAD, which resulted in apoptotic DNA damage. P16 induced apoptosis was accompanied by the down-regulation of important leukemic cell survival proteins like pAKT (S473), pAKT (T308), pP70S6K, pCRAF, and pERK1/2. However, inhibition of caspases by Z-VAD-FMK reversed the down-regulatory effect of P16 on pAKT (S473) and pP70S6K, as evident by the cell viability assay and flow cytometric analysis but this inhibition did not completely reverse the antiproliferative effect of P16, thereby indicating the role of additional factors apart from caspases in P16 induced apoptosis in MOLT-4 cells. Owing to its antiproliferative potential against leukemia cells, P16 can further be explored as an effective therapeutics against leukemia.

Geospatial Approach in Assessing Agro-Climatic Suitability of Soybean in Rainfed Agro-Ecosystem

The present study demonstrated the methodology to assess agro-climatic suitability of the soybean crop through integration of crop suitability based on FAO framework of land evaluation and biophysical (water limited) yield potential in the rainfed agro-ecosystem. A long term climatic database (1980–2003) was prepared to compute decadal rainfall and temperature variations of 13 IMD stations in part of Madhya Pradesh state. The climatic database was used in soil water balance software–BUDGET to compute crop specific length of growing period (LGP) and biophysical production potential such as water limited crop yield potential of each soil types for soybean crop. Water limited crop yield potential of soils were found to be varied from 33 to 100 and LGP ranged from 65 to 180xa0days in the area. FAO based land suitability was analyzed in association with the water limited yield potential for better appraisal of land potential and assess their suitability in rainfed area. FAO based land suitability indicated 2.45xa0% area as highly suitable and 57.49xa0% area as moderately suitable. However, integration of water limited crop yield potential with FAO based land suitability lead to agro-climatic suitability analysis indicated 17.60xa0% and 40.03xa0% area, respectively as highly suitable and moderately suitable. FAO based land evaluation showed 88.13xa0% of plains as moderately suitable whereas agro-climatic suitability indicated only 47.79xa0%. Agro-climatic suitability analysis revealed undulating plateau and undulating plains as most suitable for soybean crop.