Stage specific upregulation of antioxidant defence system in leaves for regulating drought tolerance in chickpea

Leaf is one of the early sensors for the drought stress and is important to study drought tolerance mechanism. Activities of antioxidative enzymes and status of malondialdehyde (MDA), hydrogen peroxide (H2O2), proline and total phenols were studied in leaves of drought tolerant (PDG 3 and PDG 4) and susceptible (PBG 1, GPF 2, PBG 5, L 550 and BG1053) chickpea cultivars under irrigated and rainfed conditions at different development stages. In general, with the age of plant, the activities of superoxide dismutase (SOD) and catalase (CAT) increased but the activities of glutathione reductase (GR), ascorbate peroxidase (APX) and peroxidase (POX) decreased in leaves. With some exceptions, in general, higher status of APX and POX in leaves at vegetative stage I (30 days after sowing) and II (60 days after sowing); GR at vegetative stage II and pre-flowering stage and SOD and CAT at seed filling stages in tolerant cultivars under drought stress reflected stage specific upregulation of antioxidant defence system in them. The relatively lower activities of APX and POX in old leaves during seed filling stage make them more prone to enhanced oxidative injury than the young leaves. Lower content of hydrogen peroxide and malondialdehyde in leaves of tolerant cultivars during seed filling reflects the impact of antioxidant defence system operative at that time. The higher accumulation of proline and total phenol in leaves of tolerant cultivars might be playing important role in drought stress tolerance. These results indicated the importance of upregulation of different antioxidant enzymes at variable stages of leaf development

First detections of 610 MHz radio emission from hot magnetic stars

We have carried out a study of radio emission from a small sample of magnetic O- and B-type stars using the Giant Metrewave Radio Telescope, with the goal of investigating their magnetospheres at low frequencies. These are the lowest frequency radio measurements ever obtained of hot magnetic stars. The observations were taken at random rotational phases in the 1390 and the 610 MHz bands. Out of the 8 stars, we detect five B-type stars in both the 1390 and the 610 MHz bands. The O-type stars were observed only in the 1390 MHz band, and no detections were obtained. We explain this result as a consequence of free-free absorption by the free-flowing stellar wind exterior to the closed magnetosphere. We also study the variability of individual stars. One star - HD 133880 - exhibits remarkably strong and rapid variability of its low frequency flux density. We discuss the possibility of this emission being coherent emission as reported for CU Vir by Trigilio et al. (2000).Comment: 9 pages, 4 figures, 4 tables, submitted to MNRA

Solar and Heliospheric Physics with the Square Kilometre Array

The fields of solar radiophysics and solar system radio physics, or radio heliophysics, will benefit immensely from an instrument with the capabilities projected for SKA. Potential applications include interplanetary scintillation (IPS), radio-burst tracking, and solar spectral radio imaging with a superior sensitivity. These will provide breakthrough new insights and results in topics of fundamental importance, such as the physics of impulsive energy releases, magnetohydrodynamic oscillations and turbulence, the dynamics of post-eruptive processes, energetic particle acceleration, the structure of the solar wind and the development and evolution of solar wind transients at distances up to and beyond the orbit of the Earth. The combination of the high spectral, time and spatial resolution and the unprecedented sensitivity of the SKA will radically advance our understanding of basic physical processes operating in solar and heliospheric plasmas and provide a solid foundation for the forecasting of space weather events.Comment: 15 pages, Proceedings of Advancing Astrophysics with the Square Kilometre Array (AASKA14). 9 -13 June, 2014. Giardini Naxos, Italy. Online at http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=215, id.16

Breeding tomatoes suitable for processing with triple disease resistance to tomato leaf curl disease, bacterial wilt and early blight

India is the second largest producer of tomato with 11 per cent global share and cultivated on an estimated area of 0.76 million hectares with productivity of 24 tonnes per hectare. Less than 1% of the produce is processed when compared to 26% in other major producing countries. Of the estimated more than 41 million tonnes of tomato processed globally, only 130,000 tonnes were processed in India and domestic demand for processed tomato products is expanding at an estimated 30% annually. At present traditional fresh market tomato cultivars are being processed though such cultivars are unsuitable for processing. Processors in India are looking for high yielding tomato cultivars with high total soluble solids (5-6 º Brix), acidity not less than 0.4%, pH less than 4.5 and uniform red colour with a/b colour value of at least 2. In addition, firm fruited tomato cultivars with joint less pedicel (j2) which facilitate mechanical harvesting or rapid hand picking. ICAR-Indian Institute of Horticultural Research has recently developed two high yielding F1 hybrids in tomato viz: Arka Apeksha and Arka Vishesh suitable for processing. On evaluation for three years, both the hybrids recorded good level of total soluble solids (4.5-5º Brix) and colour value of 2. Further, both the hybrids had high yield potential (80-90 tonnes / hectare) with triple disease resistance to tomato leaf curl disease, bacterial wilt and early blight. Arka Apeksha and Arka Vishesh were also bred with jointless pedicel making them suitable for mechanical harvesting. Our experimental studies on vine storability revealed that all the fruits were intact on plants even 110 days after transplanting in the main field facilitating once over harvest

Detection of Crab Giant Pulses Using the Mileura Widefield Array Low Frequency Demonstrator Field Prototype System

We report on the detection of giant pulses from the Crab Nebula pulsar at a frequency of 200 MHz using the field deployment system designed for the Mileura Widefield Array's Low Frequency Demonstrator (MWA-LFD). Our observations are among the first high-quality detections at such low frequencies. The measured pulse shapes are deconvolved for interstellar pulse broadening, yielding a pulse-broadening time of 670$\pm$100 $\mu$s, and the implied strength of scattering (scattering measure) is the lowest that is estimated towards the Crab nebula from observations made so far. The sensitivity of the system is largely dictated by the sky background, and our simple equipment is capable of detecting pulses that are brighter than $\sim$9 kJy in amplitude. The brightest giant pulse detected in our data has a peak amplitude of $\sim$50 kJy, and the implied brightness temperature is $10^{31.6}$ K. We discuss the giant pulse detection prospects with the full MWA-LFD system. With a sensitivity over two orders of magnitude larger than the prototype equipment, the full system will be capable of detecting such bright giant pulses out to a wide range of Galactic distances; from $\sim$8 to $\sim$30 kpc depending on the frequency. The MWA-LFD will thus be a highly promising instrument for the studies of giant pulses and other fast radio transients at low frequencies.Comment: 10 pages, 6 figures, Accepted for publication in the Astrophysical Journa

INTEROPERABLE MODEL FOR BIORESOURCE DISTRIBUTED DATABASES

Recently, numerous frameworks and tools are being developed for enhancing access to data and services with a standardized view to communicate the advances in open information sharing. Another emerging field of data exploration is encountered in the coordination, examination and perception of bioresource data and are prompting corresponding new innovations. The bioresource information team aims to develop standards for nationwide data exchange by the establishment of a catalog service to locate and access biological data and information from across the country and information tool for decision makers. With the growth of open data sharing initiatives, the sharing of data among different and myriad sources has increased significantly, but major challenge lies in addressing the issues of interoperability during exchange and use since the data sources are heterogeneous and the data being organization specific is prepared with different (organization) specific data standards and platforms. This paper presents the model based on the study of different metadata standards and to develop a recommended standard for biodiversity information to support interoperability among heterogeneous databases under the umbrella of Indian Bioresource Information Network (IBIN) portal. The paper presents the mapping of different data standards into the IBIN standard for sharing species data in the form of distributed and interoperable web services to set the stage for interoperability

Optimization of factors influencing osmotic dehydration of aonla (Phyllanthus emblica L.) segments in salt solution using response surface methodology

Optimization of process parameters is a critical requirement in food processing and food product industries for the development of highly acceptable product. Quantification of mass transfer kinetics under different processing conditions is essential step for optimizing the osmotic dehydration process. A Box-Behnken Design (BBD), adopted from response surface methodology (RSM) approach was used for evaluating and quantifying the moisture loss and solids gain kinetics of aonla segments in salt solution during the osmotic dehydration process. The independent variables were fixed at three levels (salt concentration- 2, 4, 6%; processtemperature - 45, 50, 55 OC and process time - 60, 120, 180 minutes). The process responses were water loss percentage (WL%) and solids gain percentage (SG%). Validation experiments were conducted at optimum conditions to verify predictions and adequacy of the models. The optimum conditions predicted were 5.02% salt concentration, 54.8 OC temperature and 60.64 minutes process time to attain a desired effect of maximum water loss (6.42%) and minimum solid gain (1.09%) in osmotic dehydration of aonla in salt medium