67 research outputs found

    The US/India Civil Nuclear Agreement of 2008: A Two-Level Game?

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    Nuclear power relationships between states have historically determined global power structures in a wider context. Following Indiaā€™s maiden nuclear test in 1974, the international community sidelined the country for a long time. However, within the next three decades, international opinions about the India significantly improved and paved the way forthe countryā€™s first civilian nuclear deal. That said, the circumstances behind this deal and the United States of America (US)ā€™ objectives involved therein merit a review, considering changes in the USā€™ domestic situation and changing political realities around the world. Did the US make an objective foreign policy decision by pivoting its nuclear policy towards India? Or was the US playing a strategic two-level game with both domestic interests as well as its international agenda at stake? This paper seeks to analyze the different layers of interests that were involved in the USā€™ decision-making process resulting in the Agreement. It also aims to apply Robert Putnamā€™s Two-Level Game Theory to understand these interests in a better way

    Chemically Catalyzed Phytoremediation of 2,4,6-Trinitrotoluene (TNT) Contaminated Soil by Vetiver Grass (Chrysopogon zizanioides L.)

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    Urban sprawl in big cities often encroaches on military land, where residual toxic explosive compounds like 2, 4, 6-trinitrotoluene (TNT) in soil could pose a serious health risk. Additionally, in demilitarized areas, lack of sustainable remediation techniques hinder the much needed residential development.. Phytoremediation is an environmentally safe and cost effective solution; however, the characterized low aqueous solubility of nitroaromatic compounds resulting in limited availability of TNT for plant uptake is a major constraint. To overcome this limitation, we propose a new innovative phytoremediation technique using urea, a common nitrogen fertilizer, as a chaotropic agent, to enhance the solubility of TNT in the soil solutions and thus enhancing the TNT uptake by plant. A multi-process approach was used which included (1) sorption studies to understand the retention/release of TNT in soil solutions in the presence and absence of urea, followed by (2) a greenhouse study to fully characterize the urea catalyzed uptake of TNT using vetiver grass from TNT contaminated soils. This study also aimed to investigate the enzyme-mediated plant detoxification activities and changes in the plant-proteomic profile, to provide important clues to the mechanism of stress response and the TNT-tolerance in vetiver grass. Results showed that the extent of TNT sorption and chaotropic effectiveness of urea varies with the soil properties, predominately with the soil organic matter. Urea significantly (p\u3c0.0001) catalyzed TNT extraction from all soils, suggesting that it mobilizes soil-TNT by increasing its solubility at the solid/liquid interface. Vetiver grass showed high uptake (73%) and significant root-to-shoot translocation (38%) of TNT. Urea significantly enhanced (p\u3c0.0001) the vetiver-TNT uptake and translocation. Within the limits of agronomic fertilizer N application rates, 125 mg kg-1 of urea was considered optimum for TNT uptake by vetiver grass (82%). However, increasing the urea rate to 1000 mg kg-1 further increased the TNT removal (91%). Three metabolites of TNT, such as 2-ADNT, 4-ADNT and 1,3,5-TNB were detected in the plant tissues. The enhanced nitroreductase (NR) enzyme activity in TNT treated vetiver grass suggests the role of NR mediated biochemical mechanism in transforming TNT. The optimum kinetic parameters of the NR enzymes were determined. To the best of our knowledge, this study is the first attempt to investigate the proteomic profiling of a plant under TNT stress. Root proteins showed a significant (p\u3c0.0001) negative correlation (r=-0.97) with TNT. Proteomics technique with integrated bioinformatics approach revealed downregulation of growth-related proteins and key functional proteins involved in important cellular mechanisms like transcription, translation, ribosome biogenesis, nucleocytoplasmic transport, and protein glycosylation. Plant defense related proteins were upregulated at lower TNT treatments suggesting vetiverā€™s innate defense mechanism against TNT stress. The highly encouraging results of the current study showed the potential of using chaotropically enhanced phytoremediation of TNT contaminated soils using vetiver grass

    Proteomic profiling of vetiver grass (Chrysopogon zizanioides) under 2,4,6-trinitrotoluene (TNT) stress

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    Vetiver grass is an ideal plant for 2,4,6-trinitrotoluene (TNT) phytoremediation, due to its ability to tolerate and metabolize TNT as previously reported. The current study is the first attempt to investigate the changes in the proteomic profile of a plant under TNT stress. Vetiver plants were grown in nutrient media with varying concentrations of TNT (0, 25, 50, and 100 mg Lāˆ’1) for 10 days. Although the plants appeared healthy, significant biomass reductions (p = 0.0008) were observed in treated plants. Total proteins in the root decreased significantly (p = 0.0003). Proteomic analysis of root proteins revealed the downregulation of functional proteins involved in key cellular mechanisms such as transcription, ribosome biogenesis, nucleo-cytoplasmic transport of proteins, protein glycosylation, and translation. Growth-related proteins were downregulated; plant defense proteins were upregulated at lower TNT concentrations but downregulated at higher concentrations. Comprehensive understanding of changes in the proteomic profile provides important clues to the mechanism of TNT stress response and tolerance in vetiver

    Role of Doppler indices of umbilical and middle cerebral artery in prediction of perinatal outcome in preeclampsia

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    Background: Hypertension which develops de novo in pregnancy appears to be unique to human and continue to be a major cause of reported perinatal mortality. The aim and objectives of the study was to evaluate the diagnostic value of Umbilical and Middle cerebral artery Doppler in predicting the perinatal outcome in preeclampsia.Methods: A prospective study at Sri Siddhartha Medical College and Hospital between October2013-September2015 on 80pregnant women with preeclampsia at >30weeks gestation. Studies of fetal vessels were performed using a pulsed Doppler ultrasound. Resistance Index (RI), Pulsatility Index (PI) and systolic/diastolic ratio (S/D) were measured in umbilical artery (UA) and Middle cerebral artery (MCA) and perinatal outcomes were monitored and statistically analyzed.Results: Out of 80 cases studied, 25 cases showed adverse perinatal outcome, among which 6 cases with perinatal death, 13 cases had low APGAR at 5minutes. 6 cases had NICU admission.Conclusions: Color Doppler has an important role in antepartum fetal surveillance in preeclampsia which can detect fetal compromise at an early stage. In our study pulsatility index of umbilical artery and ratio of MCA/UA PI was more sensitive than other parameters with PPV 78%

    Evidence for Exocellular Arsenic in Fronds of Pteris vittata

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    The arsenic (As) hyperaccumulating fern species Pteris vittata (PV) is capable of accumulating large quantities of As in its aboveground tissues. Transformation to AsIII and vacuolar sequestration is believed to be the As detoxification mechanism in PV. Here we present evidence for a preponderance of exocellular As in fronds of Pteris vittata despite numerous reports of a tolerance mechanism involving intracellular compartmentalization. Results of an extraction experiment show that 43ā€“71% of the As extruded out of the fronds of PV grown in 0.67, 3.3 and 6.7mM AsV. SEM-EDX analysis showed that As was localized largely on the lower pinna surface, with smaller amounts on the upper surface, as crystalline deposits. X-ray fluorescence imaging of pinna cross-sections revealed preferential localization of As on the pinna surface in the proximity of veins, with the majority localized near the midrib. Majority of the As in the pinnae is contained in the apoplast rather than vacuoles. Our results provide evidence that exocellular sequestration is potentially a mechanism of As detoxification in PV, particularly at higher As concentrations, raising concern about its use for phytoremediation

    Root attributes governing drought stress adaptation and the associated molecular markers in chromosome segment substitution lines in rice (Oryza sativa L.)

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    The wild relatives of cultivated rice offer crucial resistance genes for combating stresses like drought. Developing rice varieties with drought tolerance is possible through chromosome segment substitution lines (CSSLs), which blend the genetic background of a high-yielding parent with specific chromosome segments from a donor parent. This study aimed to study the effect of drought stress on various root traits of chromosome segment substitution lines (CSSLs) and their relationship with specific molecular markers. Ninety-six genotypes, including 80 chromosome segment substitution lines (Curinga x O. rufipogon and Curinga x O. meridionalis), 9 New Rice for Africa (NERICAs) and 7 controls were grown in Basket and PVC pipe methods for phenotyping different root traits. Under drought stress (DS), MER16, MER20, RUF10, RUF16, RUF44, NERICA1, and NERICA3 showed superior performance for most of the root traits. These evaluations were supplemented with association analysis of 17 root trait-linked simple sequence repeat (SSR) markers with root phenotypic traits. The marker RM201 is strongly associated with multiple root traits, found to be independent of three growth conditions (well-watered ā€œWWā€ under Basket, WW condition and DS conditions under PVC pipe). The marker RM316 is associated with root volume, and the marker RM7424 and RM1054 show maximum root length. In conclusion, these markers can be used in marker-assisted breeding programs, and the lines carrying them can be used as parental lines in variety-development programs for drought tolerance

    Phytoremediation of Explosive-Contaminated Soils

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    In order to select appropriate plant species for phytoremediation of explosive compounds, phytotoxicity, uptake proficiency, capability of the plant to degrade/transform the compounds, and several environmental factors need to be considered. The environmental factors comprise climatic attributes, soil type, the water environment, root penetration depth, contaminant kinetics, and bioavailability. Out of the plant species that have shown efficient TNT uptake, there are only a few that can do so in a variety of environments, which is imperative in case of contaminants that are widespread, such as TNT and RDX. The two most effective species for TNT uptake reported to date are Eurasian water milfoil, Myriophyllum spicatum and vetiver grass, Chrysopogon zizanioides. For RDX phytoremediation, reed canary grass, fox sedge, and rice have shown promise, although degradation of RDX in the plant tissue is limited. Over the past few decades, a considerable amount of information on phytotoxicity and metabolism of TNT and RDX in plants and microorganisms have been collected, which has led to the identification of potential plant species for use in TNT and RDX phytoremediation, as well as candidate genes for developing effective transgenic plants. Recent research has also revealed promising non-transgenic approaches, such as use of chaotropic agents for enhanced solubilization and uptake of TNT, which could prove to be practical and effective for military sites. Field trials of some of these promising new technologies are necessary for the development of effective, low-cost, and environmentally friendly phytoremediation of explosive-contaminated sites

    Vetiver grass is capable of removing TNT from soil in the presence of urea

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    The high affinity of vetiver grass for 2,4,6 trinitrotoluene (TNT) and the catalytic effectiveness of urea in enhancing plant uptake of TNT in hydroponic media we earlier demonstrated were further illustrated in this soil-pot-experiment. Complete removal of TNT in urea-treated soil was accomplished by vetiver at the low initial soil-TNT concentration (40 mg kg-1), masking the effect of urea. Doubling the initial TNT concentration (80 mg kg-1) significantly (p \u3c 0.002) increased TNT removal by vetiver, in the presence of urea. Without vetiver grass, no significant (p = 0.475) change in the soil-TNT concentrations was observed over a period of 48 days, suggesting that natural attenuation of soil TNT could not explain the documented TNT disappearance from soil
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