67 research outputs found
ANTIMICROBIAL AND ANTIOXIDANT ACTIVITIES OF TWO ENDOPHYTIC FUNGI ISOLATED FROM MELASTOMA MALABATHRICUM L. LEAVES
Objective: The objectives of this study were to isolate endophytic fungi from Melastoma malabathricum L. leaves and to study their antimicrobial and antioxidant potentials.
Methods: Disc diffusion method and Agar well diffusion method was carried out for studying the antibacterial and antifungal range of the isolated endophytes MMF5 and MMF9. DPPH (2, 2-diphenyl-2-picrilhydrazyl) reduction assay was followed for the study of antioxidant activities of the isolated. CFU counting method was followed for determining the MICs of the isolates against two selected bacteria and to know the mode of action.
Results: Two endophytic fungi have been isolated which were identified as species of Penicillium by studying their morphology under a compound light microscope. Both were found to show great antibacterial activities against Gram-negative as well as Gram-positive bacteria. The Minimum Inhibitory Concentration (MIC) value of the ethyl acetate extracts of MMF5 and MMF9 were found to be 150µg/ml and 100µg/ml respectively for Staphylococcus aureus and Escherichia coli with the bacteriostatic mode of action. They also exhibited good antifungal activities against an animal as well as plant pathogenic fungi. IC50 value of MMF5 and MMF9 in an antioxidant assay using stable DPPH radical was found to be 52.38μg/ml and 24.44μg/ml respectively in comparison to the control ascorbic acid having the value 8.5μg/ml.
Conclusion: From this study, it can be said that due to having good antimicrobial and antioxidant activities, the strains can be used as a prospective source in the medicinal industry for the drug development
BIOLOGICAL ACTIVITIES OF ALTERNARIA SP. RL4 – A POTENT ENDOPHYTIC FUNGUS ASSOCIATED WITH RAUVOLFIA SERPENTINA L. BENTH.
Objectives: Endophytic fungi are considered as an important source of bioactive metabolites. The present study focused on the isolation of potent endophytic fungal strains from well-known medicinal plant Rauvolfia serpentina L. Benth. having biological activities.Materials & Methods: Fungal endophytes were isolated from aerial parts of the plant and the potent strain was selected on the basis of antibacterial activities of cell-free supernatant (CFS). Ethyl acetate (EA) extraction of CFS was done and mode of action of EA fraction was checked against pathogenic bacteria. EA fraction was also analyzed by thin-layer chromatography (TLC). In addition, antioxidant activity was checked by 1,1-Diphenyl- 2-picrylhydrazyl-free radical scavenging assay and anticancer activity was checked against breast cancer cell line MCF-7 by MTT assay.Results: Among the different endophytic fungal isolates, CFS of Alternaria sp. RL4 produced prominent zones of inhibition against numbers of Gram-positive pathogenic bacteria including Staphylococcus aureus (12±0.5 mm) and Listeria monocytogenes (17±2.0 mm). Massive reductions in bacterial CFS were noticed upon treatment with EA fraction (2 mg/ml). It also showed strong cidal mode of action against Gram-positive organisms. TLC analysis revealed the production of two different compounds with antibacterial potentials. In addition, EA fraction of RL4 showed very good antioxidant property with an IC50 value of 49.80±2.11μg/ml. MTT assay also suggested the anticancerous properties of EA fraction of RL4.Conclusion: Alternaria sp. RL4 could be a very good source of bioactive compounds for the development of new drugs
Enhancing livelihoods in farming communities through super-resolution agromet advisories using advanced digital agriculture technologies
Agricultural production in India is highly vulnerable to climate change. Transformational change to farming systems is required to cope with this
changing climate to maintain food security, and ensure farming to remain economically viable. The south Asian rice-fallow systems occupying
22.3 million ha with about 88% in India, mostly (82%) concentrated in the eastern states, are under threat. These systems currently provide
economic and food security for about 11 million people, but only achieve 50% of their yield potential. Improvement in productivity is possible
through efficient utilization of these fallow lands. The relatively low production occurs because of sub-optimal water and nutrient management
strategies. Historically, the Agro-met advisory service has assisted farmers and disseminated information at a district-level for all the states. In
some instances, Agro-met delivers advice at the block level also, but in general, farmers use to follow the district level advice and develop an
appropriate management plan like land preparation, sowing, irrigation timing, harvesting etc. The advisories are generated through the District
Agrometeorology Unit (DAMU) and Krishi Vigyan Kendra (KVK) network, that consider medium-range weather forecast. Unfortunately, these
forecasts advisories are general and broad in nature for a given district and do not scale down to the individual field or farm. Farmers must make
complex crop management decisions with limited or generalised information. The lack of fine scale information creates uncertainty for farmers,
who then develop risk-averse management strategies that reduce productivity. It is unrealistic to expect the Agro-met advisory service to
deliver bespoke information to every farmer and to every field simply with the help of Kilometre-scale weather forecast. New technologies must
be embraced to address the emerging crises in food security and economic prosperity. Despite these problems, Agro-met has been successful.
New digital technologies have emerged though, and these digital technologies should become part of the Agro-met arsenal to deliver valuable
information directly to the farmers at the field scale. The Agro-met service is poised to embrace and deliver new interventions through technology
cross-sections such as satellite remote sensing, drone-based survey, mobile based data collection systems, IoT based sensors, using insights
derived from a hybridisation of crop and AIML (Artificial Intelligence and Machine Learning) models. These technological advancements will
generate fine-scale static and dynamic Agro-met information on cultivated lands, that can be delivered through Application Programming Interface
(APIs) and farmers facing applications. We believe investment in this technology, that delivers information directly to the farmers, can
reverse the yield gap, and address the negative impacts of a changing climate
Mesonic Chiral Rings in Calabi-Yau Cones from Field Theory
We study the half-BPS mesonic chiral ring of the N=1 superconformal quiver
theories arising from N D3-branes stacked at Y^pq and L^abc Calabi-Yau conical
singularities. We map each gauge invariant operator represented on the quiver
as an irreducible loop adjoint at some node, to an invariant monomial, modulo
relations, in the gauged linear sigma model describing the corresponding bulk
geometry. This map enables us to write a partition function at finite N over
mesonic half-BPS states. It agrees with the bulk gravity interpretation of
chiral ring states as cohomologically trivial giant gravitons. The quiver
theories for L^aba, which have singular base geometries, contain extra
operators not counted by the naive bulk partition function. These extra
operators have a natural interpretation in terms of twisted states localized at
the orbifold-like singularities in the bulk.Comment: Latex, 25pgs, 12 figs, v2: minor clarification
Negative discriminant states in N=4 supersymmetric string theories
Single centered BPS black hole solutions exist only when the charge carried
by the black hole has positive discriminant. On the other hand the exact dyon
spectrum in heterotic string theory compactified on T^6 is known to contain
states with negative discriminant. We show that all of these negative
discriminant states can be accounted for as two centered black holes. Thus
after the contribution to the index from the two centered black holes is
subtracted from the total microscopic index, the index for states with negative
discriminant vanishes even for finite values of charges, in agreement with the
results from the black hole side. Bound state metamorphosis -- which requires
us to identify certain apparently different two centered configurations
according to a specific set of rules -- plays a crucial role in this analysis.
We also generalize these results to a class of CHL string theories.Comment: LaTeX file, 32 pages; v2: reference added; v3: added new section 3.
What is the Role of Community Capabilities for Maternal Health? An Exploration of Community Capabilities as Determinants to Institutional Deliveries in Bangladesh, India, and Uganda
Background:
While community capabilities are recognized as important factors in developing resilient health systems and communities, appropriate metrics for these have not yet been developed. Furthermore, the role of community capabilities on access to maternal health services has been underexplored. In this paper, we summarize the development of a community capability score based on the Future Health System (FHS) project’s experience in Bangladesh, India, and Uganda, and, examine the role of community capabilities as determinants of institutional delivery in these three contexts.
Methods:
We developed a community capability score using a pooled dataset containing cross-sectional household survey data from Bangladesh, India, and Uganda. Our main outcome of interest was whether the woman delivered in an institution. Our predictor variables included the community capability score, as well as a series of previously identified determinants of maternal health. We calculate both population-averaged effects (using GEE logistic regression), as well as sub-national level effects (using a mixed effects model).
Results:
Our final sample for analysis included 2775 women, of which 1238 were from Bangladesh, 1199 from India, and 338 from Uganda. We found that individual-level determinants of institutional deliveries, such as maternal education, parity, and ante-natal care access were significant in our analysis and had a strong impact on a woman’s odds of delivering in an institution. We also found that, in addition to individual-level determinants, greater community capability was significantly associated with higher odds of institutional delivery. For every additional capability, the odds of institutional delivery would increase by up to almost 6 %.
Conclusion:
Individual-level characteristics are strong determinants of whether a woman delivered in an institution. However, we found that community capability also plays an important role, and should be taken into account when designing programs and interventions to support institutional deliveries. Consideration of individual factors and the capabilities of the communities in which people live would contribute to the vision of supporting people-centered approaches to health
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