Selection of solvent and extraction method for determination of antimicrobial potential of Taxus wallichiana Zucc.

Antimicrobial potential of different plant parts (needle, stem and bark) of Himalayan yew (Taxus wallichiana Zucc.) has been investigated with particular reference to selection of solvents and extraction methods. Two extraction methods (maceration and soxhlet), seven solvents (methanol, ethanol, acetone, chloroform, ethyl  acetate, di chloro methane and Petroleum ether), and 3 groups of microorganisms (bacteria, actinobacteria and fungi) were considered for detection of antimicrobial activity. While qualitative estimations were done using agar well diffusion method, quantitative analysis was based on dilution method. All the plant part showed significant activity against all 3 groups of microorganisms in qualitative bioassays; maximum being in case of needles. Among solvents, ethanolic extract of needles (maceration) showed highest antibacterial activity (15.33 ± 0.25 mm). Growth of actinobacteria was inhibited maximum (22.0±0.26 mm) by the methanolic extracts of needles (maceration). Ethyl acetate extract of needles (soxhlet) showed higher antifungal activity (7.84±0.21 mm). Antibacterial and antifungal activities were higher in maceration and soxhlet methods, respectively. The most affected group among the test microorganisms was bacteria which may be due to their prokaryotic organization. This was also supported by the low minimum inhibitory concentration (MIC) values. Di chloro methane and petroleum ether did not show any antifungal activity. The antimicrobial activity of various plant parts of T. wallichiana varied with respect to the solvent as well as the extraction method. The study will have implications in selection of the use of solvent and the extraction procedure in obtaining the antimicrobial metabolites from various plant parts of T. wallichiana

STUDY AND DESIGN OF PORTABLE ANTIMICROBIAL WATER FILTER

  Objective: This study was conducted to design a portable antimicrobial water filter which is both economic and easy to use.Methods: A prototype following the designing of the water filter was constructed. Layers of sand, cloth, activated charcoal, and cotton containing compartments were built for carrying out water analysis.Results: Most probable number index of Vellore Institute of Technology lake water was compared with that of filtered water. Complete water analysis was done, and the sand filter layer was observed to be responsible for a maximum of the antimicrobial action of the filter.Conclusion: The study demonstrated that the proposed design of water filter is efficient in removal of turbidity, odor, and microbial content of lake water along with decreasing the acidity of water

PRODUCTION OF INDUSTRIALLY IMPORTANT ENZYMES BY THERMOBACILLI ISOLATED FROM HOT SPRINGS OF INDIA

Enzymes from thermophilic bacteria have received great attention for their potential applications in various industrial sectors. The present study deals with the production of five thermozymes (amylase, lipase, xylanase, protease and cellulase) from 10 thermophilic bacterial species, originally isolated from two hot springs namely Soldhar and Ringigad in Uttarakhand Himalaya, India. The bacterial isolate GBPI_25 produced maximum amylase (1217.86 U/ml) at 45 °C and 5 pH, GBPI 3 produced maximum lipase (22.59 U/ml) at 65 °C and 9 pH, GBPI_25 produced maximum xylanase (98.07 U/ml) at45 °C and 9 pH, GBPI_35 produced maximum protease (16.66 U/ml) at 55 °C and 9 pH, and GBPI 4 produced maximum cellulose (108.68 U/ml) at 45 °C and 5 pH. Crude enzyme preparations showed thermal and pH activities at broad temperature and pH range between 10-100 °C and 3-11 pH, respectively, with different temperature and pH optima. Amylase, xylanase and cellulase showed maximum activity at 50 °C while lipase and protease showed higher activity at 40 and 60 °C, respectively. Enzyme activity at wide temperature range-cellulase and protease from 10-100 °C, amylase and xylanasefrom10-90 °C, and lipase activity from 10-80 °C were the remarkable records from this study. Similarly, pH range for amylase and lipase activity was recorded from 4-11, for xylanase from 3-9, and for protease and cellulase from 3-10. All the thermozymes showed maximum stability at 40 °C and pH 5 except cellulase that showed higher stability at40 °C and neutral pH

Loss and Damage from Climate Change: Building Knowledge and Capacity in the Most Vulnerable Countries

Mitigation and adaptation are at the center of global climate negotiations. However, as climate change impacts become more frequent and more severe, these two well-accepted pillars of climate policy are not sufficient. Burgeoning damage and loss from climate change is inevitable, and it has become urgent to expedite international policy work on Loss and Damage (L&D) response. L&D has been identified as a policy action area within the United Nations Framework Convention on Climate Change (UNFCCC) system; however, progress has been extremely slow. By undertaking a review of the current situation, including country-level examples from Bangladesh, Nepal, and Vanuatu, we consider the immediate needs of the most vulnerable countries and suggest high-priority actions to move forward. These actions include: 1. Clarifying conceptual dilemmas around loss and damage vis-à-vis adaptation, mitigation, and disaster risk reduction, demonstrating how L&D policy concepts can be implemented. 2. Assisting developing and vulnerable countries in undertaking diagnostic assessments with respect to loss and damage and identifying policy and institutional options to advance L&D at national and sub-national levels. 3. Facilitating knowledge-sharing among developing and most vulnerable countries with regard to policy, risk governance, response to Loss and Damage, and ensuring socially inclusive responses. 4. Helping create learning opportunities for key policy and research champions in vulnerable countries. 5. Helping develop a dedicated L&D financing system at national and sub-national levels. 6. Providing technical assistance to Least Developed Countries (LDCs) and the Alliance of Small Island States (AOSIS) to formulate a coherent approach to L&D negotiation within the UNFCCC system as well as enhanced representation of Loss and Damage situations for the Global Stocktake 2023 international conventions. 7. Building the Research and Development (R&D) capacity of national research and training groups in most vulnerable countries vis-à-vis comprehensive risk management, including how national institutions can deliver with respect to multiple outcomes including the Sustainable Development Goals (SDGs), Disaster Risk Reduction (DRR), adaptation at large and L&D. 8. Developing and strengthening national database systems to facilitate loss and damage accounting and financial delivery

Decrypting the multi-functional biological activators and inducers of defense responses against biotic stresses in plants

Plant diseases are still the main problem for the reduction in crop yield and a threat to global food security. Additionally, excessive usage of chemical inputs such as pesticides and fungicides to control plant diseases have created another serious problem for human and environmental health. In view of this, the application of plant growth-promoting rhizobacteria (PGPR) for controlling plant disease incidences has been identified as an eco-friendly approach for coping with the food security issue. In this review, we have identified different ways by which PGPRs are capable of reducing phytopathogenic infestations and enhancing crop yield. PGPR suppresses plant diseases, both directly and indirectly, mediated by microbial metabolites and signaling components. Microbial synthesized anti-pathogenic metabolites such as siderophores, antibiotics, lytic enzymes, hydrogen cyanide, and several others act directly on phytopathogens. The indirect mechanisms of reducing plant disease infestation are caused by the stimulation of plant immune responses known as initiation of systemic resistance (ISR) which is mediated by triggering plant immune responses elicited through pathogen-associated molecular patterns (PAMPs). The ISR triggered in the infected region of the plant leads to the development of systemic acquired resistance (SAR) throughout the plant making the plant resistant to a wide range of pathogens. A number of PGPRs including Pseudomonas and Bacillus genera have proven their ability to stimulate ISR. However, there are still some challenges in the large-scale application and acceptance of PGPR for pest and disease management. Further, we discuss the newly formulated PGPR inoculants possessing both plant growth-promoting activities and plant disease suppression ability for a holistic approach to sustaining plant health and enhancing crop productivity

Impact of COVID-19 on tourism in Nepal

N/

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level