Efficacy of silver and gold nanoparticles obtained from vermiwash: In vitro study on antimicrobial and antidiabetic activities

Emerging nanobiotechnology has provided innovative techniques to synthesize nanoparticles through biological methods to explore the potentialities of biological sources like phytoextracts, microbes, animal secretions and excretion. This research studies the potential of vermiwash to synthesize the silver and gold nanoparticles and evaluate its in vitro effect of antimicrobial   and antidiabetic activities. The characterization of the nanoparticles was analyzed through various techniques. Ultraviolet (UV)-Visible spectroscopy showed the maximum absorption spectrum at 413 nm for silver and 541 nm for gold nanoparticles. Fourier transform infrared spectroscopy (FTIR) revealed the reducing agent involved in nanoparticles synthesis. Scanning electron microscope (SEM) images revealed the size of the silver and gold nanoparticles as 24 nm and 50 nm, respectively. Energy dispersive X-ray (EDAX) analysis revealed the elemental composition of the synthesized nanoparticles. X-ray diffraction (XRD) analysis confirmed the crystalline nature of the nanoparticles that displayed the preferential orientation of the crystals toward the (111) plane.  Antimicrobial activity was assessed using the resazurin assay method.  A minimum inhibitory concentration (MIC) of less than 7.8 µg was observed in Staphylococcus aureus and Klebsiella pneumoniae. In the antifungal activity, MIC at 250 µg was noted in Mucor sp. and Candida albicans. Antidiabetic activity was assessed by α-amylase and α-glucosidase inhibitory assay. IC50 of α-amylase and α-glucosidase activity of the silver nanoparticles was noted as 218 and 221 µg/mL, respectively. IC 50 value for the enzymatic assay dose-dependently confirmed the effect. Conclusively biosynthesized nanoparticles from vermiwash showed potential efficiency of antibacterial, antifungal and antidiabetic activities

Primal-Dual 2-Approximation Algorithm for the Monotonic Multiple Depot Heterogeneous Traveling Salesman Problem

We study a Multiple Depot Heterogeneous Traveling Salesman Problem (MDHTSP) where the cost of the traveling between any two targets depends on the type of the vehicle. The travel costs are assumed to be symmetric, satisfy the triangle inequality, and are monotonic, i.e., the travel costs between any two targets monotonically increases with the index of the vehicles. Exploiting the monotonic structure of the travel costs, we present a 2-approximation algorithm based on the primal-dual method

Seasonal hand line fishery for yellowfin tuna at Colachel

In Tamil Nadu, the oceanic tunas like skipjack and yellowfin tuna are exploited mainly by multiday drift gill netters. However, in Colachel, Kanyakumari, there is a seasonal fishery targeting yellowfin tuna of medium size weighing around 30 kg, with hand lines that are operated from multiday trawlers. This is an additional income for both the fishermen and the trawl boat owners

Early investigation on cryopreservation of Dendrobium sonia-28 using encapsulation-dehydration with modified Evan blue assay

This study was conducted to determine the potential of cryostoring and regenerating Dendrobium sonia-28 protocorm-like bodies (PLBs) using the encapsulation-dehydration technique. The parameters tested for this study included the PLB size range (1 to 2 and 3 to 4 mm), preculture using six different sucrose concentrations (0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 M) and encapsulation using three different sodium alginate concentrations (2.5, 3.0 and 3.5%). Based on initial trials, 1 to 2 mm PLBs that were precultured in 1.0 M sucrose were selected for further studies as they produced the best viability as indicated by the Evans blue (EB) staining method. Subsequently, the PLBs were subjected to a 30 min encapsulation experiment involving the three sodium alginate concentrations. Finally, the chlorophyll content and total soluble protein of cryopreserved, non-cryopreserved and untreated PLBs were determined.Key words: Orchid, protocorm-like bodies, cryopreservation

A pilot study on the isolation and biochemical characterization of Pseudomonas from chemical intensive rice ecosystem

In recent times, there has been a renewed interest in the search of plant growth promoting rhizobacteria (PGPR) for sustainable crop production. Rice is an economically important food crop, which is subjected to infection by a host of fungal, viral and bacterial pathogens. In this study, an attempt was made to isolate Pseudomonas spp., a potent PGPR in the rhizosphere. Through appropriate microbiological and biochemical methods, the study demonstrated the presence of fluorescent and nonfluorescent Pseudomonads in the rhizosphere of chemical intensive rice growing environments. Augmentation of such PGPR including, Pseudomonads in the rice ecosystems will ensure a healthy micro climate for rice.Key words: Pseudomonas, rice, plant growth promoting rhizobacteria (PGPR)

A comparative assessment of the impact of computer assisted learning of knowledge and skill based competencies among undergraduate students in a medical college in South India

Background: Pharmacology has always been one subject ultimatum and a cornerstone in building up competency, based on applied therapeutics among medical graduates in prescribing and practicing skills. A focus on an integrated strategical approach towards teaching pharmacology for better proficiency in achieving clinical skills is mandatory. Thus, this study has been done to assess the impact and retainment of overall knowledge gained on various domains, based on a revised method of teaching in pharmacology.Methods: An observational, questionnaire based comparative study was done in a medical college, in Chennai. The study included two group of students, one who have completed their pharmacology course based on the revised pattern of teaching with a comparative group of students who have not been exposed to the revised pattern of teaching. A feedback survey was also done.Results: The study results indicated that the average scoring based on the questionnaire was 84% with the students who have been exposed to revised pattern of teaching in comparison to the average scoring of 70% with the students who have not been exposed to the new pattern of teaching. The average scoring of the students who were found to agree to several questions on the new method of teaching was 74% and 22% of the students were found to disagree. 4% of students were non responders.Conclusions: The ultimate improvement in the outcome of health care education can be achieved through appropriate skill building through a simple strategical modification of the regular teaching pattern with an integrated approach involving pharmacologists and clinicians. A refresher course in pharmacology in the final year curriculum and CRRI involving pharmacologists is mandatory

The effects of intrinsic noise on the behaviour of bistable cell regulatory systems under quasi-steady state conditions

We analyse the effect of intrinsic fluctuations on the properties of bistable stochastic systems with time scale separation operating under1 quasi-steady state conditions. We first formulate a stochastic generalisation of the quasi-steady state approximation based on the semi-classical approximation of the partial differential equation for the generating function associated with the Chemical Master Equation. Such approximation proceeds by optimising an action functional whose associated set of Euler-Lagrange (Hamilton) equations provide the most likely fluctuation path. We show that, under appropriate conditions granting time scale separation, the Hamiltonian can be re-scaled so that the set of Hamilton equations splits up into slow and fast variables, whereby the quasi-steady state approximation can be applied. We analyse two particular examples of systems whose mean-field limit has been shown to exhibit bi-stability: an enzyme-catalysed system of two mutually-inhibitory proteins and a gene regulatory circuit with self-activation. Our theory establishes that the number of molecules of the conserved species are order parameters whose variation regulates bistable behaviour in the associated systems beyond the predictions of the mean-field theory. This prediction is fully confirmed by direct numerical simulations using the stochastic simulation algorithm. This result allows us to propose strategies whereby, by varying the number of molecules of the three conserved chemical species, cell properties associated to bistable behaviour (phenotype, cell-cycle status, etc.) can be controlled.Comment: 33 pages, 9 figures, accepted for publication in the Journal of Chemical Physic

Tuna drift gillnet fishery at Chennai, Tamil Nadu- an update

The present study describes the status of multiday drift gillnet fishery for tuna from Chennai fishing harbour based on data for the years 2016 – 2017. The data is also compared with that during 1999- 2006. Both the craft and gear increased in size with consequent extension of fishing grounds and increase in the number of days/ fishing trip. The size of the boats increased to 20-23 m OAL from 11-12 m OAL and weight of the gear from 1 to more than 6 t. Annual average catch increased to 8523 t during 2016-2017 from 595 t during 1999-2006. Average catch per unit effort was 8310 kg as against 730 kg during 1999-2006. Yellowfin tuna, Thunnus albacares and Skipjack tuna, Katsuwonus pelamis were the dominant species. The stock position of skipjack tuna and yellowfin tuna vis-àvis the three indicators indicated that the percentage of mature yellowfin tuna in the catch in 2017 was 68%, fish in optimum length 35% and mega-spawners 33% whereas in skipjack tuna the respective percentages were 99.5, 21.1 and 79.1. Problems and prospects of multiday tuna drift gillnet fishery are also discussed

Stronger computational modelling of signalling pathways using both continuous and discrete-state methods

Starting from a biochemical signalling pathway model expresses in a process algebra enriched with quantitative information, we automatically derive both continuous-space and discrete-space representations suitable for numerical evaluation. We compare results obtained using approximate stochastic simulation thereby exposing a flaw in the use of the differentiation procedure producing misleading results