PI-controlled bioreactor as a generalized Lienard system

It is shown that periodic orbits can occur in Cholette's bioreactor model working under the influence of a PI-controller. We find a diffeomorphic coordinate transformation that turns this controlled enzymatic reaction system into a generalized Lienard form. Furthermore, we give sufficient conditions for the existence and uniqueness of limit cycles in the new coordinates. We also perform numerical simulations illustrating the possibility of the existence of a local center (period annulus). A result with possible practical applications is that the oscillation frequency is a function of the integral control gain parameterComment: 15 pages, 5 figures, accepted version at Computers & Chem. En

Coded Caching based on Combinatorial Designs

We consider the standard broadcast setup with a single server broadcasting information to a number of clients, each of which contains local storage (called \textit{cache}) of some size, which can store some parts of the available files at the server. The centralized coded caching framework, consists of a caching phase and a delivery phase, both of which are carefully designed in order to use the cache and the channel together optimally. In prior literature, various combinatorial structures have been used to construct coded caching schemes. In this work, we propose a binary matrix model to construct the coded caching scheme. The ones in such a \textit{caching matrix} indicate uncached subfiles at the users. Identity submatrices of the caching matrix represent transmissions in the delivery phase. Using this model, we then propose several novel constructions for coded caching based on the various types of combinatorial designs. While most of the schemes constructed in this work (based on existing designs) have a high cache requirement (uncached fraction being $\Theta(\frac{1}{\sqrt{K}})$ or $\Theta(\frac{1}{K})$, $K$ being the number of users), they provide a rate that is either constant or decreasing ($O(\frac{1}{K})$) with increasing $K$, and moreover require competitively small levels of subpacketization (being $O(K^i), 1\leq i\leq 3$), which is an extremely important parameter in practical applications of coded caching. We mark this work as another attempt to exploit the well-developed theory of combinatorial designs for the problem of constructing caching schemes, utilizing the binary caching model we develop.Comment: 10 pages, Appeared in Proceedings of IEEE ISIT 201

Palatability of tissues in Holothuria leucospilota (Brandt) from central west coast of India

The palatability of various organs (body wall, cuvierian gland, viscera, longitudinal muscle bands and gonads) of sea cucumber Holothuria leucospilota (Brandt) was studied by feeding experiments, performed on a freshwater fish Sarotherodon mossambicus and a marine fish Therapon jarbua. The result shows that the food pellets of the body wall were less toxic and more palatable than the gonads, viscera and cuvierian gland (p<0.001)

Formulation of Mefenamic acid loaded polymeric nanoparticles by ionotropic gelation technique for the treatment of rheumatoid arthritis

Aim:- Non steroidal anti inflammatory drugs are generally used as first line drugs for Rheumatoid arthritis. Mefenamic acid is an anthranilic acid derivative. The short biological half life of Mefenamic acid is 2hr. The aim of this investigation was to develop and characterize polymeric nanoparticles of Mefenamic acid by ionotropic gelation technique. Materials and methods: For ionic gelation technique, Chitosan was used as polymer and sodium tripolyphosphate as cross linking agent. All formulations were prepared by varying the drug and polymer concentrations. The obtained nanoparticles were characterized for surface morphology, FTIR, particle size and zeta potential and evaluated for yield, drug content, entrapment efficiency, loading capacity and Invitro drug release. Results and discussion : The mean particle size and zeta potential of the best formulation of Mefenamic acid nanoparticles for ionic gelation technique was found to be 196nm and -34 mV respectively. The drug release was found to be 96.3% till 11hrs with fickian diffusion. Conclusions : Inotropic gelation technique was found to be the best technique for the formulation of Mefenamic acid nanoparticles as they have less particle size, greater stability and controlled drug release for 12hrs

A comparative study of two layer versus three-layer repair of mediolateral episiotomy

Background: Since majority of the women attending study hospital are belonging to lower socioeconomic strata and active involvement of paramedical staff in providing obstetric care, this study was undertaken to find the utility of a two-layer repair of mediolateral episiotomy and compare it with the standard method of closure in relation to its simplicity, cost-effectiveness and superiority if any, over the traditional three-layered repair of episiotomy.Methods: This was a prospective interventional study comparing 100 women who underwent two-layer closure with 100 women who underwent three-layer closure of episiotomy in a tertiary care hospital in Pune, India over a period of 2 years from October 2012 to October 2014. The parameters assessed were operative time, number of suture materials required, immediate post procedure pain and complications at follow-up. Qualitative and quantitative data was analysed using unpaired t-test, chi square test and Fisher exact test.Results: Both the groups were comparable in terms of hospital stay and wound complications such as oedema, dehiscence, hematoma, requirement of resuturing, cosmesis and long-term complications such as dyspareunia. However, two-layer repair required less operative time, lesser number of suture materials and decreased pain during hospital stay as there was statistically significant difference observed between the two groups.Conclusions: In this study experience, it can be concluded that two-layer repair of episiotomy is faster, with less post-operative pain and more cost effective. Hence it provides mother with better services