Treating microbial systems engineering as an inverse function problem to enhance production of biomolecules

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Lattice Induced Transparency in Metasurfaces

Lattice modes are intrinsic to the periodic structures and their occurrence can be easily tuned and controlled by changing the lattice constant of the structural array. Previous studies have revealed excitation of sharp absorption resonances due to lattice mode coupling with the plasmonic resonances. Here, we report the first experimental observation of a lattice induced transparency (LIT) by coupling the first order lattice mode (FOLM) to the structural resonance of a metamaterial resonator at terahertz frequencies. The observed sharp transparency is a result of the destructive interference between the bright mode and the FOLM mediated dark mode. As the FOLM is swept across the metamaterial resonance, the transparency band undergoes large change in its bandwidth and resonance position. Besides controlling the transparency behaviour, LIT also shows a huge enhancement in the Q-factor and record high group delay of 28 ps, which could be pivotal in ultrasensitive sensing and slow light device applications.Comment: 5 figure

CORRELATION OF CONCEPT OF AMA AND FREE RADICAL THEORY

Majority of the endogenous disease begins with the formation of Ama in the body. It has tremendous capacity to vitiate the Doshas and disturbing the homeostasis (Dhatu-samya). Ama is the resultant of improper digestion or partially digestion of the food particle due to hypofunction of Jatharagni and also due to accumulation of mala in the body and also considered as Prathamdoshadusti. It may be considered as partially or incompletely metabolized Dhatu in case of Dhatvagnimandya. In modern parameters, Ama is supposed to be deadly Free radical. Free radical is an atom/molecule that contains one or more unpaired electron, which requires neutralization by free radical scavengers. Ama is not a single entity but is a generalized term, which can be applied to many malformed substances in the body. This Ama is responsible for the production of various diseases. In the same way, free radicals are also found to be the root cause of many diseases. Here we discuss about properties and qualities in both entities, which are similar and dissimilar, also whether free radicals can be considered under Ama. The present article attempts to correlate the most recent concept of todays i. e. free radical concept with that of the concept of Ama, described in research for remedies from Ayurvedic research, which may be helpful in the presentation and care of free radicals mediated disease

ROLE OF PERSONAL ATTRIBUTES AND SYSTEM CHARACTERISTICS IN PREDICTING THE EFFECTIVENESS OF ONLINE LEARNING- AN INDIAN PERSPECTIVE

Online learning has become a trend in education over the years with the emergence of Web 2.0 and the advancement in Information and Communication Technologies (ICT). As the organisational spending has risen for providing better learning and training, the expectations for outcomes also have increased. Learning effectiveness can be thought of as one of the parameters to assess the success of online learning. A survey was conducted with 377 higher education students from India who have already taken an online learning course. The study used Structural Equation Modelling (SEM) to understand the impact of personal factors (internet self-efficacy), system characteristics (information quality, system quality, service quality), and engagement (behavioural, emotional, cognitive engagement) on learning effectiveness in online learning through an integration of Social Cognitive Theory (SCT), and DeLone and McLean’s IS success model. The result shows that internet self-efficacy has a positive impact on all types of engagement whereas, system and service quality have a positive impact on emotional and cognitive engagement, and information quality has an impact on only behavioural engagement. Furthermore, all types of engagement have a positive impact on perceived learning effectiveness. Theoretical contributions and practical implications are discussed

Automated Software Testing Using Metahurestic Technique Based on An Ant Colony Optimization

Software testing is an important and valuable part of the software development life cycle. Due to time, cost and other circumstances, exhaustive testing is not feasible that's why there is a need to automate the software testing process. Testing effectiveness can be achieved by the State Transition Testing (STT) which is commonly used in real time, embedded and web-based type of software systems. Aim of the current paper is to present an algorithm by applying an ant colony optimization technique, for generation of optimal and minimal test sequences for behavior specification of software. Present paper approach generates test sequence in order to obtain the complete software coverage. This paper also discusses the comparison between two metaheuristic techniques (Genetic Algorithm and Ant Colony optimization) for transition based testingComment: Electronic System Design (ISED), 2010 International Symposium on Issue Date: 20-22 Dec. 2010 On page(s): 235 - 240 Location: Bhubaneswar Print ISBN: 978-1-4244-8979-4 INSPEC Accession Number: 11835766 Digital Object Identifier: 10.1109/ISED.2010.5

Controlling the size distribution of nanoparticles through the use of physical boundaries during laser ablation in liquids

A simple, yet effective method of controlling the size and size distributions of nanoparticles produced as a result of laser ablation of target material is presented. The method employs the presence of physical boundaries on either sides of the ablation site. In order to demonstrate the potential of the method, experiments have been conducted with copper and titanium as the target materials that are placed in two different liquid media (water and isopropyl alcohol). The ablation of the target material immersed in the liquid medium has been carried out using an Nd:YAG laser. Significant differences in the size and size distributions are observed in the cases of nanoparticles produced with and without confining boundaries. It is seen that for any given liquid medium and the target material, the mean size of the nanoparticles obtained with the boundary-fitted target surface is consistently higher than that achieved in the case of open (flat) targets. The observed trend has been attributed to the plausible role(s) of the confining boundaries in prolonging the thermalisation time of the plasma plume. In order to ascertain that the observed differences in sizes of the nanoparticles produced with and without the presence of the physical barriers are predominantly because of the prolonged thermalisation of the plasma plume and not due to the possible formation of oxide layer, select experiments with gold as the target material in water have also been performed. The experiments also show that, irrespective of the liquid medium, the increase in the mean size of the copper-based nanoparticles due to the presence of physical boundaries is relatively higher than that observed in the case of titanium target material under similar experimental conditions.Comment: 24 pages, 9 figures, a part of this work has been published in Photonics Prague 2017, (Proc. SPIE 10603, Photonics, Devices, and Systems VII, 1060304) titled "A novel method for fabrication of size-controlled metallic nanoparticles

Cellular responses to culture substrates with programmable anisotropy

Physiologically relevant culture substrates are needed to accurately model cell and tissue function in vitro to characterize function in both healthy and altered (diseased) states. In addition to their use as model systems, exerting control over cellular function in a biochemical engineering process through cell-substrate interactions may reveal new ways to increase yield or efficiency. While knowledge of cellular responses to elastic substrates has advanced greatly, it was only recently recognized that cellular interactions with viscous components of networks alters mammalian cell spreading, migration, proliferation, and differentiation. Matrix studies have shown varying results in response to stress relaxation timescales however, indicating that multiple factors contribute to the cell\u27s interpretation of its mechanical microenvironment. We hypothesize that there is an additional, critical design parameter that has not been considered: the length scales over which cells sense mechanical properties. This work seeks to investigate these questions using a new type of culture substrate based on cytocompatible liquid crystalline (LC) polymers. This work focuses on the design, synthesis, and characterization of new biomaterial substrates whose viscoelastic properties can be manipulated by controlling the liquid crystalline (LC) ordering within the material. These materials also have the ability to morph in shape in response to an external stimulus (e.g. light), which may be applied during in vitro culture to result in dynamic culture substrates. A unique feature is that order can be programmed from the molecular scale to the macroscale, which permits study of how cells interact with the substrates across different length scales. To enable these studies, liquid crystallinity must be maintained in a hydrated network, which is inherently challenging because swelling of polymers tends to increase the distance between LC molecules to weaken their ordering. This work prepares new LC networks using Click chemistry, which was selected for its efficiency under mild reaction conditions that can be used to incorporate more sensitive biological molecules. This work seeks to combine the dynamic properties of these LC materials with their low cytotoxicity, stability in a hydrated phase, and ability to be processed into scaffolds and gels for use as hydrated and responsive culture substrates. The goals are to first characterize the impact of composition on liquid crystalline ordering and culture substrate properties before quantifying the impacts of substrate anisotropy and mechanics, programmed at different length scales, on mesenchymal stem cell differentiation. To prepare the materials, alkyne-terminated liquid crystalline monomers (mesogens) and azide-terminated polyether chain extenders (PEO poly(ethylene oxide); PPO poly(propylene oxide)) were synthesized and purified by modifying established reactions. Chain extender molecular weight and composition were varied to afford control over water uptake and LC organization. For one-step LC network synthesis, chemically crosslinked networks were synthesized by polymerizing the mesogens and chain extenders with a tetraazide crosslinker. To enable cell encapsulation, a two-step network synthesis was used, where azide-terminated LC prepolymers were crosslinked in water using multifunctional strained alkyne. Scaffolds were also prepared to enable 3D studies by polymerizing the reactive mixture in the presence of sodium chloride (sieved to 500-600 μm) and extracting the salt once the reaction was complete. All LC networks were found to organize into the smectic phase. By varying the composition and molecular weight of the chain extender, the material’s elastic modulus and stability of the LC phase was tailored. The networks were found to display reversible shape changing, where the films extended in the LC phase and contracted in the isotropic phase. Composition was found to impact the ability of the network to change shape and the amount of strain generated. Additionally, stress relaxation experiments conducted in the hydrated state showed that networks that were isotropic were found to respond elastically, but LC networks displayed more viscous responses. Mesenchymal stem cells incubated with extractable materials displayed no differences in cellular toxicity compared to tissue culture controls. Cells were found to attach and proliferate on the hydrated LC networks, but attachment was found to be about 50% that of the tissue culture plastic. Adsorption of gelatin with fibronectin onto the networks successfully increased cell attachment. Cell spreading and differentiation (adipogenic vs. osteogenic) studies are ongoing at the time of abstract submission. Ultimately, this work lays the synthetic groundwork for a new synthetic platform for LC biomaterials that can be adapted to include biological molecules as well as investigates LC network utility as a dynamic culture substrate. Please click Additional Files below to see the full abstract