Quantitative Imaging of Protein-Protein Interactions by Multiphoton Fluorescence Lifetime Imaging Microscopy using a Streak camera

Fluorescence Lifetime Imaging Microscopy (FLIM) using multiphoton excitation techniques is now finding an important place in quantitative imaging of protein-protein interactions and intracellular physiology. We review here the recent developments in multiphoton FLIM methods and also present a description of a novel multiphoton FLIM system using a streak camera that was developed in our laboratory. We provide an example of a typical application of the system in which we measure the fluorescence resonance energy transfer between a donor/acceptor pair of fluorescent proteins within a cellular specimen.Comment: Overview of FLIM techniques, StreakFLIM instrument, FRET application

Dynamic Development Contests

Public, private, and not-for-profit organizations find advanced technology and product development projects challenging to manage due to the time and budget pressures, and turn to their development partners and suppliers to address their development needs. We study how dynamic development contests with enriched rank-based incentives and carefully-tailored information design can help these organizations outsource their development projects at the minimum project lead time by stimulating competition among suppliers. We show that an organization can use dynamically adjusted flexible rewards to achieve the absolute minimum expected project lead time at a significantly lower cost than a fixed-reward policy. Importantly, our flexible-reward policy pays the absolute minimum expected reward (i.e., achieves the first best). We further study the case where the organization does not have sufficient budget to offer a reward that attains the absolute minimum expected lead time. We propose that in this case, the organization can dynamically increase the contest reward until its budget constraint binds and then use information sharing as a strategic tool to incentivize suppliers. Specifically, we propose an easy-to-implement random-update policy where the organization periodically monitors the status of suppliers at random times and immediately discloses any partial progress. We show that such a random-update policy outperforms other canonical information disclosure strategies. Our results indicate that dynamic rewards and strategic information disclosure are powerful tools to help organizations outsource their development needs swiftly and cost effectively

Occurrence, type and location of calcium oxalate crystals in selected medicinal plants

Crystals in selected medical plants growing naturally in Place palayam reserve forest, Thiruvallur District were studied with Polarised light microscope. Four types of crystals were observed: druses, prismatics,  raphide and rosettes crystal. Druses more in cortical parenchyma and ground parenchyma cells in the stem & petiole region. In contrast prismatic, raphide and rosettes present in cortical, ground, axial and phloem parenchyma in the roots and stems. The Preliminary results show the presence of four types of calcium oxalate crystals in the stems, Petiole & roots of 10 Species: Achyranthes aspera, Aerva lanata, Atalantia monophylla, Bridelia Crenulata presence of Druses crystal, Plumeria rubra, Adhatoda zeylanica presence of prismatic   crystal,  Asparagus racemosus, Monochoria vaginalis presence of raphide crystal and Carica papaya and  Carissa spinarum presence of rosette type of crystal. These observations indicate that there is relationship between the distribution of calcium oxalate crystals and the medicinal parts of the plant and supports the view that the presence of calcium oxalate crystals may relate to the adulterants