Public Versus Secret Reserve Prices in eBay Auctions: Results from a Pokemon Field Experiment

Sellers in eBay auctions have the opportunity to choose both a public minimum bid amount and a secret reserve price. We ask, empirically, whether the seller is made better or worse off by setting a secret reserve above a low minimum bid, versus the option of making the reserve public by using it as the minimum bid level. In a field experiment, we auction 50 matched pairs of Pok‚mon cards on eBay, half with secret reserves and half with equivalently high public minimum bids. We find that secret reserve prices make us worse off as sellers, by reducing the probability of the auction resulting in a sale, deterring serious bidders from entering the auction, and lowering the expected transaction price of the auction. We also present evidence that some sellers choose to use secret reserve prices for reasons other than increasing their expected auction prices.

Towards a “Conflict Free” Personality

The fundamental function of human brain and sensory organs, based on empirical experience, is to communicate what we visually perceive and what is significantly linked to memory. The Absolute nature of the physical world can be understood, by an epistemological study and retrospection of sense perception and memory. This analysis can be done by a few simple tests from day to day experiences. It is also done to identify the well-known EEG signal data of individual's waking, dream and deep sleep states. My study substantiates the fact, that in an absolute sense, the human brain receives the external reality of the physical world through sensory information. When a sensory neuron is excited by electromagnetic light waves or sound waves, or other external stimuli, the brain registers it. Except for routine matters, the knowledge [of physical world] received by the brain is relatively conflicting, unnecessary and non-scientific. This phenomenon could be attributed towards the making of a “Conflict free” personality though with a caution.  “Knowledge must be practiced with wisdom”. Keywords: Brain, Neuroscience, Perception, Memor

Kinetics and dynamics of electrophoretic translocation of polyelectrolytes through nanopores

The idea of sequencing a DNA based on single-file translocation of the DNA through nanopores under the action of an electric field has received much attention over the past two decades due to the societal need for low cost and high-throughput sequencing. However, due to the high speed of translocation, interrogating individual bases with an acceptable signal to noise ratio as they traverse the pore has been a major problem. Experimental facts on this phenomenon are rich and the associated phenomenology is yet to be fully understood. This thesis focuses on understanding the underlying principles of polymer translocation, with an emphasis on pore-polymer interactions, polymer architecture, and polymer chain fluctuations. Langevin dynamics simulations are used to study a variety of polymer and pore designs. For a uniformly charged linear polymer, a nanopore with charge patterns along its length is proposed. Variation in the charge pattern length reveals the existence of a critical length at which the polymer is trapped, causing a significant delay during the pore emptying stage. This trapping is modeled using an appropriate free energy landscape and the Fokker-Planck formalism. The predictions of this theory are in qualitative agreement with the simulation results across different pore and polymer lengths. Moreover, a linear polymer with charge patterns along its backbone passing through such a charge-patterned pore shows rich kinetic behavior; a significant delay is introduced even in the pore entrance and threading stages due to pattern matching, suggesting the use of pore-polymer interactions to slow down translocation. In a related study, the translocation of charged star polymers through an uncharged pore is simulated. Star polymers with different functionalities show rich translocation kinetics while passing through such a pore. The mean translocation time varies non-monotonically with the polymer functionality, suggesting the use of nanopores as a filtering and analytical technique for star polymers. Recent experiments have suggested the use of phi29 polymerase in conjunction with a protein pore (α-Hemolysin) in the presence of an electric field to slow down the polymer translocation speed, enabling reasonably successful base-calling. The role of polymer chain fluctuations inside the nanopore is evaluated using Langevin dynamics simulations on models of this construct. By monitoring the contributions of the conformational fluctuations of the polymer, the diffusional behavior of monomers of the chain under the speed resulting from the polymerase activity and externally imposed voltage gradients is computed. The simulations show that even if the translocation speed is slowed down considerably by using the polymerase-nanopore construct, the conformational fluctuations of ssDNA inside the pore are always present at high levels, resulting in high levels of noise in the detection signal

Turtles and whale shark landed along Ratnagiri coast, Maharashtra

Two turtlescaught in hooks and line off Ratnagiri on 27-11-1995.whale shark of 20.75 m in total landed at Ratnagiri coast on 30-9-1995

STUDY OF BIG DATA ARHITECTURE LAMBDA ARHITECTURE

The lambda architecture introduced by Marz is generic, scalable and fault-tolerant data processing architecture. It aims to satisfy the needs for a robust system that is faulttolerant, both against hardware failures and human mistakes, being able to serve a wide range of workloads and use cases. The architecture proposal decomposes the problem into three layers: a) the batch layer focuses on fault tolerance and optimizes for precise results b) the speed layer is optimized for short response-times and only takes into account the most recent data and c) the serving layer provides low latency views to the results of the batch layer. The reason to divide the architecture into three layers is the flexibility it offers to the potential applications. The fast but possibly inaccurate results of the speed layer are eventually replaced by the precise results of the batch layer. The evaluation of the designed architecture measured its capabilities based on the DEBS grand challenge 2014 and percentile calculation for milestones task. As part of the project we implement the lambda architecture in different ways (i.e. using different systems). We compare these different implementations and derive the strengths and weaknesses of each different system used in the lambda architecture

Landing of tiger shark Galeocerdo cuvieri at New Ferry Wharf, Mumbai

Two tiger sharks Galeocerdo cuvieri were landed at new ferry wharf, Mumbai during 13th september 2003 and 16th october 2003 by trawl net which operated at 50 -60 kms away on north and west of mumbai coastat adepth of 40 -50 meter

Study of Probabilistic Parsing in Syntactic Analysis

Statistical parser, like statistical tagging requires a corpus of hand –parsed text. There are such corpora available, the most notably being the Penn-tree bank. The Penn-tree bank is large corpus of articles from the Wall Street Journal that have been tagged with Penn tree-Bank tags and then parsed accordingly to a simple set of phrase structure rules conforming to Chomsky Government and binding syntax