Distortion of genealogical properties when the sample is very large

Study sample sizes in human genetics are growing rapidly, and in due course it will become routine to analyze samples with hundreds of thousands if not millions of individuals. In addition to posing computational challenges, such large sample sizes call for carefully re-examining the theoretical foundation underlying commonly-used analytical tools. Here, we study the accuracy of the coalescent, a central model for studying the ancestry of a sample of individuals. The coalescent arises as a limit of a large class of random mating models and it is an accurate approximation to the original model provided that the population size is sufficiently larger than the sample size. We develop a method for performing exact computation in the discrete-time Wright-Fisher (DTWF) model and compare several key genealogical quantities of interest with the coalescent predictions. For realistic demographic scenarios, we find that there are a significant number of multiple- and simultaneous-merger events under the DTWF model, which are absent in the coalescent by construction. Furthermore, for large sample sizes, there are noticeable differences in the expected number of rare variants between the coalescent and the DTWF model. To balance the tradeoff between accuracy and computational efficiency, we propose a hybrid algorithm that utilizes the DTWF model for the recent past and the coalescent for the more distant past. Our results demonstrate that the hybrid method with only a handful of generations of the DTWF model leads to a frequency spectrum that is quite close to the prediction of the full DTWF model.Comment: 27 pages, 2 tables, 14 figure

On the Energetics of the HCO+^+ + C →\to CH+^+ + CO Reaction and Some Astrochemical Implications

We explore the energetics of the titular reaction, which current astrochemical databases consider open at typical dense molecular (i.e., dark) cloud conditions. As is common for reactions involving the transfer of light particles, we assume that there are no intersystem crossings of the potential energy surfaces involved. In the absence of any such crossings, we find that this reaction is endoergic and will be suppressed at dark cloud temperatures. Updating accordingly a generic astrochemical model for dark clouds changes the predicted gas-phase abundances of 224 species by greater than a factor of 2. Of these species, 43 have been observed in the interstellar medium. Our findings demonstrate the astrochemical importance of determining the role of intersystem crossings, if any, in the titular reaction.Comment: Accepted for publication in ApJ; 14 pages, 2 figures, and 1 tabl

Beneficiation of low-grade iron ores

The Government of India highlighted, processing and utilization of iron ore fines as pre-requisite to meet the domestic raw material requirements for the projected 110 million tonnes of domestic steel production by the year 2019-20 in the National Steel Policy announced in November 2005. This would require 190 million tonnes of iron ore. The depletion of high grade iron ore and increased generation of fines during mining and handling and demand for high grade iron orefines for export has necessitated the processing of low to medium grade fines. The R&D efforts undertaken at NML-Madras Centre, India in this direction have been highlighted. Beneficiation of iron ores in general and column flotation in particular are highlighted in this paper. This would also mitigate the environmental problem created by the dumping of huge quantities of low and medium grade iron orefines. Three case studies involving iron ore fines of varying silica and alumina content from Goa and Kudremukh regions of India have been discussed. The results clearly indicate the feasibility and significance of flotation process in treating the fines to obtain marketable concentrates

Recent developments in flotation for the beneficiation of lowgrade finely disseminated ores

Rapid increase in consumption rate of metals and minerals over the last few decades and consequent depletion of mineral resources have necessitated the effective utilization oflow-grade finely disseminated ores. The utilization of such reserves and recycling of metallic waste can help to maintain an adequate supply of minerals to meet economic and strategic needs of our nation. Since the yield of low-grade ores is generally very low, the technoiQgy/ process should be efficient to make it cost effictive. Recent equipments like flotation column and Jameson ceil which are basically designed to float fine particles are energy efficient. Selective reagents are being designed for the separation of individual minerals from complex assemblage. The necessity of biodegradable and eco-friendly reagents is highlighted. In the present paper; recent developments in flotation celis and beneficiation of low-grade ores was presented and discussed. Beneficiation of low-grade barite sample from Mangampet deposit was conducted both by direct flotation using oleic acid and reverse flotation by cationic collector. Production of barite concentrate assaying Less than 1% silica by reverseflotation was demonstrated. Similarly, limestone concentrate assaying 97% of CaC03 and Less than 1% Si02 was achieved by reverseflotation process. The viability offlotation processfor up-graddtion of siliceous iron ores waS also studied and discussed

Reliable method for Authorized Deduplication by Using Hybrid Cloud Environment

Information deduplication is one of vital data compression procedures for eliminating duplicate copies of repeating information and has been broadly utilized as a part of cloud storage to diminish the measure of storage room and spare transmission capacity .To ensure secrecy of delicate information while supporting deduplication, united encryption system has been proposed to scramble the information before out sourcing. For better assurance of information security , primary endeavor is to formally address the issue of approved information deduplication .Unique in relation to conventional deduplication frameworks ,the proposed security display bolsters differential benefits of clients in copy check other than information itself. A few new deduplication developments are displayed supporting approved copy check in a hybrid cloud environments. Security investigation shows that this plan is secure as far as definitions determined in proposed security demonstrate. As a proof of idea, the usage of a model of the proposed approved copy check conspire and additionally the lead testbed tests utilizing the model causes negligible overhead contrasted with ordinary operations

Just enough inflation: power spectrum modifications at large scales

We show that models of `just enough' inflation, where the slow-roll evolution lasted only $50-60$ e-foldings, feature modifications of the CMB power spectrum at large angular scales. We perform a systematic and model-independent analysis of any possible non-slow-roll background evolution prior to the final stage of slow-roll inflation. We find a high degree of universality since most common backgrounds like fast-roll evolution, matter or radiation-dominance give rise to a power loss at large angular scales and a peak together with an oscillatory behaviour at scales around the value of the Hubble parameter at the beginning of slow-roll inflation. Depending on the value of the equation of state parameter, different pre-inflationary epochs lead instead to an enhancement of power at low-$\ell$, and so seem disfavoured by recent observational hints for a lack of CMB power at $\ell\lesssim 40$. We also comment on the importance of initial conditions and the possibility to have multiple pre-inflationary stages.Comment: 31 pages, 13 figure

An Algorithmic approach for Localization using Single Mobile Anchor Node using Information Baton Handover Policy

The main goal of a sensor network is to collect and forward data to destination. It is very essential to know about the location of collected data. This type of information can be obtained using localization technique in wireless sensor networks (WSNs). Localization is a technique to determine the location of sensor nodes. Many research and work around is carried on Localization technique in WSN, because of its huge application in day today life. It is very important to design a low-cost, scalable, and efficient localization mechanisms for WSNs

Neutrino Mixing Predictions of a Minimal SO(10) Model with Suppressed Proton Decay

During the past year, a minimal renormalizable supersymmetric SO(10) model has been proposed with the following properties: it predicts a naturally stable dark matter and neutrino mixing angles theta_atm and theta_13 while at the same time accommodating CKM CP violation among quarks with no SUSY CP problem. Suppression of proton decay for all allowed values of tan beta strongly restricts the flavor structure of the model making it predictive for other processes as well. We discuss the following predictions of the model in this paper, e.g. down-type quark masses, and neutrino oscillation parameters, U_e3, delta_MNSP, which will be tested by long baseline experiments such as T2K and subsequent experiments using the neutrino beam from JPARC. We also calculate lepton flavor violation and the lepton asymmetry of the Universe in this model.Comment: 22 pages, 11 figure