Estimating the probability of informed trading: a Bayesian approach

The Probability of Informed Trading (PIN) is a widely used indicator of information asymmetry risk in the trading of securities. Its estimation using maximum likelihood algorithms has been shown to be problematic, resulting in biased or unavailable estimates, especially in the case of liquid and frequently traded assets. We provide an alternative approach to estimating PIN by means of a Bayesian method that addresses some of the shortcomings in the existing estimation strategies. The method leads to a natural quantification of the uncertainty of PIN estimates, which may prove helpful in their use and interpretation. We also provide an easy to use toolbox for estimating PIN

First detections of 610 MHz radio emission from hot magnetic stars

We have carried out a study of radio emission from a small sample of magnetic O- and B-type stars using the Giant Metrewave Radio Telescope, with the goal of investigating their magnetospheres at low frequencies. These are the lowest frequency radio measurements ever obtained of hot magnetic stars. The observations were taken at random rotational phases in the 1390 and the 610 MHz bands. Out of the 8 stars, we detect five B-type stars in both the 1390 and the 610 MHz bands. The O-type stars were observed only in the 1390 MHz band, and no detections were obtained. We explain this result as a consequence of free-free absorption by the free-flowing stellar wind exterior to the closed magnetosphere. We also study the variability of individual stars. One star - HD 133880 - exhibits remarkably strong and rapid variability of its low frequency flux density. We discuss the possibility of this emission being coherent emission as reported for CU Vir by Trigilio et al. (2000).Comment: 9 pages, 4 figures, 4 tables, submitted to MNRA

HSP90-CDC37-PP5 forms a structural platform for kinase dephosphorylation.

Activation of client protein kinases by the HSP90 molecular chaperone system is affected by phosphorylation at multiple sites on HSP90, the kinase-specific co-chaperone CDC37, and the kinase client itself. Removal of regulatory phosphorylation from client kinases and their release from the HSP90-CDC37 system depends on the Ser/Thr phosphatase PP5, which associates with HSP90 via its N-terminal TPR domain. Here, we present the cryoEM structure of the oncogenic protein kinase client BRAFV600E bound to HSP90-CDC37, showing how the V600E mutation favours BRAF association with HSP90-CDC37. Structures of HSP90-CDC37-BRAFV600E complexes with PP5 in autoinhibited and activated conformations, together with proteomic analysis of its phosphatase activity on BRAFV600E and CRAF, reveal how PP5 is activated by recruitment to HSP90 complexes. PP5 comprehensively dephosphorylates client proteins, removing interaction sites for regulatory partners such as 14-3-3 proteins and thus performing a 'factory reset' of the kinase prior to release

Ten-year experience of more than 35,000 orofacial clefts in Africa

Abstract Background Surgical correction of orofacial clefts greatly mitigates negative outcomes. However, access to reconstructive surgery is limited in developing countries. The present study reviews epidemiological data from a single charitable organization, Smile Train, with a database of surgical cases from 33 African countries from 2001–2011. Methods Demographic and clinical patient data were collected from questionnaires completed by the participating surgeons. These data were recorded in Excel, analyzed using SPSS and compared with previously reported data. Results Questionnaires were completed for 36,384 patients by 389 African surgeons. The distribution of clefts was: 34.44% clefts of the lip (CL), 58.87% clefts of the lip and palate (CLP), and 6.69% clefts of the palate only (CP). The male to female ratio was 1.46:1, and the unilateral: bilateral ratio 2.93:1, with left-sided predominance 1.69:1. Associated anomalies were found in 4.18% of patients. The most frequent surgeries included primary lip/nose repairs, unilateral (68.36%) and bilateral (11.84%). There was seasonal variation in the frequency of oral cleft births with the highest in January and lowest by December. The average age at surgery was 9.34 years and increased in countries with lower gross domestic products. The average hospital stay was 4.5 days. The reported complication rate was 1.92%. Conclusions With the exception of cleft palates, results follow trends of worldwide epidemiologic reports of 25% CL, 50% CLP, and 25% CP, 2:1 unilateral:bilateral and left:right ratios, and male predominance. Fewer than expected patients, especially females, presented with isolated cleft palates, suggesting that limitations in economic resources and cultural aesthetics of the obvious lip deformity may outweigh functional concerns and access to treatment for females. A fewer than expected associated anomalies suggests either true ethnic variation, or that more severely-affected patients are not presenting for treatment. The epidemiology of orofacial clefting in Africa has been difficult to assess due to the diversity of the continent and the considerable variation among study designs. The large sample size of the data collected provides a basis for further study of the epidemiology of orofacial clefting in Africa.http://deepblue.lib.umich.edu/bitstream/2027.42/110688/1/12887_2015_Article_328.pd

Detection of Crab Giant Pulses Using the Mileura Widefield Array Low Frequency Demonstrator Field Prototype System

We report on the detection of giant pulses from the Crab Nebula pulsar at a frequency of 200 MHz using the field deployment system designed for the Mileura Widefield Array's Low Frequency Demonstrator (MWA-LFD). Our observations are among the first high-quality detections at such low frequencies. The measured pulse shapes are deconvolved for interstellar pulse broadening, yielding a pulse-broadening time of 670$\pm$100 $\mu$s, and the implied strength of scattering (scattering measure) is the lowest that is estimated towards the Crab nebula from observations made so far. The sensitivity of the system is largely dictated by the sky background, and our simple equipment is capable of detecting pulses that are brighter than $\sim$9 kJy in amplitude. The brightest giant pulse detected in our data has a peak amplitude of $\sim$50 kJy, and the implied brightness temperature is $10^{31.6}$ K. We discuss the giant pulse detection prospects with the full MWA-LFD system. With a sensitivity over two orders of magnitude larger than the prototype equipment, the full system will be capable of detecting such bright giant pulses out to a wide range of Galactic distances; from $\sim$8 to $\sim$30 kpc depending on the frequency. The MWA-LFD will thus be a highly promising instrument for the studies of giant pulses and other fast radio transients at low frequencies.Comment: 10 pages, 6 figures, Accepted for publication in the Astrophysical Journa

A Novel Shared Protection Scheme Based on Aggregate Wavelength in High Speed Networks

We propose novel analytical model of dynamic link cost evaluation in IP over WDM networks. We suggest disjoint path algorithm for the primary and backup path based on wavelength aggregate information, to provide shared backup. We show the optimality of pair selected because of joint optimization of the pair paths. The shareable capacity factor is introduced to establish the effect of load balancing on resources. We compared our simulation results with that of separate protection at connection and showed improvement on resource utilization performance of the network. We also study the blocking probability of proposed scheme

ANALYSIS AND OPTIMIZATION OF PARAMETER AFFECTING BORE DEVIATION IN BORING PROCESS

This investigation applies a full factorial orthogonal table, integrating response surface methodology (RSM) to optimize parameters of a finish boring process using a computer numerical control (CNC) machine VA-50 for the finishing operation of engine crank case tappet bore. The main scope of this research work is to study the effects of various operational parameters like cutting speed, feed rate and cutting allowance on bore diameter of engine crankcase tappet bore. It is found that with the increases of cutting speed and feed the bore deviation (BD) decreases. The result of the experiment then was analyzed using DESIGN EXPERT (DOE) 9.0 software. This was done by using the FULL FACTORIAL technique with optimal (custom) design and ANOVA analysis. In this study, randomization of the run order to be carried out and analysis sequences were carried out according to the run order by Design Expert software. Full factorial with optimal design of three factors with two factor have three levels and one factor has two level was conducted which consist of 18 runs. The machining responses that were analyzed is Bore deviation (BD).All data obtained were then used as input to the Design Expert software for further analysis, according to steps outline for full factorial design. As speed and feed increased a decrement of Bore deviation approximately 40 % was observed. By applying RSM analysis, the predictive mathematical model of the bore deviation average was developed in terms of the cutting speed, feed rate, and cutting allowance. The error analysis and experimental results indicate that the proposed predictive mathematical models could adequately describe the performance indicators within the limits of the factors that are being investigated. In addition, the analysis of variance (ANOVA) was implemented to identify the significant factors and the response surface contours were constructed for determining the optimum conditions of finish boring processes using CNC machine operations

Value at Risk models with long memory features and their economic performance

We study alternative dynamics for Value at Risk (VaR) that incorporate a slow moving component and information on recent aggregate returns in established quantile (auto) regression models. These models are compared on their economic performance, and also on metrics of first-order importance such as violation ratios. By better economic performance, we mean that changes in the VaR forecasts should have a lower variance to reduce transaction costs and should lead to lower exceedance sizes without raising the average level of the VaR. We find that, in combination with a targeted estimation strategy, our proposed models lead to improved performance in both statistical and economic terms