Do Individual Investors Drive Post-Earnings Announcement Drift? Direct Evidence from Personal Trades

This study examines whether individual investors are the source of post- earnings announcement drift (PEAD). We provide evidence on how individual investors trade in response to extreme quarterly earnings surprises and on the relation between individual investors' trades and subsequent abnormal returns. We find no evidence that either individuals or any sub-category of individuals in our sample cause PEAD. Individuals are significant net buyers after both negative and positive earnings surprises. There is no indication that trading by any of our investor sub-categories explains the concentration of drift at subsequent earnings announcement dates. While post-announcement individual net buying is a significant negative predictor of stock returns over the next three quarters, individual investor trading fails to subsume any of the power of extreme earnings surprises to predict future abnormal returns.post earnings-announcement drift, trading activity, individual investors, market efficiency

3D bioprinting for tissue engineering: Stem cells in hydrogels

Surgical limitations require alternative methods of repairing and replacing diseased and damaged tissue. Regenerative medicine is a growing area of research with engineered tissues already being used successfully in patients. However, the demand for such tissues greatly outweighs the supply and a fast and accurate method of production is still required. 3D bioprinting offers precision control as well as the ability to incorporate biological cues and cells directly into the material as it is being fabricated. Having precise control over scaffold morphology and chemistry is a significant step towards controlling cellular behaviour, particularly where undifferentiated cells, i.e., stem cells, are used. This level of control in the early stages of tissue development is crucial in building more complex systems that morphologically and functionally mimic in vivo tissue. Here we review 3D printing hydrogel materials for tissue engineering purposes and the incorporation of cells within them. Hydrogels are ideal materials for cell culture. They are structurally similar to native extracellular matrix, have a high nutrient retention capacity, allow cells to migrate and can be formed under mild conditions. The techniques used to produce these materials, as well as their benefits and limitations, are outlined

A survey on touch dynamics authentication in mobile devices

© 2016 Elsevier Ltd. All rights reserved. There have been research activities in the area of keystroke dynamics biometrics on physical keyboards (desktop computers or conventional mobile phones) undertaken in the past three decades. However, in terms of touch dynamics biometrics on virtual keyboards (modern touchscreen mobile devices), there has been little published work. Particularly, there is a lack of an extensive survey and evaluation of the methodologies adopted in the area. Owing to the widespread use of touchscreen mobile devices, it is necessary for us to examine the techniques and their effectiveness in the domain of touch dynamics biometrics. The aim of this paper is to provide some insights and comparative analysis of the current state of the art in the topic area, including data acquisition protocols, feature data representations, decision making techniques, as well as experimental settings and evaluations. With such a survey, we can gain a better understanding of the current state of the art, thus identifying challenging issues and knowledge gaps for further research

Factors affecting consumers' decisions on the use of nutraceuticals: a systematic review

There is a high and increasing global prevalence of nutraceuticals use. This study aims to systematically review and critically appraise all available evidence to identify the factors affecting consumers’ decisions in taking nutraceuticals. Questionnaire, interview or focus group studies which directly reported factors affecting consumers’ decisions in using nutraceuticals were included. A thematic synthesis method was employed to synthesis the findings from the included studies. Out of the 76 studies included, the key factors identified as the most important factors motivating consumers to take nutraceuticals were the perceived health benefits and safety of nutraceuticals, as well as the advice from healthcare professionals, friends and family. The identified barriers to take nutraceuticals were a lack of belief in the health benefit of nutraceuticals, the high cost of nutraceuticals and consumers’ lack of knowledge about nutraceuticals. As a chief course of recommendation for the use of nutraceuticals, healthcare professionals should strive to utilise reliable information from clinical evidence to help consumers in making an informed decision in using nutraceuticals. Future studies should explore the possible ways to improve channelling clinical evidence information of nutraceuticals to the public

The M, E, and N structural proteins of the severe acute respiratory syndrome coronavirus are required for efficient assembly, trafficking, and release of virus-like particles

Copyright @ 2008 American Society for Microbiology.The production of virus-like particles (VLPs) constitutes a relevant and safe model to study molecular determinants of virion egress. The minimal requirement for the assembly of VLPs for the coronavirus responsible for severe acute respiratory syndrome in humans (SARS-CoV) is still controversial. Recent studies have shown that SARS-CoV VLP formation depends on either M and E proteins or M and N proteins. Here we show that both E and N proteins must be coexpressed with M protein for the efficient production and release of VLPs by transfected Vero E6 cells. This suggests that the mechanism of SARS-CoV assembly differs from that of other studied coronaviruses, which only require M and E proteins for VLP formation. When coexpressed, the native envelope trimeric S glycoprotein is incorporated onto VLPs. Interestingly, when a fluorescent protein tag is added to the C-terminal end of N or S protein, but not M protein, the chimeric viral proteins can be assembled within VLPs and allow visualization of VLP production and trafficking in living cells by state-of-the-art imaging technologies. Fluorescent VLPs will be used further to investigate the role of cellular machineries during SARS-CoV egress.The University of Hong Kong and the French Ministry of Health

The pervasive triad of food security, gender inequity and women\u27s health: Exploratory research from sub-Saharan Africa

Objectives: This study was designed to explore the interactions between food securing activities, health and gender equity from the perspective of rural east African women. The specific objectives were to document the critical interaction among these three issues - food security, gender inequity, women\u27s health within the context of sub-Saharan Africa; to describe the nature of this triad from the perspective of women farmers in Africa; and to propose a framework for linking available interventions to the vicious nature of this triad. Setting: In-depth interviews and focus group discussions were conducted with rural women farmers in Kwale District, Kenya and Bagamoyo District, Tanzania. Methods: A total of 12 in-depth interviews and 4 focus group discussions have been included in this analysis. Transcribed text from interviews and focus group discussions were coded and thematic conceptual matrices were developed to compare dimensions of common themes across interviews and settings. A thematic analysis was then performed and a framework developed to understand the nature of the triad and explore the potential for interventions within the interactions. Findings: The vicious cycle of increasing work, lack of time, and lack of independent decision making for women who are responsible for food production and health of their families, has health and social consequences. Food securing activities have negative health consequences for women, which are further augmented by issues of gender inequity. Conclusion: The African development community must respond by thinking of creative solutions and appropriate interventions for the empowerment of women farmers in the region to ensure their health

Visualizing probabilistic models in Minkowski space with intensive symmetrized Kullback-Leibler embedding

We show that the predicted probability distributions for any $N$-parameter statistical model taking the form of an exponential family can be explicitly and analytically embedded isometrically in a $N{+}N$-dimensional Minkowski space. That is, the model predictions can be visualized as control parameters are varied, preserving the natural distance between probability distributions. All pairwise distances between model instances are given by the symmetrized Kullback-Leibler divergence. We give formulas for these intensive symmetrized Kullback Leibler (isKL) coordinate embeddings, and illustrate the resulting visualizations with the Bernoulli (coin toss) problem, the ideal gas, $n$ sided die, the nonlinear least squares fit, and the Gaussian fit. We highlight how isKL can be used to determine the minimum number of parameters needed to describe probabilistic data, and conclude by visualizing the prediction space of the two-dimensional Ising model, where we examine the manifold behavior near its critical point.Comment: 18 pages, 9 figure

Rice Yield Estimation Using Below Cloud Remote Sensing Images Acquired by Unmanned Airborne Vehicle System

A method using unmanned airborne vehicle system (UAVS) and image processing technique to enable estimation of rice yield was developed. A digital Tetracam camera was mounted on a CropCam unmanned airborne vehicle (UAV) to acquire red (R), green (G) and near infrared (NIR) images of rice crops at the height of 300 m above ground.  NIR and R values were used to calculate normalised difference vegetation index (NDVI) value. Relationships between yield versus R, G, NIR and NDVI values were analysed. Results showed that the highest relationship was found in NDVI followed by R, G and NIR with coefficient of determination (r2) values of 0.748, 0.727, 0.395 and 0.014 respectively. Therefore, a yield estimation model using NDVI value was developed from the linear regression analysis. The results showed that the model was capable of estimating rice yield with an average accuracy value of 80.3%

Effect of thermal barrier coating on the performance and emissions of diesel engine operated with conventional diesel and palm oil biodiesel

In this study, the performance and emission of a thermal barrier coating (TBC) engine which applied palm oil biodiesel and diesel as a fuel were evaluated. TBC was prepared by using a series of mixture consisting different blend ratio of yttria stabilized zirconia (Y2O3·ZrO2) and aluminum oxide-silicon oxide (Al2O3·SiO2) via plasma spray coating technique. The experimental results showed that mixture of TBC with 60% Y2O3·ZrO2 + 40% Al2O3·SiO2 had an excellent nitrogen oxide (NO), carbon monoxide (CO), carbon dioxide (CO2), and unburned hydrocarbon (HC) reductions compared to other blend-coated pistons. The finding also indicated that coating mixture 50% Y2O3·ZrO2 + 50% Al2O3·SiO2 had the highest brake thermal efficiency (BTE) and lowest of brake specific fuel consumption (BSFC) compared to all mixture coating. Reductions of HC and CO emissions were also recorded for 60% Y2O3·ZrO2 + 40% Al2O3·SiO2 and 50% Y2O3·ZrO2 + 50% Al2O3·SiO2 coatings. These encouraging findings had further proven the significance of TBC in enhancing the engine performance and emission reductions operated with different types of fuel