Characterization of Cronobacter sakazakii Strains Originating from Plant-Origin Foods Using Comparative Genomic Analyses and Zebrafish Infectivity Studies

Cronobacter sakazakii continues to be isolated from ready-to-eat fresh and frozen produce, flours, dairy powders, cereals, nuts, and spices, in addition to the conventional sources of powdered infant formulae (PIF) and PIF production environments. To understand the sequence diversity, phylogenetic relationship, and virulence of C. sakazakii originating from plant-origin foods, comparative molecular and genomic analyses, and zebrafish infection (ZI) studies were applied to 88 strains. Whole genome sequences of the strains were generated for detailed bioinformatic analysis. PCR analysis showed that all strains possessed a pESA3-like virulence plasmid similar to reference C. sakazakii clinical strain BAA-894. Core genome analysis confirmed a shared genomic backbone with other C. sakazakii strains from food, clinical and environmental strains. Emerging nucleotide diversity in these plant-origin strains was highlighted using single nucleotide polymorphic alleles in 2000 core genes. DNA hybridization analyses using a pan-genomic microarray showed that these strains clustered according to sequence types (STs) identified by multi-locus sequence typing (MLST). PHASTER analysis identified 185 intact prophage gene clusters encompassing 22 different prophages, including three intact Cronobacter prophages: ENT47670, ENT39118, and phiES15. AMRFinderPlus analysis identified the CSA family class C β-lactamase gene in all strains and a plasmid-borne mcr-9.1 gene was identified in three strains. ZI studies showed that some plant-origin C. sakazakii display virulence comparable to clinical strains. Finding virulent plant-origin C. sakazakii possessing significant genomic features of clinically relevant STs suggests that these foods can serve as potential transmission vehicles and supports widening the scope of continued surveillance for this important foodborne pathogen

Economic and statistical significance of disposition effect and momentum in the US stock market

Disposition effect is the tendency of investors to ride losses and lock in gains. Capital gains overhang is a quantity used in prior literature to construct hypothesis tests for the existence of the disposition effect using publicly available stock market data. This quantity estimates the difference between the current price of a stock and the average price at which the currently held shares of the stock have been purchased by their current owners. Momentum effect is the tendency of the recent price trends to persist. We construct a number of trading strategies based on the capital gains overhang and momentum. We use the US stock market data to show that these strategies were consistently profitable during 1980-2013, and negatively correlated with the market. These conclusions hold even after eliminating small-cap and small-price stocks that may be difficult to trade, and after introducing a realistic trading cost for every transaction. We find a high empirical correlation between the strategies based on momentum and on the capital gains overhang, and argue that the former may be preferable for practitioners because of better performance and simpler implementation. These results also suggest that, rather than measuring the disposition effect, the capital gains overhang may simply be a proxy for momentum. Our findings would be of interest to portfolio managers, quantitative traders, researchers who analyze financial signals, as well as ordinary investors seeking to avoid common investor biases

Receipt management- transaction history based trust establishment

In a history-based trust-management system, users and service providers use information about past transactions to make trust-based decisions concerningcurrent transactions. One category of such systems is represented by the reputation systems. However, despite the growing body of experience in building reputation systems, there are several limitations on how they are typically implemented. They often rely on scores that are evaluated by service providers and are often not reliable or well understood. We believe that reputation hasto be based on objective and reliable information. In such context, transaction histories play an important role. In this paper, we present the VeryIDX systemthat implements an electronic receipt infrastructure and supports protocols to build and manage online transaction history of users. The receipt protocols are shown to have several essential security and privacy properties. We present a basic yet reasonably expressive language which provides service providers with a new way to establish trust based on users\u27 transaction history. We alsodescribe the architecture and prototype implementation of VeryIDX, based on several important design considerations of a real-world e-commerce system infrastructure

Regulation of Anti-Oxidative, Anti-Inflammatory, and Anti-Apoptotic Activity of Advanced Cooling Composition (ACC) in UVB-Irradiated Human HaCaT Keratinocytes

We recently demonstrated that advanced cooling composition (ACC) has effective ingredients that exhibit anti-inflammatory effects in RAW 264.7 cells stimulated with lipopolysaccharide (LPS) and exhibit strong antimicrobial effects on Pseudomonas aeruginosa, Staphylococcus aureus, MRSA (methicillin-resistant Staphylococcus aureus), Candida albicans, and Streptococcus mutans. To further investigate whether ACC has beneficial effects in ultraviolet B (UVB)-irradiated human keratinocytes (HaCaT cells), HaCaT cells were pretreated with ACC prior to UVB irradiation. Our data showed that ACC, which is effective at 100 µg/mL, is nontoxic and has an antioxidative effect against UVB-induced intracellular reactive oxygen species (ROS) in HaCaT cells. In addition, ACC exerts cytoprotective effects against UVB-induced cytotoxicity in HaCaT cells by inhibiting abnormal inflammation and apoptosis through the regulation of mitogen-activated protein kinase (MAPK) signals, such as jun-amino-terminal kinase (JNK), p38, and extracellular signal-regulated kinase (ERK). Therefore, these results indicate that ACC is a potentially beneficial raw material that possesses antioxidative, anti-inflammatory, and antiapoptotic effects against UVB-induced keratinocytes and may have applications in skin health

Verification of Receipts from M-commerce Transactions on NFC Cellular Phones

A main challenge in mobile commerce is to make it possible for users to manage their transaction histories from both online e-commerce transactions and in-person transactions. Such histories are typically useful to build credit or to establish trust based on past transactions. In this paper we propose an approach to manage electronic receipts on cellular devices by assuring their secure and privacy-preserving usage. We provide a comprehensive notion of transactions history including both on-line transaction and in-person transactions. We apply cryptographic protocols, such as secret sharing and zero knowledge proofs, in a potentially vulnerable and constrained setting. Specifically, our approach supports flexible strategies based on Shamir\u27s secret sharing to cater to different user requirements and architectural constraints. In addition, aggregate zero knowledge proofs are used to efficiently support proofs of various receipt attributes. We have implemented the system on Nokia NFC cellular phones and report in the paper performance evaluation results

An Overview of VeryIDX - A Privacy-Preserving Digital Identity Management System for Mobile Devices

Users increasingly use their mobile devices to communicate, to conduct business transaction and access resources and services. In such a scenario, digital identity management (DIM) technology is fundamental in customizing user experience, protecting privacy, underpinning accountability in business transactions, and in complying with regulatory controls. Users identity consists of data, referred to as identity attributes, that encode relevant-security properties of the clients. However, identity attributes can be target of several attacks: the loss or theft of mobile devices results in a exposure of identity attributes; identity attributes that are send over WI-FI or 3G networks can be easily intercepted; identity attributes can also be captured via Bluetooth connections without the user’s consent; and mobile viruses, worms and Trojan horses can access the identity attributes stored on mobile devices if this information is not protected by passwords or PIN numbers. Therefore, assuring privacy and security of identity attributes, as well as of any sensitive information stored on mobile devices is crucial. In this paper we address such problems by proposing an approach to manage user identity attributes by assuring their privacypreserving usage. The approach is based on the concept of privacy preserving multi-factor authentication achieved by a new cryptographic primitive which uses aggregate signatures on commitments that are then used for aggregate zero-knowledge proof of knowledge (ZKPK) protocols. We present the implementation of such approach on Nokia NFC cellular phones and report performance evaluation results