Simultaneous Inference of User Representations and Trust

Inferring trust relations between social media users is critical for a number of applications wherein users seek credible information. The fact that available trust relations are scarce and skewed makes trust prediction a challenging task. To the best of our knowledge, this is the first work on exploring representation learning for trust prediction. We propose an approach that uses only a small amount of binary user-user trust relations to simultaneously learn user embeddings and a model to predict trust between user pairs. We empirically demonstrate that for trust prediction, our approach outperforms classifier-based approaches which use state-of-the-art representation learning methods like DeepWalk and LINE as features. We also conduct experiments which use embeddings pre-trained with DeepWalk and LINE each as an input to our model, resulting in further performance improvement. Experiments with a dataset of $\sim$356K user pairs show that the proposed method can obtain an high F-score of 92.65%.Comment: To appear in the proceedings of ASONAM'17. Please cite that versio

Comprehensive genotype‐phenotype correlation in AP‐4 deficiency syndrome; Adding data from a large cohort of Iranian patients

Mutations in adaptor protein complex‐4 (AP‐4) genes have first been identified in 2009, causing a phenotype termed as AP‐4 deficiency syndrome. Since then several patients with overlapping phenotypes, comprised of intellectual disability (ID) and spastic tetraplegia have been reported. To delineate the genotype‐phenotype correlation of the AP‐4 deficiency syndrome, we add the data from 30 affected individuals from 12 out of 640 Iranian families with ID in whom we detected disease‐causing variants in AP‐4 complex subunits, using next‐generation sequencing. Furthermore, by comparing genotype‐phenotype findings of those affected individuals with previously reported patients, we further refine the genotype‐phenotype correlation in this syndrome. The most frequent reported clinical findings in the 101 cases consist of ID and/or global developmental delay (97%), speech disorders (92.1%), inability to walk (90.1%), spasticity (77.2%), and microcephaly (75.2%). Spastic tetraplegia has been reported in 72.3% of the investigated patients. The major brain imaging findings are abnormal corpus callosum morphology (63.4%) followed by ventriculomegaly (44.5%). Our result might suggest the AP‐4 deficiency syndrome as a major differential diagnostic for unknown hereditary neurodegenerative disorders

A comprehensive model of gain recovery due to unipolar electron transport after a short optical pulse in quantum cascade lasers

We have developed a comprehensive model of gain recovery due to unipolar electron transport after a short optical pulse in quantum cascade lasers (QCLs) that takes into account all the participating energy levels, including the continuum, in a device. This work takes into account the incoherent scattering of electrons from one energy level to another and quantum coherent tunneling from an injector level to an active region level or vice versa. In contrast to the prior work that only considered transitions to and from a limited number of bound levels, this work include transitions between all bound levels and between the bound energy levels and the continuum. We simulated an experiment of S. Liu et al., in which 438-pJ femtosecond optical pulses at the device’s lasing wavelength were injected into an In0:653Ga0:348As=In0:310Al0:690As QCL structure; we found that approximately 1% of the electrons in the bound energy levels will be excited into the continuum by a pulse and that the probability that these electrons will be scattered back into bound energy levels is negligible, 104. The gain recovery that is predicted is not consistent with the experiments, indicating that one or more phenomena besides unipolar electron transport in response to a short optical pulse play an important role in the observed gain recovery

Sustainability as corporate culture of a brand for superior performance

This is the post-print version of the final paper published in the Journal of World Business. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2012 Elsevier B.V.Sustainability research highlights new challenges and opportunities for businesses. This paper reviews the literature to understand the ability of sustainable green initiatives when practiced as a corporate culture to individually create new opportunities for operations, management and marketing. According to current research, business opportunities exclusively available to different functions of a firm can drive its performance. The role of marketing in the achievement of superior performance by virtue of sustainability practices is also explained by the existing literature. Branding literature, however, fails to explain the influence of a brand on sustainability-driven opportunities available to a firm for superior performance. The objective of this study is to explore if a brand can strengthen the ability of sustainability-based green initiatives of managers to drive opportunities available to a firm for superior performance. A conceptual framework grounded in the triple bottom line theory is presented based on the assumption that brand as a stimulating factor can accelerate the conversion of opportunities available to a business into superior performance. Academic and managerial perspectives have been used to draw upon the implications of the model. Both practitioners and academic researchers will benefit from future research on this topic

Laboratory desalination experiments with some algal toxins

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Desalination 293 (2012): 1-6, doi:10.1016/j.desal.2012.02.014.Over the last several decades, countries throughout the world have experienced an escalating and worrisome trend in the incidence of harmful algal blooms (HABs). A concern is that highly potent algal toxins might be retained in the treated water, posing a threat to human health. Seawater contaminated with saxitoxins, domoic acid, okadaic acid, and brevetoxins was desalinated using small (<100 mL capacity) reverse osmosis and distillation equipment. Analyses of desalinated water samples indicated efficient removal of the four toxins to greater than 99%, except brevetoxins for which some carryover was observed during distillation. Hypochlorite concentrations of 4 ppm or higher were sufficient to react with all of the saxitoxins, domoic acid and okadaic acid in the samples that contained initial toxin concentrations up to 1,250 ng.mL-1 . Brevetoxins appeared to be unaffected in experiments in which the toxins were exposed to up to 30 ppm hypochlorite in seawater at 35 °C for 60 min. These results and their implications in terms of desalination plant design and operation are discussed.This work was also supported in part by the Woods Hole Center for Oceans and Human Health (NSF Grants OCE-0430724 and OCE-0911031; NIEHS Grant P50ES012742-01) and Effects of Inhaled Florida Red Tide Brevetoxins (NIH Grant P01 ES010594-09)

Accounting for Diffusion in Agent Based Models of Reaction-Diffusion Systems with Application to Cytoskeletal Diffusion

Diffusion plays a key role in many biochemical reaction systems seen in nature. Scenarios where diffusion behavior is critical can be seen in the cell and subcellular compartments where molecular crowding limits the interaction between particles. We investigate the application of a computational method for modeling the diffusion of molecules and macromolecules in three-dimensional solutions using agent based modeling. This method allows for realistic modeling of a system of particles with different properties such as size, diffusion coefficients, and affinity as well as the environment properties such as viscosity and geometry. Simulations using these movement probabilities yield behavior that mimics natural diffusion. Using this modeling framework, we simulate the effects of molecular crowding on effective diffusion and have validated the results of our model using Langevin dynamics simulations and note that they are in good agreement with previous experimental data. Furthermore, we investigate an extension of this framework where single discrete cells can contain multiple particles of varying size in an effort to highlight errors that can arise from discretization that lead to the unnatural behavior of particles undergoing diffusion. Subsequently, we explore various algorithms that differ in how they handle the movement of multiple particles per cell and suggest an algorithm that properly accommodates multiple particles of various sizes per cell that can replicate the natural behavior of these particles diffusing. Finally, we use the present modeling framework to investigate the effect of structural geometry on the directionality of diffusion in the cell cytoskeleton with the observation that parallel orientation in the structural geometry of actin filaments of filopodia and the branched structure of lamellipodia can give directionality to diffusion at the filopodia-lamellipodia interface

Molecular identification of viral pathogens in SPF (Specific pathogen free) shrimp

After the outbreak of various viral diseases, specifically white spot syndrome (WSS) in farmed Litopenaeus vannamei in the past few years, this non-native shrimp species in Iran requires a generator-builder with specific a pathogen-free approach. This Research was done by the Iran Shrimp Research Center (ISRC) to access accurate information regarding specific pathogen-free shrimp production and avoid using shrimp broodstock production through foreign investors. This research was part of the molecular viral study. For this trial, selected shrimps in farms were sampled and screened for main viruses (OIE list). Shrimps without infection were brought to the quarantine system for one month and at the end of the quarantine they were screened again. In addition, in winter spending, before and after spawning, it’s offspring in F1 and F2 were also screened for viral pathogens by IQ2000 kit at the Iran Shrimp Research Center lab and Iranian veterinary organization lab. All shrimp products such as fresh and consumed food were tested for OIE list at all stages during project performance and the result of tests were negative. Sequenced and molecular tests with specific primers were used to determine the presence of infected samples carrying the virus in any of the products, such as shrimp and consumed food, the infected samples. The result of all the tests during last three years, shows that all the shrimp and their food products were pathogen-free and safe to use