Single firm product diffusion model for single-function and fusion products

The prosperity of multifunction products (also referred to as fusion products) has changed the landscape of the marketplace for several electronics products. To illustrate, as fusion products gain popularity in cellular phones and office machines, we observe that single-function products (e.g., stand-alone PDAs and stand-alone scanners) gradually disappear from the market as they are supplanted by fusion products. This paper presents a product diffusion model that captures the diffusion transition from two distinct single-function products into one fusion product. We investigate the optimal launch time of the fusion product in various conditions and conduct a numerical analysis to demonstrate the dynamics among the three products. Similar to previous multi-generation single product diffusion models, we find that the planning horizon, the products\u27 relative profit margin, and substitution effects are important to the launch time decision. However, there are several unique factors that warrant special consideration when a firm introduces a fusion product to the market: the firm\u27s competitive role, buyer consolidation of purchases to a multi-function product, the fusion technology and the age of current single-function products

A shared neural code for perceiving and remembering social interactions in the human superior temporal sulcus

Recognizing and remembering social information is a crucial cognitive skill. Neural patterns in the superior temporal sulcus (STS) support our ability to perceive others' social interactions. However, despite the prominence of social interactions in memory, the neural basis of remembering social interactions is still unknown. To fill this gap, we investigated the brain mechanisms underlying memory of others' social interactions during free spoken recall of a naturalistic movie. By applying machine learning-based fMRI encoding analyses to densely labeled movie and recall data we found that a subset of the STS activity evoked by viewing social interactions predicted neural responses in not only held-out movie data, but also during memory recall. These results provide the first evidence that activity in the STS is reinstated in response to specific social content and that its reactivation underlies our ability to remember others’ interactions. These findings further suggest that the STS contains representations of social interactions that are not only perceptually driven, but also more abstract or conceptual in nature

On Collaboration in Distributed Parameter Estimation with Resource Constraints

We study sensor/agent data collection and collaboration policies for parameter estimation, accounting for resource constraints and correlation between observations collected by distinct sensors/agents. Specifically, we consider a group of sensors/agents each samples from different variables of a multivariate Gaussian distribution and has different estimation objectives, and we formulate a sensor/agent's data collection and collaboration policy design problem as a Fisher information maximization (or Cramer-Rao bound minimization) problem. When the knowledge of correlation between variables is available, we analytically identify two particular scenarios: (1) where the knowledge of the correlation between samples cannot be leveraged for collaborative estimation purposes and (2) where the optimal data collection policy involves investing scarce resources to collaboratively sample and transfer information that is not of immediate interest and whose statistics are already known, with the sole goal of increasing the confidence on the estimate of the parameter of interest. When the knowledge of certain correlation is unavailable but collaboration may still be worthwhile, we propose novel ways to apply multi-armed bandit algorithms to learn the optimal data collection and collaboration policy in our distributed parameter estimation problem and demonstrate that the proposed algorithms, DOUBLE-F, DOUBLE-Z, UCB-F, UCB-Z, are effective through simulations

Fusion Product Planning: A Market Offering Perspective

Devices that integrate multiple functions together are popular in consumer electronic markets. We describe these multifunction devices as fusion products as they fuse together products that traditionally stand alone in the marketplace. In this article, we investigate the manufacturer\u27s fusion product planning decision, adopting a market offering perspective that allows us to address the design and product portfolio decisions simultaneously. The general approach adopted is to develop and analyze a profit-maximizing model for a single firm that integrates product substitution effects in identifying an optimal market offering. In the general model, we demonstrate that the product design and portfolio decisions are analytically difficult to characterize because the number of possible portfolios can be extremely large. The managerial insight from a stylized all-in-one model and numerical analysis is that the manufacturer should, in most cases, select only a subset of fusion and single-function products to satisfy the market\u27s multidimension needs. This may explain why the function compositions available in certain product markets are limited. In particular, one of the key factors driving the product portfolio decision is the margin associated with the fusion products. If a single all-in-one fusion product has relatively high margins, then this product likely dominates the product portfolio. Also, the congruency of the constituent single-function products is an important factor. When substitution effects are relatively high (i.e., the product set is more congruent), a portfolio containing a smaller number of products is more likely to be optimal

Managing children's postural risk when using mobile technology at home: Challenges and strategies

Maintaining the musculoskeletal health of children using mobile information and communication technologies (ICT) at home presents a challenge. The physical environment influences postures during ICT use and can contribute to musculoskeletal complaints. Few studies have assessed postures of children using ICT in home environments. The present study investigated the Rapid Upper Limb Assessment (RULA) scores determined by 16 novice and 16 experienced raters. Each rater viewed 11 videotaped scenarios of a child using two types of mobile ICT at home. The Grand Scores and Action Levels determined by study participants were compared to those of an ergonomist experienced in postural assessment. All postures assessed were rated with an Action Level of 2 or above; representing a postural risk that required further investigation and/or intervention. The sensitivity of RULA to assess some of the unconventional postures adopted by children in the home is questioned

Comparison of gene expression between human and mouse iPSC-derived cardiomyocytes for stem cell therapies of cardiovascular defects via bioinformatic analysis

Background: Preclinical studies have demonstrated the potential use of induced pluripotent stem cells (iPSCs) to treat cardiovascular disease (CVD). In vivo preclinical studies conducted on animal models (murine, porcine, guinea pig, etc.) have employed either syngeneic or human-derived iPSCs. However, no study has been carried out to investigate and report the key genetic differences between the human and animal-derived iPSCs. Our study analysed the gene expression profile and molecular pathway patterns underlying the differentiation of both human and mouse iPSCs to iPSC-cardiomyocytes (iPSC-CMs), and the differences between them via bioinformatic analysis. Method: Data sets were downloaded from the Gene Expression Omnibus (GEO) database and included both human and mouse models, and the data for undifferentiated iPSCs and iPSC-CMs were isolated from each. Differentially expressed genes (DEGs) were screened and then analysed. The website g:Profiler was used to obtain the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. Protein-protein interaction (PPI) networks of the DEGs were constructed using the Search Tool for the Retrieval of Interacting Genes (STRING) database and Cytoscape software. The subclusters were then extracted from the PPI network for further analysis. Results: iPSC-derived cardiomyocytes expressed many genes related to vascular, endothelial, and smooth muscle repair in the human iPSC-CMs, and prevention of calcification in the mouse iPSC-CMs with clear differences in gene expression, which will affect how iPSCs act in research. Especially in the human iPSC-CMs, and also prevention of calcification processes in the mouse data. The identified differences in gene expression of iPSCs derived from the two species suggests that in vivo studies using mouse iPSC-CMs may not reflect those in humans. Conclusion: The study provides new insights into the key genes related to the iPSCs, including genes related to angiogenesis, calcification, and striated muscle, endothelium, and bone formation. Moreover, the clear differences between both mouse and human-derived iPSCs have been identified, which could be used as new evidence and guidance for developing novel targeted therapy strategies to improve the therapeutic effects of iPSC treatment in cardiovascular defects

DEVELOPMENT OF GENOMIC AND GENETIC TOOLS FOR FOXTAIL MILLET, AND USE OF THESE TOOLS IN THE IMPROVEMENT OF BIOMASS PRODUCTION FOR BIOENERGY CROPS

Foxtail millet (Setaria italica L.) is a warm-season, C4 annual crop commonly grown for grain and forage worldwide. It has a relatively short generation time, yet produces hundreds of seeds per inflorescence. The crop is inbred and it has a small-size genome (~500 Mb). These features make foxtail millet an attractive grass model, especially for bioenergy crops. While a number of genomic tools have been established for foxtail millet, including a fully sequenced genome and molecular markers, the objectives of this project were to develop a tissue culture system, determine the best explant(s) for tissue culture, optimize transient gene expression, and establish a stable transformation system for foxtail millet cultivar Yugu1. In optimizing a tissue culture medium for the induction of calli and somatic embryos from immature inflorescences and mature seed explants, Murashige and Skoog medium containing 2.5 mg l-1 2,4-dichlorophenoxyacetic acid and 0.6 mg l-1 6- benzylaminopurine was determined to be optimal for callus induction of foxtail millet. The efficiency of callus induction from explants of immature inflorescences was significantly higher at 76% compared to that of callus induction from mature seed explants at 68%. The calli induced from this medium were regenerated into plants at high frequency (~100%) using 0.2 mg l-1 kinetin in the regeneration media. For performing transient gene expression, immature embryos were first isolated from inflorescences. Transient expression of the GUS reporter gene in immature embryos was significantly increased after sonication, a vacuum treatment, centrifugation and the addition of L-cysteine and dithiothreitol, which led to the efficiency of transient expression at levels greater than 70% after Agrobacterium inoculation. Inoculation with Agrobacterium was also tested with germinated seeds. The radicals of germinated seeds were pierced with needles and dipped into Agrobacterium solution. This method achieved a 10% transient expression efficiency. Throughout these analyses, using plasmids with the hygromycin selectable marker, it was determined that 1.5 mg l-1 hygromycin was the optimal dose for genetic transformation of foxtail millet. In contrast, the nptII selectable marker appeared to yield many escapes. Three methods of transformation were employed in an attempt to produce stable transformants. An in planta transformation experiment, similar to the floral dip method used in Arabidopsis, which utilized a red fluorescent protein pporRFP from coral Porites porites and the hygromycin selectable marker, was tested using immature inflorescences. Although several plants were PCR positive using endpoint and Real-Time PCR and there was transient expression using pporRFP and GUS reporters, no plants were positive on Southern blot. Dipping in Agrobacterium may damage the anther or the pistil because seed production was significantly reduced. Agrobacterium transformation using embryogenic calli was also tested. Although hundreds of plants were regenerated from selection, none were positive using PCR. The third method was to wound germinated seeds with an Agrobacterium coated needle, but none of the plants were PCR positive. Although the Yugu1 genotype was recalcitrant to genetic transformation, several avenues of future research should be considered for foxtail millet. Calli from different foxtail millet genotypes should be screened and selected for regeneration potential, and some genotypes may be more amenable to transformation. Additional selectable markers should also be tested as hygromycin appears to be too stringent and there are too many escapes with nptII. This project has provided training for the following personnel: Dr. Xinlu Chen (postdoc), Xiaomei Liu (postdoc), Jayashree Desai (postdoc) and Kyle Berk (Undergraduate researcher). Conference presentations and peer-reviewed journal articles partly supported by this grant includes the following: 1. Baxter H., Equi R., Chen X, Berk K. and Zale J. Establishing Efficient in vitro Protocols For Foxtail Millet (Setaria italica L. cv. Yugi 1). Plant & Animal Genomes XVIII Conference XVIII, San Diego, California, January 2010 2. Chen X, Zale J and Chen F. The Regeneration and Transformation of Foxtail Millet (Setaria italica), A Model Biofuel Crop. Genomic Science Awardee Meeting IX and USDA-DOE Plant Feedstock Genomics for Bioenergy Awardee Meeting, Crystal City, Virginia, April 2011 3. Chen, F., Tholl, D., Bohlmann, J., and Pichersky, E. (2011) The family of terpene synthases in plants: A mid-size family of genes for specialized metabolism that is highly diversified throughout the kingdom. Plant J. 66: 212-229

Dibutyryl Cyclic AMP Modulates Keratinocyte Migration Without Alteration on Integrin Expression

Cyclic adenosine monophosphate (cAMP) has long been regarded as a second messenger and a regulator of human keratinocyte proliferation. It has been demonstrated that cAMP inhibits keratinocyte proliferation when used at high concentrations. Nevertheless, new recent reports have demonstrated that cAMP may stimulate or inhibit keratinocyte growth depending upon the concentration used. Studies to examine the influence of cAMP upon the migration of other cell types have been contradictory. To determine the direct effect of dibutyryl cAMP (DBcAMP) upon human keratinocyte migration, we used a quantitative locomotion assay using a wide range of DBcAMP concentrations. We found a bi-phasic effect of DBcAMP on keratinocyte migration across connective tissue matrices. Keratinocyte locomotion on the matrices was promoted at 10-5 M and 10-6 M of DBcAMP, but not at higher or lower concentrations. Timecourse experiments demonstrated that the effect of DBcAMP on keratinocyte locomotion and proliferation occurred independently. Fluorescence-activated cell sorter analysis demonstrated that the effect of DBcAMP on the migration of human keratinocytes was independent from the modulation of integrin receptors. Although the cellular mechanisms by which DBcAMP promotes keratinocyte migration is unclear, the addition of DBcAMP or TPA to keratinocyte cultures enhanced the synthesis of a 92-kDa metalloproteinase in association with enhanced cellular migration. These observations suggest a possible link between metalloproteinase expression and cellular migration

A high-throughput transient gene expression system for switchgrass (Panicum virgatum L.) seedlings

<p>Abstract</p> <p>Background</p> <p>Grasses are relatively recalcitrant to genetic transformation in comparison to certain dicotyledons, yet they constitute some of the most important biofuel crops. Genetic transformation of switchgrass (<it>Panicum virgatum </it>L.) has previously been reported after cocultivation of explants with <it>Agrobacterium </it>and biolistics of embryogenic calli. Experiments to increase transient gene expression <it>in planta </it>may lead to stable transformation methods with increased efficiency.</p> <p>Results</p> <p>A high-throughput <it>Agrobacterium</it>-mediated transient gene expression system has been developed for <it>in planta </it>inoculation of germinating switchgrass seedlings. Four different <it>Agrobacterium </it>strains were compared for their ability to infect switchgrass seedlings, and strain AGL1 was found to be the most infective. Wounding pretreatments such as sonication, mixing by vortex with carborundum, separation by centrifugation, vacuum infiltration, and high temperature shock significantly increased transient expression of a reporter gene (GUSPlus, a variation of the β-glucuronidase (GUS) gene). The addition of L-cysteine and dithiothreitol in the presence of acetosyringone significantly increased GUS expression compared with control treatments, whereas the addition of 0.1% surfactants such as Silwet L77 or Li700 decreased GUS expression. 4-Methylumbelliferyl beta-D-galactopyranoside (MUG) assays showed a peak of β-glucuronidase (GUS) enzyme activity 3 days after cocultivation with <it>Agrobacterium </it>harboring pCambia1305.2, whereas MUG assays showed a peak of enzyme activity 5 days after cocultivation with <it>Agrobacterium </it>harboring pCambia1305.1.</p> <p>Conclusion</p> <p><it>Agrobacterium </it>strains C58, GV3101 and EHA105 are less able to deliver transfer DNA to switchgrass seedlings (cultivar Alamo) compared with strain AGL1. Transient expression was increased by double or triple wounding treatments such as mixing by vortex with carborundum, sonication, separation by centrifugation, and heat shock. The addition of thiol compounds such as L-cysteine and dithiothreitol in combination with acetosyringone during cocultivation also increased transient expression. The combination of multiple wounding treatments along with the addition of thiol compounds during cocultivation increased transient expression levels from 6% to 54%. There were differences in temporal GUS expression induced by pCambia1305.1 and pCambia1305.2.</p