Combining information seeking services into a meta supply chain of facts

The World Wide Web has become a vital supplier of information that allows organizations to carry on such tasks as business intelligence, security monitoring, and risk assessments. Having a quick and reliable supply of correct facts from perspective is often mission critical. By following design science guidelines, we have explored ways to recombine facts from multiple sources, each with possibly different levels of responsiveness and accuracy, into one robust supply chain. Inspired by prior research on keyword-based meta-search engines (e.g., metacrawler.com), we have adapted the existing question answering algorithms for the task of analysis and triangulation of facts. We present a first prototype for a meta approach to fact seeking. Our meta engine sends a user's question to several fact seeking services that are publicly available on the Web (e.g., ask.com, brainboost.com, answerbus.com, NSIR, etc.) and analyzes the returned results jointly to identify and present to the user those that are most likely to be factually correct. The results of our evaluation on the standard test sets widely used in prior research support the evidence for the following: 1) the value-added of the meta approach: its performance surpasses the performance of each supplier, 2) the importance of using fact seeking services as suppliers to the meta engine rather than keyword driven search portals, and 3) the resilience of the meta approach: eliminating a single service does not noticeably impact the overall performance. We show that these properties make the meta-approach a more reliable supplier of facts than any of the currently available stand-alone services

Regulation of growth plate and articular chondrocyte differentiation : implications for longitudinal bone growth and articular cartilage formation

Overall height and body proportions in humans are determined primarily by bone growth. Linear bone growth occurs at the growth plate, a thin layer of cartilage at the ends of long bones between the epiphysis and metaphysis. In the growth plate, resting/stem-like chondrocytes divide and give rise to proliferative chondrocytes, which, in turn, enlarge to become hypertrophic chondrocytes that ultimately undergo apoptotic cell death and are replaced by bone. Articular cartilage is an embryologically related but permanent tissue that lines the ends of long bones providing a lubricated surface for articulation and distributing loads to minimize stress on underlying subchondral bone. In both growth plate and articular cartilage, precise cell signaling mechanisms ensure normal bone growth and joint maintenance, respectively, by regulating cell differentiation, proliferation, and hypertrophy as well as matrix synthesis and turnover. A better understanding of these mechanisms has broad clinical implications for preventing, diagnosing, and treating skeletal diseases. The aim of this thesis was to study the molecular mechanisms regulating growth plate and articular chondrocyte differentiation. In this regard, similarities and differences between these structurally similar yet functionally distinct skeletal tissues were also investigated. We first explored gene expression related to the BMP signaling system in different layers of rat growth plate cartilage using manual microdissection, microarray, and real-time PCR (Paper 1). Our findings suggest a functional BMP signaling gradient across the growth plate where BMP antagonists are highly expressed in the resting and proliferative zones and BMP agonists are highly expressed in the hypertrophic zone. Gradients in BMP action may thus provide a key mechanism responsible for the spatial regulation of chondrogenesis in growth plate cartilage and thereby contribute to longitudinal bone growth. Another important mechanism is the Ihh/PTHrP feedback system, which prevents premature hypertrophic differentiation in embryonic epiphyseal cartilage. However, less is known about its organization in the growth plate after birth when the area undergoes substantial remodeling. We therefore explored Ihh/PTHrP-related gene expression in postnatal rat growth plate and surveyed Ihh activity in the Gli1-lacZ mouse growth plate (Paper 2). We found that the embryonic Ihh/PTHrP feedback system is maintained postnatally except that the source of PTHrP has shifted to a more proximal location in the resting zone. This finding provides insight into the potential role of Ihh/PTHrP signaling in growth plate senescence and fusion. Similar to the growth plate, articular cartilage is structurally organized into chondrocyte layers; however, its cellular differentiation program is not as well characterized. Thus, we explored the similarities and differences between articular and growth plate cartilage by comparing gene expression profiles of individual rat epiphyseal cartilage layers using bioinformatic approaches (Paper 3). Our findings revealed unexpected transcriptional similarities between the deeper zones of articular cartilage and the resting zone of growth plate cartilage as well as between articular cartilage superficial zone and growth plate cartilage hypertrophic zone, suggesting that in articular cartilage, superficial chondrocytes differentiate from chondrocytes in the deeper layers following a program that has some similarities to the hypertrophic differentiation program in growth plate cartilage. Based on these findings, we hypothesized that microenvironment regulates chondrocyte differentiation into either articular or growth plate cartilage. We tested this hypothesis by transplanting growth plate cartilage to the articular surface in an EGFP rat model that enabled cell tracing (Paper 4). We found that hypertrophic differentiation appeared to be inhibited in growth plate cartilage transplanted to the articular surface. The transplanted cartilage also underwent structural remodeling into articular-like cartilage, which suggests that the synovial microenvironment inhibits hypertrophic differentiation and promotes articular cartilage formation

Macroeconomic Determinants of Gold Industry Stock Returns

Over the past 12 years, the gold bullion continues to become a significant investment. Financial advisors and analysts have recommended investors invest a small portion of their portfolio into this precious metal commodity asset. Gold mining stocks offer investors the ability to leverage volatile but rising gold prices. The expected relationship between gold price and gold stock returns is that for every 1% increase in gold prices, gold stocks can be expected to gain 2-3%. Building on a multifactor model by Faff and Chan (1998), we examine how macroeconomic factors such as market returns, the foreign exchange rate, and the interest rate affect the U.S. gold industry stock returns over the period 1996-2011. We contribute to the literature by exploring the significance of business cycle’s in explaining gold stock returns

Friend Suggestion and Friend Browsing in Web 2.0 Applications

Web 2.0 and social network applications have become increasingly popular. It is important for these applications to help users in maintaining their social networks by providing functions on friend suggestion and friend browsing. However, little study in this area has been reported in the literature. This paper proposes the design of two modules for friend suggestion and friend browsing. The first module is based on Hopfield Net spreading activation, while the second module is based on hyperbolic tree and self-organizing map. The proposed evaluation plan is also presented in the paper

Understanding the sanitising efficacy of a new, environmentally friendly hot tub water treatment product, eco3spa

Infrequent cleaning increases the risk of biofilms being formed on hot tub surfaces and pipes by Escherichia coli and Pseudomonas aeruginosa. This is aided by inappropriate use of biofilm control agents which promote antimicrobial resistance. This presents a challenge for water sanitation using biofilm prevention and removal products.This study analysed the efficacy of an environmentally friendly 3-step biofilm prevention and removal product designed for hot tubs called eco3spa. Eco3spa contains Active Oxygen and a water conditioner which was assessed for growth and biofilm prevention properties. Eco3spa biofilm remover was tested in combination with Active Oxygen for biofilm removal properties.E. coli K12 and P. aeruginosa PA01 cultures were grown and biofilms formed under static conditions at 37oC, normal operating temperature and maintenance temperatures of 25oC. Various product concentrations were tested for growth and biofilm prevention from pH 5.2-8. Pre-formed biofilms were treated with biofilm removal products before subjection to dynamic forces to mimic the flushing of water and function of jets in hot tubs.Results revealed that recommended concentrations of Active Oxygen prevent growth and biofilm formation of E. coli and P. aeruginosa without losing efficacy from pH 5.2 to 8. Addition of the water conditioner does not enhance Active Oxygen activity in preventing growth and biofilm formation. Furthermore, Active Oxygen kills E. coli within 5 minutes and chemical stability is maintained for at least 7 days. Light and fluorescent microscopy illustrated that Active Oxygen in combination with the water conditioner may lead to viable but non-culturable cells.This study demonstrates the sanitising efficacy of eco3spa in hot tub environments where efficacy of Active Oxygen is maintained over a defined pH range. Therefore, the industrial sponsor has been provided with more insights into the sanitising efficacy of eco3spa which promotes a water treatment product with benefits over chlorine

The short-lived MATα2 transcriptional regulator is ubiquitinated in vivo

The substrates of ubiquitin-dependent proteolytic pathways include both damaged or otherwise abnormal proteins and undamaged proteins that are naturally short-lived. Few specific examples of the latter class have been identified, however. Previous work has shown that the cell type-specific MAT-alpha-2 repressor of the yeast Saccharomyces cerevisiae is an extremely short-lived protein. We now demonstrate that alpha-2 is conjugated to ubiquitin in vivo. More than one lysine residue of alpha-2 can be joined to ubiquitin, and some of the ubiquitin moieties form a Lys48-linked multiubiquitin chain. Overexpression of degradation-impaired ubiquitin variants was used to show that at least a significant fraction of alpha-2 degradation is dependent on its ubiquitination

Diffusion through the ex vivo vitreal body - bovine, porcine, and ovine models are poor surrogates for the human vitreous

© 2018 The Authors. Published by Elsevier B.V.The human vitreous humour is a complex gel structure whose composition and physical properties can vary considerably from person to person and also change with age. To date, the viscoelastic properties of the human vitreous gel has not been thoroughly investigated and despite many years of intensive research, an ideal vitreous substitute remains a challenge. Understanding the physical structure and properties of the vitreous is of fundamental and therapeutic interest, providing a clear insight into diffusion and transport of administered ophthalmic drug molecules into the vitreous. A number of mammalian surrogates, mainly bovine, porcine and ovine vitreous humours have been greatly used in the literature as a means of studying ophthalmic drug transport and diffusion. In this study, the mechanical, physical and rheological properties of ovine, porcine, and bovine surrogates were investigated and compared to human vitreous. In addition, a bespoke Franz cell construct was used to compare the diffusion of a model drug (i.e. fluorescein) through vitreous samples. Despite the similarity in rheological properties between bovine, porcine and human vitreous samples (p > 0.05), diffusion of fluorescein through the different vitreous samples revealed great differences in values of steady-state flux and diffusion coefficient. In addition, a first-generation vitreous mimic, composed of 4.5 mg/mL hyaluronic acid with complex viscosity of 0.3 ± 0.01 Pa has been evaluated and was demonstrated to be a better mimic of the human vitreous than the mammalian samples investigated.Peer reviewedFinal Published versio