1,881 research outputs found

    Shareholder Returns from Supplying Trade Credit

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    We examine shareholder wealth implications of supplying financing to customers. Robust results demonstrate that excess returns and trade receivables are directly and significantly related. Further evidence indicates the value of receivables is higher for suppliers with stronger motives relating to operating and contracting costs. The results also suggest a discounted value of receivables for financially unconstrained firms. Overall, we conclude that investors recognize trade credit as an effective instrument in mitigating frictions hindering sales growth. Thus, certain suppliers are positioned to derive increased strategic benefits from credit policy

    Partnerships as a potential means of increasing the production of hardwood timber on NIPF lands in North Mississippi

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    North Mississippi has significant hardwood timber resources. Hardwood timber in the region has traditionally been an important source of raw material for furniture and other wood-based industries. In recent years, however, demand has greatly increased for hardwood timber for use in the pulp and paper industry, resulting in increased harvest levels of pole-sized and small sawtimber-sized hardwoods in the region. Increased harvests of hardwood timber have given rise to concerns about the longerterm availability of hardwoods that are large enough in size to be efficiently converted into lumber and other solid wood products. Futures options, futures contracts, leases, and limited partnerships were initially considered for potential application to increase the longer-term production of hardwood sawtimber on nonindustrial private forest (NIPF) lands in North Mississippi. Considering the resource, the NIPF ownership, and the timber markets involved, limited partnerships were chosen for further evaluation. Results of informal discussions involving hardwood sawmill operators, private landowners, and timberland investment firm representatives are presented. A discussion follows, assessing the acceptability and attributes of partnerships in contrast to other possible options such as long-term leases as a positive influence for investment in the long-term production of hardwood sawtimber in North Mississippi

    Relating Satellite Imagery with Grain Protein Content

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    Satellite images, captured during the growing seasons of barley, sorghum and wheat were analysed to establish a relationship between the spectral response and the harvested grain protein content. This study was conducted near Jimbour (approx. 151 degrees 10'E and 27 degrees 05'S) in southern Queensland. Grain protein contents of the geo-referenced samples, collected manually during the harvest, were determined using a laboratory-based near-infrared spectrophotometer. Grain protein contents in grain varied between 7.4 - 15.2% in barley, 6.2 - 10.6% in sorghum and 13.1 - 15.6% in wheat. The Landsat images of 18 September 1999 (a week after barley flowering), 5 March 2000 (three weeks before sorghum harvest), and 15 August 2001 (two weeks before wheat flowering) were analysed. Additionally, an ASTER image of 24 September 2001 (three weeks after wheat flowering) was also examined. Digital numbers, extracted from raw image bands and derived indices, were correlated with grain protein contents. The grain protein content in barley was correlated strongly (r>0.80) with bands 2, 4 and 5 of the Landsat scene, first principal component, and the tasselled cap brightness and greenness indices. Similarly, wheat protein content was well correlated (r>0.75) with the near infrared band (band 4) of the Landsat scene, first principal component, and the tasselled cap brightness, greenness and wetness indices. The band 3 (near infrared band) of the ASTER image, captured well after flowering, was moderately correlated (

    Cluster analysis with MOODS‐SR illustrates a potential bipolar disorder risk phenotype in young adults with remitted major depressive disorder

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147140/1/bdi12693_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147140/2/bdi12693.pd

    Role of Natural Killer Cells in Innate Protection against Lethal Ebola Virus Infection

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    Ebola virus is a highly lethal human pathogen and is rapidly driving many wild primate populations toward extinction. Several lines of evidence suggest that innate, nonspecific host factors are potentially critical for survival after Ebola virus infection. Here, we show that nonreplicating Ebola virus-like particles (VLPs), containing the glycoprotein (GP) and matrix protein virus protein (VP)40, administered 1–3 d before Ebola virus infection rapidly induced protective immunity. VLP injection enhanced the numbers of natural killer (NK) cells in lymphoid tissues. In contrast to live Ebola virus, VLP treatment of NK cells enhanced cytokine secretion and cytolytic activity against NK-sensitive targets. Unlike wild-type mice, treatment of NK-deficient or -depleted mice with VLPs had no protective effect against Ebola virus infection and NK cells treated with VLPs protected against Ebola virus infection when adoptively transferred to naive mice. The mechanism of NK cell–mediated protection clearly depended on perforin, but not interferon-γ secretion. Particles containing only VP40 were sufficient to induce NK cell responses and provide protection from infection in the absence of the viral GP. These findings revealed a decisive role for NK cells during lethal Ebola virus infection. This work should open new doors for better understanding of Ebola virus pathogenesis and direct the development of immunotherapeutics, which target the innate immune system, for treatment of Ebola virus infection

    The coordination of cell growth during fission yeast mating requires Ras1-GTP hydrolysis

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    The spatial and temporal control of polarity is fundamental to the survival of all organisms. Cells define their polarity using highly conserved mechanisms that frequently rely upon the action of small GTPases, such as Ras and Cdc42. Schizosaccharomyces pombe is an ideal system with which to study the control of cell polarity since it grows from defined tips using Cdc42-mediated actin remodeling. Here we have investigated the importance of Ras1-GTPase activity for the coordination of polarized cell growth during fission yeast mating. Following pheromone stimulation, Ras1 regulates both a MAPK cascade and the activity of Cdc42 to enable uni-directional cell growth towards a potential mating partner. Like all GTPases, when bound to GTP, Ras1 adopts an active conformation returning to an inactive state upon GTP-hydrolysis, a process accelerated through interaction with negative regulators such as GAPs. Here we show that, at low levels of pheromone stimulation, loss of negative regulation of Ras1 increases signal transduction via the MAPK cascade. However, at the higher concentrations observed during mating, hyperactive Ras1 mutations promote cell death. We demonstrate that these cells die due to their failure to coordinate active Cdc42 into a single growth zone resulting in disorganized actin deposition and unsustainable elongation from multiple tips. These results provide a striking demonstration that the deactivation stage of Ras signaling is fundamentally important in modulating cell polarity

    Parameter identification problems in the modelling of cell motility

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    We present a novel parameter identification algorithm for the estimation of parameters in models of cell motility using imaging data of migrating cells. Two alternative formulations of the objective functional that measures the difference between the computed and observed data are proposed and the parameter identification problem is formulated as a minimisation problem of nonlinear least squares type. A Levenberg–Marquardt based optimisation method is applied to the solution of the minimisation problem and the details of the implementation are discussed. A number of numerical experiments are presented which illustrate the robustness of the algorithm to parameter identification in the presence of large deformations and noisy data and parameter identification in three dimensional models of cell motility. An application to experimental data is also presented in which we seek to identify parameters in a model for the monopolar growth of fission yeast cells using experimental imaging data. Our numerical tests allow us to compare the method with the two different formulations of the objective functional and we conclude that the results with both objective functionals seem to agree

    Syntheses, characterization, density functional theory calculations, and activity of tridentate SNS zinc pincer complexes

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    A series of tridentate SNS ligand precursors were metallated with ZnCl2 to give new tridentate SNS pincer zinc complexes. The zinc complexes serve as models for the zinc active site in liver alcohol dehydrogenase (LADH) and were characterized with single crystal X-ray diffraction, 1H, 13C, and HSQC NMR spectroscopies and electrospray mass spectrometry. The bond lengths and bond angles of the zinc complexes correlate well to those in horse LADH. The zinc complexes feature SNS donor atoms and pseudotetrahedral geometry about the zinc center, as is seen for liver alcohol dehydrogenase. The SNS ligand precursors were characterized with 1H, 13C, and HSQC NMR spectroscopies and cyclic voltammetry, and were found to be redox active. Gaussian calculations were performed and agree quite well with the experimentally observed oxidation potential for the pincer ligand. The zinc complexes were screened for the reduction of electron poor aldehydes in the presence of a hydrogen donor, 1-benzyl-1,4-dihydronicotinamide (BNAH). The zinc complexes enhance the reduction of electron poor aldehydes. Density functional theory calculations were performed to better understand why the geometry about the zinc center is pseudo-tetrahedral rather than pseudo-square planar, which is seen for most pincer complexes. For the SNS tridentate pincer complexes, the data indicate that the pseudo-tetrahedral geometry was 43.8 kcal/mol more stable than the pseudo-square planar geometry. Density functional theory calculations were also performed on zinc complexes with monodentate ligands and the data indicate that the pseudo-tetrahedral geometry was 30.6 kcal/mol more stable than pseudo-square planar geometry. Overall, the relative stabilities of the pseudo-tetrahedral and pseudo-square planar systems are the same for this coordination environment whether the ligand set is a single tridentate SNS system or is broken into three separate units. The preference of a d10 Zn center to attain a tetrahedral local environment trumps any stabilization gained by removal of constraints within the ligand set

    Charting Past, Present, and Future Research in the Semantic Web and Interoperability

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    Huge advances in peer-to-peer systems and attempts to develop the semantic web have revealed a critical issue in information systems across multiple domains: the absence of semantic interoperability. Today, businesses operating in a digital environment require increased supply-chain automation, interoperability, and data governance. While research on the semantic web and interoperability has recently received much attention, a dearth of studies investigates the relationship between these two concepts in depth. To address this knowledge gap, the objective of this study is to conduct a review and bibliometric analysis of 3511 Scopus-registered papers on the semantic web and interoperability published over the past two decades. In addition, the publications were analyzed using a variety of bibliometric indicators, such as publication year, journal, authors, countries, and institutions. Keyword co-occurrence and co-citation networks were utilized to identify the primary research hotspots and group the relevant literature. The findings of the review and bibliometric analysis indicate the dominance of conference papers as a means of disseminating knowledge and the substantial contribution of developed nations to the semantic web field. In addition, the keyword co-occurrence network analysis reveals a significant emphasis on semantic web languages, sensors and computing, graphs and models, and linking and integration techniques. Based on the co-citation clustering, the Internet of Things, semantic web services, ontology mapping, building information modeling, bioinformatics, education and e-learning, and semantic web languages were identified as the primary themes contributing to the flow of knowledge and the growth of the semantic web and interoperability field. Overall, this review substantially contributes to the literature and increases scholars’ and practitioners’ awareness of the current knowledge composition and future research directions of the semantic web field. View Full-Tex
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