131,158 research outputs found
Asymmetric Information and R&D Disclosure: Evidence from Scientific Publications
Get PDFWe examine how asymmetric information in financial markets affects voluntary research and development (R&D) disclosure, considering scientific publications as a disclosure channel. Difference-in-differences regressions around brokerage house mergers and closures, which increase information asymmetry through reductions in analyst coverage, indicate a quick and sustained increase in scientific publications from treated firms relative to the number of publications from control firms. The treatment effects are concentrated among firms with higher information asymmetry and lower investor demand, firms with greater financial constraints, and firms with lower proprietary costs. We do not find evidence of changes in financial disclosure, nor do we find changes in patenting. Results from ordinary least squares regressions show that scientific publications by firms are positively associated with investor attention toward those firms. We complement these results with qualitative evidence from conference calls. Our results highlight the limitations and tradeoffs R&D firms face in their financial market disclosure policies
Infrared thermometers for small wires drawing
No full textThis work describes the design of two contactless thermometers based respectively on a
total radiance and two-color pyrometry scheme, developed to measure the temperature
of a small brass coated steel wire during wire drawing. In this critical condition, wire oscillation and relevant insertion errors do not allow using commercial contact or contactless
sensors. Thus, ad hoc pyrometers optical layouts have been designed in order to minimize
sensitivity to the wire oscillations and emissivity changes. Moreover, performances associated to different infrared detectors have been compared using as figure of merit the
achieved measurement uncertainty simulating typical disturbances, i.e. the background
temperature variation, the slope of the wire’s emissivity and the effect of the atmosphere
transmittance. Finally, the uncertainty budgets were drawn, evidencing the limitations of
the proposed methods and identifying the best configuration for both developed
instruments
Contactless temperature measurement of thin wires: methods comparison
No full textThis work describes the design of two contactless temperature measurement methods based on total radiance and two-colour pyrometry. The methods have been conceived to measure the temperature of a small brass coated steel wire during wire drawing. Usual contact sensors cannot be applied due to the wire movement and excessively large insertion errors in this critical condition. The pyrometers optical layouts have been analysed by means of numerical simulations in order to evidence their sensitivity to the wire oscillations. Performances of different infrared sensors have been compared on the basis of the achieved measurement uncertainty simulating background temperature variation, slope of the wire???s emissivity and the effect of the atmosphere absorption
3D bioprinting of cell-laden carbopol bioinks
Get PDFTraditional in vitro culture models are unable to fully reflect the organ microenvironment, due to differences in terms of cell morphology, protein expression, cell-cell and cell-matrix interactions, and drug response. In contrast, the flexibility of bioprinting modes allows for the deposition of cell-containing biomaterials in any free-form-inspired 3D structures on chip. The main purpose of this study was to design and optimize commercially available Carbopol-based 3D printing formulations, because of their many advantages, such as low-cost, the ability to produce clear and stable gels, and the water thickening. For this purpose, three different Carbopol gels (EDT 2020 NF, Ultrez 10 NF and NF-980) were tested in terms of printability and biocompatibility, with lung cancer epithelial (A549) and normal lung fibroblast (MRC-5) cells. This study demonstrates that Carbopol is a promising candidate for the 3D printing of cell-laden constructs, both in terms of rheology and printing performance
3D Cell Culture: Recent Development in Materials with Tunable Stiffness
Get PDFIt is widely accepted that three-dimensional cell culture systems simulate physiological conditions better than traditional 2D systems. Although extracellular matrix components strongly modulate cell behavior, several studies underlined the importance of mechanosensing in the control of different cell functions such as growth, proliferation, differentiation, and migration. Human tissues are characterized by different degrees of stiffness, and various pathologies (e.g., tumor or fibrosis) cause changes in the mechanical properties through the alteration of the extracellular matrix structure. Additionally, these modifications have an impact on disease progression and on therapy response. Hence, the development of platforms whose stiffness could be modulated may improve our knowledge of cell behavior under different mechanical stress stimuli. In this review, we have analyzed the mechanical diversity of healthy and diseased tissues, and we have summarized recently developed materials with a wide range of stiffness
MeSH term explosion and author rank improve expert recommendations
Get PDFInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
Get PDFBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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