108 research outputs found

    What is the impact of Private and Public R&D on Clean Technology Firms’ Performance? An International Perspective.

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    Research and Development (R&D) has often been cited as key to promote the development of clean technologies in both the short and long run. Robust economic performance for clean technology firms may occur in countries in which research and development is conducted by governments as well as by businesses. The goal of this paper is to examine how private and public R&D affects firm profitability. Utilizing an international data set of clean technology firms, this study finds performance of clean technology firms to be quite favorable when compared to firms in the MSCI World index. The study examines how different countries perform in these industries. Finally, the impact both corporate and public R&D have had on these firms’ performance is analyze

    The Search For A Dog-Free Portfolio: Why Unions Matter To Investors

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    This paper uses portfolio filtering and weighting research to create a dog-free portfolio.  The variables used to create the dog-free portfolio include level of unionization and book-to-market.  The filtered and weighted portfolio is averaging 47 basis points alpha per month from 1991-2007 over the benchmark S&P500, outperforming in 60.8% of the months.  Using annual data, the portfolio averages 603 basis points alpha from 1991-2007 over the benchmark S&P500, outperforming 82.4% of the time.&nbsp

    Modeling the Spatial Distribution and Fruiting Pattern of a Key Tree Species in a Neotropical Forest: Methodology and Potential Applications

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    Damien Caillaud is with UT Austin and Max Planck Institute for Evolutionary Anthropology; Margaret C. Crofoot is with the Smithsonian Tropical Research Institute, Max Planck Institute for Ornithology, and Princeton University; Samuel V. Scarpino is with UT Austin; Patrick A. Jansen is with the Smithsonian Tropical Research Institute, Wageningen University, and University of Groningen; Carol X. Garzon-Lopez is with University of Groningen; Annemarie J. S. Winkelhagen is with Wageningen University; Stephanie A. Bohlman is with Princeton University; Peter D. Walsh is with VaccinApe.Background -- The movement patterns of wild animals depend crucially on the spatial and temporal availability of resources in their habitat. To date, most attempts to model this relationship were forced to rely on simplified assumptions about the spatiotemporal distribution of food resources. Here we demonstrate how advances in statistics permit the combination of sparse ground sampling with remote sensing imagery to generate biological relevant, spatially and temporally explicit distributions of food resources. We illustrate our procedure by creating a detailed simulation model of fruit production patterns for Dipteryx oleifera, a keystone tree species, on Barro Colorado Island (BCI), Panama. Methodology and Principal Findings -- Aerial photographs providing GPS positions for large, canopy trees, the complete census of a 50-ha and 25-ha area, diameter at breast height data from haphazardly sampled trees and long-term phenology data from six trees were used to fit 1) a point process model of tree spatial distribution and 2) a generalized linear mixed-effect model of temporal variation of fruit production. The fitted parameters from these models are then used to create a stochastic simulation model which incorporates spatio-temporal variations of D. oleifera fruit availability on BCI. Conclusions and Significance -- We present a framework that can provide a statistical characterization of the habitat that can be included in agent-based models of animal movements. When environmental heterogeneity cannot be exhaustively mapped, this approach can be a powerful alternative. The results of our model on the spatio-temporal variation in D. oleifera fruit availability will be used to understand behavioral and movement patterns of several species on BCI.The National Center For Ecological Analysis is supported by NSF Grant DEB-0553768, the University of California Santa Barbara and the State of California. The Forest Dynamics Plots were funded by NSF Grants to Stephen Hubbell DEB-0640386, DEB-0425651, DEB-0346488, DEB-0129874, DEB-00753102, DEB-9909347, DEB-9615226, DEB-9615226, DEB-9405933, DEB-9221033, DEB-9100058, DEB-8906869, DEB-8605042, DEB-8206992, DEB-7922197, and by the Center for Tropical Forest Science, the Smithsonian Tropical Forest Research Institute, The John D. and Catherine T. MacArthur Foundation, the Mellon Foundation and the Celera Foundation. DC is supported by NSF grant DEB-0749097 to L.A. Meyers. SS is supported by an NSF Graduate Research Fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Biological Sciences, School o

    Faculty roles and role preferences in ten fields of professional study

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    Teaching faculty in ten entry-level professional fields reported varying amounts of time devoted to teaching, research, consulting, and professional practice but did not differ in time devoted to administration. The faculty member's own role view was most closely related to time use, but for time spent in teaching and research, faculty age and institutional type (but not gender) were also significant predictors. Even after several general demographic characteristics and environmental variables that potentially differentiate professional from discipline-based faculty are taken into account, different professional fields may be characterized by group climates which influence or reinforce certain faculty roles.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43598/1/11162_2004_Article_BF00991875.pd

    Merkel cell carcinoma: Critical review with guidelines for multidisciplinary management

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    Merkel cell carcinoma (MCC) is a relatively rare cutaneous malignancy that occurs predominantly in the older white population. The incidence of MCC appears to have tripled during the past 20 years; an increase that is likely to continue because of the growing number of older Americans. The pathogenesis of MCC remains largely unknown. However, ultraviolet radiation and immunosuppression are likely to play a significant pathogenetic role. Many questions currently remain unanswered regarding the biologic behavior and optimal treatment of MCC. Large, prospective, randomized studies are not available and are unlikely to be performed because of the rarity of the disease. The objective of this review was to provide a comprehensive reference for MCC based on a critical evaluation of the current data. The authors investigated the importance of sentinel lymph node biopsy as a staging tool for MCC to assess the status of the regional lymph node basin and to determine the need for additional therapy to the lymph node basin. In an attempt to standardize prospective data collection with the intention to define prognostic indicators, the authors also present histopathologic profiles for primary MCC and sentinel lymph nodes. The controversies regarding the appropriate surgical approach to primary MCC, the use of adjuvant radiation therapy, and the effectiveness of adjuvant chemotherapy were examined critically. Finally, the authors have provided treatment guidelines based on the available evidence and their multidisciplinary experience. Cancer 2007. © 2007 American Cancer Society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56047/1/22765_ftp.pd

    A Genomewide Functional Network for the Laboratory Mouse

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    Establishing a functional network is invaluable to our understanding of gene function, pathways, and systems-level properties of an organism and can be a powerful resource in directing targeted experiments. In this study, we present a functional network for the laboratory mouse based on a Bayesian integration of diverse genetic and functional genomic data. The resulting network includes probabilistic functional linkages among 20,581 protein-coding genes. We show that this network can accurately predict novel functional assignments and network components and present experimental evidence for predictions related to Nanog homeobox (Nanog), a critical gene in mouse embryonic stem cell pluripotency. An analysis of the global topology of the mouse functional network reveals multiple biologically relevant systems-level features of the mouse proteome. Specifically, we identify the clustering coefficient as a critical characteristic of central modulators that affect diverse pathways as well as genes associated with different phenotype traits and diseases. In addition, a cross-species comparison of functional interactomes on a genomic scale revealed distinct functional characteristics of conserved neighborhoods as compared to subnetworks specific to higher organisms. Thus, our global functional network for the laboratory mouse provides the community with a key resource for discovering protein functions and novel pathway components as well as a tool for exploring systems-level topological and evolutionary features of cellular interactomes. To facilitate exploration of this network by the biomedical research community, we illustrate its application in function and disease gene discovery through an interactive, Web-based, publicly available interface at http://mouseNET.princeton.edu
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