5,285 research outputs found

    CONSUMER PREFERENCES FOR ELECTRICITY FROM BIOENERGY AND OTHER RENEWABLES

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    This study ascertains residential electricity consumers' support and willingness to pay for electricity from renewable sources. Then, willingness to pay for specified renewable energy sources (solar, wind, landfill wastes, bioenergy from fast growing crops, and bioenergy from forest products wastes). Effects of demographics and environmental behaviors are estimated.Institutional and Behavioral Economics,

    Genomic insights into the evolution of hybrid isoprenoid biosynthetic gene clusters in the MAR4 marine streptomycete clade

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    BackgroundConsiderable advances have been made in our understanding of the molecular genetics of secondary metabolite biosynthesis. Coupled with increased access to genome sequence data, new insight can be gained into the diversity and distributions of secondary metabolite biosynthetic gene clusters and the evolutionary processes that generate them. Here we examine the distribution of gene clusters predicted to encode the biosynthesis of a structurally diverse class of molecules called hybrid isoprenoids (HIs) in the genus Streptomyces. These compounds are derived from a mixed biosynthetic origin that is characterized by the incorporation of a terpene moiety onto a variety of chemical scaffolds and include many potent antibiotic and cytotoxic agents.ResultsOne hundred and twenty Streptomyces genomes were searched for HI biosynthetic gene clusters using ABBA prenyltransferases (PTases) as queries. These enzymes are responsible for a key step in HI biosynthesis. The strains included 12 that belong to the 'MAR4' clade, a largely marine-derived lineage linked to the production of diverse HI secondary metabolites. We found ABBA PTase homologs in all of the MAR4 genomes, which averaged five copies per strain, compared with 21 % of the non-MAR4 genomes, which averaged one copy per strain. Phylogenetic analyses suggest that MAR4 PTase diversity has arisen by a combination of horizontal gene transfer and gene duplication. Furthermore, there is evidence that HI gene cluster diversity is generated by the horizontal exchange of orthologous PTases among clusters. Many putative HI gene clusters have not been linked to their secondary metabolic products, suggesting that MAR4 strains will yield additional new compounds in this structure class. Finally, we confirm that the mevalonate pathway is not always present in genomes that contain HI gene clusters and thus is not a reliable query for identifying strains with the potential to produce HI secondary metabolites.ConclusionsWe found that marine-derived MAR4 streptomycetes possess a relatively high genetic potential for HI biosynthesis. The combination of horizontal gene transfer, duplication, and rearrangement indicate that complex evolutionary processes account for the high level of HI gene cluster diversity in these bacteria, the products of which may provide a yet to be defined adaptation to the marine environment

    Follow the Leader: Adoption Behavior in Food Retailers' Decision to Offer Fresh Irradiated Ground Beef

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    During the 14-month period from May 2002 to June 2003, approximately 10 percent of U.S. supermarkets began to offer fresh irradiated ground beef under the stores' own labels. Using a survey of supermarket store managers from this time period, this paper investigates the factors that influenced new product offerings and adoptions. Results from the adoption model show that factors associated with competition and structure in the food retailing industry play a strong role in the decision. Among other results, we find that variables relating to a competitor's adoption status and proximity significantly affect a store's decision to offer fresh irradiated ground beef.Marketing,

    Adoption Behavior in Food Retailers' Decision to Offer Fresh Irradiated Ground Beef

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    During the 14-month period from May 2002 to June 2003, approximately 10 percent of U.S. supermarkets began to offer fresh irradiated ground beef under the stores' own labels. Using a survey of supermarket store managers from this time period, this paper investigates the factors that influenced stores' adoption of irradiated ground beef. Results from the adoption model show that factors associated with competition, merchandising philosophy, and structure in the food retailing industry play a strong role in the decision. Among other results, we find that variables relating to a competitor's adoption status and proximity can increase the likelihood of a store's adoption decision.Marketing,

    The Chemical Origin of Behavior is Rooted in Abiogenesis

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    We describe the initial realization of behavior in the biosphere, which we term behavioral chemistry. If molecules are complex enough to attain a stochastic element to their structural conformation in such as a way as to radically affect their function in a biological (evolvable) setting, then they have the capacity to behave. This circumstance is described here as behavioral chemistry, unique in its definition from the colloquial chemical behavior. This transition between chemical behavior and behavioral chemistry need be explicit when discussing the root cause of behavior, which itself lies squarely at the origins of life and is the foundation of choice. RNA polymers of sufficient length meet the criteria for behavioral chemistry and therefore are capable of making a choice

    Strategic Alignment Map: The Ongoing Development of a Program Management Tool

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    This article explains the development and continuous modification of a tool that can be used to improve both participant experience and faculty performance in Executive Education programs. This tool is the Strategy Alignment Map (SAM). Participants that use the SAM create a document that summarizes 1) their strategic purpose for attending a program, 2) specific learning outcomes and how they align with their strategic purpose, and 3) action steps for implementing the learning. Executive Education, faculty and the Dean all benefit in different ways from this tool that improves participant educational experiences

    Two wheeled lunar dumptruck

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    The design of a two wheel bulk material transport vehicle is described in detail. The design consists of a modified cylindrical bowl, two independently controlled direct drive motors, and two deformable wheels. The bowl has a carrying capacity of 2.8 m (100 ft) and is constructed of aluminum. The low speed, high HP motors are directly connected to the wheels, thus yielding only two moving parts. The wheels, specifically designed for lunar applications, utilize the chevron tread pattern for optimum traction. The vehicle is maneuvered by varying the relative angular velocities of the wheels. The bulk material being transported is unloaded by utilizing the motors to oscillate the bowl back and forth to a height at which dumping is achieved. The analytical models were tested using a scaled prototype of the lunar transport vehicle. The experimental data correlated well with theoretical predictions. Thus, the design established provides a feasible alternative for the handling of bulk material on the moon

    Self-similar correlation function in brain resting-state fMRI

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    Adaptive behavior, cognition and emotion are the result of a bewildering variety of brain spatiotemporal activity patterns. An important problem in neuroscience is to understand the mechanism by which the human brain's 100 billion neurons and 100 trillion synapses manage to produce this large repertoire of cortical configurations in a flexible manner. In addition, it is recognized that temporal correlations across such configurations cannot be arbitrary, but they need to meet two conflicting demands: while diverse cortical areas should remain functionally segregated from each other, they must still perform as a collective, i.e., they are functionally integrated. Here, we investigate these large-scale dynamical properties by inspecting the character of the spatiotemporal correlations of brain resting-state activity. In physical systems, these correlations in space and time are captured by measuring the correlation coefficient between a signal recorded at two different points in space at two different times. We show that this two-point correlation function extracted from resting-state fMRI data exhibits self-similarity in space and time. In space, self-similarity is revealed by considering three successive spatial coarse-graining steps while in time it is revealed by the 1/f frequency behavior of the power spectrum. The uncovered dynamical self-similarity implies that the brain is spontaneously at a continuously changing (in space and time) intermediate state between two extremes, one of excessive cortical integration and the other of complete segregation. This dynamical property may be seen as an important marker of brain well-being both in health and disease.Comment: 14 pages 13 figures; published online before print September 2

    Crusticorallina gen. nov., a nongeniculate genus in the subfamily Corallinoideae (Corallinales, Rhodophyta)

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    Molecular phylogenetic analyses of 18S rDNA (SSU) gene sequences confirm the placement of Crusticorallina gen. nov. in Corallinoideae, the first non-geniculate genus in an otherwise geniculate subfamily. Crusticorallina is distinguished from all other coralline genera by the following suite of morpho-anatomical characters: 1) sunken, uniporate gametangial and bi/tetrasporangial conceptacles, 2) cells linked by cell fusions, not secondary pit connections, 3) an epithallus of 1 or 2 cell layers, 4) a hypothallus that occupies 50% or more of the total thallus thickness, 5) elongate meristematic cells, 6) trichocytes absent. Four species are recognized based on rbcL, psbA and COI-5P sequences, C. painei sp. nov., the generitype, C. adhaerens sp. nov., C. nootkana sp. nov. and C. muricata comb. nov., previously known as Pseudolithophyllum muricatum. Type material of Lithophyllum muricatum, basionym of C. muricata, in TRH comprises at least two taxa, and therefore we accept the previously designated lectotype specimen in UC that we sequenced to confirm its identity. Crusticorallina species are very difficult to distinguish using morpho-anatomical and/or habitat characters, although at specific sites, some species may be distinguished by a combination of morpho-anatomy, habitat and biogeography. The Northeast Pacific now boasts six coralline endemic genera, far more than any other region of the world. This article is protected by copyright. All rights reserved
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