5,598 research outputs found

    An Improved Approach to Measuring Sexual Dimorphism in Snakes: Morphological Variation in the Bahamian Racer (Cubophis vudii vudii)

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    Sexual dimorphism in animals exists in many forms, including overall size difference between the sexes (sexual size dimorphism, SSD) and size and structural differences in body components (sexual body component dimor­phism, SBCD). Studies of sexual dimorphism seek to determine whether dimorphic traits result from sexual selection, natural selection, or non-adaptive processes. Characterizing sexual dimorphism depends on identifying an unbiased character for overall body size, which can then be used to assess both SSD and SBCD. Most studies of snakes use snout-vent length (SVL) for this purpose, but SVL may itself be dimorphic. In this study, we examined SSD and SBCD in three island populations of the Bahamian Racer (Cubophis vudii vudii). Discriminant function analysis (DFA) showed that head width (females wider) and tail length (males longer) best discriminated between the sexes, and total length provided the least discrimination. Linear models using total length as the least-biased measure for overall size revealed an absence of SSD, but SBCD existed for head size (width 8.9% greater in females, length similar), trunk length (4.3% longer in females), and tail length (9.8% longer in males). Linear models also revealed differences among island populations for total length (New Providence < Eleuthera = Allen Cay) and head length (Allen Cay < Eleuthera < New Providence), but not head width or tail length. Extent of SBCD varied depending on choice of character to control for overall body size, with total length yielding the most female-biased values, and geometric mean, principal component 1 (PC1) of a principal components analysis, and SVL providing increasingly more male-biased values, respectively. Body condition was statistically similar for the two sexes and three seasons (spring, summer-fall, winter), but the mod­erate and large effect sizes, respectively, suggest that females were heavier than males, and both sexes were heaviest in spring. Females, which represented 64.9 of all snakes, suffered injuries disproportionately to males (19.7% and 3.1%, respectively), but no differences in sex ratio or frequency of injury existed among the island populations. Collectively, these findings illustrate the utility of using DFA and other approaches (geometric mean, PC1) to identify a relatively unbiased reference character for overall body size and suggest that sexual and natural selection interact to shape the morphology of these snakes

    Fuel supplier selection for large scale UK bioenergy schemes

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    This article presents a potential method to assist developers of future bioenergy schemes when selecting from available suppliers of biomass materials. The method aims to allow tacit requirements made on biomass suppliers to be considered at the design stage of new developments. The method used is a combination of the Analytical Hierarchy Process and the Quality Function Deployment methods (AHP-QFD). The output of the method is a ranking and relative weighting of the available suppliers which could be used to improve optimization algorithms such as linear and goal programming. The paper is at a conceptual stage and no results have been obtained. The aim is to use the AHP-QFD method to bridge the gap between treatment of explicit and tacit requirements of bioenergy schemes; allowing decision makers to identify the most successful supply strategy available

    Transient extreme ultraviolet measurement of element-specific charge transfer dynamics in multiple-material junctions

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    The absorption of solid state materials in complex photonic and optoelectronic devices overlap in the visible spectrum. Due to the overlap of spectral features, ultrafast measurements of charge carrier dynamics and transport is obscured. Here, the element specificity of transient extreme ultraviolet (XUV) spectroscopy is advanced as a probe for studying photoexcited charge transport in multiple-material junctions. The core-hole excited by the XUV transitions also imparts structural information on to the probed electronic transition. Transient XUV can therefore measure electron and averaged phonon dynamics for each elemental species in a junction. Application to polaron measurement in α-Fe_2O_3, valley-specific scattering in Si, and charge transfer in a nanoscale Ni-TiO_2-Si junction will be discussed

    A decision support system for supplier selection and order allocation in stochastic, multi-stakeholder and multi-criteria environments

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    Integrated supplier selection and order allocation is an important decision for both designing and operating supply chains. This decision is often influenced by the concerned stakeholders, suppliers, plant operators and customers in different tiers. As firms continue to seek competitive advantage through supply chain design and operations they aim to create optimized supply chains. This calls for on one hand consideration of multiple conflicting criteria and on the other hand consideration of uncertainties of demand and supply. Although there are studies on supplier selection using advanced mathematical models to cover a stochastic approach, multiple criteria decision making techniques and multiple stakeholder requirements separately, according to authors' knowledge there is no work that integrates these three aspects in a common framework. This paper proposes an integrated method for dealing with such problems using a combined Analytic Hierarchy Process-Quality Function Deployment (AHP-QFD) and chance constrained optimization algorithm approach that selects appropriate suppliers and allocates orders optimally between them. The effectiveness of the proposed decision support system has been demonstrated through application and validation in the bioenergy industry

    Prospectus, October 9, 1970

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    VETS INSTALL NEW OFFICERS; Parkland Offers Loans, Grants; Prospectus Gets New Advisor; Counselor\u27s Corner; Letters to Editor; Pollution-Solutions?: Issues and Values; Bull Page: Veterans Meeting, New Instructor, CUCT First Production, Catch 22, Edgebrook Buses, No Classes, Fashion Seminar, Organizations Officers, Scholarships; Yes Sir -- I\u27m For Real!; Coaches Corner; Cross Countryhttps://spark.parkland.edu/prospectus_1970/1025/thumbnail.jp

    Prospectus, October 16, 1970

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    PARKLAND WELCOMES NEW COUNSELORS; Letters to Editor; Oops!; Pollution-Solutions?: Real Of Objectivity; Comments: War And Peace; Bull Page: Movie Revue Joe, Decision Making, Conveniamus, Campus Organizations, Vets Meeting, Discussion Group, IOC, Movie, U.N. Week, Phi Gamma IOTA, Mailboxes, Wit N\u27 Wisdom, Mailboxes; Yes Sir -- I\u27m For Real: Illini Nips PC 7-6 In Defensive Battle; Coaches Corner; Six Man Flag Footballhttps://spark.parkland.edu/prospectus_1970/1024/thumbnail.jp
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