19,983 research outputs found

    Distribution patterns, weed incursions and origins of terrestrial flora at the Capricorn-Bunker Islands, Great Barrier Reef, Australia

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    A checklist of vascular plants of the 15 Capricorn-Bunker Islands (CBI) (lat 23° 11’ to 24° 07’S; long 151° 43’ to 152° 43’E) compiled from 2007/08 surveys, recorded 131 vascular plant species including 44 (34%) native and 87 (66%) naturalized species from 55 families and 104 genera. New native records include Hernandia nymphaeifolia and Boerhavia sp. (Bargara L.Pedley 5382). An increase of about 35 exotic species over 23 years was recorded indicating a weed incursion rate of 1.5 species per annum. Cakile edentula (13 islands) and Solanum americanum (12 islands) are the most widespread exotic weeds. The naturalised flora ranged from 5% at Erskine Island (low disturbance) to 68% at Lady Elliot Island (very high disturbance). Achyranthes aspera, Argusia argentea and Pisonia grandis are the only species found on all 15 islands. Six indigenous species are limited to one island: Boerhavia sp. (Bargara L.Pedley 5382), Calophyllum inophyllum, Clerodendrum inerme, Hernandia nymphaeifolia, Stephania japonica and Ximenia americana. Patterns of plant distributions, diversity and origin are discussed. Eleven indigenous species reach their southern limit at the CBI, indicating connectivity with the Indo-Pacific region. PATN analyses using native flora generated two island groups. Tryon, Heron, North West, Masthead, Wilson, Wreck and Erskine Islands are the most closely related islands. Another group of related islands includes North Reef, Lady Musgrave, Fairfax Islands, Hoskyn and One Tree Islands. With the inclusion of the exotic flora, Lady Elliot Island separated into its own distinct group. Greater conservation management efforts are required to control and minimise the introduction of exotic weed species to islands with high human visitation

    Factorization is not violated

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    We show that existing proofs of factorization imply the cancellation of certain multiladder contributions that Gotsman, Levin, and Maor had suggested would invalidate the basic factorization theorem in QCD. No modifications of the original argument are necessary, although the details of the example offer useful insight into the mechanisms of factorization.Comment: 11 pages including 10 figure

    The Feasibility of Using Expert Systems in the Management of Human Resources

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    The purpose of this paper is to introduce a decision aid that is being used increasingly in the business world, the expert system, and to begin to examine its potential for human resource management. First, the expert system technology is reviewed, with a special emphasis on the players, those involved in developing and using the system, and the parts, the three main components of a system. This is followed by an analysis of the costs and benefits and the advantages and disadvantages that have been ascribed to expert systems. We conclude this initial research endeavor by presenting some preliminary findings which suggest that employees are willing to cooperate with expert systems, even those that require personal information, and that they see some benefits to using expert systems as decision aids

    The Effects of a Flexible Benefits Expert System on Employee Decisions and Satisfaction

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    Anecdotal reports and recent reviews assert that expert systems are potentially useful decision aids in human resource management. This study examines the effects of an expert system designed to aid employees when they make their choices in a flexible bellcfit program. A four group quasi-field experimental design is used to examine the relative effects of the expert system compared to a conventional spreadsheet decision aid. Eighty employees at an NCR-AT&T facility were randomly selected and assigned to the groups. Employees using the expert system expressed greater benefits satisfaction compared to those using the spreadsheet aid. The spreadsheet did not have any effect on employees\u27 decisions. When the benefit choices recommended by the expert system differed from the employees\u27 current choices, employees are more likely to change their choices. Consequently, the expert system is likely to affect employees\u27 decisions. Implications are discussed and future research needs are suggested

    Phaseless three-dimensional optical nano-imaging

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    We propose a method for optical nano-imaging in which the structure of a three-dimensional inhomogeneous medium may be recovered from far-field power measurements. Neither phase control of the illuminating field nor phase measurements of the scattered field are necessary. The method is based on the solution to the inverse scattering problem for a system consisting of a weakly-scattering dielectric sample and a strongly-scattering nano-particle tip. Numerical simulations are used to illustrate the results.Comment: 10 pages, 2 figure
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