5,431 research outputs found

    Soil sustainability in organic agricultural production

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    Traditionally, the assessment of soil sustainability and the potential impact of cultivation are based upon the application of chemical procedures. In the absence of a biological context, these measurements offer little in understanding longterm changes in soil husbandry. Detailed microcosm investigations were applied as a predictive tool for management change. The microcosms were designed with homogenised soils treated with organic amendments. Key soil functional relationships were quantified using stable isotope techniques, biochemical measurements and traditional approaches

    Taxation and the Demand for Gambling: New Evidence from the United Kingdom.

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    In October 2001, the U.K. government implemented a dramatic shift in the taxation of gambling, resulting in a substantial decline in taxes levied on U.K. bookmakers. Using data before and after this event, we present econometric evidence on the demand response to this tax reduction. Our results suggest that the demand for bookmaker gambling is highly sensitive to taxation rates and that the decline in the rate of taxation led to a large increase in the demand for on-shore betting. We also find some evidence of price-induced substitution across different segments of the gambling industry. The U.K. policy initiative may provide useful information for policy makers in other countries who are contemplating changes in gambling taxation.

    Productivity Measurement in a Service Industry: Plant-Level Evidence from Gambling Establishments in the United Kingdom

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    Gambling is one of the fastest growing service industries. Unfortunately, there have been no studies of total factor productivity (TFP) in this sector. The purpose of this paper is to fill this gap, based on an analysis of U.K. establishment-level data. These data are derived from the Annual Respondents Database (ARD) file, constructed by the U.K. Office for National Statistics, consisting of individual establishment records from the Annual Census of Production. The ARD file contains detailed data on output, materials, energy, employment, and numerous plant and firm characteristics and is quite similar to the U.S.-based Longitudinal Research Database (LRD). This information can be used to construct measures of TFP. We also construct estimates of labour productivity, since TFP is may be measured with error. We use these data to estimate labour and total factor productivity equations based on a stochastic frontier production function framework. The latter approach enables us to assess whether investment in information technology enhances relative productivity. Our preliminary results suggest that the production function models fit well, generating plausible elasticity estimates and indicating constant returns to scale. While investment in computers per se does not appear to have a productivity enhancing effect, gambling establishments that use Internet-based technology appear to be closer to the frontier.

    An Econometric Analysis of Trends in Research Joint Venture Activity.

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    Edith Penrose was one of the first scholars to point out that firms may need to rely on research joint ventures (RJVs) to acquire access to resources that can help them achieve and sustain a competitive advantage. We estimate an econometric model of the propensity of firms to disclose their intension to engage in RJVs, in order to explain the recent precipitous decline in RJVs filed with the U.S. Department of Justice. We find that RJV activity is inversely related to the competitive position of U.S. firms in global high-technology industries and that the establishment of the U.S. Commerce Department's Advanced Technology Program (ATP) induced a structural change in the propensity of firms to engage in RJVs. Thus, two factors may explain the recent downturn in RJV filings: a substantial improvement in U.S. global performance in high-technology markets and a sharp decline in ATP funding.

    Economics and euthanasia

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    This paper argues that a cost-benefit type economic analysis of whether or not to prohibit euthanasia should not be undertaken by health services managers unless ethical issues have been resolved to a particular conclusion. A conclusion on ethical grounds in favour of the prohibition of euthanasia renders the consideration of economic criteria redundant. The case of the German euthanasia programme in the 1930s is used to illustrate the danger of attempting to combine ethical and economic criteria into a single decision rule

    Gathering experience in trust-based interactions

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    As advances in mobile and embedded technologies coupled with progress in adhoc networking fuel the shift towards ubiquitous computing systems it is becoming increasingly clear that security is a major concern. While this is true of all computing paradigms, the characteristics of ubiquitous systems amplify this concern by promoting spontaneous interaction between diverse heterogeneous entities across administrative boundaries [5]. Entities cannot therefore rely on a specific control authority and will have no global view of the state of the system. To facilitate collaboration with unfamiliar counterparts therefore requires that an entity takes a proactive approach to self-protection. We conjecture that trust management is the best way to provide support for such self-protection measures

    Tectonic variation and structural evolution of the West Greenland continental margin

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    Because of its geographic extent of over 2500 km (1553 mi), the West Greenland margin provides a much understudied example of a divergent continental margin, both with respect to hydrocarbon exploration and academic studies. A seismic interpretation study of representative two-dimensional reflection profiles from the Labrador Sea, Davis Strait, and Baffin Bay was undertaken to identify sedimentary and structural components to elucidate the tectonic development of the margin. Nine horizons were interpreted from six representative seismic lines in the area. Margin-scale tectono-stratigraphy was derived from isochron maps, the geometry of mappable faults and their associated stratal architecture. Rifting began in Early to Late Cretaceous at ca. 145–130 Ma, which was followed by two pulses of volcanism in Eocene and Paleocene ages. The transition to the drift stage includes a typical subsidence phase but also erosion, uplift, and deposition of Neogene postrift packages. The shift in the position of depocenters in the Davis Strait and the Labrador Sea during Paleocene and Miocene times is evidence for structural modification of the basin bounding faults. Drift stage deformation suggests a possible anticlockwise rotation in the orientation of the spreading axis in Baffin Bay culminating in an ultraslow sea-floor spreading. Sea-floor spreading on the West Greenland margin started in the south at 70 Ma in the Labrador Sea and propagated northward into the Baffin Bay by 60 Ma. Prospective petroleum systems include thick Cretaceous age strata, with structural traps provided by grabens and inversion structures. Our structural model provides insight into a margin that is highly variable in its structural configuration, further modified by other processes such as magma-assisted rifting that may result in elevated regional heat flow, which has considerable impact on hydrocarbon maturation. Further constraining the implications of heat flow associated with volcanic activities in comparison to that associated with lithospheric stretching will be critical in future exploration

    The rodent uterotrophic assay: Critical protocol features, studies with nonyl phenols, and comparison with a yeast estrogenicity assay

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    The major protocol features of the immature rat uterotrophic assay have been evaluated using a range of reference chemicals. The protocol variables considered include the selection of the test species and route of chemical administration, the age of the test animals, the maintenance diet used, and the specificity of the assay for estrogens. It is concluded that three daily oral administrations of test chemicals to 21- to 22-day-old rats, followed by determination of absolute uterus weights on the fourth day, provide a sensitive and toxicologically relevant in vivo estrogenicity assay. Rats are favored over mice for reasons of toxicological practice, but the choice of test species is probably not a critical protocol variable, as evidenced by the similar sensitivity of rats and mice to the uterotrophic activity of methoxychlor. Vaginal opening is shown to be a useful, but nondefinitive, adjunct to the uterotrophic assay. The ability of test chemicals to reduce or abolish the uterotrophic response of estradiol is suggested to provide a useful extension of the uterotrophic assay for the purpose of detecting antiestrogens. The results of a series of studies on the environmental estrogen nonyl phenol (NP), and its linear isomer n -nonyl phenol, confirm that branching of the aliphatic side chain is important for activity. 17beta-Desoxyestradiol is shown to be of similar activity to estradiol in the uterotrophic assay and is suggested to represent the "parent" estrogen of NP. Benzoylation of NP and 17-desoxyestradiol did not affect their uterotrophic activity, in contrast to the enhancing effect of benzoylation on estradiol. Selected chemicals shown to be active in the immature rat uterotrophic assay were also evaluated in an in vitro yeast human estrogen receptor transactivation assay. Most of the chemicals gave similar qualitative responses to those seen in the uterotrophic assay, and the detection of the estrogen methoxychlor by the yeast assay evidenced a degree of intrinsic metabolic competence. However, the assay had a reduced ability (compared to rodents) to hydrolyze the benzoate ester of estradiol, and the estrogenic benzoate derivative of NP was not active in the yeast assay. These last results indicate that current metabolic deficiencies of in vitro estrogenicity assays will limit the value of negative data for the immediate future. The results described illustrate the intrinsic complexity of evaluating chemicals for estrogenic activities and confirm the need for rigorous attention to experimental design and criteria for assessing estrogenic activity

    (4-Nitro­phenolato)(subphthalo­cyaninato)boron(III)1

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    The main feature of the structure of the title compound, C30H16BN7O3 or NO2PhO-BsubPc, are pairs of mol­ecules linked through π-inter­actions between the concave faces of the BsubPc fragments at a distance of 3.5430 (11) Å across an inversion centre. However, the angle between the planes of the five- and six-menbered rings involved in this inter­action is 1.44 (10)°, causing the inter­acting BsubPcs units to be slightly askew rather than parallel as is typical for π-stacking inter­actions
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