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101.
Urban and agricultural soils: conflicts and trade-offs in the optimization of ecosystem services 总被引:2,自引:0,他引:2
H. Setälä R. D. Bardgett K. Birkhofer M. Brady L. Byrne P. C. de Ruiter F. T. de Vries C. Gardi K. Hedlund L. Hemerik S. Hotes M. Liiri S. R. Mortimer M. Pavao-Zuckerman R. Pouyat M. Tsiafouli W. H. van der Putten 《Urban Ecosystems》2014,17(1):239-253
On-going human population growth and changing patterns of resource consumption are increasing global demand for ecosystem services, many of which are provided by soils. Some of these ecosystem services are linearly related to the surface area of pervious soil, whereas others show non-linear relationships, making ecosystem service optimization a complex task. As limited land availability creates conflicting demands among various types of land use, a central challenge is how to weigh these conflicting interests and how to achieve the best solutions possible from a perspective of sustainable societal development. These conflicting interests become most apparent in soils that are the most heavily used by humans for specific purposes: urban soils used for green spaces, housing, and other infrastructure and agricultural soils for producing food, fibres and biofuels. We argue that, despite their seemingly divergent uses of land, agricultural and urban soils share common features with regards to interactions between ecosystem services, and that the trade-offs associated with decision-making, while scale- and context-dependent, can be surprisingly similar between the two systems. We propose that the trade-offs within land use types and their soil-related ecosystems services are often disproportional, and quantifying these will enable ecologists and soil scientists to help policy makers optimizing management decisions when confronted with demands for multiple services under limited land availability. 相似文献
102.
José Manuel Herrerías-Velasco Rafael Herrerías-Pleguezuelo Johan René van Dorp 《Journal of applied statistics》2009,36(5):573-587
The generalized standard two-sided power (GTSP) distribution was mentioned only in passing by Kotz and van Dorp Beyond Beta, Other Continuous Families of Distributions with Bounded Support and Applications, World Scientific Press, Singapore, 2004. In this paper, we shall further investigate this three-parameter distribution by presenting some novel properties and use its more general form to contrast the chronology of developments of various authors on the two-parameter TSP distribution since its initial introduction. GTSP distributions allow for J-shaped forms of its pdf, whereas TSP distributions are limited to U-shaped and unimodal forms. Hence, GTSP distributions possess the same three distributional shapes as the classical beta distributions. A novel method and algorithm for the indirect elicitation of the two-power parameters of the GTSP distribution is developed. We present a Project Evaluation Review Technique example that utilizes this algorithm and demonstrates the benefit of separate powers for the two branches of activity GTSP distributions for project completion time uncertainty estimation. 相似文献
103.
Although the urgency with which the Dutch East India Company administration at the Cape built defensive works was a direct result of their fear of attack from both land and sea, there was an additional imperative, for the Castle at Cape Town stood as a symbol of Dutch colonial aspirations. In this paper, we compare written and material texts of one part of the Castle's architecture to show firstly, how the discordances between such sources can reveal an underside of early colonization and secondly, how the Castle moat, in the seventeenth century a stamp of aspirant power, was by the mid‐nineteenth century a dump and a public nuisance. 相似文献
104.
This paper considers five test statistics for comparing the recovery of a rapid growth‐based enumeration test with respect to the compendial microbiological method using a specific nonserial dilution experiment. The finite sample distributions of these test statistics are unknown, because they are functions of correlated count data. A simulation study is conducted to investigate the type I and type II error rates. For a balanced experimental design, the likelihood ratio test and the main effects analysis of variance (ANOVA) test for microbiological methods demonstrated nominal values for the type I error rate and provided the highest power compared with a test on weighted averages and two other ANOVA tests. The likelihood ratio test is preferred because it can also be used for unbalanced designs. It is demonstrated that an increase in power can only be achieved by an increase in the spiked number of organisms used in the experiment. The power is surprisingly not affected by the number of dilutions or the number of test samples. A real case study is provided to illustrate the theory. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
105.
Jacquelien van Stekelenburg Bert Klandermans Wilco W. van Dijk 《The Journal of social issues》2009,65(4):815-838
The emphasis in the social-psychological collective action literature is on why individuals take part in collective action; however, it does not elaborate on how different mobilizing contexts may appeal to distinct motivational dynamics to participate. The present study connects the microlevel of motivational dynamics of individual protesters with the mesolevel of social movement characteristics. To do so a field study was conducted. Protesters were surveyed in the act of protesting in two different demonstrations in two different town squares simultaneously organized by two social movements at exactly the same time against the same budget cuts proposed by the same government. But with one fundamental difference, the movements emphasized different aspects of the policies proposed by the government. This most similar systems design created a unique natural experiment, which enabled the authors to examine whether the motivational dynamics of individual protesters are moderated by the social movement context. Previous research suggested an instrumental path to collective action, and the authors added an ideology path. The authors expected and found that power-oriented collective action appeals to instrumental motives and efficacy and that value-oriented collective action appeals to ideological motives, and, finally, that efficacy mediates on instrumental motives and motivational strength, but only so in power-oriented action. 相似文献
106.
Barry van Driel 《Intercultural Education》2018,29(5-6):651-666
107.
In this paper we investigate differences between the organizational values of ministries and semi-autonomous executive agencies
(quangos) that operate at arms’ length. Quangos are expected to operate more business-like, hence they can be expected to
value profitability and other NPM-related values higher than ministries. Value incongruence between quangos and ministries
is hypothesized to decrease their level of trust. These hypotheses are tested, using combined data from two Dutch surveys
(n = 324). The results confirm the expectations, although different types of quangos have different degrees of value (in)congruence,
which may lead to variations in the quality of the relationship with their parent ministry. 相似文献
108.
This article is devoted to the construction and asymptotic study of adaptive, group‐sequential, covariate‐adjusted randomized clinical trials analysed through the prism of the semiparametric methodology of targeted maximum likelihood estimation. We show how to build, as the data accrue group‐sequentially, a sampling design that targets a user‐supplied optimal covariate‐adjusted design. We also show how to carry out sound statistical inference based on such an adaptive sampling scheme (therefore extending some results known in the independent and identically distributed setting only so far), and how group‐sequential testing applies on top of it. The procedure is robust (i.e. consistent even if the working model is mis‐specified). A simulation study confirms the theoretical results and validates the conjecture that the procedure may also be efficient. 相似文献
109.
This article describes a method for solving the one-good stochastic growth model by parameterizing the expectations part of the stochastic Euler equation. The conditional expectation is specified as a function of the state of the system, and the parameters of that function are estimated to solve the model. The article includes a discussion of how to find the parameters of the function and determine systematically the complexity of the functional form necessary to solve the model. 相似文献
110.
We investigate the interplay of smoothness and monotonicity assumptions when estimating a density from a sample of observations. The nonparametric maximum likelihood estimator of a decreasing density on the positive half line attains a rate of convergence of [Formula: See Text] at a fixed point t if the density has a negative derivative at t. The same rate is obtained by a kernel estimator of bandwidth [Formula: See Text], but the limit distributions are different. If the density is both differentiable at t and known to be monotone, then a third estimator is obtained by isotonization of a kernel estimator. We show that this again attains the rate of convergence [Formula: See Text], and compare the limit distributions of the three types of estimators. It is shown that both isotonization and smoothing lead to a more concentrated limit distribution and we study the dependence on the proportionality constant in the bandwidth. We also show that isotonization does not change the limit behaviour of a kernel estimator with a bandwidth larger than [Formula: See Text], in the case that the density is known to have more than one derivative. 相似文献