1,687 research outputs found

    The Problem of Confirmation in the Everett Interpretation

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    I argue that the Oxford school Everett interpretation is internally incoherent, because we cannot claim that in an Everettian universe the kinds of reasoning we have used to arrive at our beliefs about quantum mechanics would lead us to form true beliefs. I show that in an Everettian context, the experimental evidence that we have available could not provide empirical confirmation for quantum mechanics, and moreover that we would not even be able to establish reference to the theoretical entities of quantum mechanics. I then consider a range of existing Everettian approaches to the probability problem and show that they do not succeed in overcoming this incoherence

    Residential irrigation as a driver of urban bird communities

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    *Background/Question/Methods*
The demand for fresh water has largely outpaced supply both globally and locally with current water management policies unable to meet the needs of urban, agricultural, and industrial activities. Irrigation is one of the many anthropogenic uses of water and is arguably the most important maintenance factor in a landscape. This is particularly true in an arid climate, such as the Central Valley of California. Urban residents' decisions about the design and maintenance of their landscapes affect bird species richness. Published research indicates that these decisions are also affected by the residents' socioeconomic status. However, the driver of this relationship remains unknown. This paper uses data from the Fresno Bird Count, a citizen science organization, to test the hypothesis that neighborhood socioeconomic status influences residential irrigation regimes, which influences plant cover, in turn influencing bird diversity and abundance. A random sampling grid containing 460 points are used as locations for five minute point counts for the Fresno Bird Count ("fresnobirds.org":http://fresnobirds.org/). Socioeconomic data has been obtained from the U.S. Census and irrigation regimes from the city of Fresno. Aerial imagery and ground sampling on point count locations are used for characterizing habitat.

*Results/Conclusions*
Preliminary analysis of the first year of data (2008) supports this hypothesis and reveals a north/south gradient of bird diversity paralleling the socioeconomic gradient of Fresno. This paper will present results from a more comprehensive analysis of data including the spring 2009 bird census. Policies in the U.S. regarding the distribution and cost of water are changing in response to increased water demands, and the city of Fresno is about to undergo such a change. In 2013 a policy of metered water is scheduled to begin, which is predicted to increase water conservation by residents due to an increase in it overall cost. In addition to examining coupled socio-ecological drivers of urban diversity, this study will be the first part of a Before After Control Impact experiment taking advantage of the planned implementation of metering the cost of water use. The results can help guide the city in improving its management of urban habitat and biodiversity.
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    I\u27ve Got the Blues For Tennessee

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    Photograph of Lucas Sisters; Illustration of woman on hill looking toward homehttps://scholarsjunction.msstate.edu/cht-sheet-music/9305/thumbnail.jp

    CEO Compensation Structure following Succession: Evidence of Optimal Incentives with Career Concerns

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    To motivate managers to pursue shareholder interests, boards may design management compensation packages to reward managers for good firm performance. However, note that when CEOs are far from retirement, they have career concerns. In these cases, Gibbons and Murphy argue that it may not be optimal for their current compensation to be too dependent on firm performance. Testing this proposition, we find that abnormal returns are negatively related to the percentage of performance-based pay of newly hired CEOs when companies announce CEO successions. Since these newly hired CEOs are likely some distance from retirement, we interpret these results as being consistent with Gibbons and Murphy; it may be better to allow newly hired CEOs to be paid in human capital increases from the managerial labor market than to have their current pay too closely related to performance

    Assembly Time Modeling Through Connective Complexity Metrics

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    This paper presents an approach for the development of surrogate models predicting the assembly time of a system based on complexity metrics of the physical system architecture when detailed geometric information is unavailable. A convention for modelling physical architecture is presented, followed by a sample of 10 analysed systems used for training and three systems used for validation. These systems are evaluated on complexity metrics developed from graph theoretic measures. An example model is developed based on a series of regressions of trends observed within the sample data. This is validated against the systems that are not used to develop the model. The model developed uses average path length, part count and path length density to approximate assembly time within the standard deviation of the subjective variation possible in Boothroyd and Dewhurst design for assembly (DFA) analysis. While the specific example model developed is generalisable only to systems similar to those in the sample set, the capability to develop mappings between physical architecture and assembly time in early-stage design is demonstrated

    Evolution of a 3 \msun star from the main sequence to the ZZ Ceti stage: the role played by element diffusion

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    The purpose of this paper is to present new full evolutionary calculations for DA white dwarf stars with the major aim of providing a physically sound reference frame for exploring the pulsation properties of the resulting models in future communications. Here, white dwarf evolution is followed in a self-consistent way with the predictions of time dependent element diffusion and nuclear burning. In addition, full account is taken of the evolutionary stages prior to the white dwarf formation. In particular, we follow the evolution of a 3 \msun model from the zero-age main sequence (the adopted metallicity is Z=0.02) all the way from the stages of hydrogen and helium burning in the core up to the thermally pulsing phase. After experiencing 11 thermal pulses, the model is forced to evolve towards its white dwarf configuration by invoking strong mass loss episodes. Further evolution is followed down to the domain of the ZZ Ceti stars on the white dwarf cooling branch. Emphasis is placed on the evolution of the chemical abundance distribution due to diffusion processes and the role played by hydrogen burning during the white dwarf evolution. Furthermore, the implications of our evolutionary models for the main quantities relevant for adiabatic pulsation analysis are discussed. Interestingly, the shape of the Ledoux term is markedly smoother as compared with previous detailed studies of white dwarfs. This is translated into a different behaviour of the Brunt-Vaisala frequency.Comment: 11 pages, 11 figures, accepted for publication in MNRA

    The Development and Validation of the Successful Psychopathy Scale

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    The personality construct known as ‘Successful Psychopathy’ has attracted the interests of researchers and clinicians alike. The concept suggests an individual who demonstrates the core traits associated with psychopathy but is able to adapt and function within society to prototypical or superior standards. There has yet to be a sound theoretical model of this construct by which to base a psychometric measure. This protocol presents the ethical procedure that will endeavour to create such a measure and validate it within general population samples
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