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101.
The American electric utility industry is entering a moment of transition. Once viewed as a stable and secure consortium of publicly regulated monopolies that produce and distribute electricity, the industry has weathered market restructuring only to face the ever-present risk of natural disasters, price fluctuations, terrorist attacks, and blackouts. This paper uses five criteria—technical feasibility, cost, negative externalities, reliability, and security—to evaluate the broad portfolio of energy technologies available to American electricity policymakers. Upon close inspection, energy efficiency practices, renewable energy systems, and small-scale distributed generation technologies appear to offer many advantages over large and centralized nuclear and fossil fueled generators. Contrary to the mimetic commentary produced by the media, these three approaches would present policymakers a superior alternative for curbing electricity demand, minimizing the risk of fuel interruptions and shortages, helping improve the fragile transmission network, and reducing environmental harm  相似文献   
102.
The public administration literature asserts that autonomy is central to performance. In this article we develop a managerial autonomy index, which we apply to 22 water utilities in Africa, Asia and the Middle East. The 16 items that underlie our composite autonomy index display a high degree of internal consistency. This speaks for the validity of the autonomy concept. We find that the autonomy scores of the 22 utilities vary widely. We also find strong and positive associations between autonomy scores and six out of eight key performance indicators. Our results support the idea that autonomy is central to the performance of water service providers. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
103.
This paper formulates a medium-term macroeconomic model of disposable income, unemployment, inflation and state spending, proposes a theory of qualitative choice to explain electoral popularity in terms of these variables and develops three approaches to the formulation of political-economic policy. The first approach is static, sets the tax rate to reconcile the interests of various pressure groups and yields a political trade-off between the private and public sector. The second approach relies on maximizing the probability of winning the next election and gives rise to a political business cycle unless the electorate votes strategically. The implications of crowding out of private investment under alternative monetary rules, autonomous behaviour of the state bureaucracy and tax-indexation for the political business cycle are also examined. The third approach analyzes the objective of maximizing the uninterrupted length in office. It yields a short-run political cycle superimposed on a longer cycle.  相似文献   
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Development of a 3D-based automated firearms evidence comparison system   总被引:1,自引:0,他引:1  
Since the early 1990's, the idea of automated systems for the comparison of microscopic firearms evidence has received considerable attention. The main objective of such systems is to enable the analysis of large amounts of evidence, therefore, transforming the comparison of firearms evidence from an evidence verification tool into a crime-fighting tool. Two such systems have been widely used in United States forensic laboratories: namely, the Integrated Ballistics Identification System (IBIS) (1) and DRUGFIRE (2). Both IBIS and DRUGFIRE have in common the fact that their characterization of a specimen is based on a two-dimensional (2D) representation of the specimen's surface. Although these systems have provided satisfactory results in the identification of cartridge cases, their performance in the identification of bullets has not yet met firearms examiner's expectations. This project was motivated by the premise that a better characterizations of the bullet's surface should translate into better performance of automated identification systems. A three-dimensional (3D) characterization of the bullet's surface is proposed as an alternative to a 2D characterization. This paper discusses the development and preliminary results obtained with SciClops, an automated microscopic comparison system based on the use of a 3D characterization of a bullet's surface.  相似文献   
107.
Validation of a 16-locus fluorescent multiplex system   总被引:24,自引:0,他引:24  
STR multiplexes have been indispensable for the efficient genotyping of forensic samples. The PowerPlex 16 System contains the coreCODIS loci, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, CSF1PO, FGA, THOI, TPOX, vWA, the sex determinant locus, amelogenin, and two pentanucleotide STR loci, Penta D and Penta E. This multiplex satisfies the locus requirements for most national databases and is the most efficient currently available system due to its single PCR amplification. To provide the groundwork for judicial acceptance, including the publication of primer sequences, and to evaluate laboratory-to-laboratory variation, a developmental validation for casework on this commercially available system was performed in 24 laboratories and produced the following conclusions. Amplification was reliable on a variety of thermal cyclers and product could be analyzed on either an ABI PRISM 310 Genetic Analyzer or an ABI PRISM 377 DNA Sequencer. Genotyping using single source samples was consistent between 0.25 and 2 ng of input DNA template with a few laboratories obtaining complete genotypes at 0.0625 ng. However, heterozygote allele imbalance (<60% peak height balance) caused by stochastic effects was observed at a rate of 13% with 0.125 ng DNA and 22% at 0.0625 ng DNA. Mixture analyses were done using a total of 1 ng of DNA template. Most alleles were detected in mixtures of 4 to 1 and some minor alleles were detected in mixtures of 19 to 1. Optimum amplification cycle number was dependent on the sensitivity of the detection instrument used and could also be adjusted to accommodate larger amounts of DNA on solid supports such as FTA paper. Reaction conditions including volume, annealing temperature, and concentrations of primer, AmpliTaq Gold, and magnesium were shown to be optimal yet robust enough to withstand moderate variations without affecting genotype analysis. Environmental, matrix and standard source analyses revealed an ability to obtain complete genotypes in all sample types except those exposed to 80 degrees C for 12-48 days. Finally, comparison of genotype results from the PowerPlex 16 System with other commercially available systems on non-probative reference and forensic samples showed consistent results.  相似文献   
108.
Self-report questionnaires are frequently used in youth research, but doubt remains whether total anonymity affects the results. This study compared the responses of 704 mainly 16–17-year-old adolescents to self-report measures of various health indicators in 2 groups: anonymous and confidential collection. For most health indicators no significant differences were found. Perceived health, use of alcohol, and aggressive behavior (for boys) were reported significantly less frequently in the confidential group (small effect size). It appeared that pupils with high scores on social desirability do not respond differently at most health indicators in the 2 conditions. For most health characteristics, epidemiologically useful outcomes may be derived from confidential self-report measures, which are also valuable for detecting individual at-risk children. Similar studies in lower grades and other types of education should confirm the results.Youth Department, Municipal Health Service Rotterdam area. Main research interests are emotional and behavioral problems of adolescents, youth health care, monitoring.Youth Department, Municipal Health Service Rotterdam area. Main research interests are emotional and behavioral problems of adolescents, youth health care, monitoring.Research Department, Municipal Health Service Rotterdam area. Major research interests include emotional and behavioral problems of adolescents, suicidal behavior, youth health care, monitoring.  相似文献   
109.
This article examines the prevalence and consequences of authoritarian attitudes among elites in Argentina, Brazil, Chile, Colombia, Mexico, and Venezuela. We focus on the connection between antidemocratic elite attitudes and support for democracy; the causes and effects of authoritarian attitudes among elites and their implications for authoritarianism; and the impact of authoritarian attitudes beyond social policy preferences to other policy areas that have indirect implications for order. Contrary to some of the literature, we find that antidemocratic attitudes affect elites' support for democracy. Our analysis also speaks to the debate on the origins of authoritarianism. Much of the evidence supports Altemeyer's notion that perceived threat raises levels of authoritarianism, rather than Feldman's contention that threat strengthens the influence of authoritarian attitudes. Finally, we demonstrate that there is a broader influence of authoritarian attitudes on economic policy preferences, but only where those policies appear to have implications for social order.  相似文献   
110.
Several recent studies examine the degree to which congressional behavior affects candidates’ electoral fortunes (e.g., Carson, 2005). Research examining electoral competitiveness (Bond, Campbell, & Cottrill, 2001; Koetzle, 1998) and roll call voting (Bailey & Brady, 1998; Jones, 2003) finds that diversity in the electorate mediates the impact of numerous variables upon election outcomes and representation. However, the influence of diversity on other modes of representation – such as the policy positions taken by Senate candidates–remains unexplored. We investigate the link between representation and Senate candidates’ policy positions and thereby examine the degree to which voter diversity affects candidates’ policy responsiveness. We find that diversity significantly influences responsiveness, both directly and indirectly – candidates in homogenous states are more responsive to constituents than are candidates in heterogeneous states.  相似文献   
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