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311.
The U.S. electric power sector has experienced a substantial shift of the generation mix since the turn of the century, moving from heavy reliance on coal‐powered generation to one drawing more from natural gas and, more recently, renewables. This transition has been forged by a mix of macroeconomic factors (recession and recovery); technological breakthroughs (horizontal drilling coupled with hydraulic fracturing; improvements in natural gas plant efficiency); clean energy policies at federal, state, and local levels of government; and private sector demands for carbon‐free energy sources. These factors have combined to reduce carbon emissions from electric power generation substantially this century. In this article we examine the extent of this transition, its causes, as well as the distinct American institutional factors steering it, including energy and environmental federalism, electoral politics, and the political economy of clean energy policy enactment and resistance.  相似文献   
312.
Journal of Youth and Adolescence - Court-involved youth exhibit high rates of psychiatric symptoms, substance use, and delinquency, yet little is known about the contributing roles of caregiver and...  相似文献   
313.
Why do political parties in parliamentary systems undertake actions, such as joining a coalition government, that will entail significant costs for their members in subsequent elections? Recent research points to the incentive structures faced by differentially positioned members of a parliamentary party: unlike backbenchers, MPs who hold a ministerial portfolio can use the prerequisites of executive office to shield themselves from the costs of governance. This article tests the theory of executive particularism by examining the electoral fortunes of government ministers in India. Sitting government ministers are found to outperform other candidates; however, tests of causality fail to demonstrate that holding a ministerial portfolio causes this electoral benefit. Instead, it appears that a candidate’s electoral performance enhances the likelihood of being granted a ministerial portfolio in the first place. This finding raises questions about the generalizability of claims that party elites can use ministerial office to shield themselves from the costs of governing.  相似文献   
314.
Ammonium nitrate fuel oil is an explosive mixture found in most antipersonnel landmines (APL) buried throughout the Colombian territory. During more than 50 years of internal conflict, the Colombian government has found that trained dogs are the most effective method to detect APL. However, the olfactive signature in ANFO is unknown and also if there are differences in detection related to the explosive manufacturing origin. Therefore, this work begins with the analytical validation of the method used to determine ammonia, in its derivatized form as carbamate, released by home-made ANFO using HS-SPME-GC-FID. Once validated, the method was used to identify ammonia and other organic volatile compounds present in ANFO, under laboratory and simulated field conditions. The validation process includes the evaluation of the optimum conditions for the derivation and extraction of butylcarbamate, the determination of the working ranges with linear response in FID, the limits of detection and quantification, the sensitivity, and the precision. The results of the validation established linearity and sensitivity in a concentration between 20 and 120 mg/L, as well as low limits of detection and quantification of 6.4 and 21.4 mg/L, respectively. Also, an intermediate precision of 11% for butylcarbamate with a repeatability of 8%. The validated method showed in real samples of home-made ANFO besides ammonia, the presence of low molecular methylamines, and also exhibited differences in volatile compositions according to the origin. The objective of this work is to offer a reliable analytical methodology for the extraction and analysis of volatile compounds from ANFO.  相似文献   
315.
Gunshot residue (GSR) analysis and their interpretation provide crucial information on a criminal investigation involving the use of firearms. To date, several approaches have been proposed for the implementation of a combined sampling and analysis of inorganic (IGSR) and organic GSR (OGSR). However, it is not clear at this stage if concurrent analyses of both types of residue might be detrimental to the analysis of IGSR currently applied in forensic laboratories. Thus, this work aims to compare and evaluate three different protocols for the combined collection and analysis of IGSR and OGSR. These methods, respectively, involve the use of a modified stub (with two halves, one for the detection of IGSR and the other for the analysis of OGSR); the sequential recovery of GSR with two stubs mounted with different adhesives (double-sided carbon tape and Tesa® TACK) and the sequential analysis of IGSR and OGSR from a single carbon stub following carbon deposition. The detection of IGSR was carried out using SEM-EDX, while OGSR analysis was performed using ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS). Obtained results for experiments performed using Geco Sinoxid® ammunition indicated that sequential analysis was the most suitable protocol for the combined collection and analysis of both IGSR and OGSR. A higher number of inorganic (characteristic and consistent) particles and higher concentrations of ethylcentralite, N-nitrosodiphenylamine, diphenylamine, and nitroglycerin were recovered with this method.  相似文献   
316.
Adolescent networks include parents, friends, and romantic partners, but research on the social learning mechanisms related to delinquency has not typically examined the characteristics of all three domains simultaneously. Analyses draw on data from the Toledo Adolescent Relationships Study (n = 957), and our analytic sample contains 51% male and 49% female as well as 69% white, 24% African-American, and 7% Latino respondents. Parents,’ peers,’ and partners’ deviance are each related to respondents’ delinquency, and affiliation with a greater number of deviant networks is associated with higher self-reported involvement. Analyses that consider enmeshment type indicate that those with both above average romantic partner and friend delinquency report especially high levels of self-reported involvement. In all comparisons, adolescents with deviant romantic partners are more delinquent than those youths with more prosocial partners, regardless of friends’ and parents’ behavior. Findings highlight the importance of capturing the adolescent’s entire network of affiliations, rather than viewing these in isolation, and suggest the need for additional research on romantic partner influences on delinquent behavior and other adolescent outcomes.
Robert A. LonardoEmail:
  相似文献   
317.
Experiences with racism are a common occurrence for African American youth and may result in negative self perceptions relevant for the experience of depressive symptoms. This study examined the longitudinal association between perceptions of racism and depressive symptoms, and whether perceived academic or social control mediated this association, in a community epidemiologically-defined sample of urban African American adolescents (N = 500; 46.4% female). Structural equation modeling revealed that experiences with racism were associated with low perceived academic control, which in turn was associated with increased depressive symptoms. Findings suggest that experiences with racism can have long lasting effects for African American youth’s depressive symptoms, and highlight the detrimental effects of experiences with racism for perceptions of control in the academic domain. Implications for intervention are discussed.
Sharon F. LambertEmail:
  相似文献   
318.
Asia's growing share of the global economy provides one of the strongest themes in contemporary analysis of international affairs. The remarkable economic achievements of Japan, Korea, and Taiwan over the past 50 years have been compounded more recently by the rise of the Chinese and Indian economies. While the significance of this change in the way international wealth is shared was beyond doubt before the onset of the current global financial crisis, many commentators expect that when the world eventually emerges from the crisis Asia's share of the global economy will have grown even further.

This shift clearly has strategic importance: economic decisions made in Asia, whether by governments or business, are now more important for the rest of the world than they have been for centuries. If military power were moving in the same direction, and at the same pace, the strategic consequences would be even greater.

This paper examines trends in Asian military spending and modernisation. It begins with a summary of defence spending among Asian countries.1 In this paper the term “Asia” is used to include the 22 countries from Pakistan to Japan. It does not include Afghanistan or any of the countries of central Asia, or Russia, Australia, New Zealand, or the Pacific Island countries. As explained above, data is not equally available for all 22 countries. View all notes It next considers the nature of the capabilities and equipment they are acquiring, and comments on the way in which forces are being structured, commanded, and managed. It then comments on the range of different factors that are driving military spending and modernisation in Asia, and offers particular comment on China in this regard. The paper then concludes with brief comments on United States and Australian military spending and development.  相似文献   

319.
Growth curve analyses were used to investigate parents’ and peers’ influence on adolescents’ choice to abstain from antisocial behavior in a community-based sample of 416 early adolescents living in the Southeastern United States. Participants were primarily European American (91%) and 51% were girls. Both parents and peers were important influences on the choice to abstain from antisocial behavior. Over the four-year period adolescents relied increasingly on parents as influences and relied less on peers as influences to deter antisocial behavior. Significant gender differences emerged and suggested that female adolescents relied more on social influences than did male adolescents but that as time progressed male adolescents increased the rate at which they relied on peers. Higher family income was associated with choosing peers as a social influence at wave 1, but no other significant income associations were found. Understanding influences on adolescents’ abstinence choices is important for preventing antisocial behavior.
Emily C. CookEmail:

Emily C. Cook   is in her final year of doctoral studies in human development and family studies at the University of North Carolina at Greensboro. Her research interests include peer influences and parental influences on adolescents’ problem behaviors, parental influences on adolescents’ social development, and effective prevention and interventions for adolescents who exhibit problem behaviors. Cheryl Buehler   is a professor of human development and family studies at the University of North Carolina at Greensboro. Her research interests include marital conflict, marital relations, parenting, and adolescent well-being. Robert Henson   is an assistant professor of educational research methodology at the University of North Carolina at Greensboro. Dr. Henson’s research interests include educational measurement, cognitive diagnosis models, hierarchical linear models, and mathematical statistics.  相似文献   
320.
Humanitarian organisations respond to increasing donor requests to assess economic aspects of their programmes, including cost-effectiveness. This article presents results from a survey of humanitarian agency staff and donor agencies, investigating such requests. Findings indicate a need for clear guidelines and capacity building in these economic assessments, expressed by both humanitarian staff and donor agencies themselves. While improving efficiency is important to ensure effective humanitarian response, caution is warranted in adopting overly burdensome and complex assessments of efficiency which are poorly understood by staff requesting and responding to them, the outcomes of which may lead to reductive and decontextualised decision-making.  相似文献   
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