60 research outputs found

    A note on the universality of the Hagedorn behavior of pp-wave strings

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    Following on from recent studies of string theory on a one-parameter family of integrable deformations of AdS5Ă—S5AdS_{5}\times S^{5} proposed by Lunin and Maldacena, we carry out a systematic analysis of the high temperature properties of type IIB strings on the associated pp-wave geometries. In particular, through the computation of the thermal partition function and free energy we find that not only does the theory exhibit a Hagedorn transition in both the (J,0,0)(J,0,0) and (J,J,J)(J,J,J) class of pp-waves, but that the Hagedorn temperature is insensitive to the deformation suggesting an interesting universality in the high temperature behaviour of the pp-wave string theory. We comment also on the implications of this universality on the confinement/deconfinement transition in the dual N=1\mathcal{N}=1 Leigh-Strassler deformation of N=4{\cal N}=4 Yang-Mills theory.Comment: 25 pages; fixed minor typo; added reference

    Deformed PP-waves from the Lunin-Maldacena Background

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    In this article we study a pp-wave limit of the Lunin-Maldacena background. We show that the relevant string theory background is a homogeneous pp-wave. We obtain the string spectrum. The dual field theory is a deformation of N=4 super Yang-Mills theory. We have shown that, for a class of operators, at O(g_{YM}^2) and at leading order in N, all contributions to the anomalous dimension come from F-terms. We are able to identify the operator in the deformed super Yang-Mills which is dual to the lowest string mode. By studying the undeformed theory we are able to provide some evidence, directly in the field theory, that a small set of nearly protected operators decouple. We make some comments on operators in the Yang-Mills theory that are dual to excited string modes.Comment: 22 pages, 1 figure; Final version to appear in JHE

    Application of Wear-Resistant, NanoComposite Coatings Produced from Iron-Based Glassy Powders

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    This report talks about Application of Wear-Resistant, NanoComposite Coatings Produced from Iron-Based Glassy Powders

    The persistence of early childhood maturity: International evidence of longrun age effects,”

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    Abstract A continuum of ages exists at school entry due to the use of a single school cut-off date -making the "oldest" children approximately twenty percent older than the "youngest" children. We provide substantial evidence that these initial maturity differences have long lasting effects on student performance across OECD countries. In particular, the youngest members of each cohort score 4-12 percentiles lower than the oldest members in grade four and 2-9 percentiles lower in grade eight. In fact, data from Canada and the United States shows that the youngest members of each cohort are even less likely to attend university

    What makes health impact assessments successful? Factors contributing to effectiveness in Australia and New Zealand

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    Background: While many guidelines explain how to conduct Health Impact Assessments (HIAs), less is known about the factors that determine the extent to which HIAs affect health considerations in the decision making process. We investigated which factors are associated with increased or reduced effectiveness of HIAs in changing decisions and in the implementation of policies, programs or projects. This study builds on and tests the Harris and Harris-Roxas' conceptual framework for evaluating HIA effectiveness, which emphasises context, process and output as key domains. Methods: We reviewed 55 HIA reports in Australia and New Zealand from 2005 to 2009 and conducted surveys and interviews for 48 of these HIAs. Eleven detailed case studies were undertaken using document review and stakeholder interviews. Case study participants were selected through purposeful and snowball sampling. The data were analysed by thematic content analysis. Findings were synthesised and mapped against the conceptual framework. A stakeholder forum was utilised to test face validity and practical adequacy of the findings. Results: We found that some features of HIA are essential, such as the stepwise but flexible process, and evidence based approach. Non-essential features that can enhance the impact of HIAs include capacity and experience; 'right person right level'; involvement of decision-makers and communities; and relationships and partnerships. There are contextual factors outside of HIA such as fit with planning and decision making context, broader global context and unanticipated events, and shared values and goals that may influence a HIA. Crosscutting factors include proactive positioning, and time and timeliness. These all operate within complex open systems, involving multiple decision-makers, levels of decision-making, and points of influence. The Harris and Harris-Roxas framework was generally supported. Conclusion: We have confirmed previously identified factors influencing effectiveness of HIA and identified new factors such as proactive positioning. Our findings challenge some presumptions about 'right' timing for HIA and the rationality and linearity of decision-making processes. The influence of right timing on decision making needs to be seen within the context of other factors such as proactive positioning. This research can help HIA practitioners and researchers understand and identify what can be enhanced within the HIA process. Practitioners can adapt the flexible HIA process to accommodate the external contextual factors identified in this report

    The impact of power and relationship commitment on the integration between manufacturers and customers in a supply chain

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    Supply chain integration (SCI) has received increasing attention from scholars and practitioners in recent years. However, our knowledge of what influences SCI is still very limited. Although marketing and management researchers have investigated power and relationship commitment issues between organizations, few have examined their impact on SCI. This paper extends the power–relationship commitment theory established in Western marketing literature and links it with SCI in China, through examining the relationship between power, relationship commitment and the integration between manufacturers and their customers. We propose and empirically test a model using data collected from 617 manufacturing companies in China. The results show that different types of customer power impact manufacturers’ relationship commitment in different ways. Expert power, referent power and reward power are important in improving manufacturers’ normative relationship commitment, while reward power and coercive power enhance instrumental relationship commitment. We also found that normative relationship commitment had a greater impact on customer integration than instrumental relationship commitment. These findings are interpreted in light of national culture differences between China and the U.S. in terms of power distance and collectivism, which provide a new perspective on SCI

    Agency culture, constitutional provisions and entrepreneurship: a cross-country analysis

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    Substantial and systematic cross-country variation in entrepreneurship rates has been found in vari- ous studies. We attempt to explain such differences focusing on the interaction between institutional factors and population psychological characteristics. Constitutional provisions supporting economic freedom are our measure of the institutional context, whereas we proxy psychological characteristics with a country’s endowment of agency culture. We apply an IV-GMM treatment to deal with endoge- 20 neity to a data set comprising 86 countries over the period 2004–2013, and we control for de facto vari- ables and other factors that are likely to influence entrepreneurship. Our results demonstrate that agency culture is indeed an important predictor of entrepreneurship and that this effect is moderated by constitutional provisions supporting economic freedom. In particular, the impact of agency culture on entrepreneurship becomes stronger as a country expands the constitutional protection of eco- 25 nomic rights

    Guidelines for Genome-Scale Analysis of Biological Rhythms

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    Genome biology approaches have made enormous contributions to our understanding of biological rhythms, particularly in identifying outputs of the clock, including RNAs, proteins, and metabolites, whose abundance oscillates throughout the day. These methods hold significant promise for future discovery, particularly when combined with computational modeling. However, genome-scale experiments are costly and laborious, yielding “big data” that are conceptually and statistically difficult to analyze. There is no obvious consensus regarding design or analysis. Here we discuss the relevant technical considerations to generate reproducible, statistically sound, and broadly useful genome-scale data. Rather than suggest a set of rigid rules, we aim to codify principles by which investigators, reviewers, and readers of the primary literature can evaluate the suitability of different experimental designs for measuring different aspects of biological rhythms. We introduce CircaInSilico, a web-based application for generating synthetic genome biology data to benchmark statistical methods for studying biological rhythms. Finally, we discuss several unmet analytical needs, including applications to clinical medicine, and suggest productive avenues to address them
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