Bounded automorphisms and quasi-isometries of finitely generated groups

Let G be any finitely generated infinite group. Denote by K(G) the FC-centre of G, i.e., the subgroup of all elements of G whose centralizers are of finite index in G. Let QI(G) denote the group of quasi-isometries of G with respect to word metric. We observe that the natural homomorphism from the group of automorphisms of G to QI(G) is a monomorphism only if K(G) equals the centre Z(G) of G. The converse holds if K(G)=Z(G) is torsion free. We apply this criterion to many interesting classes of groups.Comment: This is the corrected version. Published in J. Group Theory, 8 (2005), 515--52

An Overview of environmental issues and protection measures in Indian non-ferrous plants

In the industrial scenario of the country, non-ferrous industry plays a predominant role producing variety of metals and alloys for application in chemical, petrochemical, structural, power and engineering sectors. Base metal industries have witnessed remarkable changes in the past two decades besides registering considerable growth. But, most of these base metal industrial developments are generally associated with environmental degradation viz., by way of discharge of wastes into air, natural water bodies or subsoil. Release of harmful gases and suspended particulate matters (SPM) into air leads to ecological imbalance, resulting in de¬struction of natural life cycle of flora and fauna and many other associ¬ated harmful effects. Environmental degradation has become one of the most pressing problems facing India today. Tackling the pollution prob¬lem needs innovative and effective approach and industries should be encouraged to adopt non-polluting technologies rather than seeking to regulate the discharged toxic effluents. This critical review includes en¬vironmental impacts due to base metal production, approaches to envi¬ronmental improvement and finally examines various options to prevent pollution in base metal industries

Smooth rationally connected threefolds contain all smooth curves

We show that if X is a smooth rationally connected threefold and C is a smooth projective curve then C can be embedded in X. Furthermore, a version of this property characterises rationally connected varieties of dimension at least 3. We give some details about the toric case.Comment: Version 1 was called "Any smooth toric threefold contains all curves". This version is completely rewritten and proves a much stronger result, following suggestions of Janos Kolla

An Investigation of the Accuracy of Finite-Volume Radial Domain Truncation Technique

© Copyright 2007 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.The accuracy and performance of the radial domain truncation technique is presented in the framework of finite-volume time-domain method. In the present approach all the electromagnetic field quantities are co-located in both space and time and the performance is evaluated using unstructured grid. The influence of the radius of curvature of the absorber is investigated using a waveguide and a horn-antenna as practical examples. Numerical reflection errors are computed using a reference solutions and the convergence of the results is studied for increasing radius of curvature of the absorber. Low-level effects on the antenna radiation patterns further illustrates the convergence of the technique.Krishnaswamy Sankaran, Christophe Fumeaux and Rudiger Vahldiec

Time to make space for practice-based research in project portfolio management

Practice-based research is extending understanding in the disciplines of strategy and project management, in part as a result of strong advocacy of research from ‘strategy-as-practice’ and ‘projects-as-practice’ perspectives. Such perspectives provide holistic contextual information and reveal the evolutionary and responsive nature of project and strategy processes. As environments shift and become more complex, dynamic capabilities are required for projects to flourish. Normative project management approaches are being challenged and practice-based project portfolio management (PPM) research is emerging. Increasingly, PPM defines the space between strategy and project management, with a key project focus on temporality. There is a need for further development and encouragement of practice-based approaches in PPM research that are alert to the becoming of projects as spatial manifestations that unfold in (different conceptions of) time. We identify three themes in project and portfolio management research that employ practice-based and strategically anchored perspectives. We illustrate the trajectory of early work on strategy and the front end of projects through to the development and application of increasingly sophisticated theoretical perspectives in project portfolio management (PPM) research. The dynamic capabilities perspective is shown to provide a strong theoretical foundation for investigating PPM and its role in implementing and informing strategy through projects. Theoretically grounded and practice-based research represents the interplay between structure and practice, with these reciprocally and recursively shaping each other over time. Building on these examples we call for practice-based research in PPM, and we suggest a convergence of strategy-as-practice perspectives and practice-based PPM research

Understanding megaproject success beyond the project close-out stage

© 2015 Johan Fahri. Project success has always been an important topic in the project management literature. One of the main discussions is concerned with how a project’s success is evaluated and what factors lead to achieving this success. Traditionally project success has been measured at the point where the project outputs are handed over, after the close out phase. Recently, questions have been raised in the literature as to whether we should be evaluating project success beyond the close out phase, to better account for organizational and societal outcomes. However, not much has been published about how the long term impacts and outcomes are measured. This is of particular concern in megaprojects as they often attract a high level of public attention and political interest, and have both direct and indirect impacts on the community, environment, and national budgets. In this paper the authors review success factors and criteria that are applicable to projects in general and megaprojects in particular. They identify the significance of evaluating outcomes and impact and propose an ex-post project evaluation megaprojects

Applying institutional theories to managing megaprojects

© 2017 Elsevier Ltd, APM and IPMA This paper contributes to Rodney Turner's initiative to develop a theory of project management from practice. Organizational scholars studying strategy suggest that more attention needs to be paid to practices involved in organizing, as well as the institutional contexts in which these practices are embedded. Taking a cue from strategy-in-practice approaches, it is proposed that institutional theories can be used to address some questions that have not been answered adequately regarding megaprojects. Institutional theories also seem to be gaining the attention of scholars investigating large, global, infrastructure projects as reported in engineering, management and construction journals. Increasingly, it is evident that the problem areas attached to these projects stretch beyond technical issues: they must be considered as socio-technical endeavours embedded in complex institutional frames. The authors suggest that studying how to deal with institutional differences in the environment of megaprojects has both theoretical and practical implications

Gut immune dysfunction through impaired innate pattern recognition receptor expression and gut microbiota dysbiosis in chronic SIV infection.

HIV targets the gut mucosa early in infection, causing immune and epithelial barrier dysfunction and disease progression. However, gut mucosal sensing and innate immune signaling through mucosal pattern recognition receptors (PRRs) during HIV infection and disease progression are not well defined. Using the simian immunodeficiency virus (SIV)-infected rhesus macaque model of AIDS, we found a robust increase in PRRs and inflammatory cytokine gene expression during the acute SIV infection in both peripheral blood and gut mucosa, coinciding with viral replication. PRR expression remained elevated in peripheral blood following the transition to chronic SIV infection. In contrast, massive dampening of PRR expression was detected in the gut mucosa, despite the presence of detectable viral loads. Exceptionally, expression of Toll-like receptor 4 (TLR4) and TLR8 was downmodulated and diverged from expression patterns for most other TLRs in the gut. Decreased mucosal PRR expression was associated with increased abundance of several pathogenic bacterial taxa, including Pasteurellaceae members, Aggregatibacter and Actinobacillus, and Mycoplasmataceae family. Early antiretroviral therapy led to viral suppression but only partial maintenance of gut PRRs and cytokine gene expression. In summary, SIV infection dampens mucosal innate immunity through PRR dysregulation and may promote immune activation, gut microbiota changes, and ineffective viral clearance