Connecting homomorphisms associated to Tate sequences

Tate sequences are an important tool for tackling problems related to the (ill-understood) Galois structure of groups of $S$-units. The relatively recent Tate sequence "for small $S$" of Ritter and Weiss allows one to use the sequence without assuming the vanishing of the $S$-class-group, a significant advance in the theory. Associated to Ritter and Weiss's version of the sequence are connecting homomorphisms in Tate cohomology, involving the $S$-class-group, that do not exist in the earlier theory. In the present article, we give explicit descriptions of certain of these connecting homomorphisms under some assumptions on the set $S$.Comment: 22 pages. To appear in Acta Arithmetic

Introducing Identity

This chapter provides an introductory overview of theories of identity and indicates some of the broad ways in which they might be applied to young people's interactions with digital media. The first part of the chapter offers a brief account of five major areas of theory: social-psychological theories of adolescence; sociological theories of youth culture; theories of social identity, and the relations between individuals and groups; notions of identity politics; and theories of subjectivity and modernity. The second part of the chapter covers three major themes that are at stake in the analysis of young people and digital media: theories of technology; the notion of young people as a "digital generation"; and the place of learning, both in and beyond schools. In this course of this broad-ranging overview, the chapter also prefigures some of the more specific themes addressed in the chapters that make up the remainder of the volume

The canonical fractional Galois ideal at s=0

The Stickelberger elements attached to an abelian extension of number fields conjecturally participate, under certain conditions, in annihilator relations involving higher algebraic K-groups. In [Victor P. Snaith, Stark's conjecture and new Stickelberger phenomena, Canad. J. Math. 58 (2) (2006) 419--448], Snaith introduces canonical Galois modules hoped to appear in annihilator relations generalising and improving those involving Stickelberger elements. In this paper we study the first of these modules, corresponding to the classical Stickelberger element, and prove a connection with the Stark units in a special case.Comment: 22 page

Sensemaking on the Pragmatic Web: A Hypermedia Discourse Perspective

The complexity of the dilemmas we face on an organizational, societal and global scale forces us into sensemaking activity. We need tools for expressing and contesting perspectives flexible enough for real time use in meetings, structured enough to help manage longer term memory, and powerful enough to filter the complexity of extended deliberation and debate on an organizational or global scale. This has been the motivation for a programme of basic and applied action research into Hypermedia Discourse, which draws on research in hypertext, information visualization, argumentation, modelling, and meeting facilitation. This paper proposes that this strand of work shares a key principle behind the Pragmatic Web concept, namely, the need to take seriously diverse perspectives and the processes of meaning negotiation. Moreover, it is argued that the hypermedia discourse tools described instantiate this principle in practical tools which permit end-user control over modelling approaches in the absence of consensus

Gendered geographies of environmental injustice

This is the accepted version of the following article: Buckingham, S. and Kulcur, R. (2009), Gendered Geographies of Environmental Injustice. Antipode, 41: 659–683. doi: 10.1111/j.1467-8330.2009.00693.x, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/j.1467-8330.2009.00693.x/abstract. Copyright @ 2009 The Authors.As environmental justice concerns become more widely embedded in environmental organizations and policy making, and increasingly the focus of academic study, the gender dimension dissolves into an exclusive focus on race/ethnicity and class/income. While grass roots campaigning activities were often dominated by women, in the more institutionalized activities of organizations dominated by salaried professionals, gender inequality is neglected as a vector of environmental injustice, and addressing this inequality is not considered a strategy for redress. This paper explores some of the reasons why this may be so, which include a lack of visibility of gendered environmental injustice; professional campaigning organizations which are themselves gender blind; institutions at a range of scales which are still structured by gender (as well as class and race) inequalities; and an intellectual academy which continues to marginalize the study of gender – and women’s – inequality. The authors draw on experience of environmental activism, participant observation, and other qualitative research into the gendering of environmental activity, to first explore the constructions of scale to see how this might limit a gender-fair approach to environmental justice. Following this, the practice of ‘gender mainstreaming’ in environmental organizations and institutions will be examined, demonstrating how this is limited in scope and fails to impact on the gendering of environmental injustice

A note on the nature of utility in time and health and implications for cost utility analysis

Time Trade-Off valuations of health are widely used in economic evaluation of health care. Current approaches to eliciting TTO values, and their use in economic evaluation, rests on specific assumptions about the way utility relates to time and health. Both the assumptions themselves and evidence of violations of them are discussed in the literature - yet the issues appear not to be widely appreciated by those using and applying TTO. This paper adds to that literature by demonstrating both the requirements of TTO and violations of these assumptions in terms of the underlying indifference curve maps and utility functions. The advantage of this approach is that is demonstrates very clearly a number of fundamental problems for the way TTO values are currently elicited and used in Cost Utility Analysis. In essence, it is extremely unwise to assume that the current "tariffs" of TTO values, such as those routinely used by NICE and other organisations, can be applied irrespective of the duration of the health states to which they are assigned. The estimates of QALYs that result will, quite often, simply be wrong. We suggest a number of solutions, including the provision of multiple value sets, for a range of durations