Soft Phonon Anomalies in the Relaxor Ferroelectric Pb(Zn_1/3Nb_2/3)_0.92Ti_0.08O_3

Neutron inelastic scattering measurements of the polar TO phonon mode dispersion in the cubic relaxor Pb(Zn_1/3Nb_2/3)_0.92Ti_0.08O_3 at 500K reveal anomalous behavior in which the optic branch appears to drop precipitously into the acoustic branch at a finite value of the momentum transfer q=0.2 inverse Angstroms, measured from the zone center. We speculate this behavior is the result of nanometer-sized polar regions in the crystal.Comment: 4 pages, 4 figure

Habitat‐dependent occupancy and movement in a migrant songbird highlights the importance of mangroves and forested lagoons in Panama and Colombia

Climate change is predicted to impact tropical mangrove forests due to decreased rainfall, sea‐level rise, and increased seasonality of flooding. Such changes are likely to influence habitat quality for migratory songbirds occupying mangrove wetlands during the tropical dry season. Overwintering habitat quality is known to be associated with fitness in migratory songbirds, yet studies have focused primarily on territorial species. Little is known about the ecology of nonterritorial species that may display more complex movement patterns within and among habitats of differing quality. In this study, we assess within‐season survival and movement at two spatio‐temporal scales of a nonterritorial overwintering bird, the prothonotary warbler (Protonotaria citrea), that depends on mangroves and tropical lowland forests. Specifically, we (a) estimated within‐patch survival and persistence over a six‐week period using radio‐tagged birds in central Panama and (b) modeled abundance and occupancy dynamics at survey points throughout eastern Panama and northern Colombia as the dry season progressed. We found that site persistence was highest in mangroves; however, the probability of survival did not differ among habitats. The probability of warbler occupancy increased with canopy cover, and wet habitats were least likely to experience local extinction as the dry season progressed. We also found that warbler abundance is highest in forests with the tallest canopies. This study is one of the first to demonstrate habitat‐dependent occupancy and movement in a nonterritorial overwintering migrant songbird, and our findings highlight the need to conserve intact, mature mangrove, and lowland forests

The political identities of neighbourhood planning in England

The rise of neighbourhood planning has been characterised as another step in a remorseless de-politicisation of the public sphere. A policy initiated by the Coalition Government in England to create the conditions for local communities to support housing growth, neighbourhood planning appears to evidence a continuing retreat from political debate and contestation. Clear boundaries are established for the holistic integration of participatory democracy into the strategic plan-making of the local authority. These boundaries seek to take politics out of development decisions and exclude all issues of contention from discussion. They achieve this goal at the cost of arming participatory democracy with a collective identity around which new antagonisms may develop. Drawing on the post-political theories of Chantal Mouffe this paper identifies the return of antagonism and conflict to participation in spatial planning. Key to its argument is the concept of the boundary or frontier that in Mouffe’s theoretical framework institutionalises conflict between political entities. Drawing on primary research with neighbourhood development plans in England the paper explores how boundary conditions and boundary designations generate antagonism and necessitate political action. The paper charts the development of the collective identities that result from these boundary lines and argues for the potential for neighbourhood planning to restore political conflict to the politics of housing development

Anomalous transverse acoustic phonon broadening in the relaxor ferroelectric Pb(Mg_1/3Nb_2/3)O_3

The intrinsic linewidth $\Gamma_{TA}$ of the transverse acoustic (TA) phonon observed in the relaxor ferroelectric compound Pb(Mg$_{1/3}$Nb$_{2/3})_{0.8}$Ti$_{0.2}$O$_3$ (PMN-20%PT) begins to broaden with decreasing temperature around 650 K, nearly 300 K above the ferroelectric transition temperature $T_c$ ($\sim 360$ K). We speculate that this anomalous behavior is directly related to the condensation of polarized, nanometer-sized, regions at the Burns temperature $T_d$. We also observe the ``waterfall'' anomaly previously seen in pure PMN, in which the transverse optic (TO) branch appears to drop precipitously into the TA branch at a finite momentum transfer $q_{wf} \sim 0.15$ \AA$^{-1}$. The waterfall feature is seen even at temperatures above $T_d$. This latter result suggests that the PNR exist as dynamic entities above $T_d$.Comment: 6 pages, 4 figure

Phase diagram for morphological transitions of wetting films on chemically structured substrates

Using an interface displacement model we calculate the shapes of thin liquidlike films adsorbed on flat substrates containing a chemical stripe. We determine the entire phase diagram of morphological phase transitions in these films as function of temperature, undersaturation, and stripe widthComment: 15 pages, RevTeX, 7 Figure

Are Labour Markets Necessarily Local? Spatiality, Segmentation and Scale

This paper draws on recent debates about scale to approach the geography of labour markets from a dynamic perspective sensitive to the spatiality and scale of labour market restructuring. Its exploration of labour market reconfigurations after the collapse of a major firm (Ansett Airlines) raises questions about geography’s faith in the inherently ‘local’ constitution of labour markets. Through an examination of the job reallocation process after redundancy, the paper suggests that multiple labour markets use and articulate scale in different ways. It argues that labour market rescaling processes are enacted at the critical moment of recruitment, where social networks, personal aspirations and employer preferences combine to shape workers’ destinations

Governing the governors : a case study of college governance in English further education

This paper addresses the nature of governors in the governance of further education colleges in an English context (1). It explores the complex relationship between governors (people/agency), government (policy/structure) and governance (practice), in a college environment. While recent research has focused on the governance of schooling and higher education there has been little attention paid to the role of governors in the lifelong learning sector. The objective of the paper is to contribute to the debate about the purpose of college governance at a time when the Learning and Skills Council (LSC) commissioning era ends, and new government bodies responsible for further education and training, including local authorities, arrive. The paper analyses the nature of FE governance through the perspectives and experiences of governors, as colleges respond to calls from government for greater improvement and accountability in the sector (LSIS, 2009a). What constitutes creative governance is complex and controversial in the wider framework of regulation and public policy reform (Stoker, 1997; Seddon, 2008). As with other tricky concepts such as leadership, professionalism and learning, college governance is best defined in the contexts, cultures and situations in which it is located. College governance does not operate in a vacuum. It involves governors, chairs, principals, professionals, senior managers, clerks, community, business and wider agencies, including external audit and inspection regimes. Governance also acts as a prism through which national education and training reforms are mediated, at local level. While governing bodies are traditionally associated with the business of FE - steering, setting the tone and style, dealing with finance, funding, audit and procedural matters – they are increasingly being challenged to be more creative and responsive to the wider society. Drawing on a recent case study of six colleges, involving governors and key policy stakeholders, this paper explores FE governance in a fast changing policy environment

Public Benefits of Undeveloped Lands on Urban Outskirts: Non-Market Valuation Studies and their Role in Land Use Plans

Over the past three decades, the economics profession has developed methods for estimating the public benefits of green spaces, providing an opportunity to incorporate such information into land-use planning. While federal regulations routinely require such estimates for major regulations, the extent to which they are used in local land use plans is not clear. This paper reviews the literature on public values for lands on urban outskirts, not just to survey their methods or empirical findings, but to evaluate the role they have played--or have the potential to play-- in actual land use plans. Based on interviews with authors and representatives of funding agencies and local land trusts, it appears that academic work has had a mixed reception in the policy world. Reasons for this include a lack of interest in making academic work accessible to policy makers, emphasizing revealed preference methods which are inconsistent with policy priorities related to nonuse values, and emphasis on benefit-cost analyses. Nevertheless, there are examples of success stories that illustrate how such information can play a vital role in the design of conservation policies. Working Paper 07-2

Competing orders in PZN-xPT and PMN-xPT relaxor ferroelectrics

Neutron and x-ray scattering studies on relaxor ferroelectric systems Pb(Zn$_{1/3}$Nb$_{2/3}$)O$_3$ (PZN), Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_3$ (PMN), and their solid solutions with PbTiO$_3$ (PT) have shown that inhomogeneities and disorder play important roles in the materials properties. Although a long-range polar order can be established at low temperature - sometimes with the help of an external electric field; short-range local structures called the ``polar nano-regions'' (PNR) still persist. Both the bulk structure and the PNR have been studied in details. The coexistence and competition of long- and short-range polar orders and how they affect the structural and dynamical properties of relaxor materials are discussed.Comment: Article submitted for JPSJ Special Topics (Novel States of Matter Induced by Frustration