Suchergebnisse

7 pages, 3 figures, 5 tables, 34 references. ; The effect of the ionic strength on adsorption of Cu on Ca-montmorillonite (SAz-1) was studied at concentrations ranging from 31 to 516 BM. An adsorption model was employed in the analysis of the data. When the background electrolyte was NaClO4 the ionic interchange was suppressed at 0.5 M, and Cu adsorption was taking place on edge sites, reaching a plateau at about 24 mmol/kg. A further increase in ionic strength did not make any effect on Cu adsorption, suggesting that the heavy metal was being adsorbed by inner sphere complexes on the edge sites. A binding coefficient for Cu2+ on the edge sites K= 2x104 M-1 was determined indicating very high affinity of Cu2+ for these sites. When the electrolyte used was NaCl the amounts of Cu adsorbed were reduced. The model predicted well the adsorption data by considering adsorption of CuCl+ species. Adsorption-desorption processes of Cu on Ca-montmorillonite in media of 0.01 and 0.1 M NaCl showed hysteresis. Model calculations predict the desorbed amounts fairly well. According to the model the hysteresis is mainly attributed to the heterogeneity of sites for the adsorption of Cu. The hysteresis arising from the planar sites is largely due to reduced competition for adsorption and enhancement in the magnitude of the surface potential. ; Dr. Undabeytia acknowledges the European Community (Contract N. FAIR-BM- 970892) for a postdoctoral fellowship at the Seagram Centre and the Spanish Government for a research contract (ref. AMB98-0888) at the Institute of Natural Resources and Agrobiology. ; Peer reviewed

An important consequence of habitat fragmentation for wildlife communities is
the effect of an increase in the ratio of habitat edge to interior. This study
compares the bird communities at forest/farmland edges and in forest
interior at Bunyip State Park, Victoria. Overall, there was a significantly
higher number of bird species and individuals in forest edge than in forest
interior sites. The greater diversity of species at edge sites appeared to be
due to an increase in forest-edge specialists, as opposed to an influx of
open-country species. Four bird species: the white-throated treecreeper
(Cormobates leucophaeus), the superb fairy-wren
(Malurus cyaneus), the grey shrike-thrush
(Colluricincla harmonica) and the grey fantail
(Rhipidura fuliginosa) were significantly more abundant
in edge sites. There were no species that were significantly more abundant in
interior sites. Differences between the bird communities in edge and interior
sites were attributed to increased foraging opportunities in the open country
adjacent to forest edges.

Predation rates of nests at human-induced habitat edges may be greater than in forest interior due to differences in predator assemblages and predator activity. I compared the predation rates on 192 artificial nests containing plasticine eggs placed in forest edge and interior sites at Bunyip State Park, Victoria. The nest-predation rates at the forest edge sites were significantly greater (mean = 52–58%) than that at the forest interior sites (mean = 30–39%). The relative rates of predation by birds compared with mammals were significantly greater at forest edge sites (mean = 78–94%) than at forest interior sites (mean = 36–67%). Higher rates of nest predation at forest edges appeared to be due to greater densities of avian predators such as the grey shrike-thrush (Colluricincla harmonica), and/or lower abundances of small mammals. However, biases towards certain predator types may mask real, or create false, patterns in predation rates of artificial nests. A better understanding of how predators respond to artificial nests compared with natural nests is required. Until then, results of predation studies that use artificial nests should be interpreted with caution.

This report uses video analysis and semi-structured interviews to describe a case of community use of multi-site videoconferencing. The event in 2007 connected a number of First Nation communities across Canada for simultaneous audio-visual exchange. The meeting was hosted by K-Net Services in Ontario. The research project VideoCom organized the event to study the feasibility of public meetings through videoconferencing and to document an example of community uses of the technology. Our report suggests videoconferencing creates a public sphere in these First Nations communities. K-Net Services works to develop their videoconferencing infrastructure to better support this public space. The public sphere is way of thinking about how media practices have a political effect and how they contribute to the well-being of the community. The case meeting shows a potential new opportunity to further integrate videoconferencing into community development.

Both sport and tourism are deeply modernist forms that rely on the circulation of people, media, and capital for their endurance. In this article, I analyze both forms through the ethnographic examination of surf-related tourism in Papua New Guinea. For many Papua New Guineans, surf tourism is an avenue for gaining positions in wage labor. For some the development of the industry is an attempt to foster "sustainable" economic development in the country. These forms of participation rely on international tourists who see the sport and the industry in Papua New Guinea as a site for recreation and play. This article deals with these people, surf tourists who visit Papua New Guinea and for whom surfing is a major part of their social identity. Surfing as an embedded, affective practice and a set of deeply socio-ecological propositions about people-in-nature is historically tractable to indigenous Pacific Island societies. It was deterritorialized, or removed from the context of its origin, by Australian and American youth who took up the practice as a sport in the early part of the twentieth century. Today surfing has been reassembled as a form of development in the very places from which it emerged. Through the analysis of the movements of media, people, and capital involved in the surf tourism industry in Papua New Guinea, this article demonstrates the new social assemblages that emerge when labor, development, and play intertwine.

From self-driving cars to smart city sensors, billions of devices will be connected to networks in the next few years. These devices will collect vast amounts of data which needs to be processed in real-time, overwhelming centralized cloud architectures. To address this need, the industry seeks to process data closer to the source, driving a major shift from the cloud to the 'edge.' This article critically investigates the privacy implications of edge computing. It outlines the abilities introduced by the edge by drawing on two recently published scenarios, an automated license plate reader and an ethnic facial detection model. Based on these affordances, three key questions arise: what kind of data will be collected, how will this data be processed at the edge, and how will this data be 'completed' in the cloud? As a site of intermediation between user and cloud, the edge allows data to be extracted from individuals, acted on in real-time, and then abstracted or sterilized, removing identifying information before being stored in conventional data centers. The article thus argues that edge affordances establish a fundamental new 'privacy condition' while sidestepping the safeguards associated with the 'privacy proper' of personal data use. Responding effectively to these challenges will mean rethinking person-based approaches to privacy at both regulatory and citizen-led levels.

Managing in the public sector can be characterized as "managing on the edges", between politics and administration and between administration and operations, as well as between external pressures and internal processes. Interestingly, this seems to come out most sharply, not in the upper offices of the capital, but down on the ground, where conflicting parties do direct battle with each other. But as these battles escalate, and enter the abstractions of administration as well as the peculiarities of politics, management gets caught in the middle. Describes three days in succession in the working lives of three managers of Parks Canada who sit in hierarchical order: a regional director, a park superintendent, and a park warden for the front country. Describes and compares their activities, in terms of a comprehensive model of the manager's job, and concludes with a model of managing on the edges.

Building on the author's earlier book, Effective Multi-Unit Leadership, this book has a cross-border perspective on leading from the middle in international subsidiaries that are committing significant capital to land-based multi-unit infrastructures. It captures the zeitgeist of internationalizing hospitality, retail, service and leisure organizations facing challenges in relation to multi-channel/smart technology spread, divergent national cultures and emergent, imitative local competition. It also addresses the conundrum that most subsidiary multi-unit leaders (regional, area and district managers) face, generating commitment amongst their unit managers and team members, whilst coping with their firm's country of origin-based control and change agendas. Continuing the themes that emerged in his earlier book, particularly around how multi-unit leaders (MULs) and directors are expected to expedite a number of competing and contradictory functions, the author finds that in subsidiary-based international situations, complexity and ambiguity escalates due to 'distance decay' and the level of internal and external contextual turbulence. Based on exemplary case studies the author examines how high-performance MULs manage paradox and ambiguity within an international context and how organizations can deliver local effectiveness within a strategic framework determined by a policy-making centre hundreds or thousands of miles away. This book will appeal to managers within international multi-unit enterprises, service directors wishing to train and coach others, students on any of the increasing number of multi-unit management programmes being run in business schools, and academics with an interest internationalizing service-based enterprises.