901 resultados para Local-Global topics


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When we actively explore the visual environment, our gaze preferentially selects regions characterized by high contrast and high density of edges, suggesting that the guidance of eye movements during visual exploration is driven to a significant degree by perceptual characteristics of a scene. Converging findings suggest that the selection of the visual target for the upcoming saccade critically depends on a covert shift of spatial attention. However, it is unclear whether attention selects the location of the next fixation uniquely on the basis of global scene structure or additionally on local perceptual information. To investigate the role of spatial attention in scene processing, we examined eye fixation patterns of patients with spatial neglect during unconstrained exploration of natural images and compared these to healthy and brain-injured control participants. We computed luminance, colour, contrast, and edge information contained in image patches surrounding each fixation and evaluated whether they differed from randomly selected image patches. At the global level, neglect patients showed the characteristic ipsilesional shift of the distribution of their fixations. At the local level, patients with neglect and control participants fixated image regions in ipsilesional space that were closely similar with respect to their local feature content. In contrast, when directing their gaze to contralesional (impaired) space neglect patients fixated regions of significantly higher local luminance and lower edge content than controls. These results suggest that intact spatial attention is necessary for the active sampling of local feature content during scene perception.

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About one-sixth of the world’s land area, that is, about one-third of the land used for agriculture, has been affected by soil degradation in the historic past. While most of this damage was caused by water and wind erosion, other forms of soil degradation are induced by biological, chemical, and physical processes. Since the 1950s, pressure on agricultural land has increased considerably owing to population growth and agricultural modernization. Small-scale farming is the largest occupation in the world, involving over 2.5 billion people, over 70% of whom live below the poverty line. Soil erosion, along with other environmental threats, particularly affects these farmers by diminishing yields that are primarily used for subsistence. Soil and water conservation measures have been developed and applied on many farms. Local and science-based innovations are available for most agroecological conditions and land management and farming types. Principles and measures developed for small-scale as well as modern agricultural systems have begun to show positive impacts in most regions of the world, particularly in wealthier states and modern systems. Much more emphasis still needs to be given to small-scale farming, which requires external support for investment in sustainable land management technologies as an indispensable and integral component of farm activities.

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Most desertification research focuses on degradation assessments without putting sufficient emphasis on prevention and mitigation strategies, although the concept of Sustainable Land Management (SLM) is increasingly being acknowledged. A variety of already applied conservation measures exist at the local level, but they are not adequately recognised, evaluated and shared, either by land users, technicians, researchers, or policy makers. Likewise, collaboration between research and implementation is often insufficient. The aim of this paper is to present a new methodology for a participatory process of appraising and selecting desertification mitigation strategies, and to present first experiences from its application in the EU-funded DESIRE project. The methodology combines a collective learning and decision approach with the use of evaluated global best practices. In three parts, it moves through a concise process, starting with identifying land degradation and locally applied solutions in a stakeholder workshop, leading to assessing local solutions with a standardised evaluation tool, and ending with jointly selecting promising strategies for implementation with the help of a decision support tool. The methodology is currently being applied in 16 study sites. Preliminary analysis from the application of the first part of the methodology shows that the initial stakeholder workshop results in a good basis for stakeholder cooperation, and in promising land conservation practices for further assessment. Study site research teams appreciated the valuable results, as burning issues and promising options emerged from joint reflection. The methodology is suitable to initiate mutual learning among different stakeholder groups and to integrate local and scientific knowledge.

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There has been much commentary about the re-ordering of the relations between nation state government, geographical territory, and populations in the advanced liberal democracies. This is seen as a product of: increasing demographic and cultural diversity due to legal and illegal migration; economic, cultural, and political global interdependence; footloose mobility of capital and the outsourcing of jobs to poorer countries; the growing power of international corporations and financial markets; and the growth of supra-national bodies like the European Union and The North Atlantic Free Trade Association, the World Trade Organisation, and (debatably), the UN. These developments are held to be associated with the gradual demise of the model of the increasingly secular nation state first crystallised by the Treaty of Westphalia in 1648. This conception provided a mutual, guarantee of states’ jurisdiction over territory and populations through their legitimated attempts to monopolise the use of force. Though, the relations between these states have always been asymmetrical and often challenged (Hunter 1998).

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The article seeks a re-conceptualization of the global digital divide debate. It critically explores the predominant notion, its evolution and measurement, as well as the policies that have been advanced to bridge the digital divide. Acknowledging the complexity of this inequality, the article aims at analyzing the disparities beyond the connectivity and skills barriers. Without understating the first two digital divides, it is argued that as the Internet becomes more sophisticated and more integrated into economic, social, and cultural processes, a “third” generation of divides becomes critical. These divides are drawn not at the entry to the net but within the net itself, and limit access to content. The increasing barriers to content, though of a diverse nature, all relate to some governance characteristics inherent in cyberspace, such as global spillover of local decisions, regulation through code, and proliferation of self- and co-regulatory models. It is maintained that as the practice of intervention intensifies in cyberspace, multiple and far-reaching points of control outside formal legal institutions are created, threatening the availabil- ity of public goods and making the pursuit of public objectives difficult. This is an aspect that is rarely ad- dressed in the global digital divide discussions, even in comprehensive analyses and political initiatives such as the World Summit on the Information Society. Yet, the conceptualization of the digital divide as impeded access to content may be key in terms of ensuring real participation and catering for the longterm implications of digital technologies.

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Tropical cyclogenesis is generally considered to occur in regions devoid of baroclinic structures; however, an appreciable number of tropical cyclones (TCs) form in baroclinic environments each year. A global climatology of these baroclinically influenced TC developments is presented in this study. An objective classification strategy is developed that focuses on the characteristics of the environmental state rather than on properties of the vortex, thus allowing for a pointwise “development pathway” classification of reanalysis data. The resulting climatology shows that variability within basins arises primarily as a result of local surface thermal contrasts and the positions of time-mean features on the subtropical tropopause. The pathway analyses are sampled to generate a global climatology of 1948–2010 TC developments classified by baroclinic influence: nonbaroclinic (70%), low-level baroclinic (9%), trough induced (5%), weak tropical transition (11%), and strong tropical transition (5%). All basins other than the North Atlantic are dominated by nonbaroclinic events; however, there is extensive interbasin variability in secondary development pathways. Within each basin, subregions and time periods are identified in which the relative importance of the development pathways also differs. The efficiency of tropical cyclogenesis is found to be highly dependent on development pathway. The peak efficiency defined in the classification subspace straddles the nonbaroclinic/trough-induced boundary, suggesting that the optimal environment for TC development includes a baroclinic contribution from an upper-level disturbance. By assessing the global distribution of baroclinically influenced TC formations, this study identifies regions and pathways whose further study could yield improvements in our understanding of this important subset of TC developments.

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The WOCAT network has collected, documented, and assessed more than 350 case studies on promising and good practices of SLM. Information on on- and off-site benefits of different SLM types, as well as on investment and maintenance costs is available, sometimes in quantitative and often in qualitative form. The objective of the present paper is to analyse what kind of economic benefits accrue to local stakeholders, and to better understand how these benefits compare to investment and maintenance costs. The large majority of the technologies contained in the database are perceived by land users as having positive benefits that outweigh costs in the long term. About three quarters of them also have positive or at least neutral benefits in the short term. The analysis shows that many SLM measures exist which can generate important benefits to land users, but also to other stakeholders. However, methodological issues need to be tackled and further quantitative and qualitative data are needed to better understand and support the adoption of SLM measures. Keywords: Sustainable Land Management, Costs, Benefits, Technologies

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This article provides an overview of the most essential issues in the trade and culture discourse from a global law perspective. It looks into the intensified disconnect between trade and culture and exposes its flaws and the considerable drawbacks that it brings with it. It is argued that these drawbacks become especially pronounced in the digital media environment, which has strongly affected both the conditions of trade with cultural products and services and cultural diversity in local and global contexts. In this modified setting, there could have been a number of feasible ‘trade and culture’ solutions – i.e. regulatory designs that whilst enhancing trade liberalisation are also conducive to cultural policy. Yet, the realisation of any of these options becomes chimerical as the line between trade and culture matters is drawn in a clear and resolute manner. The article is meant for an interdisciplinary audience and forthcoming in the Journal of Arts Management, Law and Society.

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The paper seeks a re-conceptualization of the global digital divide debate. It critically explores the predominant notion, its evolution and measurement, as well as the policies that have been advanced to bridge the digital divide. Acknowledging the complexity of this inequality, the paper aims at analyzing the disparities beyond the connectivity and the skills barriers. Without understating the first two digital divides, it is argued that as the Internet becomes more sophisticated and more integrated into economic, social and cultural processes, a ‘third’ generation of divides becomes critical. These divides are drawn not at the entry to the net but within the net itself, and limit access to content. The increasing barriers to content, although of diverse nature, all relate to some governance characteristics inherent in cyberspace, such as global spillover of local decisions, regulation through code or proliferation of self- and co-regulatory models. It is maintained that as the practice of intervention intensifies in cyberspace, multiple and far-reaching points of control outside formal legal institutions are created, which threaten the availability of public goods and make the pursuit of public objectives difficult. This is an aspect that is rarely addressed in the global digital divide discussions, even in comprehensive analysis and political initiatives such as the World Summit on the Information Society. Yet, the conceptualization of the digital divide as impeded access to content may be key in terms of ensuring real participation and catering for the long-term implications of digital technologies.

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The article seeks a re-conceptualization of the global digital divide debate. It critically explores the predominant notion, its evolution and measurement, as well as the policies that have been advanced to bridge the digital divide. Acknowledging the complexity of this inequality, the article aims at analyzing the disparities beyond the connectivity and skills barriers. Without understating the first two digital divides, it is argued that as the Internet becomes more sophisticated and more integrated into economic, social, and cultural processes, a “third” generation of divides becomes critical. These divides are drawn not at the entry to the net but within the net itself, and limit access to content. The increasing barriers to content, though of a diverse nature, all relate to some governance characteristics inherent in cyberspace, such as global spillover of local decisions, regulation through code, and proliferation of self- and co-regulatory models. It is maintained that as the practice of intervention intensifies in cyberspace, multiple and far-reaching points of control outside formal legal institutions are created, threatening the availability of public goods and making the pursuit of public objectives difficult. This is an aspect that is rarely addressed in the global digital divide discussions, even in comprehensive analyses and political initiatives such as the World Summit on the Information Society. Yet, the conceptualization of the digital divide as impeded access to content may be key in terms of ensuring real participation and catering for the long-term implications of digital technologies.

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Digital technologies and the Internet in particular have transformed the ways we create, distribute, use, reuse and consume cultural content; have impacted on the workings of the cultural industries, and more generally on the processes of making, experiencing and remembering culture in local and global spaces. Yet, few of these, often profound, transformations have found reflection in law and institutional design. Cultural policy toolkits, in particular at the international level, are still very much offline/analogue and conceive of culture as static property linked to national sovereignty and state boundaries. The article describes this state of affairs and asks the key question of whether there is a need to reform global cultural law and policy and if yes, what the essential elements of such a reform should be.

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The rate of ice-sheet thickness change is calculated for 10 sites in Greenland by comparing measured values of ice vertical velocity and snow-accumulation rate. Vertical velocities are derived from repeat surveys of markers using precision global positioning system techniques, and accumulation rates are determined from stratigraphic analysis of firn cores. The results apply to time-scales covered by the firn-core records, which in most cases are a few decades. A spectrum of thickness-change rates is obtained, ranging from substantial thinning to slow thickening. The sites where ice-sheet thinning is indicated are located near the ice-sheet margin or in outlet glacier catchments. Interior and high-elevation sites are predominantly in balance or thickening slowly. Uncertainties in the rates of thickness change are dominated by errors in the determination of accumulation rates. The results of this work are broadly comparable with regional estimates of mass balance obtained from the analysis of catchment input vs discharge.

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Predicting the response of species to environmental changes is a great and on-going challenge for ecologists, and this requires a more in-depth understanding of the importance of biotic interactions and the population structuration in the landscape. Using a reciprocal transplantation experiment, we tested the response of five species to an elevational gradient. This was combined to a neighbour removal treatment to test the importance of local adaptation and biotic interactions. The trait studied was performance measured as survival and biomass. Species response varied along the elevational gradient, but with no consistent pattern. Performance of species was influenced by environmental conditions occurring locally at each site, as well as by positive or negative effects of the surrounding vegetation. Indeed, we observed a shift from competition for biomass to facilitation for survival as a response to the increase in environmental stress occurring in the different sites. Unlike previous studies pointing out an increase of stress along the elevation gradient, our results supported a stress gradient related to water availability, which was not strictly parallel to the elevational gradient. For three of our species, we observed a greater biomass production for the population coming from the site where the species was dominant (central population) compared to population sampled at the limit of the distribution (marginal population). Nevertheless, we did not observe any pattern of local adaptation that could indicate adaptation of populations to a particular habitat. Altogether, our results highlighted the great ability of plant species to cope with environmental changes, with no local adaptation and great variability in response to local conditions. Our study confirms the importance of taking into account biotic interactions and population structure occurring at local scale in the prediction of communities’ responses to global environmental changes.