10 resultados para Natural context

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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Since the first demonstration of how to simultaneously measure brain activity using functional magnetic resonance imaging (fMRI) on two subjects about 10 years ago, a new paradigm in neuroscience is emerging: measuring brain activity from two or more people simultaneously, termed "hyperscanning". The hyperscanning approach has the potential to reveal inter-personal brain mechanisms underlying interaction-mediated brain-to-brain coupling. These mechanisms are engaged during real social interactions, and cannot be captured using single-subject recordings. In particular, functional near-infrared imaging (fNIRI) hyperscanning is a promising new method, offering a cost-effective, easy to apply and reliable technology to measure inter-personal interactions in a natural context. In this short review we report on fNIRI hyperscanning studies published so far and summarize opportunities and challenges for future studies.

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Argillaceous formations generally act as aquitards because of their low hydraulic conductivities. This property, together with the large retention capacity of clays for cationic contaminants, has brought argillaceous formations into focus as potential host rocks for the geological disposal of radioactive and other waste. In several countries, programmes are under way to characterise the detailed transport properties of such formations at depth. In this context, the interpretation of profiles of natural tracers in pore waters across the formations can give valuable information about the large-scale and long-term transport behaviour of these formations. Here, tracer-profile data, obtained by various methods of pore-water extraction for nine sites in central Europe, are compiled. Data at each site comprise some or all of the conservative tracers: anions (Cl(-), Br(-)), water isotopes (delta(18)O, delta(2)H) and noble gases (mainly He). Based on a careful evaluation of the palaeo-hydrogeological evolution at each site, model scenarios are derived for initial and boundary pore-water compositions and an attempt is made to numerically reproduce the observed tracer distributions in a consistent way for all tracers and sites, using transport parameters derived from laboratory or in situ tests. The comprehensive results from this project have been reported in Mazurek et al. (2009). Here the results for three sites are presented in detail, but the conclusions are based on model interpretations of the entire data set. In essentially all cases, the shapes of the profiles can be explained by diffusion acting as the dominant transport process over periods of several thousands to several millions of years and at the length scales of the profiles. Transport by advection has a negligible influence on the observed profiles at most sites, as can be shown by estimating the maximum advection velocities that still give acceptable fits of the model with the data. The advantages and disadvantages of different conservative tracers are also assessed. The anion Cl(-) is well suited as a natural tracer in aquitards, because its concentration varies considerably in environmental waters. It can easily be measured, although the uncertainty regarding the fraction of the pore space that is accessible to anions in clays remains an issue. The stable water isotopes are also well suited, but they are more difficult to measure and their values generally exhibit a smaller relative range of variation. Chlorine isotopes (delta(37)Cl) and He are more difficult to interpret because initial and boundary conditions cannot easily be constrained by independent evidence. It is also shown that the existence of perturbing events such as the activation of aquifers due to uplift and erosion, leading to relatively sharp changes of boundary conditions, can be considered as a pre-requisite to obtain well-interpretable tracer signatures. On the other hand, gradual changes of boundary conditions are more difficult to parameterise and so may preclude a clear interpretation.

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Integration of indigenous knowledge and ethnoscientific approaches into contemporary frameworks for conservation and sustainable management of natural resources will become increasingly important in policies on an international and national level. We set the scene on how this can be done by exploring the key conditions and dimensions of a dialogue between ‘ontologies’ and the roles, which ethnosciences could play in this process. First, the roles which ethnosciences in the context of sustainable development were analysed, placing emphasis on the implications arising when western sciences aspire to relate to indigenous forms of knowledge. Secondly, the contributions of ethnosciences to such an ‘inter-ontological dialogue’ were explored, based on an ethnoecological study of the encounter of sciences and indigenous knowledge in the Andes of Bolivia, and reviewed experiences from mangrove systems in Kenya, India and Sri Lanka, and from case-studies in other ecosystems world-wide.

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Soil conservation technologies that fit well to local scale and are acceptable to land users are increasingly needed. To achieve this at small-holder farm level, there is a need for an understanding of specific erosion processes and indicators, the land users’ knowledge and their willingness, ability and possibilities to respond to the respective problems to decide on control options. This study was carried out to assess local erosion and performance of earlier introduced conservation terraces from both technological and land users’ points of view. The study was conducted during July to August 2008 at Angereb watershed on 58 farm plots from three selected case-study catchments. Participatory erosion assessment and evaluation were implemented along with direct field measurement procedures. Our focus was to involve the land users in the action research to explore with them the effectiveness of existing conservation measures against the erosion hazard. Terrace characteristics measured and evaluated against the terrace implementation guideline of Hurni (1986). The long-term consequences of seasonal erosion indicators had often not been known and noticed by farmers. The cause and effect relationships of the erosion indicators and conservation measures have shown the limitations and gaps to be addressed towards sustainable erosion control strategies. Less effective erosion control has been observed and participants have believed the gaps are to be the result of lack of landusers’ genuine participation. The results of both local erosion observation and assessment of conservation efficacy using different aspects show the need to promote approaches for erosion evaluation and planning of interventions by the farmers themselves. This paper describes the importance of human factor involving in the empirical erosion assessment methods towards sustainable soil conservation.

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Reducing risk that emerges from hazards of natural origin and societal vulnerability is a key challenge for the development of more resilient communities and the overall goal of sustainable development. The following chapter outlines a framework for multidimensional, holistic vulnerability assessment that is understood as part of risk evaluation and risk management in the context of Disaster Risk Management (DRM) and Climate Change Adaptation (CCA). As a heuristic, the framework is a thinking tool to guide systematic assessments of vulnerability and to provide a basis for comparative indicators and criteria development to assess key factors and various dimensions of vulnerability, particularly in regions in Europe, however, it can also be applied in other world regions. The framework has been developed within the context of the research project MOVE (Methods for the Improvement of Vulnerability Assessment in Europe; ) sponsored by the European Commission within the framework of the FP 7 program.

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In recent years developing countries have faced highly dynamic changes affecting their natural resource base and their potential for development. Taking into account these changes in the development context, InfoResources initiated a critical reassessment of the results of InfoResources Trends 2005 and again invited experts from around the world to assess trends that least developed countries are likely to be facing by 2025. The unanimous signal conveyed by the international experts for this assessment is alarming: The degradation of natural resources is progressing. By 2025 it will reach a point where livelihoods in least developing countries will be significantly threatened and an increasing number of agro-ecosystems will lose their capacity to deliver important services. Expected positive social trends will not suffice as leverage to reverse the degradation of natural resources and thus alleviate poverty and hunger. However, the present reassessment clearly reveals that a change in thinking and a shift in paradigms have begun to take place. However, a turnaround can only succeed if the emerging awareness of the need to reorient policy-making and the economy is followed by concrete action. It will be crucial that policies and institutions regain regulating power over greedy economic forces. This reassessment does not claim to be comprehensive. However, the present publication, which synthesises the experts’ inputs, aims at providing food for thought and initiating discussions.

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Following the collapse of the communist regime in 1989, Bulgaria has undergone dramatic political, economic and social transformations. The transition process of the past two decades was characterized by several reforms to support democratisation of the political system and the functioning of a free-market economy. Since 1992, Switzerland has been active in Bulgaria providing assistance to the transition process, with support to Sustainable Management of Natural Resources (SMNR) starting in 1995. The SMNR Capitalisation of Experiences (CapEx) took place between March and September 2007, in the context of SDC phasing out its programmes in Bulgaria by the end of 2007 due to the country’s accession to the European Union. The CapEx exercise has culminated in the identification of 17 lessons learned. In the view of the CapEx team, many of these lessons are relevant for countries that are in the process of joining the EU, facing similar democratisation challenges as Bulgaria. Overall, the Swiss SMNR projects have been effective entry points to support areas that are crucial to democratic transitions, namely participation in public goods management, decentralisation, human capacity development in research and management, and preparation for EU membership. The specificity of the Swiss support stems from an approach that combines a long-term commitment with a clear thematic focus (forestry, biodiversity conservation and organic agriculture). The multistakeholder approach and diversification of support between local, regional and national levels are also important elements that contributed to make a difference in relation to other donors supporting the Bulgarian transition. At the institutional level, there are a number of challenges where the contribution of SMNR activities was only modest, namely improving the legal framework and creating more transparency and accountability, both of which are time and resource-consuming processes. In addition, the emergence of competent and sustainable non-government organisations (NGOs) is a complex process that requires support to membership based organisations, a challenge that was hardly met in the case of SMNR. Finally, reform of government institutions involved in management of natural resources is difficult to achieve via project support only, as it requires leverage and commitment at the level of policy dialogue. At the programme management level, the CapEx team notes that corruption was not systematically addressed in SMNR projects, indicating that more attention should be given to this issue at the outset of any new project.

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The present understanding of the initiation of boudinage and folding structures is based on viscosity contrasts and stress exponents, considering an intrinsically unstable state of the layer. The criterion of localization is believed to be prescribed by geometry-material interactions, which are often encountered in natural structures. An alternative localization phenomenon has been established for ductile materials, in which instability emerges for critical material parameters and loading rates from homogeneous conditions. In this thesis, conditions are sought under which this type of instability prevails and whether localization in geological materials necessarily requires a trigger by geometric imperfections. The relevance of critical deformation conditions, material parameters and the spatial configuration of instabilities are discussed in a geological context. In order to analyze boudinage geometries, a numerical eigenmode analysis is introduced. This method allows determining natural frequencies and wavelengths of a structure and inducing perturbations on these frequencies. In the subsequent coupled thermo-mechanical simulations, using a grain size evolution and end-member flow laws, localization emerges when material softening through grain size sensitive viscous creep sets in. Pinch-and-swell structures evolve along slip lines through a positive feedback between the matrix response and material bifurcations inside the layer, independent from the mesh-discretization length scale. Since boudinage and folding are considered to express the same general instability, both structures should arise independently of the sign of the loading conditions and for identical material parameters. To this end, the link between material to energy instabilities is approached by means of bifurcation analyses of the field equations and finite element simulations of the coupled system of equations. Boudinage and folding structures develop at the same critical energy threshold, where dissipative work by temperature-sensitive creep overcomes the diffusive capacity of the layer. This finding provides basis for a unified theory for strain localization in layered ductile materials. The numerical simulations are compared to natural pinch-and-swell microstructures, tracing the adaption of grain sizes, textures and creep mechanisms in calcite veins. The switch from dislocation to diffusion creep relates to strain-rate weakening, which is induced by dissipated heat from grain size reduction, and marks the onset of continuous necking. The time-dependent sequence uncovers multiple steady states at different time intervals. Microstructurally and mechanically stable conditions are finally expressed in the pinch-and-swell end members. The major outcome of this study is that boudinage and folding can be described as the same coupled energy-mechanical bifurcation, or as one critical energy attractor. This finding allows the derivation of critical deformation conditions and fundamental material parameters directly from localized structures in the field.

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We present an overview on different environmental zones within coastal areas and summarise the physical basis behind the three most important methods that are available to date Holocene coastal sediments. Besides radiocarbon and uranium series dating, Optically Stimulated Luminescence (Osl) has increasingly been applied for dating in coastal settings over the past decade. This is illustrated by a number of case studies showing that Osl can be applied to sediments from almost any kind of coastal environment, covering a potential dating range from some years up to several hundred thousand years. Osl dating may hence be the method of choice for deciphering natural environmental change along coasts as well as the presence and the impact of human occupation in such areas. In addition, we briefly show how and where these dating methods could be applied to constrain the palaeo-environmental context of an archaeological site at Vohemar in north-eastern Madagascar.

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Focusing on an overlapping protected area and indigenous territory in the Bolivian Amazon, this article discusses how indigenous people continue to negotiate access to natural resources. Using the theoretical framework of New Institutionalism, ethnographic data from participatory observations, and interviews with Takana indigenous resource users and park management staff, we identified four phases of institutional change. We argue that under the current institutionally pluralistic setting in the overlapping area, indigenous users apply “institutional shopping” to choose, according to their power and knowledge, the most advantageous institutional framework in a situation. Indigenous users strategically employed arguments of conservation, indigeneity, or long-term occupation to legitimize their claims based on the chosen institution. Our results highlight the importance of ideologies and bargaining power in shaping the interaction of individuals and institutions. As a potential application of our research to practice, we suggest that rather than seeing institutional pluralism solely as a threat to successful resource management, the strengths of different frameworks may be combined to build robust institutions from the bottom up that are adapted to the local context. This requires taking into account local informal institutions, such as cultural values and beliefs, and integrating them with conservation priorities through cross-cultural participatory planning.