282 research outputs found
Social movements in sustainability transitions : identity, social learning & power in the Spanish & Turkish water domains /
Descripció del recurs: el 02 de novembre de 2010Dominant economic growth and nation-state building practices are often based on detaching individuals from other individuals and communities from their natural environment in which their livelihoods used to be based. Water plays a key role in these development strategies as it is the case of the building of dams and large water transfer infrastructures. Social-ecological detachment allows on the one hand, to merge former communities into the abstract idea of national citizenship, while at the same time, has a disempowering effect on individuals who try to protect 'their land' and their identity in contrast to the national identity. In this comparative case study, I look at theconflicts and social-ecological detachment processes observed in two communities of Spain and Turkey, and in particular the social movements against the Itoiz Dam in Spain and the Ilısu Dam in the Turkish Kurdistan. These conflicts are representative in the ways water 'policies' become the arena for multiple identities and interests, such as the claims of the stateless nations of the Basques and the Kurds. The anti-Itoiz Dam movement was integrated with the New Water Culture (NWC) movement which emerged as a response to the large scale threat posed by the Spanish National Hydrology Plan (NHP) 2001. Similarly, the anti-Ilısu Dam movement was integrated with the Turkish water movement which emerged as a social justice platform against the threats posed by the 5th World Water Forum (WWF) 2009 which took place in Turkey. On the one hand, through this multi-level alliance formation, these local movements helped to empower their own communities. But on the other hand, they also demonstrated the larger urban public (who, to a great extent, had already been socially and ecologically detached from their traditional lands) that this particular type of development was destructive, resulted in blatant cases of environmental injustice, and that other ways of development less destructive and fairer could be possible. On many grounds, these movements aspire to find ways of reattaching the detached individuals/people back to their communities and nature or, in other words, to reframe the cultural basis of what they see as an unfair growth development paradigm. New community and nature identities have been used to challenge such paradigm and to recreate a more holistic and inclusive social-ecological identity in which human-nature separation becomes increasingly questioned. Empirical data has been gathered from in-depth interviews and focus group meetings held with key actors of these movements, participative-observation, and analysis of secondary sources. Results showed that one clear strategy apparent in both movements was to try to empower people through practices of multi-level networking and collaboration. This enhanced social learning in a way that they learnt not only about the problem they faced, but also on how to build new collective skills to challenge the dominant cultural paradigms which created those unsustainability problems in the first place. Learning, then, in the face of these pro-growth nation-state building strategies, means not only protecting small communities from market forces and global environmental change, but also, in particular, learning to change this dominant cultural paradigm which sees the detachment of people from their communities and from their natural world a necessary condition of progress and development. In this way, new social movements, by aiming to reconstruct such social-ecological identities, may contribute to sustainability learning
New formulations for the hop-constrained minimum spanning tree problem via Sherali and Driscoll's tightened Miller-Tucker-Zemlin constraints
Given an undirected network with positive edge costs and a natural number p, the hop-constrained minimum spanning tree problem (HMST) is the problem of finding a spanning tree with minimum total cost such that each path starting from a specified root node has no more than p hops (edges). In this paper, the new models based on the Miller-Tucker-Zemlin (MTZ) subtour elimination constraints are developed and computational results together with comparisons against MTZ-based, flow-based, and hop-indexed formulations are reported. The first model is obtained by adapting the MTZ-based Asymmetric Traveling Salesman Problem formulation of Sherali and Driscoll [18] and the other two models are obtained by combining topology-enforcing and MTZ-related constraints offered by Akgün and Tansel (submitted for publication) [20] for HMST with the first model appropriately. Computational studies show that the best LP bounds of the MTZ-based models in the literature are improved by the proposed models. The best solution times of the MTZ-based models are not improved for optimally solved instances. However, the results for the harder, large-size instances imply that the proposed models are likely to produce better solution times. The proposed models do not dominate the flow-based and hop-indexed formulations with respect to LP bounds. However, good feasible solutions can be obtained in a reasonable amount of time for problems for which even the LP relaxations of the flow-based and hop-indexed formulations can be solved in about 2 days. © 2010 Elsevier Ltd. All rights reserved
Optimization of transportation requirements in the deployment of military units
We study the deployment planning problem (DPP) that may roughly be defined as the problem of the planning of the physical movement of military units, stationed at geographically dispersed locations, from their home bases to their designated destinations while obeying constraints on scheduling and routing issues as well as on the availability and use of various types of transportation assets that operate on a multimodal transportation network. The DPP is a large-scale real-world problem for which analytical models do not exist. We propose a model for solving the problem and develop a solution methodology which involves an effective use of relaxation and restriction that significantly speeds up a CPLEX-based branch-and-bound. The solution times for intermediate-sized problems are around 1 h at maximum, whereas it takes about a week in the Turkish Armed Forces to produce a suboptimal feasible solution based on trial-and-error methods. The proposed model can be used to evaluate and assess investment decisions in transportation infrastructure and transportation assets as well as to plan and execute cost-effective deployment operations at different levels of planning. © 2006 Elsevier Ltd. All rights reserved
New formulations of the Hop-Constrained Minimum Spanning Tree problem via Miller-Tucker-Zemlin constraints
Given an undirected network with positive edge costs and a natural number p, the Hop-Constrained Minimum Spanning Tree problem (HMST) is the problem of finding a spanning tree with minimum total cost such that each path starting from a specified root node has no more than p hops (edges). In this paper, we develop new formulations for HMST. The formulations are based on Miller-Tucker-Zemlin (MTZ) subtour elimination constraints, MTZ-based liftings in the literature offered for HMST, and a new set of topology-enforcing constraints. We also compare the proposed models with the MTZ-based models in the literature with respect to linear programming relaxation bounds and solution times. The results indicate that the new models give considerably better bounds and solution times than their counterparts in the literature and that the new set of constraints is competitive with liftings to MTZ constraints, some of which are based on well-known, strong liftings of Desrochers and Laporte (1991). © 2011 Elsevier B.V. All rights reserved
Toroidal Magnetic Fields in Type II Superconducting Neutron Stars
We determine constraints on the form of axisymmetric toroidal magnetic fields
dictated by hydrostatic balance in a type II superconducting neutron star with
a barotropic equation of state. Using Lagrangian perturbation theory, we find
the quadrupolar distortions due to such fields for various models of neutron
stars with type II superconducting and normal regions. We find that the star
becomes prolate and can be sufficiently distorted to display precession with a
period of the order of years. We also study the stability of such fields using
an energy principle, which allows us to extend the stability criteria
established by R. J. Tayler for normal conductors to more general media with
magnetic free energy that depends on density and magnetic induction, such as
type II superconductors. We also derive the growth rate and instability
conditions for a specific instability of type II superconductors, first
discussed by P. Muzikar, C. J. Pethick and P. H. Roberts, using a local
analysis based on perturbations around a uniform background.Comment: 32 pages, 6 figures; derivations shortened, comments and references
added; accepted for publication in MNRA
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Theory Learning with Symmetry Breaking
This paper investigates the use of a Prolog coded SMT solver in tackling a well known constraints problem, namely packing a given set of consecutive squares into a given rectangle, and details the developments in the solver that this motivates. The packing problem has a natural model in the theory of quantifier-free integer difference logic, a theory supported by many SMT solvers. The solver used in this work exploits a data structure consisting of an incremental Floyd-Warshall matrix paired with a watch matrix that monitors the entailment status of integer difference constraints. It is shown how this structure can be used to build unsatisfiable theory cores on the fly, which in turn allows theory learning to be incorporated into the solver. Further, it is shown that a problem-specific and non-standard approach to learning can be taken where symmetry breaking is incorporated into the learning stage, magnifying the effect of learning. It is argued that the declarative framework allows the solver to be used in this white box manner and is a strength of the solver. The approach is experimentally evaluated
Cardiac tamponade from a giant thymoma: case report
Thymoma, the most common neoplasm of the anterior mediastinum especially in adults, accounts for 20-25% of all mediastinal tumors and 50% of anterior mediastinal masses. These tumors are routinely asymptomatic for prolonged periods of time. Pericardial tamponade is a very rare initial manifestation of a thymoma. This report presents a patient who had hemorrhagic pericardial tamponade that likely resulted from the largest symptomatic mixed type (type AB) thymoma described in the literature
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Impedimetric Microfluidic Sensor-in-a-Tube for Label-Free Immune Cell Analysis
Analytical platforms based on impedance spectroscopy are promising for non-invasive and label-free analysis of single cells as well as of their extracellular matrix, being essential to understand cell function in the presence of certain diseases. Here, an innovative rolled-up impedimetric microfulidic sensor, called sensor-in-a-tube, is introduced for the simultaneous analysis of single human monocytes CD14+ and their extracellular medium upon liposaccharides (LPS)-mediated activation. In particular, rolled-up platinum microelectrodes are integrated within for the static and dynamic (in-flow) detection of cells and their surrounding medium (containing expressed cytokines) over an excitation frequency range from 102 to 5 × 106 Hz. The correspondence between cell activation stages and the electrical properties of the cell surrounding medium have been detected by electrical impedance spectroscopy in dynamic mode without employing electrode surface functionalization or labeling. The designed sensor-in-a-tube platform is shown as a sensitive and reliable tool for precise single cell analysis toward immune-deficient diseases diagnosis
Structure, Deformations and Gravitational Wave Emission of Magnetars
Neutron stars can have, in some phases of their life, extremely strong
magnetic fields, up to 10^15-10^16 G. These objects, named magnetars, could be
powerful sources of gravitational waves, since their magnetic field could
determine large deformations. We discuss the structure of the magnetic field of
magnetars, and the deformation induced by this field. Finally, we discuss the
perspective of detection of the gravitational waves emitted by these stars.Comment: 11 pages, 2 figures, prepared for 19th International Conference on
General Relativity and Gravitation (GR19), Mexico City, Mexico, July 5-9,
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