OALib Journal期刊

ISSN: 2333-9721



匹配条件: “Boelens” ,找到相关结果约18条。
Water Rights Arenas in the Andes: Upscaling Networks to Strengthen Local Water Control
Rutgerd Boelens
Water Alternatives , 2008,
Abstract: The threats that Andean water user collectives face are ever-growing in a globalizing society. Water is power and engenders social struggle. In the Andean region, water rights struggles involve not only disputes over the access to water, infrastructure and related resources, but also over the contents of water rules and rights, the recognition of legitimate authority, and the discourses that are mobilized to sustain water governance structures and rights orders. While open and large-scale water battles such as Bolivia’s 'Water Wars' or nationwide mobilizations in Ecuador get the most public attention, low-profile and more localized water rights encounters, ingrained in local territories, are far more widespread and have an enormous impact on the Andean waterscapes. This paper highlights both water arenas and the ways they operate between the legal and the extralegal. It shows how local collectives build on their own water rights foundations to manage internal water affairs but which simultaneously offer an important home-base for strategizing wider water defence manoeuvres. Hand-in-hand with inwardly reinforcing their rights bases, water user groups aim for horizontal and vertical linkages thereby creating strategic alliances. Sheltering an internal school for rights and identity development, reflection and organisation, these local community foundations, through open and subsurface linkages and fluxes, provide the groundwork for upscaling their water rights defence networks to national and transnational arenas.
Luchas y defensas escondidas. Pluralismo legal y cultural como una práctica de resistencia creativa en la gestión local del agua en los Andes
Boelens, Rutgerd
Anuario de Estudios Americanos , 2011,
Abstract: In the Andes, water rights are enforced in processes of social struggle. This paper explains how water struggles by Andean user collectives cannot be understood aside from their rootedness in dynamic ‘undertows’: the multi-layered, often concealed water-rights foundations. They entwine plural legal sources and livelihood strategies; there, water rights are shaped materially and discursively. Undertows also constitute the socio-territorial home bases for communities’ efforts to upscale their water rights battlegrounds into broader political-legal networks. In practice, this often happens in disguised political forms: through ‘mimicry’ shields and strategies, which also enable them to shop around in rulers’ power factory. Dynamic sub-surface creation and proliferation of water rights repertoires constitute a strong source of defense against encroachment and disciplinary policies. En los Andes, los derechos de agua se materializan en procesos de lucha social. El artículo examina cómo la lucha por el agua de los colectivos locales no puede comprenderse sin su enraizamiento en subcorrientes dinámicas: los cimientos multicapas, a menudo ocultos, de los derechos de agua. Aquí se entrelazan estrategias comunitarias y fuentes socio-legales plurales. Las subcorrientes alimentan los socio-territorios y las culturas hidráulicas, estableciendo las bases para la defensa de los derechos locales hacia redes político-legales multi-escala. En la práctica, los arreglos y derechos propios a menudo están disfrazados por medio de escudos y estrategias de mimetismo (o imitación), que también permiten hacer uso de los medios de poder dominantes. La creación y la proliferación subsuperficiales de los repertorios sociolegales locales constituyen una importante fuente de defensa contra la usurpación de los derechos de agua y las políticas disciplinarias.
Aguas diversas. Derechos de agua y pluralidad legal en las comunidades andinas
Boelens, Rutgerd
Anuario de Estudios Americanos , 2009,
Abstract: Water rights and property relations have become pivotal issues in water debates, reforms and intervention programs. Governments, development agencies and expert centers tend to consider ‘water rights’ as merely standard black boxes that juxtapose the frameworks of positivist technical and economist water science. But far beyond universal manuals and irrigation regulations, there is another water world, entrenched in the everyday lives of real people, male and female water users. The paper makes clear how Andean user collectives practice an enormous variety of water rights and management forms, as localnational- international hybrids that are created and affirmed in local water territories, embedded in historical and cultural-political contexts. Por el aumento generalizado de los conflictos por el agua, los derechos a este recurso se han vuelto ejes en los debates, reformas y programas de intervención hídrica. Los gobiernos, las agencias de desarrollo y los centros expertos tienden a considerar los ‘derechos de agua’ como meras cajas negras estándar que se yuxtaponen a los marcos de las ciencias técnicas y económicas positivistas. Pero mucho más allá de los manuales y las regulaciones de riego, hay otro mundo del agua íntimamente ligado a la vida diaria de gente real, hombres y mujeres que usan ese agua. Este artículo estudia cómo los colectivos de usuarios en la región andina practican una enorme variedad de derechos de agua y formas de gestión, como híbridos locales-nacionales-internacionales que se crean y afirman en los territorios hídricos locales, embebidos en contextos históricos y cultural-políticos.
The dynamics of general relativistic isotropic stellar cluster models -- Do relativistic extensions of the Plummer model exist?
Sven De Rijcke,Robbert Verbeke,Thomas Boelens
Physics , 2014, DOI: 10.1093/mnras/stu1912
Abstract: We show that the general relativistic theory of the dynamics of isotropic stellar clusters can be developed essentially along the same lines as the Newtonian theory. We prove that the distribution function can be derived from any isotropic momentum moment and that every higher-order moment of the distribution can be written as an integral over a zeroth-order moment. We propose a mathematically simple expression for the distribution function of a family of isotropic general relativistic cluster models and investigate their dynamical properties. In the Newtonian limit, these models obtain a distribution function of the form F(E) ~ (E-E_0)^alpha, with E binding energy and E_0 a constant that determines the model's outer radius. The slope alpha sets the steepness of the distribution function and the corresponding radial density and pressure profiles. We show that the field equations only yield solutions with finite mass for alpha<3.5. Moreover, in the limit alpha->3.5, only Newtonian models exist. In other words: within the context of this family of models, no general relativistic version of the Plummer model exists. The most strongly bound model within the family is characterized by alpha=2.75 and a central redshift z_c~0.55.
Rotational relaxation time as unifying time scale for polymer and fiber drag reduction
A. M. P. Boelens,M. Muthukumar
Physics , 2015,
Abstract: Using hybrid Direct Numerical Simulation with Langevin dynamics, a comparison is performed between polymer and fiber stress tensors in turbulent flow. The stress tensors are found to be similar, suggesting a common drag reducing mechanism in the onset regime for both flexible polymers and rigid fibers. Since fibers do not have an elastic backbone this must be a viscous effect. Analysis of the viscosity tensor reveals that all terms are negligible, except the off-diagonal shear viscosity associated with rotation. Based on this analysis, we identify the rotational orientation time as the unifying time scale setting a new time criterion for drag reduction by both flexible polymers and rigid fibers.
SAMPLEX: Automatic mapping of perturbed and unperturbed regions of proteins and complexes
Micka?l Krzeminski, Karine Loth, Rolf Boelens, Alexandre MJJ Bonvin
BMC Bioinformatics , 2010, DOI: 10.1186/1471-2105-11-51
Abstract: We describe an innovative, automatic and unbiased method to distinguish perturbed and unperturbed regions in a protein existing in two distinct states (folded/partially unfolded, bound/unbound). The SAMPLEX program takes as input a set of data and the corresponding three-dimensional structure and returns the confidence for each residue to be in a perturbed or unperturbed state. Its performance is demonstrated for different applications including the prediction of disordered regions in partially unfolded proteins and of interacting regions in protein complexes.The proposed approach is suitable for partially unfolded states of proteins, local perturbations due to small ligands and protein-protein interfaces. The method is not restricted to NMR data, but is generic and can be applied to a wide variety of information.During the last decennia, there has been a growing interest in biological system dynamics, which consist for instance of interactions between proteins and folding pathways. This also includes proteins that partially unfold under specific environmental stimuli (taxis), and act as intermediates in a cascade of events [1]. In all cases, only a part of the protein is involved in the biological process while the remaining part stays dormant. Indeed, in a protein-protein complex, only the interaction surface is often affected, even though, sometimes, a larger part of the protein is modified, like in the case of allosteric interactions or conformational changes upon binding. As for partially unfolded proteins, which are typically composed of mobile regions linked to a folded core, they show some flexibility due to the internal motions of the protein and the reorganization of the unfolded part upon partial unfolding. In order to structurally characterize such systems, it is crucial to distinguish the unperturbed regions from the perturbed ones.Nuclear Magnetic Resonance (NMR) is particularly convenient for monitoring, at atomic level, structural and/or environmenta
Contested Territories: Water Rights and the Struggles over Indigenous Livelihoods
Rutgerd Boelens,Bibiana Duarte,Rossana Manosalvas,Patricio Mena
International Indigenous Policy Journal , 2012,
Abstract: This paper examines the threats to Indigenous water rights and territories in the Andean countries. It analyzes how water and water rights are embedded in Indigenous territories, and how powerful actors and intervention projects tend to undermine local societies and indigenous livelihoods by developing large-scale water infrastructure. Three cases illustrate the encroachment process. In Colombia, the Embera Katio people’s water territory is colonized by a large-scale hydropower development project. In Ecuador, large-scale drinking water development for megacities aims the water belonging to the Oyacachi community’s indigenous highland territory. In Peru, communal water rights of the Colca Valley indigenous peasantry are under threat because of large-scale irrigation development. As the cases show, Indigenous peoples and communities actively contest the undermining and subordination of their water and territorial rights through a myriad of multi-scalar livelihood defense strategies. The challenges that indigenous peoples face to defend their water-based livelihoods are, however, enormous and growing every day.
Glycosylation of Conotoxins
Gerrit J. Gerwig,Henry G. Hocking,Reto St?cklin,Johannis P. Kamerling,Rolf Boelens
Marine Drugs , 2013, DOI: 10.3390/md11030623
Abstract: Conotoxins are small peptides present in the venom of cone snails. The snail uses this venom to paralyze and capture prey. The constituent conopeptides display a high level of chemical diversity and are of particular interest for scientists as tools employed in neurological studies and for drug development, because they target with exquisite specificity membrane receptors, transporters, and various ion channels in the nervous system. However, these peptides are known to contain a high frequency and variability of post-translational modifications—including sometimes O-glycosylation—which are of importance for biological activity. The potential application of specific conotoxins as neuropharmalogical agents and chemical probes requires a full characterization of the relevant peptides, including the structure of the carbohydrate part. In this review, the currently existing knowledge of O-glycosylation of conotoxins is described.
Pseudophosphorylated αB-Crystallin Is a Nuclear Chaperone Imported into the Nucleus with Help of the SMN Complex
John den Engelsman, Chantal van de Schootbrugge, Jeongsik Yong, Ger J. M. Pruijn, Wilbert C. Boelens
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0073489
Abstract: The human small heat shock protein αB-crystallin (HspB5) is a molecular chaperone which is mainly localized in the cytoplasm. A small fraction can also be found in nuclear speckles, of which the localization is mediated by successional phosphorylation at Ser-59 and Ser-45. αB-crystallin does not contain a canonical nuclear localization signal sequence and the mechanism by which αB-crystallin is imported into the nucleus is not known. Here we show that after heat shock pseudophosphorylated αB-crystallin mutant αB-STD, in which all three phosphorylatable serine residues (Ser-19, Ser-45 and Ser-59) were replaced by negatively charged aspartate residues, is released from the nuclear speckles. This allows αB-crystallin to chaperone proteins in the nucleoplasm, as shown by the ability of αB-STD to restore nuclear firefly luciferase activity after a heat shock. With the help of a yeast two-hybrid screen we found that αB-crystallin can interact with the C-terminal part of Gemin3 and confirmed this interaction by co-immunoprecipitation. Gemin3 is a component of the SMN complex, which is involved in the assembly and nuclear import of U-snRNPs. Knockdown of Gemin3 in an in situ nuclear import assay strongly reduced the accumulation of αB-STD in nuclear speckles. Furthermore, depletion of SMN inhibited nuclear import of fluorescently labeled recombinant αB-STD in an in vitro nuclear import assay, which could be restored by the addition of purified SMN complex. These results show that the SMN-complex facilitates the accumulation of hyperphosphorylated αB-crystallin in nuclear speckles, thereby creating a chaperone depot enabling a rapid chaperone function in the nucleus in response to stress.
Key Role for Clumping Factor B in Staphylococcus aureus Nasal Colonization of Humans
Heiman F. L Wertheim ,Evelyn Walsh,Roos Choudhurry,Damian C Melles,Hélène A. M Boelens,Helen Miajlovic,Henri A Verbrugh,Timothy Foster,Alex van Belkum
PLOS Medicine , 2008, DOI: 10.1371/journal.pmed.0050017
Abstract: Background Staphylococcus aureus permanently colonizes the vestibulum nasi of one-fifth of the human population, which is a risk factor for autoinfection. The precise mechanisms whereby S. aureus colonizes the nose are still unknown. The staphylococcal cell-wall protein clumping factor B (ClfB) promotes adhesion to squamous epithelial cells in vitro and might be a physiologically relevant colonization factor. Methods and Findings We define the role of the staphylococcal cytokeratin-binding protein ClfB in the colonization process by artificial inoculation of human volunteers with a wild-type strain and its single locus ClfB knock-out mutant. The wild-type strain adhered to immobilized recombinant human cytokeratin 10 (CK10) in a dose-dependent manner, whereas the ClfB? mutant did not. The wild-type strain, when grown to the stationary phase in a poor growth medium, adhered better to CK10, than when the same strain was grown in a nutrient-rich environment. Nasal cultures show that the mutant strain is eliminated from the nares significantly faster than the wild-type strain, with a median of 3 ± 1 d versus 7 ± 4 d (p = 0.006). Furthermore, the wild-type strain was still present in the nares of 3/16 volunteers at the end of follow-up, and the mutant strain was not. Conclusions The human colonization model, in combination with in vitro data, shows that the ClfB protein is a major determinant of nasal-persistent S. aureus carriage and is a candidate target molecule for decolonization strategies.

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