314 research outputs found
Second-tier community forestry organisations and equitable resource management in the Maya Biosphere Reserve, Guatemala
Whilst community forestry programmes have combined sustainable forestry with community empowerment and poverty alleviation since the late 1970s, the role of intermediary organisations in shaping the technical and political capacities of forest user groups has rarely been systematically studied. The long-term durability of community forestry groups has been linked with the congruence between local and national determinations of tenure rights, and the involvement of local communities in determining the ‘rules' that govern the management of the forests. However, the role of intermediary organisations in negotiating such rights and rules is of central analytical importance - especially in contexts where pre-existing power and gender relationships influence who makes which decisions and how, and where long-standing conflicts over access to land constantly over-determine the possibilities for upscaling successful projects. As part of an interdisciplinary project on community forestry in Mesoamerica led by Bioversity International, this paper focuses on the case of the Asociación de Comunidades Forestales de Petén [ACOFOP], a second-tier community organisation founded in the mid-1990s to coordinate and represent first-tier organisations that were granted community concessions in the Maya Biosphere Reserve in the Petén region of Guatemala. Drawing on interviews, the outcomes of participative workshops, and a review of key literature, we trace ACOFOP's emergence as a forestry organisation from existing agricultural and non-timber product cooperatives, and its subsequent consolidation as a platform for regional coordination and advocacy. Using a ‘Sociology of Knowledge' approach to discourse analysis (SKAD), we highlight three important dimensions of ACOFOP's evolving strategy that facilitate the development of both local autonomies and collective coherence: the mobilisation of concepts of ‘environmental justice' and associated international rights frameworks to link local concerns with national governance issues; the elaboration of legal knowledges and mechanisms in these terms to negotiate improved tenure relationships; and a concentration of resources in the development of local leadership with an emphasis on elaborating the fixed ‘rules' of forestry management in a manner that is appropriate to each community's individual characteristics. We conclude by highlighting key strategies that may be applied to strengthen community forestry in other regional settings
Geographies of authority
This is the final version. Available on open access from SAGE Publications via the DOI in this recordWe propose a geography that pluralises the sites, practices, and politics of authority. We defend an
approach that tracks less perceptible forms of authority emerging through everyday micropolitics
and experimental practices. In contrast to dominant definitions of authority as institutionalized
legitimate power, we propose a definition of authority as a relation of guidance emerging from
recognition of inequalities in access to truth, experience, or objectivity. Analysing four intersecting
areas of authority (algorithmic, experiential, expert, and participatory authority), we propose
analyses that trace authority’s affective force, and which address the tension between, but also
mutual constitution of, authority and equality
Quantifying resilience of socio-ecological systems through dynamic Bayesian networks
This is the final version. Available on open access from Frontiers Media via the DOI in this recordQuantifying resilience of socio-ecological systems (SES) can be invaluable to delineate management strategies of natural resources and aid the resolution of socio-environmental conflicts. However, resilience is difficult to quantify and the factors contributing to it are often unknown. We provide a theoretical and conceptual framework to quantify resilience in a long-term context. Our approach uses elements from interdisciplinarity and network perspectives to establish links and causalities between social and ecological variables and resilience attributes. The evaluation and modeling of SES structure and function are established from the analysis of dynamic Bayesian networks (DBN). DBN models allow quantifying resilience through probabilities and offer a platform of interdisciplinary dialogue and an adaptive framework to address questions on ecosystem monitoring and management. The proposed DBN is tested in Monquentiva, a SES located in the high Andes of Colombia. We determined historical socio-ecological resilience from paleoecological evidence (palynological diversity, forest cover, fires, and precipitation) and social-economic factors (governance, social organization, and connectivity) between 1920 and 2019. We find that transformation processes in Monquentiva are mainly related to social change (e.g., social organization) and increased ecological diversity that in turn have fostered SES resilience between 1980 and 2019. The ability to predict the SES response over time and under cumulative, non-linear interactions across a complex ecosystem highlights the utility of DBNs for decision support and environmental management. We conclude with a series of management and policy-relevant applications of the DBN approach for SES resilience assessment.Natural Environment Research Council (NERC
Transmogrifying Fuzzy Vortices
We show that the construction of vortex solitons of the noncommutative
Abelian-Higgs model can be extended to a critically coupled gauged linear sigma
model with Fayet-Illiopolous D-terms. Like its commutative counterpart, this
fuzzy linear sigma model has a rich spectrum of BPS solutions. We offer an
explicit construction of the degree static semilocal vortex and study in
some detail the infinite coupling limit in which it descends to a degree
\C\Pk^{N} instanton. This relation between the fuzzy vortex and
noncommutative lump is used to suggest an interpretation of the noncommutative
sigma model soliton as tilted D-strings stretched between an NS5-brane and a
stack of D3-branes in type IIB superstring theory.Comment: 21 pages, 4 figures, LaTeX(JHEP3
Polycomb-mediated repression of EphrinA5 promotes growth and invasion of glioblastoma
Glioblastoma (GBM) is the most common and most aggressive intrinsic brain tumour in adults. Integrated transcriptomic and epigenomic analyses of glioblastoma initiating cells (GIC) in a mouse model uncovered a novel epigenetic regulation of EfnA5. In this model, Bmi1 enhances H3K27me3 at the EfnA5 locus and reinforces repression of selected target genes in a cellular context-dependent fashion. EfnA5 mediates Bmi1-dependent proliferation and invasion in vitro and tumour formation in an allograft model. Importantly, we show that this novel Polycomb feed-forward loop is also active in human GIC and we provide pre-clinical evidence of druggability of the EFNA5 signalling pathway in GBM xenografts overexpressing Bmi1
Microglia promote glioblastoma via mTOR-mediated immunosuppression of the tumour microenvironment
Tumour-associated microglia/macrophages (TAM) are the most
numerous non-neoplastic populations in the tumour microenvironment in glioblastoma multiforme (GBM), the most common malignant brain tumour in adulthood. The mTOR pathway, an important
regulator of cell survival/proliferation, is upregulated in GBM, but
little is known about the potential role of this pathway in TAM. Here,
we show that GBM-initiating cells induce mTOR signalling in the
microglia but not bone marrow-derived macrophages in both in vitro
and in vivo GBM mouse models. mTOR-dependent regulation of STAT3
and NF-jB activity promotes an immunosuppressive microglial
phenotype. This hinders effector T-cell infiltration, proliferation and
immune reactivity, thereby contributing to tumour immune evasion
and promoting tumour growth in mouse models. The translational
value of our results is demonstrated in whole transcriptome datasets
of human GBM and in a novel in vitro model, whereby expandedpotential stem cells (EPSC)-derived microglia-like cells are conditioned by syngeneic patient-derived GBM-initiating cells. These
results raise the possibility that microglia could be the primary target
of mTOR inhibition, rather than the intrinsic tumour cells in GB
Chaos in an Exact Relativistic 3-body Self-Gravitating System
We consider the problem of three body motion for a relativistic
one-dimensional self-gravitating system. After describing the canonical
decomposition of the action, we find an exact expression for the 3-body
Hamiltonian, implicitly determined in terms of the four coordinate and momentum
degrees of freedom in the system. Non-relativistically these degrees of freedom
can be rewritten in terms of a single particle moving in a two-dimensional
hexagonal well. We find the exact relativistic generalization of this
potential, along with its post-Newtonian approximation. We then specialize to
the equal mass case and numerically solve the equations of motion that follow
from the Hamiltonian. Working in hexagonal-well coordinates, we obtaining
orbits in both the hexagonal and 3-body representations of the system, and plot
the Poincare sections as a function of the relativistic energy parameter . We find two broad categories of periodic and quasi-periodic motions that we
refer to as the annulus and pretzel patterns, as well as a set of chaotic
motions that appear in the region of phase-space between these two types.
Despite the high degree of non-linearity in the relativistic system, we find
that the the global structure of its phase space remains qualitatively the same
as its non-relativisitic counterpart for all values of that we could
study. However the relativistic system has a weaker symmetry and so its
Poincare section develops an asymmetric distortion that increases with
increasing . For the post-Newtonian system we find that it experiences a
KAM breakdown for : above which the near integrable regions
degenerate into chaos.Comment: latex, 65 pages, 36 figures, high-resolution figures available upon
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High-precision photometric redshifts from Spitzer/IRAC : extreme [3.6] - [4.5] colors identify galaxies in the redshift range z ~ 6.6 - 6.9.
One of the most challenging aspects of studying galaxies in the z 7 universe is the infrequent confirmation of their redshifts through spectroscopy, a phenomenon thought to occur from the increasing opacity of the intergalactic medium to Lyα photons at z \u3e 6.5. The resulting redshift uncertainties inhibit the efficient search for [C II] in z ~ 7 galaxies with sub-millimeter instruments such as ALMA, given their limited scan speed for faint lines. One means by which to improve the precision of the inferred redshifts is to exploit the potential impact of strong nebular emission lines on the colors of z ∼ 4 – 8 galaxies as observed by Spitzer/IRAC. At z ~ 6.8, galaxies exhibit IRAC colors as blue as[3.6] [4.5] 1 - ~- , likely due to the contribution of [O III]+Hβ to the 3.6 μm flux combined with the absence of line contamination in the 4.5 μm band. In this paper we explore the use of extremely blue [3.6] [4.5] - colors to identify galaxies in the narrow redshift window z ~ 6.6 – 6.9. When combined with an I-dropout criterion, we demonstrate that we can plausibly select a relatively clean sample of z ~ 6.8 galaxies. Through a systematic application of this selection technique to our catalogs from all five CANDELS fields, we identify 20 probable z ~ 6.6 – 6.9 galaxies. We estimate that our criteria select the ∼50% strongest line emitters at z ~ 6.8 and from the IRAC colors we estimate a typical [O III]+Hb rest-frame equivalent width of 1085 Å for this sample. The small redshift uncertainties on our sample make it particularly well suited for follow-up studies with facilities such as ALMA
Exploring the opportunities and risks of aerial monitoring for biodiversity conservation
Drones are unoccupied aerial systems (UAS) whose technology has evolved rapidly over the past 15 years. Increasingly used in conservation to manage and monitor biodiversity, drones offer rich capabilities to observe in difficult terrain, have relatively affordable hardware costs and are likely to continue to proliferate rapidly in the years ahead. Drones are useful for tasks as diverse as monitoring wildlife poaching and illegal timber extraction, managing ecotourism and disaster responses, and tracking the regeneration or degradation of forests, and offer potential for more specialised tasks as their sensory payloads are developed. However, although associated technical issues and applications have been explored in wide-ranging ways within conservation science, there has been relatively little social-scientific engagement with drones to date. This leaves a gap surrounding the potential social benefits and risks of drones, as well as in interdisciplinary conversations. This introduction is the first of four papers under the heading ‘Drone ecologies’, building on an interdisciplinary workshop held under the same name at the University of Bristol in July 2021. Expanding from the plenary dialogues that opened this workshop, this introduction explores what interdisciplinary perspectives on drones can offer in addressing global social and ecological challenges, drawing on expertise from the fields of conservation biology, human and physical geography, rainforest ecology and environmental systems. Setting out the aims of the overall special collection, we review here the ways that drones are being used, and might be used, in biodiversity conservation, setting out important considerations to minimise risks of inadvertent harms
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