479 research outputs found
Indigenous territories and tropical forest management in Latin America
Using data from Latin America, the authors argue that fundamental changes must take place in the legal recognition and demarcation of indigenous territories if indigenous peoples are to fulfill their potential as resource managers for threatened tropical forest ecosystems. The authors compare different national land tenure models for forest-dwelling indigenous peoples (contained in national Indian, agrarian, and protected-area laws in Latin America) and a model proposed by indigenous organizations in Latin America. The conventional models emerged during an era when most governments were more concerned with the rapid occupation and exploitation of frontier zones and the assimilation of indigenous peoples. Recent attention to the environmental degradation of these areas and the need to create alternative models of land use and development have directed attention to the potential contribution of indigenous peoples to the conservation and management of the vast tropical forests of Latin America. The authors find that indigenous peoples must be given some degree of control over their territories and resources. They contend that for successful management of tropical forests there must be a new type of partnership between indigenous peoples, the scientific community, national governments, and international development agencies. This relationship should be a contractual one, in which indigenous peoples are provided with juridical recognition and control over large areas of forest in exchange for a commitment to conserve the ecosystem and preserve biodiversity.Municipal Financial Management,Agricultural Knowledge&Information Systems,Forestry,Environmental Economics&Policies,Banks&Banking Reform
Mouvement maya et culture nationale au Guatemala
Introduction En 1981, lâanthropologue mexicain Guillermo Bonfil Batalla publiait une collection de textes Ă©crits par plusieurs jeunes leaders dâorganisations indigĂšnes qui mettaient en avant lâĂ©mergence dâune nouvelle forme de conscience ethnique parmi les quelque 40  millions dâindigĂšnes dâAmĂ©rique latine. Durant la prĂ©cĂ©dente dĂ©cade, ces leaders et organisations avaient commencĂ© Ă contester la vision conventionnelle selon laquelle la rĂ©gion Ă©tait composĂ©e dâĂtats-nations monolithiques qui a..
Is There Genetic Diversity in the âLeucaena Bugâ \u3cem\u3eSynergistes jonesii\u3c/em\u3e Which May Reflect Ability to Degrade Leucaena Toxins?
Leucaena leucocephala, a nutritionally rich forage tree legume, contains a non-protein amino acid, mimosine, which is degraded by ruminal bacteria to toxic metabolites 3,4-DHP and 2,3-DHP resulting in goitre-like symptoms in animals, severely restricting weight gain. Raymond Jones, in the early 1980s, discovered the âleucaena bugâ in the rumen of goats in Hawaii that degraded these toxic DHP metabolites into non-toxic compounds (Jones and Lowry 1984) which was named Synergistes jonesii (Allison et al. 1992) Subsequently, a rumen inoculum containing S. jonesii was used as an âoral drenchâ for cattle, kept in continuous culture (Klieve et al. 2002) and supplied to farmers to dose cattle foraging on leucaena.
Studies on Queensland herds that received this oral drench showed that up to 50% of 44 herds grazing on leucaena had apparent subclinical toxicity based on high 3,4- and 2,3-DHP excretion in urine (Dalzell et al., 2012). In another study by Graham et al. (2013), a 16S rDNA nested PCR showed that rumen digesta from 6 out of 8 properties tested had a variant DNA profile from S. jonesii ATCC 78.1 strain, which suggested a different strain of the bacterium.
It was postulated that either the continually cultured oral inoculum may have undergone genetic modification and/or that animals could harbor other DHP degrading bacteria or S. jonesii strains with differential DHP degrading potential (McSweeney et al. unpublished). The present study looks at changes in the 16S rDNA gene at the molecular level that may suggest divergence from the type strain S. jonesii 78.1 (ATCC) in Queensland cattle as well as in cattle and other ruminants, internationally. These changes can appear as discrete mutations or âsingle nucleotide polymorphismsâ (SNPs) and may be correlated to their ability to degrade DHP, relative to the type strain
Graph products of spheres, associative graded algebras and Hilbert series
Given a finite, simple, vertex-weighted graph, we construct a graded
associative (non-commutative) algebra, whose generators correspond to vertices
and whose ideal of relations has generators that are graded commutators
corresponding to edges. We show that the Hilbert series of this algebra is the
inverse of the clique polynomial of the graph. Using this result it easy to
recognize if the ideal is inert, from which strong results on the algebra
follow. Non-commutative Grobner bases play an important role in our proof.
There is an interesting application to toric topology. This algebra arises
naturally from a partial product of spheres, which is a special case of a
generalized moment-angle complex. We apply our result to the loop-space
homology of this space.Comment: 19 pages, v3: elaborated on connections to related work, added more
citations, to appear in Mathematische Zeitschrif
The link between accretion mode and environment in radio-loud active galaxies
The interactions between radio-loud AGN and their environments play an important rĂŽle in galaxy and cluster evolution. Recent work has demonstrated fundamental differences between high- and low-excitation radio galaxies (HERGs and LERGs), and shown that they may have different relationships with their environments. In the Chandra Large Project ERA (Environments of Radio-loud AGN), we made the first systematic X-ray environmental study of the cluster environments of radio galaxies at a single epoch (z ~ 0.5), and found tentative evidence for a correlation between radio luminosity and cluster X-ray luminosity. We also found that this relationship appeared to be driven by the LERG subpopulation. We have now repeated the analysis with a low-redshift sample (z ~ 0.1), and found strong correlations between radio luminosity and environment richness and between radio luminosity and central density for the LERGs but not for the HERGs. These results are consistent with models in which the HERGs are fuelled from accretion discs maintained from local reservoirs of gas, while LERGs are fuelled more directly by gas ingested from the intracluster medium. Comparing the samples, we found that although the maximum environment richness of the HERG environments is similar in both samples, there are poorer HERG environments in the z ~ 0.1 sample than in the z ~ 0.5 sample. We have therefore tentative evidence of evolution of the HERG environments. We found no differences between the LERG subsamples for the two epochs, as would be expected if radio and cluster luminosities are related.Peer reviewedFinal Accepted Versio
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
The Interstellar Environment of our Galaxy
We review the current knowledge and understanding of the interstellar medium
of our galaxy. We first present each of the three basic constituents - ordinary
matter, cosmic rays, and magnetic fields - of the interstellar medium, laying
emphasis on their physical and chemical properties inferred from a broad range
of observations. We then position the different interstellar constituents, both
with respect to each other and with respect to stars, within the general
galactic ecosystem.Comment: 39 pages, 12 figures (including 3 figures in 2 parts
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