119 research outputs found
Apropiación de la naturaleza por una Comunidad Maya Yucateca : un análisis económico-ecológico
A partir de un modelo económico-ecológico de apropiación de la naturaleza, en este artículo analizamos como una comunidad de mayas yucatecos, situados al noreste de la península de Yucatán, incorporó el ecoturismo a su estrategia de manejo de los recursos naturales. Utilizando información proveniente de 63 entrevistas a nivel de hogar, describimos, cuantificamos y analizamos las diferentes actividades productivas desarrolladas con el fin de mostrar las condiciones sociales, económicas y ecológicas en las que basan su estrategia de uso múltiple de los recursos naturales. Los resultados muestran que los hogares manejan hasta 5 unidades paisajísticas: milpas, huertos familiares, selvas secundarias, selvas maduras y sistemas acuáticos, en las cuales llevan a cabo un total de 13 actividades económicas. Dado que la región se ha convertido en un destino turístico importante y el ecoturismo está reemplazando algunas de las actividades tradicionales, discutimos la importancia de que exista un balance entre actividades económicas tradicionales y alternativas.Using an ecological-economic approach to ecosystems appropriation, in this paper we analyze the adaptive openness of contemporary Yucatec Maya multiple use management of natural resources to ecotourism activities. Using data obtained from 63 household interviews in three Yucatec Maya communities located in the northeastern portion of the Yucatan Peninsula, we describe, quantify and analyze the communities' productive activities in order to reveal the ecological, economic and social conditions under which their productive strategies are developed. Results show that households from these communities implement a strategy based on the management of 5 land use units: milpa; homegardens; secondary forest; aquatic systems; and old-growth forest, in which they implement 15 different economic activities. Since the region is quickly becoming an important tourist destination and ecotourism is replacing many traditional activities, we discuss the need for a balance between traditional and alternative economic activities
Pseudomonas protegens sp. nov., widespread plant-protecting bacteria producing the biocontrol compounds 2,4-diacetylphloroglucinol and pyoluteorin
Fluorescent Pseudomonas strains producing the antimicrobial secondary metabolite 2,4-diacetylphloroglucinol (Phl) play a prominent role in the biocontrol of plant diseases. A subset of Phl-producing fluorescent Pseudomonas strains, which can additionally synthesize the antimicrobial compound pyoluteorin (Plt), appears to cluster separately from other fluorescent Pseudomonas spp. based on 16S rRNA gene analysis and shares at most 98.4% 16S rRNA gene sequence identity with any other Pseudomonas species. In this study, a polyphasic approach based on molecular and phenotypic methods was used to clarify the taxonomy of representative Phl+ Plt+ strains isolated from tobacco, cotton or wheat on different continents. Phl+ Plt+ strains clustered separately from their nearest phylogenetic neighbors (i.e. species from the ‘P. syringae’, ‘P. fluorescens’ and ‘P. chlororaphis’ species complexes) based on rpoB, rpoD or gyrB phylogenies. DNA-DNA hybridization experiments clarified that Phl+ Plt+ strains formed a tight genomospecies that was distinct from P. syringae, P. fluorescens, or P. chlororaphis type strains. Within Phl+ strains, the Phl+ Plt+ strains were differentiated from other biocontrol fluorescent Pseudomonas strains that produced Phl but not Plt, based on phenotypic and molecular data. Discriminative phenotypic characters were also identified by numerical taxonomic analysis and siderotyping. Altogether, this polyphasic approach supported the conclusion that Phl+ Plt+ fluorescent Pseudomonas strains belonged to a novel species for which the name Pseudomonas protegens is proposed, with CHA0T (=CFBP 6595T, =DSM 19095T) as the type strain
OTX015 (MK-8628), a novel BET inhibitor, exhibits antitumor activity in non-small cell and small cell lung cancer models harboring different oncogenic mutations.
Inhibitors targeting epigenetic control points of oncogenes offer a potential mean of blocking tumor progression in small cell and non-small cell lung carcinomas (SCLC, NSCLC). OTX015 (MK-8628) is a BET inhibitor selectively blocking BRD2/3/4. OTX015 was evaluated in a panel of NSCLC or SCLC models harboring different oncogenic mutations. Cell proliferation inhibition and cell cycle arrest were seen in sensitive NSCLC cells. MYC and MYCN were downregulated at both the mRNA and protein levels. In addition, OTX015-treatment significantly downregulated various stemness cell markers, including NANOG, Musashi-1, CD113 and EpCAM in H3122-tumors in vivo. Conversely, in SCLC models, weak antitumor activity was observed with OTX015, both in vitro and in vivo. No predictive biomarkers of OTX015 activity were identified in a large panel of candidate genes known to be affected by BET inhibition. In NSCLC models, OTX015 was equally active in both EML4-ALK positive and negative cell lines, whereas in SCLC models the presence of functional RB1 protein, which controls cell progression at G1, may be related to the final biological outcome of OTX015. Gene expression profiling in NSCLC and SCLC cell lines showed that OTX015 affects important genes and pathways with a very high overlapping between both sensitive and resistant cell lines. These data support the rationale for the OTX015 Phase Ib (NCT02259114) in solid tumors, where NSCLC patients with rearranged ALK gene or KRAS-positive mutations are currently being treated
Payments for ecosystem services and the fatal attraction of win-win solutions
In this commentary we critically discuss the suitability of payments for ecosystem services and the most important challenges they face. While such instruments can play a role in improving environmental governance, we argue that over-reliance on payments as win-win solutions might lead to ineffective outcomes, similar to earlier experience with integrated conservation and development projects. Our objective is to raise awareness, particularly among policy makers and practitioners, about the limitations of such instruments and to encourage a dialogue about the policy contexts in which they might be appropriate. © 2013 Wiley Periodicals, Inc
3D Mass Spectrometry Imaging Reveals a Very Heterogeneous Drug Distribution in Tumors
Mass Spectrometry Imaging (MSI) is a widespread technique used to qualitatively describe in two dimensions the distribution of endogenous or exogenous compounds within tissue sections. Absolute quantification of drugs using MSI is a recent challenge that just in the last years has started to be addressed. Starting from a two dimensional MSI protocol, we developed a three-dimensional pipeline to study drug penetration in tumors and to develop a new drug quantification method by MALDI MSI. Paclitaxel distribution and concentration in different tumors were measured in a 3D model of Malignant Pleural Mesothelioma (MPM), which is known to be a very heterogeneous neoplasm, highly resistant to different drugs. The 3D computational reconstruction allows an accurate description of tumor PTX penetration, adding information about the heterogeneity of tumor drug distribution due to the complex microenvironment. The use of an internal standard, homogenously sprayed on tissue slices, ensures quantitative results that are similar to those obtained using HPLC. The 3D model gives important information about the drug concentration in different tumor sub-volumes and shows that the great part of each tumor is not reached by the drug, suggesting the concept of pseudo-resistance as a further explanation for ineffective therapies and tumors relapse
- …