7,791 research outputs found
Turismo y migración entre los mayas de Yucatán. Las nuevas milpas de Chan Kom
El artículo analiza el fenómeno del turismo en el actual contexto de globalización y postmodernidad a través de las relaciones entre Chan Kom, una comunidad maya de la península de Yucatán, y Cancún, el emporio turístico internacional. El estudio examina el diálogo entre la fragmentación social de Chan Kom, debida a la emigración a Cancún, y la mayanización de la geografía humana de Cancún. El objetivo es auscultar las diversidad de respuestas ante el aumento de las influencias del turismo entre los campesinos y emigrantes de Chan Kom. El símbolo de la milpa constituye un núcleo ideológico que muestra gran plasticidad en los esfuerzos de los diferentes grupos por legitimar su poder político dentro de la fragmentación social de Chan Kom. Se subraya particularmente el papel que el capital humano de los emigrantes desempeña en los planes de desarrollo económico de la comunidadThis article analyzes the phenomenon of tourism within the current globalizing and postmodern contexts. It is based on the relationships between Chan Kom, a Maya community in the Yucatan peninsula, and Cancun, the international tourist emporium. The study examines the dialogue between Chan Kom's social fragmentation due to out-migration to Cancun, and the Mayanization of the human geography of Cancun. The goal is to scrutinize the multifaceted responses to the expansion of tourism influences among Chan Kom's peasants and migrants. The symbol of milpa is an ideological core that shows great plasticity in different groups efforts to legitimize their political power within Chan Kom's social fragmentation. Particular emphasis is placed on the role that migrants' human capital plays in the community plans for economic development
Interculturality: Where Do We Go From Here?
This issue provides striking examples of how current educational policies and practices play a fundamental role in processes that constitute immigrant and ethnic minority children as ‘others’. This collective compendium not only interweaves theory and practice but also initiates a trans-Atlantic conversation about intercultural education embracing ethnographic cases from North America (Texas), South America (Bolivia) and Europe (Spain). These conversations lead towards an interesting exercise of similarities and differences in how interculturality is used and understood in the classroom, based on the local fluid composition of ideological, ethnic, political and economic factors. The exercise in comparison of these intercontinental ethnographic exercises points out crucial common themes that authors use as prisms to show the articulation of education policies and epistemological contradictions. It is with particular attention that these contributions examine educational policies and practices in intercultural contexts and their effects in essentializing the concept of culture as if it were a fixed attribute believed to determine students’ behaviours, attitudes, school expectations and social relationships. Most of the ethnographic cases presented clearly document how cultural differences, rather than being seen as an asset in intercultural education contexts, are more often understood in terms of ‘deficits’. In sum, the core anthropological contribution of these articles is centred on the analysis of the processes that lead to cultural reifications, how these transform into stereotypes that weigh down students’ trajectories in schools, and how this culminates in the very opposite of the original intention of educational policies
Long-term visual and microperimetry outcomes following autologous retinal pigment epithelium choroid graft for neovascular age-related macular degeneration
To describe the 2- to 4-year visual and microperimetry outcomes of autologous retinal pigment epithelium (RPE)-choroid graft in patients with neovascular age-related macular degeneration (AMD).In this retrospective cohort study, 12 patients with subfoveal neovascular AMD who had undergone autologous RPE-choroid graft between August 2004 and June 2005 were reviewed. Change in visual acuity (VA), contrast sensitivity (CS), fixation stability and retinal sensitivity on microperimetry after 2-3 years and the rates of late postoperative complications were examined.Patients were followed for 26-48 months (mean, 39). Median preoperative VA (logMAR) was 0.87 but declined to 1.43 (1 year), 1.46 (2 years) and 1.38 (3 years), P = 0.001. Median CS (logCS) was 0.75 preoperatively but declined to 0.45 at 2 years. Six patients had serial microperimetry. Fixation stability declined in 1 but improved in 2 patients. All 6 had decline in retinal sensitivity over the graft during follow up. Retinal detachment did not occur after 12 months but 8 developed epiretinal membrane, 12 had cystic retinal change over the graft and 4 developed recurrent choroidal neovascularization. However, 10 grafts retained autofluorescence signal at 18-48 months of follow up.Autologous RPE-choroid graft can maintain VA, stable fixation and retinal sensitivity in some patients for over 3 years. The spatial correlation between graft autofluorescence, outer retinal structures on optical coherence tomography and retinal sensitivity are consistent with photoreceptor cell rescue. However, we caution the use of this technique as there is high complication rate and delayed loss of retinal function
Efficient and Unbiased Estimation of Population Size
Population sizing from still aerial pictures is of wide applicability in ecological and social sciences. The problem is long standing because current automatic detection and counting algorithms are known to fail in most cases, and exhaustive manual counting is tedious, slow, difficult to verify and unfeasible for large populations. An alternative is to multiply population density with some reference area but, unfortunately, sampling details, handling of edge effects, etc., are seldom described. For the first time we address the problem using principles of geometric sampling. These principles are old and solid, but largely unknown outside the areas of three dimensional microscopy and stereology. Here we adapt them to estimate the size of any population of individuals lying on an essentially planar area, e.g. people, animals, trees on a savanna, etc. The proposed design is unbiased irrespective of population size, pattern, perspective artifacts, etc. The implementation is very simple—it is based on the random superimposition of coarse quadrat grids. Also, an objective error assessment is often lacking. For the latter purpose the quadrat counts are often assumed to be independent. We demonstrate that this approach can perform very poorly, and we propose (and check via Monte Carlo resampling) a new theoretical error prediction formula. As far as efficiency, counting about 50 (100) individuals in 20 quadrats, can yield relative standard errors of about 8% (5%) in typical cases. This fact effectively breaks the barrier hitherto imposed by the current lack of automatic face detection algorithms, because semiautomatic sampling and manual counting becomes an attractive option
RNA:DNA ratios as a proxy of egg production rates of Acartia
Estimates of copepod secondary production are of great importance to infer the global organic matter fluxes in aquatic ecosystems and species-specific responses of zooplankton to hydrologic variability. However, there is still no routine method to determine copepods secondary production in order to eliminate time consuming experimental analyses. Therefore, we determined whether there is a correlation between Egg Production Rates (EPR) and RNA:DNA ratios of Acartia species, by measuring their seasonal and spatial variability and the influence of environmental factors for Acartia sp. collected in the Guadiana river estuary. EPR of Acartia tonsa was positively related with chlorophyll a concentration, freshwater inflow and biomass of dinoflagellates, while Acartia clausi was only related to dinoflagellates. Dinoflagellates seem to be the optimal food item influencing the reproduction of both Acartia species in the studied area. The biochemical index RNA:DNA was positively related to EPR, indicating that it is a good proxy of copepod production and a promising method to use in the future to estimate secondary production. (C) 2017 Elsevier Ltd. All rights reserved.Portuguese Foundation for Science and Technology (FCT) [SFRH/BD/28198/2006]FCT [SFRH/BSAB/113684/2015, SFRH/BPD/105419/2014, IF/01546/2015]FTC [UID/Multi/04326/2013]info:eu-repo/semantics/publishedVersio
Embryological staging of the Zebra Finch, Taeniopygia guttata
Zebra Finches (Taeniopygia guttata) are the most commonly used laboratory songbird species, yet their embryological development has been poorly characterized. Most studies to date apply Hamburger and Hamilton stages derived from chicken development; however, significant differences in development between precocial and altricial species suggest that they may not be directly comparable. We provide the first detailed description of embryological development in the Zebra Finch under standard artificial incubation. These descriptions confirm that some of the features used to classify chicken embryos into stages are not applicable in an altricial bird such as the Zebra Finch. This staging protocol will help to standardize future studies of embryological development in the Zebra Finch. J. Morphol. 274:1090-1110, 2013. (c) 2013 Wiley Periodicals, Inc
Clinical, genetic and pharmacological data support targeting the MEK5/ERK5 module in lung cancer
Article number: 78 (2021)[EN]Despite advances in its treatment, lung cancer still represents the most common and lethal tumor. Because of that, efforts to decipher the pathophysiological actors that may promote lung tumor generation/progression are being made, with the final aim of establishing new therapeutic options. Using a transgenic mouse model, we formerly demonstrated that the sole activation of the MEK5/ERK5 MAPK route had a pathophysiological role in the onset of lung adenocarcinomas. Given the prevalence of that disease and its frequent dismal prognosis, our findings opened the possibility of targeting the MEK5/ERK5 route with therapeutic purposes. Here we have explored such possibility. We found that increased levels of MEK5/ERK5 correlated with poor patient prognosis in lung cancer. Moreover, using genetic as well as pharmacological tools, we show that targeting the MEK5/ERK5 route is therapeutically effective in lung cancer. Not only genetic disruption of ERK5 by CRISPR/Cas9 caused a relevant inhibition of tumor growth in vitro and in vivo; such ERK5 deficit augmented the antitumoral effect of agents normally used in the lung cancer clinic. The clinical correlation studies together with the pharmacological and genetic results establish the basis for considering the targeting of the MEK5/ERK5 route in the therapy for lung cancer.Cancer Center Network Program from the ISCIII (RD12/0036/0003
Proximity of Iron Pnictide Superconductors to a Quantum Tricritical Point
We determine the nature of the magnetic quantum critical point in the doped
LaFeAsO using a set of constrained density functional calculations that provide
ab initio coefficients for a Landau order parameter analysis. The system turns
out to be remarkably close to a quantum tricritical point, where the nature of
the phase transition changes from first to second order. We compare with the
effective field theory and discuss the experimental consequences.Comment: 4 pages, 4 figure
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