Minería y vulnerabilidad de los territorios rurales en los Andes ecuatorianos: evidencias desde la provincia del Azuay

En los Andes ecuatorianos, la agricultura familiar se encuentra desde hace varias décadas en una situación de gran vulnerabilidad. A pesar de la reciente renovación del discurso político en Ecuador y del advenimiento de la era del “Buen Vivir”, el auge de la minería constituye un factor adicional de esta vulnerabilidad. En este contexto, el presente artículo, basado en los resultados de una investigación desarrollada en la parroquia Victoria del Portete, en la provincial de Azuay, propone analizar la situación actual del campesinado en esta zona, antes de discutir la necesidad de repensar el desarrollo de los territorios rurales en Azuay y en el resto de la sierra ecuatoriana a partir del fortalecimiento de las organizaciones campesinas.Family farming in the Ecuadorian Andes has been undergoing a situation of high vulnerability for several decades. Despite the recent renewal of political discourse in Ecuador and the beginning of the “Buen Vivir” era, the mining boom is an additional factor contributing to that vulnerability. In this context, the article, which is based on the results of a research project carried out in the parish of Victoria del Portete, province of Azuay, analyses the current situation of the rural population in the area, before going on to discuss the need to rethink the development of rural territories in Azuay and the rest of the Ecuadorian highlands, on the basis of strengthening rural organizations.Nos Andes equatorianos, a agricultura familiar encontra-se há várias décadas em uma situação de grande vulnerabilidade. Apesar da recente renovação do discurso político no Equador e do advento da era do “Bem viver”, o boom da mineração é um fator adicional nessa vulnerabilidade. Nesse contexto, este artigo, escrito a partir dos resultados da pesquisa realizada em Victoria del Portete, na província de Azuay, tem como objetivo analisar a atual situação do campesinato nessa área, antes de discutir sobre a necessidade de repensar o desenvolvimento das zonas rurais da região Azuay e do resto da serra equatoriana a partir do fortalecimento de organizações de agricultores

Likelihood Ratio Test process for Quantitative Trait Locus detection

International audienceWe consider the likelihood ratio test (LRT) process related to the test of the absence of QTL (a QTL denotes a quantitative trait locus, i.e. a gene with quantitative effect on a trait) on the interval [0,T] representing a chromosome. The observation is the trait and the composition of the genome at some locations called ''markers''. We give the asymptotic distribution of this LRT process under the null hypothesis that there is no QTL on [0,T] and under local alternatives with a QTL at t* on [0,T]. We show that the LRT is asymptotically the square of some Gaussian process. We give a description of this process as an '' non-linear interpolated and normalized process ''. We propose a simple method to calculate the maximum of the LRT process using only statistics on markers and their ratio. This gives a new method to calculate thresholds for QTL detection

Numerical study of thermosolutal convection with Soret effect in a square cavity

Purpose – The purpose of this paper is to present a numerical and an analytical study of the thermohaline convection with Soret effect in a square enclosure filled with a binary fluid mixture. Design/methodology/approach – The horizontal boundaries of the enclosure are impermeable and heated from below while its vertical walls are assumed to be adiabatic and impermeable. The Navier‐Stokes equations under the Boussinesq‐Oberbeck approximation are solved numerically. The results are given for different values of the separation ratio. The critical Rayleigh number at the onset of convection is determined analytically and numerically. The Hopf frequency at the onset of convection is obtained. Findings – The existence of two stable stationary bifurcation branches is illustrated. Furthermore, it is shown that the existence of stable traveling waves in the transition from one branch to the other depends on the value of the separation ratio. For some values of Rayleigh number, asymmetric flows are observed. A good agreement is found between the numerical solution and analytical analysis. Originality/value – The present work is the first to consider thermosolutal convection with Soret effect in a square enclosure

Joint QTL Linkage Mapping for Multiple-Cross Mating Design Sharing One Common Parent

BACKGROUND: Nested association mapping (NAM) is a novel genetic mating design that combines the advantages of linkage analysis and association mapping. This design provides opportunities to study the inheritance of complex traits, but also requires more advanced statistical methods. In this paper, we present the detailed algorithm of a QTL linkage mapping method suitable for genetic populations derived from NAM designs. This method is called joint inclusive composite interval mapping (JICIM). Simulations were designed on the detected QTL in a maize NAM population and an Arabidopsis NAM population so as to evaluate the efficiency of the NAM design and the JICIM method. PRINCIPAL FINDINGS: Fifty-two QTL were identified in the maize population, explaining 89% of the phenotypic variance of days to silking, and nine QTL were identified in the Arabidopsis population, explaining 83% of the phenotypic variance of flowering time. Simulations indicated that the detection power of these identified QTL was consistently high, especially for large-effect QTL. For rare QTL having significant effects in only one family, the power of correct detection within the 5 cM support interval was around 80% for 1-day effect QTL in the maize population, and for 3-day effect QTL in the Arabidopsis population. For smaller-effect QTL, the power diminished, e.g., it was around 50% for maize QTL with an effect of 0.5 day. When QTL were linked at a distance of 5 cM, the likelihood of mapping them as two distinct QTL was about 70% in the maize population. When the linkage distance was 1 cM, they were more likely mapped as one single QTL at an intermediary position. CONCLUSIONS: Because it takes advantage of the large genetic variation among parental lines and the large population size, NAM is a powerful multiple-cross design for complex trait dissection. JICIM is an efficient and specialty method for the joint QTL linkage mapping of genetic populations derived from the NAM design

Magnetic dating of the Holocene monogenetic Tkarsheti volcano in the Kazbeki region (Great Caucasus)

The radiocarbon technique is widely used to date Late Pleistocene and Holocene lava flows. The significant difference with palaeomagnetic methods is that the 14C dating is performed on the organic matter carbonized by the rock formation or the paleosols found within or below the lava flow. On the contrary, the archaeomagnetic dating allows to date the moment when the lava is cooling down below the Curie temperatures. In the present study, we use the paleomagnetic dating to constrain the age of the Tkarsheti monogenetic volcano located within the Kazbeki Volcanic Province (Great Caucasus). A series of rock-magnetic experiments including the measurement of hysteresis curves, isothermal remanence, back-field and continuous thermomagnetic curves were applied. These experiments indicated that Pseudo-Single-Domain Ti-poor titanomagnetite is responsible for remanence. A characteristic remanent magnetization was obtained for all twenty analyzed samples yielding a stable single magnetization component observed upon both thermal and alternating field treatments. Comparison of the mean directions obtained (Inc = 48.6º, Dec = 6.4º, A95 = 4.0° and K = 67) with the SCHA.DIF.14k model yielded two main time intervals (4740–4650 or 4427– 4188 BC) as the best age estimate of the Lesser Tkarsheti lava flow. These results suggest an earlier age (between approximately 200 and 700 years) for this monogenetic lava flow than expected from the estimated age provided by a former 14C dating obtained in 1973 on woody remains. This first attempt to use the archaeomagnetic technique in the Caucasus indicates that the SCHA.DIF.14k geomagnetic model may be successfully used for dating purposes in the region.Projects BU0066U16 and BU235P18 (Junta de Castilla y Leon, Spain) and the European Regional Development Fund (ERDF). AG is grateful for financial support of CONACyT 252149 and UNAM-PAPIIT project 101717. MC-R and AC acknowledge the financial support given by the Junta de Castilla y León (project BU235P18) and the European Regional Development Fund (ERD)

EM algorithm and Varible Neighborhood Search for fitting Finite Mixture Model parameters

Finding maximum likelihood parameter values for Finite Mixture Model (FMM) is often done with the Expectation Maximization (EM) algorithm. However the choice of initial values can severely affect the time to attain convergence of the algorithm and its efficiency in finding global maxima. We alleviate this defect by embedding the EM algorithm within the variable Neighborhood Search (VNS) methaheurestic framework. Computational experiment in several problems in literature as well as some larger ones are reported

Minería y vulnerabilidad de los territorios rurales en los Andes ecuatorianos: evidencias desde la provincia del Azuay

En los Andes ecuatorianos, la agricultura familiar se encuentra desde hace varias décadas en una situación de gran vulnerabilidad. A pesar de la reciente renovación del discurso político en Ecuador y del advenimiento de la era del “Buen Vivir”, el auge de la minería constituye un factor adicional de esta vulnerabilidad. En este contexto, el presente artículo, basado en los resultados de una investigación desarrollada en la parroquia Victoria del Portete, en la provincial de Azuay, propone analizar la situación actual del campesinado en esta zona, antes de discutir la necesidad de repensar el desarrollo de los territorios rurales en Azuay y en el resto de la sierra ecuatoriana a partir del fortalecimiento de las organizaciones campesinas

Trajectoires de vulnérabilité des territoires ruraux dans les Andes d’Équateur : une analyse comparative

While the peasant populations of the Ecuadorian Sierra have been marked by multiple constraints in their history, for thirty years, the liberal policies that aimed at the “modernization” of the primary sector of the economy in Ecuador have led to profound changes in the Andean regions. From fieldwork conducted in the provinces of Azuay, Cotopaxi and Chimborazo, during which interviews with institutional actors and surveys within family farms were carried out, it was highlighted that the disappearance of public agricultural services, the promotion of chemical pesticides and the development of mining have favored the disunity of the peasant groups. In addition, we observed that in recent years, family farmers have developed agricultural practices that have adverse effects on the environment while, at the same time, their food security was not ensured. Finally, the work done over the past three years provides an opportunity to take stock of the negative effects of the “modernizing” project of the primary sector in Ecuador and, through the comparison of several local situations, to characterize the extension of the trajectory of vulnerability of Andean rural territories