El Colegio de México, A.C. is a prestigious Mexican institute of higher education, specializing in teaching and research in social science and humanities. This Institution received the Prince of Asturias Award for Social science in 2001. The library of El Colegio de México is one of the largest academic libraries in Mexico, and it contains one of the most important Latin American collections in social science and humanities.The college was founded in 1940 by the Mexican Federal Government, the Bank of Mexico , the National Autonomous University of Mexico , and the Fondo de Cultura Económica. After the Spanish Civil War, the President of Mexico Lázaro Cardenas created The House of Spain in Mexico to host the Spanish intellectuals in exile in that country. Under the direction of renowned intellectual Alfonso Reyes, the House of Spain became a higher education center, and was renamed El Colegio de México in 1940. The College now operates under a 1961 charter that allows the institution to provide college-level teaching in the fields of humanistic knowledge and social and political science. In 1976, the university's campus was moved from the Colonia Roma to its current location.The college encompasses seven separate academic centers, teaching a total of three degrees, seven master's degrees and eight doctorates. The campus is located in a purpose-built and architecturally striking building on the southern fringes of Mexico City, and it was designed by the prestigious Mexican architect Teodoro González de León. Wikipedia.
Romo R.,National Autonomous University of Mexico |
Romo R.,Colegio de Mexico |
de Lafuente V.,National Autonomous University of Mexico
Progress in Neurobiology | Year: 2013
A fundamental problem in neurobiology is to understand how brain circuits represent sensory information and how such representations give rise to perception, memory and decision-making. We demonstrate that a sensory stimulus engages multiple areas of the cerebral cortex, including primary sensory, prefrontal, premotor and motor cortices. As information transverses the cortical circuits it shows progressively more relation to perception, memory and decision reports. In particular, we show how somatosensory areas on the parietal lobe generate a parameterized representation of a tactile stimulus. This representation is maintained in working memory by prefrontal and premotor areas of the frontal lobe. The presentation of a second stimulus, that monkeys are trained to compare with the first, generates decision-related activity reflecting which stimulus had the higher frequency. Importantly, decision-related activity is observed across several cortical circuits including prefrontal, premotor and parietal cortices. Sensory information is encoded by neuronal populations with opposite tuning, and suggests that a simple subtraction operation could be the underlying mechanism by which past and present sensory information is compared to generate perceptual decisions. © 2012 Elsevier Ltd.
Gama A.,Colegio de Mexico
Transportation Research Part D: Transport and Environment | Year: 2017
In 2009, the U.S. Federal Government announced its plan to invest in the expansion of the passenger rail system, instead of adding to the freeway or aviation systems. On the other hand, environmental studies show that passenger rails have a lower polluting impact than flights or cars. In order to evaluate whether consumers would switch from flights to trains and use the new rail system, this paper estimates the own and cross-price elasticities of demand for domestic flights and passenger trains using the methodology described in Berry (1994). Specifically, the changes in demand for domestic flights and trains with respect to their prices are evaluated. The static model in this study suggests that the substitutability between these two modes of transport is minimal, in other words, travelers will to change their choices is very small given the configuration of the transportation system when the notice was made. In particular, train trips are substituted more easily. © 2017 Elsevier Ltd
Romo R.,National Autonomous University of Mexico |
Romo R.,Colegio de Mexico |
Lemus L.,National Autonomous University of Mexico |
de Lafuente V.,National Autonomous University of Mexico
Current Opinion in Neurobiology | Year: 2012
The brain constructs representations of objects and concepts based in sensory information combined with experience. This mental process, that we call perception, is the result of a chain of events consisting of phenomena such as detection, memory, discrimination, categorization and decision-making. Although the phenomenon of perception is not necessarily dependent on a given sensory modality (e.g. visual perception, auditory, tactile), single sensory models are indispensable for studying the neural mechanisms that generate it. The somatosensory system is a suitable model for studying the manner in which presentation of a single physical variable (e.g. vibration) triggers a perceptual process. Here, we discuss some recent studies in the somatosensory system that in our view, constitute a breakthrough to understanding decision making. © 2012 Elsevier Ltd.
Perez P.,Colegio de Mexico |
De Los Campos G.,University of Alabama at Birmingham
Genetics | Year: 2014
Many modern genomic data analyses require implementing regressions where the number of parameters (p, e.g., the number of marker effects) exceeds sample size (n). Implementing these large-p-with-small-n regressions poses several statistical and computational challenges, some of which can be confronted using Bayesian methods. This approach allows integrating various parametric and nonparametric shrinkage and variable selection procedures in a unified and consistent manner. The BGLR R-package implements a large collection of Bayesian regression models, including parametric variable selection and shrinkage methods and semiparametric procedures (Bayesian reproducing kernel Hilbert spaces regressions, RKHS). The software was originally developed for genomic applications; however, the methods implemented are useful for many nongenomic applications as well. The response can be continuous (censored or not) or categorical (either binary or ordinal). The algorithm is based on a Gibbs sampler with scalar updates and the implementation takes advantage of efficient compiled C and Fortran routines. In this article we describe the methods implemented in BGLR, present examples of the use of the package, and discuss practical issues emerging in real-data analysis. © 2014 by the Genetics Society of America All rights reserved.
Garcia-Morales A.E.,Colegio de Mexico |
Elias-Gutierrez M.,Colegio de Mexico
Molecular Ecology Resources | Year: 2013
DNA barcodes are useful tools to identify and discover new species in a wide range of taxa. Here, we report the first barcode study of monogonont rotifers from fresh and brackish waters in Mexico, and discuss the taxonomic implications of this work. We used DNA barcodes based on the sequence of cytochrome oxidase I to examine patterns of divergence among 417 specimens that represented 63 morphological taxa of rotifers. The mean sequence divergence among conspecific rotifer individuals was 0.75%, whereas the mean sequence divergence among congeneric taxa was 20.8%. The barcodes could discriminate between all the morphospecies identified. Moreover, the barcoding data revealed the presence of possible cryptic species in Ascomorpha ovalis, Lecane bulla, L. cornuta, L. curvicornis, L. crepida, L. lunaris, L. hastata, Platyias quadricornis, Keratella cochlearis, Brachionus calyciflorus and Testudinella patina, as well as in some forms and varieties such as B. quadridentatus f. brevispinus, B. quadridentatus f. cluniorbicularis and Mytilina ventralis var. macracantha. Barcode analysis also enabled some forms and varieties of common species to be identified as separate species. The results obtained support recent taxonomic revisions, such as the recognition of the genus Plationus, and the presence of cryptic speciation in L. bulla. This work shows that DNA barcoding identifies species effectively, can aid taxonomists by identifying cryptic species, and is an important tool for resolving taxonomic controversies. © 2013 John Wiley & Sons Ltd.
Perez-Lachaud G.,Colegio de Mexico
Entomologia Experimentalis et Applicata | Year: 2010
Polygynous parasitoid males may be limited by the amount of sperm they can transmit to females, which in turn may become sperm limited. In this study, I tested the effect of male mating history on copula duration, female fecundity, and offspring sex ratio, and the likelihood that females will have multiple mates, in the gregarious parasitoid Cephalonomia hyalinipennis Ashmead (Hymenoptera: Bethylidae: Epyrinae), a likely candidate for sperm depletion due to its local mate competition system. Males were eager to mate with the seven females presented in rapid succession. Copula duration did not differ with male mating history, but latency before a first mating was significantly longer than before consecutive matings. Male mating history had no bearing on female fecundity (number of offspring), but significantly influenced offspring sex ratio. The last female to mate with a given male produced significantly more male offspring than the first one, and eventually became sperm depleted. In contrast, the offspring sex ratio of first-mated females was female biased, denoting a high degree of sex allocation control. Once-mated females, whether sperm-depleted or not, accepted a second mating after a period of oviposition. Sperm-depleted females resumed production of fertilized eggs after a second mating. Young, recently mated females also accepted a second mating, but extended in-copula courtship was observed. Carrying out multiple matings in this species thus seems to reduce the cost of being constrained to produce only haploid males after accepting copulation with a sperm-depleted male. I discuss the reproductive fitness costs that females experience when mating solely with their sibling males and the reproductive fitness gain of males that persist in mating, even when almost sperm-depleted. Behavioural observations support the hypothesis that females monitor their sperm stock. It is concluded that C. hyalinipennis is a species with a partial local mating system. © 2010 The Author. Journal compilation © 2010 The Netherlands Entomological Society.
Perez-Rodriguez P.,Colegio de Mexico
G3 (Bethesda, Md.) | Year: 2012
In genome-enabled prediction, parametric, semi-parametric, and non-parametric regression models have been used. This study assessed the predictive ability of linear and non-linear models using dense molecular markers. The linear models were linear on marker effects and included the Bayesian LASSO, Bayesian ridge regression, Bayes A, and Bayes B. The non-linear models (this refers to non-linearity on markers) were reproducing kernel Hilbert space (RKHS) regression, Bayesian regularized neural networks (BRNN), and radial basis function neural networks (RBFNN). These statistical models were compared using 306 elite wheat lines from CIMMYT genotyped with 1717 diversity array technology (DArT) markers and two traits, days to heading (DTH) and grain yield (GY), measured in each of 12 environments. It was found that the three non-linear models had better overall prediction accuracy than the linear regression specification. Results showed a consistent superiority of RKHS and RBFNN over the Bayesian LASSO, Bayesian ridge regression, Bayes A, and Bayes B models.
Appendini K.,Colegio de Mexico
Journal of Agrarian Change | Year: 2014
The transition in Mexico from a maize market once characterized by heavy state intervention along the entire maize-tortilla chain to the 'free market' of today has been a long and complex process. Over two decades, the production of maize has seen a radical transition both in the geographical location of maize agriculture and the type of farmers growing maize. In this paper, I argue that the restructuring of the domestic maize supply is due to policy decisions to support private agents in the maize market; hence the state did not withdraw its involvement but, rather, has had a key role in the construction of the 'free' maize market, with the result that domestic supply for the market is concentrated in the hands of relatively few agents and in relatively few regions. I discuss the background to these policies and analyse the programmes implemented by the state agency ASERCA (Apoyos y Servicios a la Comercialización Agropecuaria) that support the commercialization of maize. © 2013 John Wiley & Sons Ltd.
Schmook B.,Colegio de Mexico
Regional Environmental Change | Year: 2010
Shifting cultivation around the Calakmul Biosphere Reserve of Mexico, part of the Mesoamerican Biological Corridor, appears to be intensifying temporally through reductions in crop-fallow cycles, with potential impacts on species diversity in the regenerating forest patches surrounding the reserve. This paper documents the temporal intensity of shifting maize cultivation in the region and links it to the species diversity found in secondary vegetation of different ages following different crop-fallow cycles. It finds that younger secondary growth, which is increasing under intensification, has less diversity in species composition. Simultaneously, the concentration of cultivation practices appears to foster more patches in older and more species-diverse vegetation. The implications for the preservation of the region's forest remain uncertain, however, given the spatial concentration of open lands along two key axes, one which dissects the reserve. © 2010 Springer-Verlag.
Arevalo-Galarza L.,Colegio de Mexico
Journal of Economic Entomology | Year: 2011
Metabolic stress disinfection and disinfestation (MSDD) is a postharvest treatment designed to control pathogens and arthropod pests on commodities that combines short cycles of low pressure/vacuum and high CO2 with ethanol vapor. Experiments were conducted to evaluate the effect of MSDD treatment on various life stages of Ceratitis capitata (Wiedemann), Mediterranean fruit fly; Bactrocera dorsalis Hendel, oriental fruit fly; and Bactrocera Cucurbitae Coquillett, melon fly, in petri dishes and in papaya, Carica papaya L., fruit. In some experiments, the ethanol vapor phase was withheld to separate the effects of the physical (low pressure/ambient pressure cycles) and chemical (ethanol vapor plus low pressure) phases of treatment. In the experiments with tephritid fruit fly larvae and adults in petri dishes, mortality was generally high when insects were exposed to ethanol and low when ethanol was withheld during MSDD treatment, suggesting that ethanol vapor is highly lethal but that fruit flies are quite tolerant of short periods of low pressure treatment alone. When papaya fruit infested with fruit fly eggs or larvae were treated by MSDD, they produced fewer pupae than untreated control fruit, but a substantial number of individuals developed nonetheless. This suggests that internally feeding insects in fruit may be partially protected from the toxic effects of the ethanol because the vapor does not easily penetrate the fruit pericarp and pulp. MSDD treatment using the atmospheric conditions tested has limited potential as a disinfestation treatment for internal-feeding quarantine pests such as fruit flies infesting perishable commodities.