Valley Of Mexico Research Articles

GIS Spatial Optimization for Corridor Alignment Using Simulated Annealing

Planning corridors for new facilities such as pipeline or transmission lines through geographical spaces is a topographical constraint optimization problem. The corridor planning problem requires finding an optimal route or a set of alternative paths between two locations. This article presents a simulated-annealing-based (SA) approach applying a variable neighborhood strategy in a continuous space to generate competitive and different alternative paths to solve the corridor planning problem. The variable neighborhood method randomly selects two points from a variable interval of the current solution generated by SA creating pseudo-random paths inside a corridor and finding spatially different alternatives. The proposed approach is evaluated with three practical problems using real topographic data from the Veracruz Basin in Mexico. The experimental results show that this approach obtains efficient and competitive solutions with improvements above 18% over those gotten by the compared method.

Gobernanza y movilidad urbana hacia la sustentabilidad. Comunidad educativa en Monterrey, México

Las autoridades mexicanas reconocen que el problema de la movilidad urbana en el país es un asunto que se ha ignorado por años, lo que ha acarreado diversas consecuencias socioespaciales y medioambientales. De igual manera, afirman que se requiere impulsar la estructura de gobernanza urbana, establecer marcos de apoyo y favorecer la planificación y gestión del desarrollo urbano para alinearse con los compromisos de la Nueva Agenda Urbana y los Objetivos de Desarrollo Sustentable de ONU-Hábitat. El presente documento expone un esfuerzo de gobernanza tripartita entre el gobierno de San Nicolás de los Garza, Nuevo León, México, la Universidad del Valle de México, campus Monterrey Norte (UVMCMN) y su comunidad estudiantil para construir patrones locativos y de tipología de movilidad a partir de la implementación de un instrumento cualitativo-cuantitativo. Los resultados evidencian que, aunque existe una buena cobertura de la red de transporte urbano y la comunidad tiene acceso a ella, dicha red es desaprovechada porque sus recorridos no responden a criterios de eficiencia, seguridad o economía para los estudiantes y, en consecuencia, la proximidad entre la vivienda y el espacio educativo, más que considerarse un atributo locativo positivo, es un factor de diferenciación y desigualdad social.

A Lacustrine Cultural Landscape in the Prehispanic Basin of Mexico

This article provides a new application of Westerdahl's concepts of maritime cultural landscape and maritime cultures within the context of Mesoamerica, and more specifically during the Postclassic...

Origin, migration, and characterization of petroleum in the Perdido Fold Belt, Gulf of Mexico basin

Herein, the characteristics and origin of petroleum in the Perdido Fold Belt (PFB) were studied and the petroleum migration processes and system elements are discussed. The molecular compositions and stable carbon isotopes indicate that natural gases in the PFB are mainly organic and have similar origins. Further, they are mainly sapropel type gases and originated from kerogen cracking. The oil in this region has a high API gravity and contains a relatively high sulfur content. The light hydrocarbon values indicate that most of the oil samples are sapropel type oil. Based on the geochemical characteristics of petroleum, Tithonian is considered to be the dominant source rock in the PFB. Various parameters regarding petroleum maturity suggest that the natural gases and oil are mature. The calculated temperature and vitrinite reflectance of the oil samples indicate that petroleum charging occurred from the Middle to Late Eocene. API gravity and sulfur content are related to maturity and herein, indicate that the Tithonian source rocks are mainly type II-S kerogen and the associated high API gravity of petroleum can be primarily attributed to this kerogen. Petroleum migration in the PFB was jointly controlled by salt activity and petroleum generation, wherein. The active faults and the Wilcox sandstones acted as petroleum migration pathways, allowing large petroleum reservoirs to form from the Middle to Late Eocene.

Let’s get fiscal: The social relations of finance and technological change in Aztec and Colonial Mexico

This paper argues that finance should matter to archaeologists and shows how archaeological research enhances our understanding of the history of finance. It presents archaeological and ethnohistoric evidence of saltmaking, finance, and technological change in the Basin of Mexico during the Aztec and Spanish empires. Studies of past technological change often leave unasked how people finance their adoption of innovations. The means of finance—surplus production, saving, debt, cost sharing, etc.—are applied in culturally and historically specific ways that have systemic and long-term consequences for adopters. Saltmakers’ widespread adoption of new technologies in the Late Postclassic (CE 1350–1521) was enabled by finance at the household scale. In the sixteenth century, Indigenous saltmakers adapted existing tools to manufacture new products, like saltpeter, for Spanish consumers without new financial arrangements. Eighteenth-century innovations in the production of saltpeter required equipment that was beyond the financial means of most Indigenous saltmakers. Nevertheless, I suggest that some saltmakers solved the problem and continued to produce salt and saltpeter by expanding their social relations of finance beyond their households. These findings show how finance operated in a non-Western, preindustrial context and in an economic sphere that was relatively independent of the political economies of states and empires.

Aztec diets at the residential site of San Cristobal Ecatepec through stable carbon and nitrogen isotope analysis of bone collagen

This paper presents the first systematic study of Aztec diets using bone collagen stable carbon and nitrogen isotope analysis. The objective was to identify the dietary patterns of an Aztec community living in the Basin of Mexico. The collection analyzed includes adult and subadult skeletons from the residential site of San Cristobal Ecatepec (in present-day Mexico State) (A.D. 900–1521). The isotopic data were compared with available ethnohistoric and archeological information about Aztec diets. We conclude that Ecatepec residents consumed mostly C4 and CAM plants (as opposed to C3 plants), terrestrial animals, and some lacustrine resources. They shared similar diets and foodways, as indicated by the fact that they belonged to the same socio-economic group and that there were no substantial sex-based differences indicated by the isotopic data. The slightly higher carbon isotope compositions of the men compared with the women could be evidence of pulque consumption by the men—as noted in the ethnohistoric record. The nitrogen isotope compositions of the subadults, however, show some variability related to breastfeeding and weaning practices, with infants weaning between 2 and 4 years of age.

Molecular and Morphological Identification of Dermanyssoid Mites (Parasitiformes: Mesostigmata: Dermanyssoidea) Causatives of a Parasitic Outbreak on Captive Snakes.

A parasitic outbreak caused by dermanyssoid mites in a herpetarium of the Metropolitan area of the Valley of Mexico is revealed. This outbreak was caused by Hemilaelaps triangulus (Ewing), but a second mite species, Ophionyssus natricis (Gervais), was found in low abundance. The parasitic load is analyzed, and the morphological and molecular diagnostic characters to identify each of the two species involved are given. A barcode analysis is presented, and two more molecular markers are presented and analyzed. Hemilaelaps triangulus is recorded for the first time in Mexico, and this is the first record of massive infestation on captive snakes caused by ixodorhynchid mites, and DNA sequences of ixodorhynchid mites are publicly available for the first time.

Unified Shear-Flexural Model for Vibration Control of Buildings Using Passive Dynamic Absorbers

A unified design model is proposed for various kinds of passive dynamic absorbers (PDAs) attached to buildings with different lateral resisting systems. A total of five different PDAs are considered in this study: (1) tuned mass damper (TMD), (2) circular tuned sloshing damper (C-TSD), (3) rectangular tuned sloshing damper (R-TSD), (4) two-way liquid damper (TWLD), and (5) pendulum tuned mass damper (PTMD). The unified model consists of a coupled shear-flexural (CSF) discrete model with equivalent tuned mass dampers (TMDs), which allows the consideration of intermediate modes of lateral deformation. By modifying the nondimensional lateral stiffness ratio, the CSF model can consider lateral deformations varying from those of a flexural cantilever beam to those of a shear cantilever beam. The unified model was applied to a 144-meter-tall building located in the Valley of Mexico, which was subjected to both seismic and along-wind loads. The building has similar fundamental periods of vibration and different nondimensional lateral stiffness ratios for both translational directions, which shows the importance of considering both bending and shear stiffness in the design of PDAs. The results show a great effectiveness of PDAs in controlling along-wind RMS accelerations of the building; on the contrary, PDAs were ineffective in controlling peak lateral displacements. For a single PDA attached at the rooftop level, the maximum possible value of the PDA mass efficiency index increases as the nondimensional lateral stiffness ratio decreases; therefore, there is an increase in the vibration control effectiveness of PDAs for lateral flexural-type deformations.

MODELACIÓN Y ESTIMACIÓN DE NO2 Y O3 EN ZONAS RURALES Y SUBURBANAS DEL VALLE DE MÉXICO

Forests surrounding the Valley of Mexico are affected by air pollution produced within the valley; however, air pollution monitoring stations are scarce within the forest areas. This condition prevents the impacts of air pollution on forests from being studied. The aim of this study was to investigate the technical feasibility of using mathematical models to estimate O3 and NO2 concentrations in rural and suburban sites around the Valley of Mexico. Models for estimation of O3 and NO2 from data collected from the stations of the Red Automática de Monitoreo Atmosférico (automatic air quality monitoring network, RAMA) and climatological variables from the Red de Meteorología y Radiación Solar (meteorology and solar radiation network, REDMET) of the Valley of Mexico were developed. We made 12 lineal multiple regression models for estimating air pollutants for stations Ajusco Medio, Cuajimalpa, Cuautitlán, and Montecillo. Estimations of O3 are a function of O3 concentrations and/or concentrations of NO2, O3, and meteorological variables from RAMA and REDMET. Models for NO2 estimate this pollutant as a function of concentrations of NO2 and meteorological variables. The best models for estimating O3 are those that depend on O3 concentrations from other stations, being temperature, relative humidity, and wind velocity the meteorological variables that impacted O3 estimations the most. Models for NO2 concentrations behaved correctly, except that of Cuautitlán. Temperature and wind direction are the variables that impacted NO2 concentrations the most.

The Sureste Basin of Mexico: its framework, future oil exploration opportunities and key challenges ahead

Abstract The Sureste Basin of Mexico is a story of split exploration maturity, with more than 139 discoveries in the onshore and shallow-water area of the Sureste in a series of stacked prolific plays, but less than 12 exploration wildcat wells on the Campeche slope, in water depths greater than 500 m. Over 50% of the basin area lies in this under-explored deep-water Campeche slope, with future oil potential shown by the presence of wide seabed oil seepage indicating a regionally mature world-class source rock to be present. With the 2014 opening of Mexico's oil industry, basin-wide 3D seismic imaging of this under-explored deep-water extension to the Sureste Basin is now in the hands of international oil companies that hold substantial exploration well commitments over the next few years. This paper discusses the hydrocarbon play potential of both the classic Tertiary slope clastic reservoir systems as well as the significant Mesozoic carbonate reservoir potential for which there are fewer analogues outside of Mexico. Subsurface challenges originating from dry hole analysis relate to charge timing and deep charge focus, subsalt deep structural imaging, deep reservoir quality issues and uncertainty in column height prediction, given the high-relief nature of many undrilled salt related structures.

Dynamic conservation of genetic resources: Rematriation of the maize landrace Jala

The conservation of landraces is fundamental to safeguarding crop diversity, food security, and sustainable production. Jala is a special maize landrace from the region in and around the Jala Valley of Mexico that produces the largest ear and tallest plant of all maize landraces in the world. Changing socio-economic and environmental conditions in the Jala Valley could lead to the genetic erosion of the ancestral Jala landrace, which can have global consequences. This study outlines the sequence of events in the history of Jala and describes the evolution of strategies for complementary in situ and ex situ conservation of maize genetic resources that are being developed and tested by the Jala Rematriation Project. The concept of dynamic conservation is discussed and applied to the specific case of Jala. The rematriation approach could be instrumental in creating an environment that enables the dynamic conservation of maize landraces in Mexico, the primary centre of this crop’s origin and diversity, and throughout its ancestral range in the Americas.

The collapse of Teotihuacan and the regeneration of Epiclassic societies: a Bayesian approach

The collapse of premodern states is an enduring theme of archaeological research, and it is increasingly clear that understanding how states dissolve requires research at sites beyond regional capitals, as well as attention to subsequent developments. Recent literature reflects substantial interest in the ways in which people rebuild communities after states break down and in how the legacies of failed states influence processes of regeneration. Here, I examine the transformation of communities in the Basin of Mexico in response to the fragmentation of the Teotihuacan state system during the 500s CE. I focus on the development of Chicoloapan, a large settlement in the southern Basin that expanded as the state declined. Demographic growth, changes to the built environment, and shifting practices at Chicoloapan reflect decisions made by local residents amid severe regional instability and infrastructural disruption. A temporal framework for the reorganization of the Chicoloapan community is presented, based on the Bayesian modeling of 24 radiocarbon dates from residential contexts. These dates reveal a spate of local construction activity in the 600s CE. This research advances knowledge of the close relationship between the deterioration of a centralized state and the development of new communities, practices, and identities.

Evaluating escarpment evolution and bedrock erosion rates in the western Guadalupe Mountains, West Texas and New Mexico

The Guadalupe Mountains tower above surrounding plains and basins in western Texas and southeast New Mexico. Although this mountain range is extensively studied for the Permian stratigraphy related to the petroleum reservoirs in the adjacent Delaware Basin, little is known about the geomorphic history. The western escarpment, in particular, rises abruptly from the Salt Basin to the west of the range, and Guadalupe Peak rises ~1600 m above the surrounding landscape. This study investigates how geologic processes create and maintain the steep profile of the escarpment on the western boundary of the Guadalupe Mountain Range. In-situ produced cosmogenic nuclides were used to quantify erosion rates across the steep western front of the range to assess how tectonic, climatic, and lithologic forces influence the escarpment profile. Erosion rates range from 1 to 73 m/Myr. Faster erosion rates in the southern area of the escarpment coincide with more frequently mapped faults, higher elevations at the top of the Rim, and locations with colder temperatures and higher precipitation. Topographic profiles across the western escarpment surfaces indicate greater retreat from the original positions of fault surfaces at the north end of the mountain range. Faster erosion rates in the mountain range are linked to greater uplift and more recent activity in the southern end of the Guadalupe Mountains.

A multimethod paleointensity approach applied to the historical Xitle lava flows (Central Mexico): towards the accurate paleointensity determination

An inclusive rock-magnetic and absolute paleointensity survey of the ~ 2-ka-old Xitle volcano (southerly Basin of Mexico) was undertaken to assess the faithfulness of the paleomagnetic log carried by fresh, widely exposed and well-preserved lava flows. Paleomagnetic samples from six lava flows were subjected to paleointensity analysis with a multi-method approach: the Thellier–Coe, IZZI, and multi-specimen methods. Overall mean flow PI values from flows 4–6 obtained by the Thellier-type methods used yielded 68.4 µT (σ = ± 5.6 µT), 63.9 µT (σ = ± 5.8 µT) and 61.5 µT (σ = ± 4.3 µT) for the TC, IZZI, and IZZI with CR correction methods, respectively. Although multi-specimen paleointensity results were, in general, lower than that obtained with the other methods for the same flows, that for Flow 5 (61.8 µT) was very similar to those obtained with the Thellier-type methods. Based on the results obtained, this lava flows sequence could correspond to two eruptive periods; one related with the Xitle volcano (flows 3–6), and another older (flows 1 and 2). The combined archeomagnetic dating of the different flows reinforces this hypothesis, as well as the multi-modal distribution for the age of the Xitle, proposed two decades ago. The application of stricter acceptance criteria and consideration of cooling-rate correction could slightly reduce the scattered observations. The multi-method approach employed under this study, combined with detailed rock-magnetic experiments, may definitively increase the accuracy of paleointensity determinations.

Un aro de juego de pelota en el Suroeste de Puebla: ¿un culto al sol?

<p>El Suroeste del actual estado de Puebla es una región de la que se tienen muy pocos estudios sobre su pasado. A pesar de ello, con base en las fuentes etnohistóricas y los registros arqueológicos, es posible comenzar a vislumbrar las relaciones existentes entre las poblaciones ahí asentadas con sus vecinos inmediatos así como con otros más lejanos, incluso con los nahuas de la Cuenca de México. Tal es el caso que aquí se presenta. Por medio del registro, descripción y análisis iconográfico de un aro de juego de pelota, inédito hasta ahora, se presentan algunos puntos sustantivos sobre las relaciones existentes entre esta región y la Cuenca de México.</p>

Grain yield and population densities of new corn hybrids released by the INIFAP and UNAM for the High Valleys of Mexico†

In Mexico, corn (Zea mays L.) is one of the most important cereals from the alimentary, industrial, social, political, and cultural points of view. It is grown in different agroecological niches, water regimes, and management systems. The objective of the present research work was to study the optimum plant density per area unit and its effect on grain yield and agronomical characteristics of different corn hybrids. Six corn hybrids (H-51 AE, H 53 AE, H 47 AE, H 49 AE, Tsíri PUMA, and H-48) and three plant densities (50 000, 65 000, and 80 000 plants ha-1) were evaluated. Sowing was done during the spring-summer season, 2015, in field owned by the FESC-UNAM and CEVAMEX-INIFAP. A completely randomized block design was used with four replicates. Significant differences (P ≤ 0.05) were detected for genotypes (G) in the variables of grain yield, plant height, ear height, days to male and female flowering, volumetric weight, grain weight, ear length, and grains per ear. Moreover, the effect of the environment (E) was significant (P ≤ 0.05) for the same variables, with the exception of ear length. No significant differences (P ≥ 0.05) were registered for the densities factor (D). Only the G×E interaction had significant differences (P ≤ 0.05) in the grain yield trait. The better environment was CEVAMEX, with a mean yield of 5497 kg ha-1. The Tsíri PUMA hybrid had the best grain yield with 5856 kg ha-1. Although there were no differences for the studied interactions, the 65 000 plants ha-1 population density was the most appropriate. The densities factor did not affect the performance of the evaluated hybrids. Therefore, we recommend using 65 000 plants ha-1 to avoid investing in large amounts of seeds.

Shallow structure of the Chalco and Xochimilco sub-basins (southern Mexico basin) based on wave propagation modelling and seismic data

The shallow structures of the Chalco and Xochimilco sub-basins (southeastern Mexico Basin) are established based on a seismic line that stretches trough both depressions. Interpretation of the seismic line was constraint by the stratigraphic column cut by the approximately 3000 m deep Tulyehualco well. The seismic line was converted to depth based on a vertical transverse isotropy velocity model determined from the interval, and root mean square (rms) velocities of the geologic units as established at the Tulyehualco deep well. P-wave modelling confirmed the results. The volcano-sedimentary infill established is consistent with the stratigraphic column of the 502 m deep MexiDrill borehole. It was possible to establish 1) the base of the fine stratified lacustrine sediments, and 2) the top of the basalts along the Xochimilco and Chalco sub-basins. The Xochimilco and Chalco sub-basins are separated by a shallow structural high (interpreted as due volcanic flows) against which the lacustrine sediments abut. A conspicuous anticline shaped structural high (adjacent to Xico tuff ring) divides the Chalco sub-basin into two depressions. The top of the basaltic basement matches with the upper volcanic unit horizon. In the western trough, the basement gets deeper from east to west (from 336 m at the structural high, to 660 m to the west). Immediately east of the anticline-shaped structural high, the basement is located at 510 m. Beneath the Xochimilco trough (at 180 m approximately) the volcanic basement shallows up smoothly northwestwards. In the eastern part of the Xochimilco sub-basin, the shallow lacustrian sediments are relatively thin. Northwestwards of the Tulyehualco well, their thickness diminishes. This apparent thinning is accounted by the fact that there the seismic line occupies the northern rim of the depression. Reflections in the upper 300 m of the section are not continuous. Beneath the central part of Chalco lake the reflectors are horizontal with a slight westward dip. At both sides of this central zone, reflectors are inclined or have dome shapes. This indicates that deposition along the Chalco sub-basin has been deformed. The thickness of the reflections associated with the fine laminated to volcanoclastic material transition zone is approximately constant, but thins and finally abuts against the structural high. In the eastern trough, seismic reflections at the shallow first 300 m are not as fine as in the western trough. These low magnitude seismic reflections might be associated with coarse fluvial volcanoclastic material from nearby Popocatéptl volcano. Seismic amplification in these two tectonic depressions by numerical modelling of seismic wave propagation can be based on the structure here established. Between 8 and 9 high amplitude reflectors in the first 300 m of the infill sequence are interpreted as due to impedance contrasts between geological units. Density and velocity logs along the MexiDrill borehole support this interpretation. Shallow strata are approximately 30 m thick. Towards the basin base, the strata are thicker (70 m approximately). These thicknesses are consistent with the nature of the volcano-sedimentary infill cut by the MexiDrill borehole. In particular, each seismic reflection would represent a sedimentation cycle of approximately 30,000 years (corresponding to a mean thickness of 30 m). If a sedimentation rate of 0.8 mm per year holds along the first 200–300 m of the basin infill (i.e., neglecting compaction effects, etc.) then this upper sequence comprises a record of paleo-ambiental changes that affected the southern Mexico Basin during the last 250,000 to 375,000 years.

Water footprint sustainability at valley of Mexico’s basin

El objetivo del trabajo consiste en estimar la huella hídrica (consumo de agua fresca) de la Cuenca del Valle de México (CVM) ―la región más poblada y de mayor actividad económica de México―, aplicando una metodología que incorpora el agua virtual al esquema ingenieril basado en cuantificar la extracción y los usos de agua, y que mide con mayor precisión el estrés que enfrentan los recursos hídricos por el enorme consumo en la cuenca. La huella hídrica estimada fue de 3 895.59 hm3 de agua fresca anual en 2015, que mostró los requerimientos del consumo de los residentes en la CVM. La huella equivale a la captación de agua anual promedio en la presa Falcón (Tamaulipas, al norte de México), que da cuenta del enorme requerimiento del recurso. Abastecer tal nivel de consumo de agua ha requerido la creación de una complicada y costosa ingeniería de suministro, y la sobreexplotación de recursos hídricos propios y externos. En la CVM, cuando se consumen 202 m3 de agua, 100 m3 se explican por agua renovable y 102 m3 de agua no renovable. De este último valor, 39.3 m3 provienen de acuíferos sobreexplotados en la misma cuenca; 32.8 m3 de la importación de otras cuencas sobreexplotadas, y 30.4 m3 es agua virtual importada vía el comercio exterior de la cuenca. Dicha composición muestra que la mitad del consumo se basa en la extracción predatoria de recursos hídricos, que se capta en el índice de sustentabilidad de 202%, que registra la huella hídrica en la CVM, valor que indica su extrema fragilidad para mantenerse en el tiempo.

Thresholds of Time and Space

Analysis of the iconography in a directional almanac on Codex Borgia pages 49–52 invites comparison with almanacs in a related set of divinatory manuscripts known as the Borgia Group, but one aspect of the Codex Borgia almanac remains unique. It records real-time dates employing the central Mexican system of year dates that help identify the images as year-end rituals. These fifteenth-century dates correlate with the last twenty-day “month” in the year, known as Izcalli in the Valley of Mexico and neighboring Tlaxcala. Izcalli rituals in February involved drilling a new fire, the erection of sacred trees, and animal sacrifice, all of which appear on Borgia 49–52. During Izcalli, human sacrifice was performed only every fourth year, a pattern like that seen in the Codex Borgia and the Codex Cospi, where death imagery and decapitated humans appear prominently on the fourth year-bearer page, associated with the southern direction. Borgia Group codices also depict trees and birds representing the four cardinal directions. These are most prominent on Codex Fejérváry-Mayer page 1 in a cosmogram representing two different calendar formats, like those seen in the Borgia almanac. The 5 × 52-day format was used to measure the solar year and Venus cycle, and a second set of day signs appears in a 4 × 65-day pattern useful in calculating the fifty-two-year cycle and the Venus cycle. This provides a subtext for understanding the dates represented on Borgia 49–52 and the extension of the almanac on page 53, where the Venus almanac begins.

Reproduction and Age Structure of the Plains Killifish Fundulus zebrinus from Two Tributaries of the Upper Red River, Texas

Plains Killifish Fundulus zebrinus (subgenus Plancterus) is native to river basins in Oklahoma, New Mexico, and Texas. Original descriptions of Plains Killifish life history information are now applicable to the sister taxon Northern Plains Killifish Fundulus kansae following recognition of the 2 species in 2001. Study objectives were to quantify (1) length of the reproductive season, using the gonadosomatic index and categories of gonadal maturation, (2) batch fecundity, and (3) number of age groups for Plains Killifish taken from 2 rivers within the upper Red River basin of Texas. Reproductive season was from March through September, with the production of multiple batches and a maximum batch of 131 mature oocytes. Plains Killifish were sexually mature at age 1 and had an estimated life span of 2–3 years. Reproductive season, production of multiple batches, and age of Plains Killifish were similar to those reported for Northern Plains Killifish and 2 other closely related subgenera, Wileyichthys and Zygonectes. These similarities suggest strong trait conservatism among a monophyletic group of fundulids that inhabit a diversity of freshwater and saltwater environments in western shallow bays and salt marshes, southwestern arid and prairie streams, and eastern low-gradient streams of North America.