In Mexico, corn (Zea mays L.) is the most important crop (59% of its agriculture land) and the primary source of sediment yield. This study looks for alternatives to maintain corn productivity by means of sustainable soil and water conservation practices at central Mexico. In order to understand broad tendencies between soil erosion and crop productivity in the region, the EPIC (Erosion Productivity Impact Calculator) model was applied in the Texcoco's district as follows:1) Calibrate the model using 352 experimental corn plots established between 1972 and 1992 in 36 rural communities.2) Validate the model on a spatial basis, using GIS tools, by means of historic corn yields.3) Identify the most vulnerable areas where corn productivity is being affected by soil erosion.4) Analyze the relationship between soil erosion and crop productivity, over a 100 years of simulation, comparing the Current Management (CM) and the Recommended Management (RM) by governmental institutions.5) Evaluate the most feasible soil and water conservation practices for the region.From the calibration process, it was concluded that the EPIC model, under a wide range of environmental conditions, simulates very good corn yield (r2 between 0.88 and 0.90), annual runoff (r2=0.98), and annual sediment production (r2=0.96).Base on the official environmental inputs available in the region, the EPIC model can assess only a moderately strong relationship (r2=0.58) between the official historical crop records and the simulated ones.Comparison between CM and RM shows that the average crop yield in the region can be increased by 32.6% if RM were followed. Under the CM, the loss of soil fertility in the district reduces corn productivity by 3% over a hundred years. At least 50.0% of the region's agricultural area needs soil conservation practices, mainly on areas with slopes over 5%. If it is decided to grow corn under conventional till in such areas it is recommended to construct bench terraces in order to maintain soil erosion below 20 t/ha/yr. Corn under no till, besides control erosion, can also increase grain productivity by at least 40% (0.6 t/ha) by combining contouring, mulching, and manures.

abstract: There has been debate and uncertainty on two important issues in the Basin of Mexico: the formation of Epiclassic city-states following Teotihuacan state collapse (ca. A.D. 650), and the nature of the subsequent Early Postclassic Tula state expansion. I evaluate the Basin as a case of regeneration of socio-political complexity using stylistic and compositional pottery analysis to examine patterns of interaction from the Epiclassic (ca. A.D. 600/650-850) through the Early Postclassic (ca. A.D. 850-1150). I selected representative specimens of temporally diagnostic pottery from the three large settlement clusters in the northwestern Basin (Tula and the Zumpango region), the northeastern Basin (Teotihuacan Valley), and the southeastern Basin (Cerro Portezuelo, the Ixtapalapa and Chalco regions) to assess: 1) participation in regional cultural complexes, 2) direct exchange or local production of particular pottery types, 3) regional variation in the production of pottery. For certain time periods, ceramic patterns among smaller settlements clusters were distinguished. The combination of chemical and attribute analysis provided a robust method for identifying regional variation in pottery. Chemical characterization using Instrumental Neutron Activation Analysis (INAA) was used to provide fine-scaled compositional reference groups to assess regional production and exchange. Stylistic and technological attributes were used to define highly visible decorative traditions that were easily copied and low visibility production steps that were learned. Teotihuacan withdrawal from the southeastern Basin prompted reorganization and adoption of a distinctive pottery complex. Epiclassic settlement patterns throughout the Basin were reorganized into nucleated settlement clusters with unoccupied areas between them. Results indicate regional participation in the Coyotlatelco pottery tradition and a strong pattern of consumption of locally produced pottery by settlement cluster. Tula underwent significant urban growth in the Early Postclassic, while the Basin was marked by a process of "ruralization" as the Epiclassic centers dispersed and settlements filled the previously unoccupied landscape. Tula expanded its influence into the Basin with varying degrees of integration. The closest settlements in the northwestern Basin acquired the most Tula-produced pottery. The Teotihuacan Valley and Cerro Portezuelo settlements consumed mostly locally produced Tula style pottery. The southeastern settlements were least connected to Tula and initiated interactions towards Puebla-Tlaxcala. / Dissertation/Thesis / Notes authorizing use of figures. Not to be posted to public or part of publication / Ph.D. Anthropology 2011

Florida is ranked as one of the United States' top three destination states for human trafficking; many of those victims originate from Mesoamerica--Southern Mexico, Guatemala, Honduras, and El Salvador. Human trafficking is a growing problem which hinders universal human rights for hundreds of new victims in Florida every year. Mesoamericans have a high risk of becoming victims due to the situations in their home countries. The issue of human trafficking has only recently gained the national and state attention of law makers and law enforcement officers. This study uses several human trafficking cases to educate and exemplify why Mesoamerican victims are selected and how human trafficking takes place in Florida. The results of this study demonstrate that traffickers use their knowledge of victims and victims' societies to lure and then enslave them into sex and labor trafficking. This research uses criminal cases to illustrate the conditions of the enslavement of human trafficking victims, the methods used by the traffickers, and the culmination of the court cases for both victims and perpetrators. Furthermore, it provides points of discussion to initiate future research and to guide legislature and law enforcement in methods to end this barrier to universal human rights.

This study evaluates how prehispanic central Mexicans made stone tools—primarily from obsidian—and used them in their homes over a period of 3,000 years. Mesoamerican scholars have often assumed the functional purposes of different lithic tools based on their material or technological attributes. Most limit their studies to single sites and extrapolate broader reconstructions of economic activities. I assess stone tool functions and associated economic activities through technological analyses of more than 43,000 lithic artifacts and, in addition, a feasibility study for high magnification use-wear analysis utilizing 589 of these artifacts from multiple household contexts in the central Mexican villages of Amomoloc (900-650 B.C.), Tetel (750-500 B.C.), and Mesitas (600-500 B.C.); the town of La Laguna (600 B.C.-A.D. 150); the city of Teotihuacan (A.D. 200-550); and the Aztec village of Cihuatecpan (A.D. 1150-1550). I determine that pressure blades—the most common tool form—were multifunctional. They were regularly modified via pressure trimming or notching and recycled through bipolar percussion to suit specific tasks. Blade production error rates decreased consistently, especially after the invention of core platform grinding near the end of the Classic period (A.D. 100-600). Preliminary results of the use-wear feasibility study suggest that certain tools became associated with specific tasks. Scrapers were mainly used to produce goods of maguey, wood, and hide. People came to use hafted atlatl dart points and bifacial knives almost exclusively for hunting and meat butchering tasks, respectively, and smaller bifacial drills mostly for shell craft production. Bipolar tools created through anvil percussion were more common during the Formative period (1500 B.C.-A.D. 100), when they were probably used as expedient kitchen utensils. Obsidian tools in central Mexico were not exclusively staple goods. Ritual bloodletting implements are spatially associated with communal altars and commoner and elite residences, but after the Epiclassic period (A.D. 600-900) bloodletting was restricted primarily to temples. Likewise, although weaponry was common during the Classic through Postclassic periods, and jewelry was relatively common during the Late Postclassic period (A.D. 1325-1521), in prehispanic times their spatial distributions were much more restricted across site contexts compared to obsidian staple goods. I demonstrate that in prehispanic central Mexico stone tools were produced and used primarily in household spaces, contrary to models that have emphasized sponsorship by elites or religious institutions. Residents produced stone tools in their homes primarily to satisfy their own needs during the Formative period. As rising populations contributed to urban densities and the development of marketplace economies, household lithic production increased to satisfy broader consumer demand. Producing households often specialized in blade production or followed a multicrafting strategy, in which the scale of production exceeded their own needs.

In the San Dimas district, on the western flank of the Sierra Madre Occidental, near the small town of Tayoltita, Durango, gold and silver epithermal ore deposits are mined from the complex Arana fault system. The structural relationships of the Tayoltita system are well-mapped, but their kinematic relationship to ore deposition is unclear. In plan view and in cross-section, the Arana system has a horsetail or wedge-shaped geometry. Subsurface mapping of slickenside striae as movement indicators suggest that the N13°W-striking Arana fault, forming the eastern boundary of the system, is a normal slip fault with at least 250 m of throw. Subsidiary system faults display normal separation with varying degrees of dextral horizontal separation (which is a function of fault orientation). Experimental modeling of the Arana system indicated that the system formed under simple shear as the σ₂ and σ₃ stress axes rotated in a subhorizontal plane about σ₁. Rotational strain caused the developing fault strands to rotate and to be captured by the Arana fault, forming the typical wedge-shaped geometry. Later, a more complex rotation of the three major stress axes enabled hydrothermal fluids to progressively mineralize faults, which had more northerly strikes, by a process similar to progressive strain. This is documented by mineral assemblages that record the instants of fault opening and by the lack of mineralization along the high-angle, northwest- striking faults.