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101.
This paper analyzes how Mexican hometown associations in New York City practice solidarity so that they might best meet the needs of the transnational communities that they serve. Commonly formed by immigrants in the United States, hometown associations are organizations which send money collectively to their home countries, supporting public infrastructure and community projects. Scholars have debated both the merits of remittance programs that channel migrant funds as economic development and the agency of immigrant economies in neoliberal development structures. Through primary data collected from interviews in New York City, I review the frustrations that hometown associations have with one such program: Mexico's programa tres por uno para migrantes. Concurrently, I examine how the same hometown associations engage ethical economic practices of collective remittance sending and community service provision in New York City. Drawing on feminist literature on diverse economies, I argue that the solidarity work of hometown associations disrupts the dominant remittance as development discourse. Migrants are not content to participate in tres por uno and through practicing solidarity they distance themselves from this neoliberal policy.  相似文献   
102.
The Cerro del Pueblo Formation in the state of Coahuila, Mexico is becoming recognized worldwide due to its abundant and diverse fossil material. While most previous paleontological work from this rock unit has been directed towards taxonomic investigation, this study is directed towards the taphonomy of a “duck-billed” dinosaur (Ornithischia: Hadrosauridae). The hadrosaur skeleton is represented by several skull bones, vertebrae and ribs, a scapula, pubis, and various appendicular elements. The following taphonomic parameters were considered: (1) bone frequency; (2) hydraulic equivalence; (3) degree of bone articulation; (4) abrasion; (5) weathering; (6) breakage; (7) tooth marks; and (8) trampling activities. The low degree of weathering and abrasion suggests that the specimen experienced a short time of subaerial exposure and underwent a short transportation distance before deposition. Burial occurred within a perimarine lagoonal environment. Furthermore, the lack of hydraulic equivalence with the rock matrix, a high degree of disarticulation and a chaotic distribution of the bones in the fossiliferous bed, suggest that it was transported as a “bloated carcass”. The finding of distinct types of tooth marks evidence some sort of predator/scavenging activities on the specimen. Finally, an almost vertical orientation of various bones and the presence of spiral fractures may indicate that these elements were trampled by other animals.  相似文献   
103.
In recent years, physical geography in Mexico has contributed to the enterprise of geographical science by integrating with fields of study closely related to topics of sustainable development. This paper outlines the contribution of the discipline to environmental public policy development, particularly ecological land use planning and integrated watershed management. In terms of applications, physical geography appears to have reached a stage of maturity in Mexico. However, it must offer a stronger leadership in areas such as ecoregional analysis (in an integrated fashion, and not only from the biological‐ecological perspective) and regional vulnerability to global change processes. An excellent opportunity exists for scientists and decision makers to develop a common agenda.  相似文献   
104.
The widespread adoption of neoliberal reforms during the past quarter century has had profound implications for the livelihoods of those who live and work in cities throughout Latin America. This case study of Mérida, Mexico, builds directly on recent research about the changing nature of work and the role of informality as a livelihood strategy in Latin America and attempts to explain how place-specific patterns of informal work emerge from neoliberal reforms and concomitant urban economic restructuring. Drawing on field research and a large household survey, this article reveals that general patterns of informality coincide with previous findings from Latin America: high levels of informal work; increased heterogeneity of informality; and significant mobility, with a large share of workers “opting out” of the formal sector voluntarily. However, compared with previous research in Mexico, this study shows that informal work is significantly more pervasive, particularly among women; less likely to be voluntary; and pays considerably less. In light of gender considerations and significant discrepancies between local patterns of informality and national trends, this case study casts doubt on recent World Bank encyclicals affirming the resemblance between self-employment in Mexico and microentrepreneurship in more developed countries. Moreover, the article concludes that World Bank literature conveniently overlooks the gendered nature of informal work in Latin America and the profound divergence between the express purposes of neoliberalism and its actual implications. As a result, World Bank research on informality serves to justify the neoliberal model, rather than improve the livelihoods of those who live and work in cities throughout Latin America.  相似文献   
105.
Books reviewed:

Bassin, Mark, Imperial Visions: Nationalist Imagination and Geographical Expansion in the Russian Far East, 1840 – 1865

Shortridge, James R., Our Town on the Plains: J. J. Pennell's Photographs of Junction City, Kansas, 1893 – 1922

Jakle, John A. and Sculle, Keith A., Fast Food: Roadside Restaurants in the Automobile Age

Boeschenstein, Walter, Historic American Towns along the Atlantic Coast

McKee, Jesse O., Ethnicity in Contemporary America: A Geographical Appraisal

Luciuk, Lubomyr Y., Searching for Place: Ukrainian Displaced Persons, Ottawa, and the Migration of Memory

Hausladen, Gary, Places for Dead Bodies

Phillips, Richard, Watt, Diane and Shuttleton, David, De-Centering Sexualities: Politics and Representations beyond the Metropolis

Goldin, Liliana R., Identities on the Move, Transnational Processes in North America and the Caribbean Basin

McDonald, David A., On Borders: Perspectives on International Migration in Southern Africa

Fox, Roddy and Rowntree, Kate, The Geography of South Africa in a Changing World

Takeuchi, Keiichi, Modern Japanese Geography: An Intellectual History

Amery, Hussein A., and Wolf, Aaron T., Water in the Middle East: A Geography of Peace

Karl, Thomas R., Nicholls, Neville and Ghazi, Anver, Weather and Climate Extremes: Changes, Variations, and a Perspective from the Insurance Industry

Pittman, Blair, Texas Caves  相似文献   
106.

Tropical deforestation is widely believed to directly influence the climate at a number of scales. Yet while much has been written about the tropical forest-climate relationship, there is little empirical evidence showing if and how local and regional climates are modified by deforestation. This study presents the results of an analysis of deforestation and climate change in a rain forest in southern Mexico. Records from 18 climate stations in the Selva Lacandona of Chiapas, Mexico were examined and related to an analysis of deforestation based on Landsat images. The area surrounding some stations has been deforested since the stations were established, while the area surroundings others has remained forested. Strong climatic trends were generally evident at the deforested stations, including decreases in the average daily maximum temperature and temperature range. No precipitation changes were observed. A comparison of the results with microclimatic experiments and modeling studies suggests that the climatic impacts of deforestation are overgeneralized at the local scale. Landscape heterogeneity appears to influence the biophysical mechanisms linking tropical forests and climate, and should be explicitly represented in modeling studies.  相似文献   
107.
Abstract

According to recent research, one of the most promising strategies for intraurban job growth lies promoting localized clusters that produce goods and services which are primarily sold within a single city, metropolitan area, or urban region. However, in order to design urban policies to create or reinforce local clusters, the first challenge is to measure in a reliable way the clustering tendencies of different kinds of economic units in intraurban space. The aim is to compare the similarities and differences in results obtained from two methods designed to measure global clustering tendencies (the planar and network K-functions) in terms of characterization, scale, and intensity of intraurban localization patterns for tertiary economic units in a Latin American metropolis. It is concluded that the network K-function is a more appropriate method for measuring agglomeration patterns, scale, and intensity at the intra-urban level.  相似文献   
108.
Abstract

The estimation and review of discharge flow rates in hydraulic works is a fundamental problem in water management. In the case of dams with large regulating capacity, in order to estimate return periods of discharge flow rates from the spillways, it becomes necessary to consider both peak flow and volume of the incoming floods. In this paper, the results of the validation for several methods of assessing design floods for spillways of dams with a large flood control capacity are presented; the validation is performed by comparing the maximum outflows (or the maximum levels reached in the reservoir) obtained from the routing of the design floods with those obtained from the routing of the historical annual maximum floods. The basin of Malpaso Dam, Mexico, is used as the case study.

Editor D. Koutsoyiannis

Citation Domínguez, M.R. and Arganis, J.M.L., 2012. Validation of methods to estimate design discharge flow rates for dam spillways with large regulating capacity. Hydrological Sciences Journal, 57 (3), 460–478.  相似文献   
109.
《水文科学杂志》2013,58(2):375-381
Abstract

Vegetation structure in semi-arid regions of northern Mexico and the southwestern USA has changed dramatically over the last century; shrubs such as mesquite (Prosopis sp.) have expanded into, and have become dominant in, ecosystems that once supported semi-arid grassland. The upper San Pedro River watershed, which extends from northern Sonora (Mexico) to southeastern Arizona (USA), highlights these changes. Between 1973 and 1992, grasslands decreased by 18% and the total area dominated by mesquite increased during the same period by 412%. In the areas where the density of mesquite shrub is medium to high, grass has completely disappeared under the shrub canopy and has been replaced by bare soil. Undoubtedly these cover changes have affected surface—atmosphere interactions by introducing a different partitioning of net available energy into sensible and latent heat flux. At the same time, different root system and root density and plant physiology have introduced a change to the surface water balance, reducing inflitration and increasing runoff. Our study addressed the sources of water used by mesquite (Prosopis velutina) along a natural gradient from an area of high mesquite cover with no herbaceous grass cover, to open savanna with high grass cover and widely spaced mesquite. The presented results from the SALSA 1997 monsoon-season campaign (July—October) show that mesquite shrubs that have access to both ground-water and surface water use surface water when available, potentially competing with grass for surface water and out-competing grass during successive periods of drought when only groundwater is available.  相似文献   
110.
In August 2009, a marine geophysical survey was conducted in Lake Tequesquitengo (located in the state of Morelos, Mexico) to delineate the extent of the remains of a small town that has been submerged since the mid 19th century. The survey consists of the acquisition and mapping of magnetic, single beam bathymetric and side-scan sonar data. A dual receiver marine GPS navigation system was used to position the boat during the survey. Except for the larger structural remains that are visible on the side scan sonar images, the magnetic anomaly map proved to be most useful in delineating the extent of the town. These anomalies exhibit short wavelength components in the area surrounding a submerged church, with the shortest wavelength components being confined to the area immediately east of the church. These short wavelength components are only observed near the church; therefore, we propose that they delineate the buried remnants of the submerged town.  相似文献   
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