WorldWideScience

Sample records for mexican smelting community

  1. Successional change in the Lake Superior fish community: population trends in ciscoes, rainbow smelt, and lake trout, 1958-2008

    Science.gov (United States)

    Gorman, Owen T.

    2012-01-01

    The Lake Superior fish community underwent massive changes in the second half of the 20th century. Those changes are largely reflected in changes in abundance of the adults of principal prey species, the ciscoes (Coregonus spp.), the invasive rainbow smelt (Osmerus mordax), and the principal predator, lake trout (Salvelinus namaycush). To better understand changes in species abundances, a comprehensive series of gillnet and bottom trawl data collected from 1958 to 2008 were examined. In the late 1950s/early 1960s, smelt abundance was at its maximum, wild lake trout was at its minimum, and an abundance of hatchery lake trout was increasing rapidly. The bloater (Coregonus hoyi) was the prevalent cisco in the lake; abundance was more than 300% greater than the next most abundant cisco, shortjaw cisco (C. zenithicus), followed by kiyi (C. kiyi) and lake cisco (C. artedi). By the mid-1960s, abundance of hatchery lake trout was nearing maximum, smelt abundance was beginning to decline, and abundances of all ciscoes declined, but especially that of shortjaw cisco and kiyi. By the late 1970s, recovery of wild lake trout stocks was well underway and abundances of hatchery lake trout and smelt were declining and the ciscoes were reaching their nadir. During 1980–1990, the fish community underwent a dramatic shift in organization and structure. The rapid increase in abundance of wild lake trout, concurrent with a rapid decline in hatchery lake trout, signaled the impending recovery. Rainbow smelt abundance dropped precipitously and within four years, lake cisco and bloater populations rebounded on the heels of a series of strong recruitment events. Kiyi populations showed signs of recovery by 1989, and shortjaw by 2000, though well below historic maximum abundances. High abundance of adult smelt prior to 1980 appears to be the only factor linked to recruitment failure in the ciscoes. Life history traits of the cisco species were examined to better understand their different

  2. Bacterial community structure and diversity responses to the direct revegetation of an artisanal zinc smelting slag after 5 years.

    Science.gov (United States)

    Luo, Youfa; Wu, Yonggui; Wang, Hu; Xing, Rongrong; Zheng, Zhilin; Qiu, Jing; Yang, Lian

    2018-05-01

    This comparative field study examined the responses of bacterial community structure and diversity to the revegetation of zinc (Zn) smelting waste slag with eight plant species after 5 years. The microbial community structure of waste slag with and without vegetation was evaluated using high-throughput sequencing. The physiochemical properties of Zn smelting slag after revegetation with eight plant rhizospheres for 5 years were improved compared to those of bulk slag. Revegetation significantly increased the microbial community diversity in plant rhizospheres, and at the phylum level, Proteobacteria, Acidobacteria, and Bacteroidetes were notably more abundant in rhizosphere slags than those in bulk waste slag. Additionally, revegetation increased the relative abundance of plant growth-promoting rhizobacteria such as Flavobacterium, Streptomyces, and Arthrobacter as well as symbiotic N 2 fixers such as Bradyrhizobium. Three dominant native plant species (Arundo donax, Broussonetia papyrifera, and Robinia pseudoacacia) greatly increased the quality of the rhizosphere slags. Canonical correspondence analysis showed that the differences in bacterial community structure between the bulk and rhizosphere slags were explained by slag properties, i.e., pH, available copper (Cu) and lead (Pb), moisture, available nitrogen (N), phosphorus (P), and potassium (K), and organic matter (OM); however, available Zn and cadmium (Cd) contents were the slag parameters that best explained the differences between the rhizosphere communities of the eight plant species. The results suggested that revegetation plays an important role in enhancing bacterial community abundance and diversity in rhizosphere slags and that revegetation may also regulate microbiological properties and diversity mainly through changes in heavy metal bioavailability and physiochemical slag characteristics.

  3. The Food Environment in an Urban Mexican American Community

    OpenAIRE

    Lisabeth, Lynda D; Sánchez, Brisa N; Escobar, James; Hughes, Rebecca; Meurer, William J; Zuniga, Belinda; Garcia, Nelda; Brown, Devin L; Morgenstern, Lewis B

    2010-01-01

    The objective was to determine whether ethnic composition of neighborhoods is associated with number and type of food stores in an urban, Mexican American US community. Data were from a commercial food store data source and the US Census. Multivariate count models were used to test associations with adjustment for neighborhood demographics, income, and commercialization. Neighborhoods at the 75th percentile of percent Mexican American (76%) had nearly four times the number of convenience stor...

  4. Effects of heavy metal pollution from mining and smelting on enchytraeid communities under different land management and soil conditions.

    Science.gov (United States)

    Kapusta, Paweł; Sobczyk, Łukasz

    2015-12-01

    We studied enchytraeid communities in several habitats polluted by heavy metals from Zn-Pb mining and smelting activities. We sampled 41 sites that differed in the type of substratum (carbonate rock, metal-rich carbonate mining waste, siliceous sand) and land management (planting Scots pine, topsoiling, leaving to natural succession), and the distance from the smelter. Our main aims were to determine which pollution variables and natural factors most influenced enchytraeid species composition, richness and density, and examine what was the effect of planting Scots pine (reclamation) on enchytraeid communities. The soils harboured on average 1 to 5 enchytraeid species and 700 to 18,300 individuals per square metre, depending on the habitat. These figures were generally lower than those reported from unpolluted regions. Redundancy and multiple regression analyses confirmed the negative impact of heavy metal pollution on both enchytraeid community structure and abundance. Among pollution variables, the distance from the smelter best explained the variation in enchytraeid communities. The concentrations of heavy metals in the soil had less (e.g. total Pb and exchangeable Zn) or negligible (water-soluble forms) explanatory power. Natural soil properties were nearly irrelevant for enchytraeids, except for soil pH, which determined the species composition. Plant species richness was an important explanatory variable, as it positively affected most parameters of enchytraeid community. The results of two-by-two factorial comparisons (planting Scots pine vs. natural succession; carbonate mining waste vs. siliceous sand) suggest that reclamation can improve soil quality for biota, since it increased the diversity and abundance of enchytraeids; this effect was not dependent on the type of substratum. In conclusion, enchytraeids responded negatively to heavy metal pollution and their response was consistent and clear. These animals can be used as indicators of metal toxicity

  5. Oribatid mite communities in contaminated soils nearby a lead and zinc smelting plant in Zanjan, Iran

    NARCIS (Netherlands)

    Jamshidian, M.K.; Saboori, A.; Akrami, M.A.; van Straalen, N.M.

    2015-01-01

    Many studies have shown that the composition of invertebrate communities in soil changes under the influence of stressors in the soil ecosystem. Conversely, an observed altered community structure may be indicative of stress. In this study we aimed to investigate responses of oribatid mite

  6. Program of active aging in a rural Mexican community: a qualitative approach

    OpenAIRE

    Mendoza-Núñez Víctor; Correa-Muñoz Elsa; de la Luz Martínez-Maldonado María

    2007-01-01

    Abstract Background Education is one of the key elements in the promotion of a thorough paradigm for active aging. The aim of this study is to analyze factors that contribute the empowerment of older adults in a rural Mexican community and, thus, promote active aging. Methods The study was conducted in a rural Mexican community (Valle del Mezquital), based on an action-research paradigm. One hundred and fifty-five elderly subjects with elementary school education participated in a formal trai...

  7. Recruitment Strategies and Costs Associated with Community-Based Research in a Mexican-Origin Population

    Science.gov (United States)

    Mendez-Luck, Carolyn A.; Trejo, Laura; Miranda, Jeanne; Jimenez, Elizabeth; Quiter, Elaine S.; Mangione, Carol M.

    2011-01-01

    Purpose: We describe the recruitment strategies and personnel and materials costs associated with two community-based research studies in a Mexican-origin population. We also highlight the role that academic-community partnerships played in the outreach and recruitment process for our studies. We reviewed study documents using case study…

  8. Sexual Abuse and Eating Disorders in a Community Sample of Mexican American Women

    Science.gov (United States)

    Cachelin, Fary M.; Schug, Robert A.; Juarez, Laura C.; Monreal, Teresa K.

    2005-01-01

    The purpose of this study was to examine the association between sexual abuse and eating disorders in a voluntary community sample of Mexican American women. Eighty eating disorder cases were compared to 110 healthy controls on presence of sexual abuse and on characteristics of the abuse. The Structured Clinical Interview for the "Diagnostic and…

  9. Migration Decision-Making among Mexican Youth: Individual, Family, and Community Influences

    Science.gov (United States)

    Tucker, Christine M.; Torres-Pereda, Pilar; Minnis, Alexandra M.; Bautista-Arredondo, Sergio A.

    2013-01-01

    We explored migration decisions using in-depth, semistructured interviews with male and female youth ages 14 to 24 (n = 47) from two Mexican communities, one with high and one with low U.S. migration density. Half were return migrants and half were nonmigrants with relatives in the United States. Migrant and nonmigrant youth expressed different…

  10. Mexican Americans on the Home Front: Community Organizations in Arizona during World War II.

    Science.gov (United States)

    Marin, Christine

    During World War II Arizona's Mexican-American communities organized their own patriotic activities and worked, in spite of racism, to support the war effort. In Phoenix the Lenadores del Mundo, an active fraternal society, began this effort by sponsoring a festival in January 1942. Such "mutualistas" provided an essential support system…

  11. Exploring the Lived Experiences and Intersectionalities of Mexican Community College Transfer Students: Qualitative Insights toward Expanding a Transfer Receptive Culture

    Science.gov (United States)

    Castro, Erin L.; Cortez, Edén

    2017-01-01

    This qualitative study examines the experiences of six Mexican community college transfer students attending a research-intensive institution in the Pacific Northwest. Using semi-structured interviews, the objectives of this study were to 1) understand how Mexican students made meaning of their transfer experiences and 2) how those experiences…

  12. Program of active aging in a rural Mexican community: a qualitative approach

    Directory of Open Access Journals (Sweden)

    Mendoza-Núñez Víctor

    2007-10-01

    Full Text Available Abstract Background Education is one of the key elements in the promotion of a thorough paradigm for active aging. The aim of this study is to analyze factors that contribute the empowerment of older adults in a rural Mexican community and, thus, promote active aging. Methods The study was conducted in a rural Mexican community (Valle del Mezquital, based on an action-research paradigm. One hundred and fifty-five elderly subjects with elementary school education participated in a formal training program promoting gerontological development and health education. Participants in turn became coordinators of mutual-help groups (gerontological nucleus in Mexico. In-depth interviews were carried out to assess the empowerment after training for active aging. Results It was found that there was an increasing feeling of empowerment, creativity and self-fulfillment among participants. Among the main factors that positively influenced training of the elderly toward active aging were the teaching of gerontology topics themselves; besides, their motivation, the self-esteem, the increased undertaking of responsibility, the feeling of belonging to the group, and the sharing of information based on personal experience and on gerontological knowledge. Conclusion The main factors that contribute to empowerment of older adults in a rural Mexican community for participate in active aging programs are the training and teaching of gerontology topics themselves; besides, their interest, experience and involvement.

  13. Program of active aging in a rural Mexican community: a qualitative approach.

    Science.gov (United States)

    de la Luz Martínez-Maldonado, María; Correa-Muñoz, Elsa; Mendoza-Núñez, Víctor Manuel

    2007-10-03

    Education is one of the key elements in the promotion of a thorough paradigm for active aging. The aim of this study is to analyze factors that contribute the empowerment of older adults in a rural Mexican community and, thus, promote active aging. The study was conducted in a rural Mexican community (Valle del Mezquital), based on an action-research paradigm. One hundred and fifty-five elderly subjects with elementary school education participated in a formal training program promoting gerontological development and health education. Participants in turn became coordinators of mutual-help groups (gerontological nucleus) in Mexico. In-depth interviews were carried out to assess the empowerment after training for active aging. It was found that there was an increasing feeling of empowerment, creativity and self-fulfillment among participants. Among the main factors that positively influenced training of the elderly toward active aging were the teaching of gerontology topics themselves; besides, their motivation, the self-esteem, the increased undertaking of responsibility, the feeling of belonging to the group, and the sharing of information based on personal experience and on gerontological knowledge. The main factors that contribute to empowerment of older adults in a rural Mexican community for participate in active aging programs are the training and teaching of gerontology topics themselves; besides, their interest, experience and involvement.

  14. [Metabolic syndrome in adults from 20 to 40 years old in a rural Mexican community].

    Science.gov (United States)

    Echavarría-Pinto, Mauro; Hernández-Lomelí, Adrián; Alcocer-Gamba, Marco Antonio; Morales-Flores, Héctor; Vázquez-Mellado, Alberto

    2006-01-01

    Metabolic syndrome is the main health problem in Mexico. Its two principal complications (ischemic cardiopathy and type-2 diabetes) are the two main causes of death in Mexico since 2000. To describe the prevalence of the metabolic syndrome in adults from 20 to 40 years old in a Mexican rural community (Senegal de Palomas, San Juan del Río, Querétaro) using the National Cholesterol Education Program (NCEP III) definition. A descriptive study with a random sample was carried out. We present a univariate analysis with a 95% confidence interval. 73 cases were studied. The prevalence of the metabolic syndrome was 45.2% slightly higher in men (48.4%) than in women (42.8%). The prevalence of hypertension was 27.3%. The prevalence of obesity was 26.1% using the definition of the WHO and this prevalence rises up to 49.4% using the definition of the Mexican Official Norm. 90.5% of women and 93.5% of men had low HDLc. The prevalence of metabolic syndrome in adults from 20 to 40 years old in this Mexican rural community is much higher than the national mean for the same age cohort. The results show the necessity to increase the research of our rural communities in order to identify the possible causes to this problem and to create therapeutic programs for patients with metabolic syndrome.

  15. Habaneros and shwarma: Jewish Mexicans in Israel as a transnational community

    Directory of Open Access Journals (Sweden)

    Paulette Kershenovich Schuster

    2015-01-01

    Full Text Available Food is the cultural expression of society food as a marker of class, ethnic, and religious identity. What happens when the location changes? Does food continue to play such an important role or do other cultural nodes take over? Do layers of traditions, adaptation and cultural blends emerge? This seems to be the case with third and fourth generation Mexican Jews who have moved to Israel. Not only have they brought their spiritual and cultural connections from Mexico, their birth country; they have also brought the food experiences of their great-grandparents and grandparents who were they themselves immigrants. Jewish Mexicans have transplanted their sense of community to Israel and in doing so they have also brought overlooked cultural interactions and unique food experiences. Are these simply by-products of religious and migration patterns? Or are there other elements that have affected this cultural hybridity?

  16. The conjoint influence of home enriched environment and lead exposure on children's cognition and behaviour in a Mexican lead smelter community.

    Science.gov (United States)

    Moodie, Sue; Ialongo, Nick; López, Patricia; Rosado, Jorge; García-Vargas, Gonzalo; Ronquillo, Dolores; Kordas, Katarzyna

    2013-01-01

    A range of studies has been conducted on the detrimental effects of lead in mining and smelting communities. The neurocognitive and behavioural health effects of lead on children are well known. This research characterized the conjoint influence of lead exposure and home enriched environment on neurocognitive function and behaviour for first-grade children living in a Mexican lead smelter community. Structural equation models were used for this analysis with latent outcome variables, Cognition and Behaviour, constructed based on a battery of assessments administered to the first-grade children, their parents, and teachers. Structural equation modelling was used to describe complex relationships of exposure and health outcomes in a manner that permitted partition of both direct and indirect effects of the factors being measured. Home Environment (a latent variable constructed from information on mother's education and support of school work and extracurricular activities), and child blood lead concentration each had a main significant effect on cognition and behaviour. However, there were no statistically significant moderation relationships between lead and Home Environment on these latent outcomes. Home Environment had a significant indirect mediation effect between lead and both Cognition and Behaviour (p-valueEnvironment has a moderate mediation effect with respect to lead effects on Behaviour (β=0.305) and a lower mediation effect on Cognition (β=0.184). The extent of home enrichment in this study was most highly related to the mother's support of schoolwork and slightly less by the mother's support of extracurricular activities or mother's education. Further research may be able to develop approaches to support families to make changes within their home and child rearing practices, or advocate for different approaches to support their child's behaviour to reduce the impact of lead exposure on children's cognitive and behavioural outcomes. Copyright © 2012

  17. Consequences of migration and remittances for Mexican transnational communities.

    Science.gov (United States)

    Conway, D; Cohen, J H

    1998-01-01

    "Our aims in this paper are to broaden explanation of remittance expenditures and to evaluate the positive contributions of remittances, return migrants, or circulating sojourners. Specifically focusing on the situation in ¿home' communities, we illustrate the multifaceted consequences of remittances and migration, emphasizing positive nonmonetary and social impacts." Data are from ethnographic research carried out in 1992-1993 in Santa Ana del Valle, Oaxaca, Mexico. excerpt

  18. Reassessment of the predatory effects of rainbow smelt on ciscoes in Lake Superior

    Science.gov (United States)

    Myers, Jared T.; Jones, Michael L.; Stockwell, Jason D.; Yule, Daniel L.

    2009-01-01

    Evidence from small lakes suggests that predation on larval ciscoes Coregonus artedi by nonnative rainbow smelt Osmerus mordax can lead to cisco suppression or extirpation. However, evidence from larger lakes has led to equivocal conclusions. In this study, we examine the potential predation effects of rainbow smelt in two adjacent but contrasting embayments in Lake Superior (Thunder and Black bays, Ontario). During May 2006, we sampled the ichthyoplankton, pelagic fish communities, and diet composition of rainbow smelt in both bays. Using acoustics and midwater trawling, we estimated rainbow smelt densities to be 476 ± 34/ha (mean ± SE) in Thunder Bay and 3,435 ± 460/ha in Black Bay. We used a bioenergetics model to estimate the proportion of cisco larvae consumed by rainbow smelt. Our results suggest that predation by rainbow smelt accounts for 15–52% and 37–100% of the mortality of larval ciscoes in Thunder and Black bays, respectively, depending on the predator feeding rate and the scale of predator–prey overlap. We also examined the sensitivity of past conclusions (based on 1974 field collections) to assumptions of temporal overlap between rainbow smelt and larval ciscoes and estimates of rainbow smelt abundance derived from bottom trawl samples. After adjusting these parameters to reflect current understanding, we found that the previous predation estimates may have been conservative. We conclude that rainbow smelt may have been a more important contributor to the demise and slow recovery of ciscoes in Lake Superior than previously thought.

  19. Psychometric Evaluation of the Demographic Index of Cultural Exposure (DICE) in Two Mexican-Origin Community Samples

    Science.gov (United States)

    Cruz, Rick A.; Wilkinson, Anna V.; Bondy, Melissa L.; Koehly, Laura M.

    2012-01-01

    Reliability and validity evidence is provided for the Demographic Index of Cultural Exposure (DICE), consisting of six demographic proxy indicators of acculturation, within two community samples of Mexican-origin adults (N= 497 for each sample). Factor analytic procedures were used to examine the common variance shared between the six demographic…

  20. Factors associated with occasional and recurrent falls in Mexican community-dwelling older people.

    Directory of Open Access Journals (Sweden)

    Marcela Agudelo-Botero

    Full Text Available Falls are a frequent event among older adults that can cause wounds, disability, psychological disorders, and premature death. Although the large number of existing studies on the issue, few have been conducted in middle- and low-income countries. The objective of the present study is to identify the sociodemographic, medical, and functional performance factors associated with occasional and recurrent falls in Mexican older adults dwelling in community. Cross-sectional analysis of 9 598 adults ≥60 years old who participated in the fourth round (2015 of the Mexican Health and Aging Study. Bivariate tests were performed to evaluate the differences between covariates by distinct fall groups (no falls, occasional falls, and recurrent falls. Multiple logistic regressions with unadjusted and adjusted models were estimated. Approximately 46% of older adults had had at least one fall during the previous two years (one fall 16% and recurrent falls 30%. Occasional falls were only associated with being a woman; in addition to the sex, recurrent falls were strongly associated with advanced age, rural residence, bad and very bad self-perception of health status, activity-limiting pain, urinary incontinence, depression, arthritis, limitations in basic activities of daily living, and limitations in advanced activities of daily living. Falls, primarily recurrent falls, deserve to be addressed through multifactorial strategies that include different areas of intervention.

  1. Factors associated with occasional and recurrent falls in Mexican community-dwelling older people

    Science.gov (United States)

    Mino-León, Dolores; Cruz-Arenas, Esteban

    2018-01-01

    Falls are a frequent event among older adults that can cause wounds, disability, psychological disorders, and premature death. Although the large number of existing studies on the issue, few have been conducted in middle- and low-income countries. The objective of the present study is to identify the sociodemographic, medical, and functional performance factors associated with occasional and recurrent falls in Mexican older adults dwelling in community. Cross-sectional analysis of 9 598 adults ≥60 years old who participated in the fourth round (2015) of the Mexican Health and Aging Study. Bivariate tests were performed to evaluate the differences between covariates by distinct fall groups (no falls, occasional falls, and recurrent falls). Multiple logistic regressions with unadjusted and adjusted models were estimated. Approximately 46% of older adults had had at least one fall during the previous two years (one fall 16% and recurrent falls 30%). Occasional falls were only associated with being a woman; in addition to the sex, recurrent falls were strongly associated with advanced age, rural residence, bad and very bad self-perception of health status, activity-limiting pain, urinary incontinence, depression, arthritis, limitations in basic activities of daily living, and limitations in advanced activities of daily living. Falls, primarily recurrent falls, deserve to be addressed through multifactorial strategies that include different areas of intervention. PMID:29462159

  2. Initial validation of the Personality Assessment Inventory-Spanish version with clients from Mexican American communities.

    Science.gov (United States)

    Rogers, R; Flores, J; Ustad, K; Sewell, K W

    1995-04-01

    Psychological assessment of Hispanic populations are thwarted by the absence of clinical research on comparability of Spanish translations and the stability of their findings. In this study we examined the potential usefulness of the Spanish Personality Assessment Inventory (PAI; Morey, 1991) for Hispanic clients residing in Mexican American communities. We administered the Spanish version on two occasions to 48 monolingual clients and the Spanish and English versions to 21 bilingual clients. Results indicated that the clinical scales had a moderate to good correspondence for Spanish-English (M r = .72) and good test-retest reliability for Spanish-Spanish (M r = .79). Much more variation was observed for the validity scales and the treatment/interpersonal scales. Also more variability was observed in the convergence of elevations across administrations. Because of these mixed results, we discuss the potential usefulness of the PAI clinical scales to screen for major psychopathology.

  3. Migration Decision-Making among Mexican Youth: Individual, Family, and Community Influences.

    Science.gov (United States)

    Tucker, Christine M; Torres-Pereda, Pilar; Minnis, Alexandra M; Bautista-Arredondo, Sergio A

    2013-05-07

    We explored migration decisions using in-depth, semi-structured interviews with male and female youth ages 14 to 24 (n=47) from two Mexican communities, one with high and one with low U.S. migration density. Half were return migrants and half were non-migrants with relatives in the U.S. Migrant and non-migrant youth expressed different preferences, especially in terms of education and their ability to wait for financial gain. Reasons for migration were mostly similar across the two communities; however, the perceived risk of the migration journey was higher in the low density migration community while perceived opportunities in Mexico were higher in the high density migration community. Reasons for return were related to youths' initial social and economic motivations for migration. A greater understanding of factors influencing migration decisions may provide insight into the vulnerability of immigrant youth along the journey, their adaptation process in the U.S., and their reintegration in Mexico.

  4. Recruitment strategies and costs associated with community-based research in a Mexican-origin population.

    Science.gov (United States)

    Mendez-Luck, Carolyn A; Trejo, Laura; Miranda, Jeanne; Jimenez, Elizabeth; Quiter, Elaine S; Mangione, Carol M

    2011-06-01

    We describe the recruitment strategies and personnel and materials costs associated with two community-based research studies in a Mexican-origin population. We also highlight the role that academic-community partnerships played in the outreach and recruitment process for our studies. We reviewed study documents using case study methodology to categorize recruitment methods, examine community partnerships, and calculate study costs. We employed several recruitment methods to identify and solicit 154 female caregivers for participation in qualitative interviews and quantitative surveys. Recruitment approaches included using flyers and word of mouth, attending health fairs, and partnering with nonprofit community-based organizations (CBOs) to sponsor targeted recruitment events. Face-to-face contact with community residents and partnerships with CBOs were most effective in enrolling caregivers into the studies. Almost 70% of participants attended a recruitment event sponsored or supported by CBOs. The least effective recruitment strategy was the use of flyers, which resulted in only 7 completed interviews or questionnaires. Time and costs related to carrying out the research varied by study, where personal interviews cost more on a per-participant basis ($1,081) than the questionnaires ($298). However, almost the same amount of time was spent in the community for both studies. Partnerships with CBOs were critical for reaching the target enrollment for our studies. The relationship between the University of California-Los Angeles (UCLA) Resource Center for Minority Aging Research/Center for Health Improvement for Minority Elderly and the Department of Aging provided the infrastructure for maintaining connections with academic-community partnerships. Nevertheless, building partnerships required time, effort, and resources for both researchers and local organizations.

  5. Recruitment Strategies and Costs Associated With Community-Based Research in a Mexican-Origin Population

    Science.gov (United States)

    Mendez-Luck, Carolyn A.; Trejo, Laura; Miranda, Jeanne; Jimenez, Elizabeth; Quiter, Elaine S.; Mangione, Carol M.

    2011-01-01

    Purpose: We describe the recruitment strategies and personnel and materials costs associated with two community-based research studies in a Mexican-origin population. We also highlight the role that academic–community partnerships played in the outreach and recruitment process for our studies. We reviewed study documents using case study methodology to categorize recruitment methods, examine community partnerships, and calculate study costs. Results: We employed several recruitment methods to identify and solicit 154 female caregivers for participation in qualitative interviews and quantitative surveys. Recruitment approaches included using flyers and word of mouth, attending health fairs, and partnering with nonprofit community-based organizations (CBOs) to sponsor targeted recruitment events. Face-to-face contact with community residents and partnerships with CBOs were most effective in enrolling caregivers into the studies. Almost 70% of participants attended a recruitment event sponsored or supported by CBOs. The least effective recruitment strategy was the use of flyers, which resulted in only 7 completed interviews or questionnaires. Time and costs related to carrying out the research varied by study, where personal interviews cost more on a per-participant basis ($1,081) than the questionnaires ($298). However, almost the same amount of time was spent in the community for both studies. Implications: Partnerships with CBOs were critical for reaching the target enrollment for our studies. The relationship between the University of California–Los Angeles (UCLA) Resource Center for Minority Aging Research/Center for Health Improvement for Minority Elderly and the Department of Aging provided the infrastructure for maintaining connections with academic–community partnerships. Nevertheless, building partnerships required time, effort, and resources for both researchers and local organizations. PMID:21565824

  6. The prevalence of nervios and associated symptomatology among inhabitants of Mexican rural communities.

    Science.gov (United States)

    Salgado de Snyder, V N; Diaz-Perez, M J; Ojeda, V D

    2000-12-01

    The purpose of the present contribution is to describe the prevalence of nervios through self-report, to identify psychological and somatic symptoms associated with nervios, and to report the comorbidity of nervios with mood and anxiety disorders among Mexican rural-origin adults. The data reported here were collected as part of a larger project, whose aims were to determine the prevalence of selected mental health problems, their sociocultural manifestation and interpretation, and the utilization of mental health services among the inhabitants of rural communities in Mexico. A multi-stage, stratified, random sample of two regions in Mexico was obtained. The total number of participants used in the analyses was 942 adults: 441 men and 501 women. We found a prevalence of nervios of 15.5% in the general population. When analyzed by sex, women had a significantly higher prevalence (20.8%) of this condition than men (9.5%). Also, all the somatic and psychological symptoms associated with nervios had a higher prevalence among women than men.

  7. Oral health conditions and frailty in Mexican community-dwelling elderly: a cross sectional analysis

    Directory of Open Access Journals (Sweden)

    Castrejón-Pérez Roberto

    2012-09-01

    Full Text Available Abstract Background Oral health is an important component of general well-being for the elderly. Oral health-related problems include loss of teeth, nonfunctional removable dental prostheses, lesions of the oral mucosa, periodontitis, and root caries. They affect food selection, speaking ability, mastication, social relations, and quality of life. Frailty is a geriatric syndrome that confers vulnerability to negative health-related outcomes. The association between oral health and frailty has not been explored thoroughly. This study sought to identify associations between the presence of some oral health conditions, and frailty status among Mexican community-dwelling elderly. Methods Analysis of baseline data of the Mexican Study of Nutritional and Psychosocial Markers of Frailty, a cohort study carried out in a representative sample of people aged 70 and older residing in one district of Mexico City. Frailty was defined as the presence of three or more of the following five components: weight loss, exhaustion, slowness, weakness, and low physical activity. Oral health variables included self-perception of oral health compared with others of the same age; utilization of dental services during the last year, number of teeth, dental condition (edentate, partially edentate, or completely dentate, utilization and functionality of removable partial or complete dentures, severe periodontitis, self-reported chewing problems and xerostomia. Covariates included were gender, age, years of education, cognitive performance, smoking status, recent falls, hospitalization, number of drugs, and comorbidity. The association between frailty and dental variables was determined performing a multivariate logistic regression analysis. Final models were adjusted by socio-demographic and health factors Results Of the 838 participants examined, 699 had the information needed to establish the criteria for diagnosis of frailty. Those who had a higher probability of being

  8. Effects of terrestrial runoff on the coral communities in Santiago Bay, Colima, Mexican Pacific Coast.

    Science.gov (United States)

    Liñán-Cabello, Marco Agustín; Olivos-Ortiz, Aramis; Quijano-Scheggia, Sonia; Muñiz Anguiano, Daniela; Reséndiz-Flores, María Luisa; Ortega-Ortíz, Christian D

    2016-09-01

    the coastal zone, deforestation and erosion resulting from inappropriate development, and the runoff of nutrients from agricultural lands nearby the lagoon. All these significantly contributed to the nutrient-enriched waters of the lagoon, especially in summer, with negative effects on the coral community. Continued exposure to these factors, coupled with the lack of control over other anthropogenic components, has promoted the maintenance of a chronic stress state in the studied coral community. Our findings highlight the need for the development of appropriate coastal management and conservation policies for the coral reefs of the Mexican Pacific Coast.

  9. Status of rainbow smelt in the U.S. waters of Lake Ontario, 2013

    Science.gov (United States)

    Weidel, Brian C.; Connerton, Michael J.

    2014-01-01

    Rainbow Smelt Osmerus mordax are the second most abundant pelagic prey fish in Lake Ontario after Alewife Alosa psuedoharengus. The 2013, USGS/NYSDEC bottom trawl assessment indicated the abundance of Lake Ontario age-1 and older Rainbow Smelt decreased by 69% relative to 2012. Length frequency-based age analysis indicated that age-1 Rainbow Smelt constituted approximately 50% of the population, which is similar to recent trends where the proportion of age-1 has ranged from 95% to 42% of the population. While they constituted approximately half of the catch, the overall abundance index for age 1 was one of the lowest observed in the time series, potentially a result of cannibalism from the previous year class. Combined data from all bottom trawl assessments along the southern shore and eastern basin indicate the proportion of the fish community that is Rainbow Smelt has declined over the past 30 years. In 2013 the proportion of the pelagic fish catch (only pelagic species) that was Rainbow Smelt was the second lowest in the time series at 3.1%. Community diversity indices, based on bottom trawl catches, indicate that Lake Ontario fish community diversity, as assessed by bottom trawls, has sharply declined over the past 36 years and in 2013 the index was the lowest value in the time series. Much of this community diversity decline is driven by changes in the pelagic fish community and dominance of Alewife.

  10. The Relation of Drug Trafficking Fears and Cultural Identity to Attitudes Toward Mexican Immigrants in Five South Texas Communities.

    Science.gov (United States)

    Ramirez, Manuel; Argueta, Nanci L; Castro, Yessenia; Perez, Ricardo; Dawson, Darius B

    This paper reports the findings of research investigating the relationship of spill-over fears related to drug trafficking and of cultural identity to Mexican Americans' attitudes toward recent immigrants from Mexico in five non-metropolitan communities in the US-Mexico borderlands of South Texas. A mixed methods design was used to collect data from 91 participants (30 intact families with two parents and at least one young adult). Quantitative findings showed that the majority of participants expressed the view that most people in their communities believed that newcomers were involved in drug trafficking and in defrauding welfare programs. A significant interaction indicated that Mexican cultural identity buffered the negative effects of drug trafficking fears as related to the view that the newcomers were creating problems in the communities and region. Qualitative data yielded positive and negative themes, with those that were negative being significantly more numerous. The findings have implications for intra-ethnic relations in borderlands communities as well as for immigration policy.

  11. The Mexican American.

    Science.gov (United States)

    Rowan, Helen

    The purpose of this paper, prepared for the U. S. Commission on Civil Rights, is to indicate the types and ranges of problems facing the Mexican American community and to suggest ways in which these problems are peculiar to Mexican Americans. Specific examples are cited to illustrate major problems and personal experiences. Topics covered in the…

  12. Towards the Development of a Mexican Speech-to-Sign-Language Translator for the Deaf Community

    Directory of Open Access Journals (Sweden)

    Santiago-Omar Caballero-Morales

    2012-03-01

    Full Text Available Una parte significativa de la población mexicana es sorda. Esta discapacidad restringe sus habilidades de interacción social con personas que no tienen dicha discapacidad y viceversa. En este artículo presentamos nuestros avances hacia el desarrollo de un traductor Voz-a-Lenguaje-de-Señas del español mexicano para asistir a personas sin discapacidad a interactuarcon personas sordas. La metodología de diseño propuesta considera limitados recursos para(1 el desarrollo del Reconocedor Automático del Habla (RAH mexicano, el cual es el módulo principal del traductor, y (2 el vocabulario del Lenguaje de Señas Mexicano (LSM disponible para representar las oraciones reconocidas. La traducción Voz-a-Lenguaje-de-Señas fue lograda con un nivel de precisión mayor al 97% para usuarios de prueba diferentes de aquellos seleccionados para el entrenamiento del RAH.A significant population of Mexican people are deaf. This disorder restricts their social interac-tion skills with people who don't have such disorder and viceversa. In this paper we presentour advances towards the development of a Mexican Speech-to-Sign-Language translator toassist normal people to interact with deaf people. The proposed design methodology considerslimited resources for (1 the development of the Mexican Automatic Speech Recogniser (ASRsystem, which is the main module in the translator, and (2 the Mexican Sign Language(MSL vocabulary available to represent the decoded speech. Speech-to-MSL translation wasaccomplished with an accuracy level over 97% for test speakers different from those selectedfor ASR training.

  13. Purchases Made with a Fruit and Vegetable Voucher in a Rural Mexican-Heritage Community.

    Science.gov (United States)

    Hanbury, Meagan M; Gomez-Camacho, Rosa; Kaiser, Lucia; Sadeghi, Banafsheh; de la Torre, Adela

    2017-10-01

    Recent recommendations for US food assistance programs are intended to ensure foods provided through these programs help households consume a varied, healthful diet. From a policy viewpoint, it is important to examine the impact of economic incentives to purchase healthy foods across subpopulations, particularly low-income Latinos, who comprise 40% of the WIC program nationwide. Our aim was to determine how rural, Mexican-heritage households (N = 227) residing in California's Central Valley distributed fruit and vegetable (F/V) voucher spending among F/V subgroups and specific items over a 1-year period. Households contained at least one child who was between 3 and 8 years old at baseline and had a parent of Mexican-heritage. F/V voucher purchase data were collected via grocery store scanners. Expenditure and frequency shares of subgroups and individual items were analyzed to determine purchasing habits. Fruits were the most commonly purchased subgroup, representing 55% of spending and 45% of frequency. Households allocated low percentages of their voucher to dark green and red/orange vegetables-7 and 9% respectively. Approximately 20% of purchases were good potassium sources and 30% of purchases were good fiber sources. Many of the most frequently purchased items were of cultural significance (tomatillo, chayote, chili/jalapeño pepper, and Mexican squash). This study suggests that economic incentives can contribute important nutrients to participants' diets and targeted vouchers provided by food assistance programs should continue to include culturally important foods and be aware of the cultural values of their participants.

  14. Smelting of Scandium by Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Satoshi Fujii

    2017-09-01

    Full Text Available Scandium is being explored as an alloying element for aluminum alloys, which are gaining importance as high-performance lightweight structural alloys in the transportation industry. A few years ago, Sc was also found to be suitable for use in electrical devices. High-Sc-content ScAlN thin films have attracted significant attention because of their strong piezoelectricity. The piezoelectric response of ScAlN suggests that ScAlN thin films formed on a hard substrate would be suitable surface acoustic wave wideband filters for next-generation wireless communication systems. However, it is often difficult to use ScAlN thin films in MEMS devices—including acoustic ones—because of the extremely high price of metallic Sc, given the difficulty associated with smelting it. Here, we propose a novel process for smelting Sc metal by microwave irradiation. Sc metal was able to be obtained successfully from ScF3 through a microwave-irradiation-based carbon reduction reaction. The reaction temperature for this reduction process was approximately 880°C, which is half of that for the conventional smelting process involving reduction with Ca. Thus, the proposed microwave irradiation process has significant potential for use in the smelting of Sc metal.

  15. MIGRATION AND INSTITUTIONAL CHANGE: THE CASES OF SOUTHERN MEXICAN STATES AND THEIR EMIGRANT COMMUNITIES IN THE UNITED STATES OF AMERICA

    Directory of Open Access Journals (Sweden)

    Sascha Krannich

    2016-04-01

    Full Text Available This paper illustrates institutional approaches of emigrant states toward emigrants abroad, and how these approaches can change over time. These can range from absolute exclusion and non-communication, over fractional collaboration in specific matters, to even permanent institutional inclusion, for instance, through representation of migrants in home parliaments or governments. The approach for institutional incorporation can not only take place on the national, but also on the subnational level. This is the case in Mexico, a federal state in which many member states conduct their own emigrant policy, partially in accord with federal efforts, and partially independently or contrary to the national attempt to address the emigrant community abroad. To highlight these different approaches, I would like to take a look at the Southern Mexican states of Oaxaca and Chiapas. Although these states show similar political and social structures, and hold relatively large emigrant populations in the United States of America, the institutional approaches toward their emigrants changed in two different ways: while the institutional opening in Oaxaca goes back to various initiatives by the Oaxacan migrant community in the United States of America, the policy change in Chiapas toward more inclusion of the emigrant community was actively promoted by the government of Chiapas.

  16. “Adiós soccer, here comes fútbol!”: Transnationalization of the Mexican Sports Communities in the U.S.

    Directory of Open Access Journals (Sweden)

    Ingrid Kummels

    2012-03-01

    Full Text Available This article discusses the sport dynamics of the Mexican communities in the United States in the context of soccer. From the analysis of Mexican groups which immigrated to the American territory, and from their soccer practices (of resistance, this research questions whether we would be witnessing a sportive “latinoamericanization” of the U.S. through the soccer practices. As a counter-response to a homogenization and subordination, the Mexican Americans (and, by extension, the Latinos in general have created new cultural practices (and, among them sportive ones that put together Mexican traditions with American values of society constituting, in that way, “a third space”, which extends beyond the borders of both national States. This paper, therefore, examines why a growing number of migrants strengthens relationships with their communities of origin in Mexico through the (recreation of a soccer world itself, expressing thereby a “transnational mexicanity”, which is not “harmonic” by itself, but marked by conflicts. In this “new mexicanities” gender, class and ethnic, national and local conflicts – which occur simultaneously in the U.S. and Mexico, influencing each other – appear.

  17. Community Participation and Domiciliary Occurrence of Infected Meccus longipennis in Two Mexican Villages in Jalisco State

    Science.gov (United States)

    Brenière, Simone Frédérique; Bosseno, Marie-France; Gastélum, Ezequiel Magallón; Margarita Soto Gutiérrez, María; de Jesús Kasten Monges, Marina; Horacio Barraza Salas, José; Justo Romero Paredes, José; de Jesús Lozano Kasten, Felipe

    2010-01-01

    The entomological features of Chagas disease in two western Mexican villages were analyzed through triatomines collection by the inhabitants and active research in the peridomicile. The inhabitant collections have the following comparable characteristics: 1) Meccus longipennis was the dominant species (> 91%), 2) around 43% of the insects were collected indoors, 3) about 70% of triatomines were adults, 4) cumulated rates of infestation of the dwellings reached 40–50%, 5) the triatomine infection rate by Trypanosoma cruzi was > 50%, and 6) the indoor triatomines frequently feed on humans (range 38.5–56.2%). However, the collection was twice as abundant in the first village and the peridomicile infestation, evaluated by the active collection, reached up to 60% and only 4.9% in the other village. Furthermore, females predominated in the first village, whereas males in the other. The current results allow discussing the course of action to prevent Chagas disease in this region. PMID:20682887

  18. Stimulating Parenting Practices in Indigenous and Non-Indigenous Mexican Communities

    Directory of Open Access Journals (Sweden)

    Heather A. Knauer

    2017-12-01

    Full Text Available Parenting may be influenced by ethnicity; marginalization; education; and poverty. A critical but unexamined question is how these factors may interact to compromise or support parenting practices in ethnic minority communities. This analysis examined associations between mothers’ stimulating parenting practices and a range of child-level (age; sex; and cognitive and socio-emotional development; household-level (indigenous ethnicity; poverty; and parental education; and community-level (economic marginalization and majority indigenous population variables among 1893 children ages 4–18 months in poor; rural communities in Mexico. We also explored modifiers of associations between living in an indigenous community and parenting. Key findings were that stimulating parenting was negatively associated with living in an indigenous community or family self-identification as indigenous (β = −4.25; SE (Standard Error = 0.98; β = −1.58; SE = 0.83 respectively. However; living in an indigenous community was associated with significantly more stimulating parenting among indigenous families than living in a non-indigenous community (β = 2.96; SE = 1.25. Maternal education was positively associated with stimulating parenting only in indigenous communities; and household crowding was negatively associated with stimulating parenting only in non-indigenous communities. Mothers’ parenting practices were not associated with child sex; father’s residential status; education; or community marginalization. Our findings demonstrate that despite greater community marginalization; living in an indigenous community is protective for stimulating parenting practices of indigenous mothers.

  19. Energy consumption in smelting reduction (SR) processes

    International Nuclear Information System (INIS)

    Assis, Paulo Santos; Salierno, Giovanni Felice; Fang, Jue; Mankhand, Tilak R.; Assis, Carlos Frederico Campos de

    2010-01-01

    In contrast, conventional processes use coke and hematite/sinter in the blast furnace, in SR processes, other alternative fuels and iron ore sources, like charcoal and fine iron ores, can be used to produce sponge iron. The use of these alternative sources, by SR processes, can reduce environmental impacts and lower production costs. At first, the concepts of the theoretical gas utilization ratio, the smelting heat of the iron ore and the effective calorific value of coal were introduced. Then, the reason for gas utilization ratio and its performance in the shaft as a reducer in the smelting process are discussed and calculated. The relationship between coal consumption and iron ore reduction in the fluidized bed are also discussed. Finally, the influence of post-combustion on coal consumption in an iron bath furnace are calculated and discussed. (author)

  20. A Food Transfer Program without a Formal Education Component Modifies Complementary Feeding Practices in Poor Rural Mexican Communities.

    Science.gov (United States)

    Ramírez-Luzuriaga, María J; Unar-Munguía, Mishel; Rodríguez-Ramírez, Sonia; Rivera, Juan A; González de Cosío, Teresa

    2016-01-01

    Inadequate complementary feeding partially explains micronutrient deficiencies in the first 2 y of life. To prevent malnutrition, the Mexican government implemented the Programa de Apoyo Alimentario (PAL), which transferred either food baskets containing micronutrient-fortified milk and animal food products or cash to beneficiary families along with educational sessions. This study evaluated the impact of PAL on 2 indicators of complementary feeding: minimum dietary diversity and consumption of iron-rich or iron-fortified foods in children aged 6-23 mo. A secondary analysis of the original PAL evaluation design was conducted through a randomized community trial implemented with 3 intervention groups (food basket with education, food basket without education, and cash transfer with education) and a control. The impact of PAL after 14 mo of exposure was estimated in 2 cross-sectional groups of children aged 6-23 mo at baseline and at follow-up in a panel of 145 communities by using difference-in-difference models. Only children who lived in households and communities that were similar between treatment groups at baseline were included in the analysis. These children were identified by using a propensity score. Of the 3 intervention groups, when compared with the control, only the food basket without education group component increased the consumption of iron-rich or iron-fortified foods by 31.2 percentage points (PP) (P diversity by 21.6 PP (P effective than cash transfers. The fact that the 2 food basket groups differed in the observed impact does not allow for more convincing conclusions to be made about the education component of the program. This trial was registered at clinicaltrials.gov as NCT01304888. © 2016 American Society for Nutrition.

  1. Life on the edge: hydrogen sulfide and the fish communities of a Mexican cave and surrounding waters.

    Science.gov (United States)

    Tobler, Michael; Schlupp, Ingo; Heubel, Katja U; Riesch, Rüdiger; de León, Francisco J García; Giere, Olav; Plath, Martin

    2006-12-01

    Most eucaryotic organisms classified as living in an extreme habitat are invertebrates. Here we report of a fish living in a Mexican cave (Cueva del Azufre) that is rich in highly toxic H(2)S. We compared the water chemistry and fish communities of the cave and several nearby surface streams. Our study revealed high concentrations of H(2)S in the cave and its outflow (El Azufre). The concentrations of H(2)S reach more than 300 muM inside the cave, which are acutely toxic for most fishes. In both sulfidic habitats, the diversity of fishes was heavily reduced, and Poecilia mexicana was the dominant species indicating that the presence of H(2)S has an all-or-none effect, permitting only few species to survive in sulfidic habitats. Compared to habitats without H(2)S, P. mexicana from the cave and the outflow have a significantly lower body condition. Although there are microhabitats with varying concentrations of H(2)S within the cave, we could not find a higher fish density in areas with lower concentrations of H(2)S. We discuss that P. mexicana is one of the few extremophile vertebrates. Our study supports the idea that extreme habitats lead to an impoverished species diversity.

  2. Effect of smelt aluminium on mechanical properties of steels

    International Nuclear Information System (INIS)

    Ryabov, V.R.; Dykhno, I.S.; Deev, G.F.; Karikh, V.V.

    1987-01-01

    Effect of smelt aluminium on mechanical properties of armco-iron and 12 Kh18N10T steel is studied. It is stated that in smelt aluminium and aluminium alloy contact with armco-iron the sample ductility is decreased. Corrosion effect of smelt alluminium on (18Kh15N5AM3) steel in the form of reinforced wire in aluminium-steel KAS-1A composite material is investigted. It is stated in experiment that during smelt alluminium-steel contact interaction of heterogeneous phases takes place

  3. Mexican Identification. Project Mexico.

    Science.gov (United States)

    Castellano, Rita

    This document presents an outline and teacher's guide for a community college-level teaching module in Mexican identification, designed for students in introductory courses in the social sciences. Although intended specifically for cultural anthropology, urban anthropology, comparative social organization and sex roles in cross-cultural…

  4. Breaking the Bounds of Rationality: Values, Relationships, and Decision-making in Mexican Fishing Communities

    Directory of Open Access Journals (Sweden)

    Nicole D Peterson

    2014-01-01

    Full Text Available In fishing communities in Baja California Sur, Mexico, fisheries management is heavily influenced by models of individual economic rationality held by biologists and others involved in management, in which fishermen ′choose′ to overfish because they are motivated by selfish individual rationality. Yet there is much that is neglected by these models, including the pressures of economic markets, family and community expectations, and cultural and personal value systems. Actual decisions about fishing and resource management rarely match the expectations of classical or neoliberal economic models of individual behaviour. I argue here that rational choice theory is a historically and culturally constructed discourse that becomes a taken-for-granted lens for viewing behaviour around the world. The effects of this discourse can be seen in the policies that are derived from them, as shown through this case study.

  5. Yunnan Smelting Group Examines an Aluminum Project for Possible Investment

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Tian Yong,General Manager of Yunnan Smelt- ing Group,has gone to Zha gai NuoEr in Heilongjiang Province with a study group to conduct a full careful examination on the feasi- bility of the investment in the aluminum pro- ject.Yunnan Smelting Group is a large-scale

  6. Helminth parasite communities of spotted rose snapper Lutjanus guttatus from the Mexican Pacific

    Directory of Open Access Journals (Sweden)

    Morales-Serna F. N.

    2017-09-01

    Full Text Available The helminth communities of L. guttatus from Mazatlan Bay (MB and Banderas Bay (BB, on the Pacific coast of Mexico, were studied during two consecutive years. A total of 536 fish were collected and 19 parasite taxa registered (six digeneans, two cestodes, nine nematodes, and two monogeneans. Infection levels of common helminth species (Helicometrina nimia, Siphodera vinaledwardsii, Tetraphyllidea gen. sp., Pseudoterranova sp., Ancyrocephalidae gen. sp. and Microcotyloides incisa as well as the infracommunity indices varied significantly between MB and BB, and among dry and rainy seasons; however, no clear seasonal patterns were observed. Pseudoterranova larvae appeared frequently in MB, possibly because of the presence of the California sea lion in this locality. Similarity analysis did not show a clear separation of parasite species composition between both localities, which suggest that fish samples came from a single population of L. guttatus.

  7. Recirculation of Chilean copper smelting dust with high impurities contents to the smelting process

    Energy Technology Data Exchange (ETDEWEB)

    Sano, H.; Fujisawa, T. [Nagoya Univ., Nagoya (Japan). EcoTopia Science Inst.; Montenegro, V. [Nagoya Univ., Nagoya (Japan). Dept. of Materials Science and Engineering

    2007-07-01

    Dust generated during the copper smelting process is generally stabilized using hydrometallurgical methods as it contains high concentrations of arsenic. In this laboratory study, dust was recirculated during the smelting process in order to recover more copper and decrease dust emissions while recovering more copper. The behaviour of impurities and their influence on matte quality was also investigated. Industrial matte, flue dust, slag, and copper concentrates from a Chilean smelter were used as test materials. Dust recirculation tests were conducted in a simulated electric furnace. Off-gases were collected in a reaction tube, and the condensed volatile matter, slag, and matte phases were analyzed for their elemental content by inductively coupled plasma atomic emission spectrometry. The distribution of arsenic (As); antimony (Sb), bismuth (Bi), lead (Pb), and zinc (Zn) were investigated by varying the amounts of dust recirculating to the smelting stage with 21 per cent of the oxygen. Results showed that distributions of all analyzed elements increased with recirculation. It was concluded that copper can be recovered using the dust recirculation technique. However, impurities may limit the efficacy of the dust recirculation process. 6 refs., 3 tabs., 4 figs.

  8. From Golden Age Mexican Cinema to Transnational Border Feminism: The Community of Spectators in "Loving Pedro Infante"

    Science.gov (United States)

    Heredia, Juanita

    2008-01-01

    The novel "Loving Pedro Infante" by Chicana writer Denise Chavez provides an insightful transcultural feminist critique of Golden Age Mexican cinema culture through a careful examination of gender roles. In the novel, the reception of Pedro Infante's films by spectators bridges generations and national spaces and leads to the formation…

  9. Analysis of bacterial community during the fermentation of pulque, a traditional Mexican alcoholic beverage, using a polyphasic approach.

    Science.gov (United States)

    Escalante, Adelfo; Giles-Gómez, Martha; Hernández, Georgina; Córdova-Aguilar, María Soledad; López-Munguía, Agustín; Gosset, Guillermo; Bolívar, Francisco

    2008-05-31

    In this study, the characterization of the bacterial community present during the fermentation of pulque, a traditional Mexican alcoholic beverage from maguey (Agave), was determined for the first time by a polyphasic approach in which both culture and non-culture dependent methods were utilized. The work included the isolation of lactic acid bacteria (LAB), aerobic mesophiles, and 16S rDNA clone libraries from total DNA extracted from the maguey sap (aguamiel) used as substrate, after inoculation with a sample of previously produced pulque and followed by 6-h fermentation. Microbiological diversity results were correlated with fermentation process parameters such as sucrose, glucose, fructose and fermentation product concentrations. In addition, medium rheological behavior analysis and scanning electron microscopy in aguamiel and during pulque fermentation were also performed. Our results showed that both culture and non-culture dependent approaches allowed the detection of several new and previously reported species within the alpha-, gamma-Proteobacteria and Firmicutes. Bacteria diversity in aguamiel was composed by the heterofermentative Leuconostoc citreum, L. mesenteroides, L. kimchi, the gamma-Proteobacteria Erwinia rhapontici, Enterobacter spp. and Acinetobacter radioresistens. Inoculation with previously fermented pulque incorporated to the system microbiota, homofermentative lactobacilli related to Lactobacillus acidophilus, several alpha-Proteobacteria such as Zymomonas mobilis and Acetobacter malorum, other gamma-Proteobacteria and an important amount of yeasts, creating a starting metabolic diversity composed by homofermentative and heterofermentative LAB, acetic and ethanol producing microorganisms. At the end of the fermentation process, the bacterial diversity was mainly composed by the homofermentative Lactobacillus acidophilus, the heterofermentative L. mesenteroides, Lactococcus lactis subsp. lactis and the alpha-Proteobacteria A. malorum. After

  10. Smelting Associated with the Advanced Spent Fuel Conditioning Process

    International Nuclear Information System (INIS)

    Hur, J-M.; Jeong, M-S.; Lee, W-K.; Cho, S-H.; Seo, C-S.; Park, S-W.

    2004-01-01

    The smelting process associated with the advanced spent fuel conditioning process (ACP) of Korea Atomic Energy Research Institute was studied by using surrogate materials. Considering the vaporization behaviors of input materials, the operation procedure of smelting was set up as (1) removal of residual salts, (2) melting of metal powder, and (3) removal of dross from a metal ingot. The behaviors of porous MgO crucible during smelting were tested and the chemical stability of MgO in the salt-being atmosphere was confirmed

  11. Mexican Revolution

    OpenAIRE

    Scheuzger, Stephan

    2016-01-01

    It was the complex and far-reaching transformation of the Mexican Revolution rather than the First World War that left its mark on Mexican history in the second decade of the 20th century. Nevertheless, although the country maintained its neutrality in the international conflict, it was a hidden theatre of war. Between 1914 and 1918, state actors in Germany, Great Britain and the United States defined their policies towards Mexico and its nationalist revolution with a view not only to improve...

  12. Los Dos Mundos: Rural Mexican Americans, Another America.

    Science.gov (United States)

    Baker, Richard

    This book explores race relations between Mexican Americans and Anglo Americans in "Middlewest," a fictitious name for an actual rural Idaho community with the highest proportion of Mexican Americans in the state. Many Mexican Americans in this predominantly agricultural area are current or former migrant workers. The first chapter…

  13. Association of Household and Community Characteristics with Adult and Child Food Insecurity among Mexican-Origin Households in Colonias along the Texas-Mexico Border

    Directory of Open Access Journals (Sweden)

    Dean Wesley R

    2011-05-01

    Full Text Available Abstract Background Food insecurity is a critical problem in the United States and throughout the world. There is little published data that provides insights regarding the extent and severity of food insecurity among the hard-to-reach Mexican-origin families who reside in the growing colonias along the Texas border with Mexico. Considering that culture, economics, and elements of the environment may increase the risk for food insecurity and adverse health outcomes, the purpose of this study was to examine the relation between household and community characteristics and food insecurity. Methods The study used data from the 2009 Colonia Household and Community Food Resource Assessment (C-HCFRA. The data included 610 face-to-face interviews conducted in Spanish by promotoras (indigenous community health workers in forty-four randomly-identified colonias near the towns of Progreso and La Feria in Hidalgo and Cameron counties along the Texas border with Mexico. C-HCFRA included demographic characteristics, health characteristics, food access and mobility, food cost, federal and community food and nutrition assistance programs, perceived quality of the food environment, food security, eating behaviors, and alternative food sources. Results 78% of participants experienced food insecurity at the level of household, adult, or child. The most severe - child food insecurity was reported by 49% of all households and 61.8% of households with children. Increasing levels of food insecurity was associated with being born in Mexico, increasing household composition, decreasing household income, and employment. Participation in federal food assistance programs was associated with reduced severity of food insecurity. Greater distance to their food store and perceived quality of the community food environment increased the odds for food insecurity. Conclusions The Mexican-origin population is rapidly expanding; record numbers of individuals and families are

  14. Association of household and community characteristics with adult and child food insecurity among Mexican-origin households in colonias along the Texas-Mexico border.

    Science.gov (United States)

    Sharkey, Joseph R; Dean, Wesley R; Johnson, Cassandra M

    2011-05-13

    Food insecurity is a critical problem in the United States and throughout the world. There is little published data that provides insights regarding the extent and severity of food insecurity among the hard-to-reach Mexican-origin families who reside in the growing colonias along the Texas border with Mexico. Considering that culture, economics, and elements of the environment may increase the risk for food insecurity and adverse health outcomes, the purpose of this study was to examine the relation between household and community characteristics and food insecurity. The study used data from the 2009 Colonia Household and Community Food Resource Assessment (C-HCFRA). The data included 610 face-to-face interviews conducted in Spanish by promotoras (indigenous community health workers) in forty-four randomly-identified colonias near the towns of Progreso and La Feria in Hidalgo and Cameron counties along the Texas border with Mexico. C-HCFRA included demographic characteristics, health characteristics, food access and mobility, food cost, federal and community food and nutrition assistance programs, perceived quality of the food environment, food security, eating behaviors, and alternative food sources. 78% of participants experienced food insecurity at the level of household, adult, or child. The most severe - child food insecurity was reported by 49% of all households and 61.8% of households with children. Increasing levels of food insecurity was associated with being born in Mexico, increasing household composition, decreasing household income, and employment. Participation in federal food assistance programs was associated with reduced severity of food insecurity. Greater distance to their food store and perceived quality of the community food environment increased the odds for food insecurity. The Mexican-origin population is rapidly expanding; record numbers of individuals and families are experiencing food insecurity; and for those living in rural or

  15. Evaluation of quality improvement performance in the Community Diabetes Education (CoDE) program for uninsured Mexican Americans: results of a randomized controlled trial.

    Science.gov (United States)

    Prezio, Elizabeth A; Balasubramanian, Bijal A; Shuval, Kerem; Cheng, Dunlei; Kendzor, Darla E; Culica, Dan

    2014-01-01

    The objective of this article is to quantify quality improvement using data from a randomized controlled trial that tested the effectiveness of a community health worker in the primary role of diabetes educator in a clinic serving uninsured Mexican Americans. The intervention group received 7 hours of diabetes education/case management in excess of usual medical care. Of 16 process and outcome measures evaluated, the intervention group was significantly more likely to have received a dilated retinal examination, and 53% achieved a hemoglobin A1c below 7% compared with 38% of the control group participants. Composite quality measures were similar in magnitude with published practice-based benchmarks at study conclusion. This suggests that the overall diabetes care delivered in this clinic serving uninsured patients was comparable to the levels of excellence achieved in other primary care settings. Quantitative measurements of quality improvement can inform health policy regarding the relative effectiveness of diabetes interventions.

  16. Uranium decontamination of common metals by smelting, a review (handbook)

    International Nuclear Information System (INIS)

    Mautz, E.W.; Briggs, G.G.; Shaw, W.E.; Cavendish, J.H.

    1975-01-01

    The published and unpublished literature relating to the smelting of common metals scrap contaminated with uranium-bearing compounds has been searched and reviewed. In general, standard smelting practice produces ingots having a low uranium content, particularly for ferrous, nickel, and copper metals or alloys. Aluminum recovered from uranium contaminated scrap shows some decontamination by smelting but the uranium content is not as low as for other metals. Due to the heterogeneous nature and origin of scrap metals contaminated with uranium, information is frequently missing as to the extent of the initial contamination and the degree of decontamination obtained. The uranium content of the final cast ingots is generally all that is available. Results are summarized below by the primary composition of the uranium contaminated scrap metal. (U.S.)

  17. 76 FR 9409 - National Emission Standards for Hazardous Air Pollutants: Primary Lead Smelting

    Science.gov (United States)

    2011-02-17

    ... National Emission Standards for Hazardous Air Pollutants: Primary Lead Smelting; Proposed Rule #0;#0... Emission Standards for Hazardous Air Pollutants: Primary Lead Smelting AGENCY: Environmental Protection... standards for hazardous air pollutants (NESHAP) for Primary Lead Smelting to address the results of the...

  18. Cross-Cultural Adaptation and Validation of the Spanish-Language Version of the SARC-F to Assess Sarcopenia in Mexican Community-Dwelling Older Adults.

    Science.gov (United States)

    Parra-Rodríguez, Lorena; Szlejf, Claudia; García-González, Ana Isabel; Malmstrom, Theodore K; Cruz-Arenas, Esteban; Rosas-Carrasco, Oscar

    2016-12-01

    To cross-culturally adapt and validate the Spanish-language version of the SARC-F in Mexican community-dwelling older adults. Cross-sectional analysis of a prospective cohort. The FraDySMex study, a 2-round evaluation of community-dwelling adults from 2 municipalities in Mexico City. Participants were 487 men and women older than 60 years, living in the designated area in Mexico City. Information from questionnaires regarding demographic characteristics, comorbidities, mental status, nutritional status, dependence in activities of daily living, frailty, and quality of life. Objective measurements of muscle mass, strength and function were as follows: skeletal muscle mass index (SMI) was taken using dual-energy x-ray, grip strength using a hand dynamometer, 6-meter gait speed using a GAIT Rite instrumented walkway, peak torque and power for knee extension using a isokinetic dynamometer, lower extremity functioning measured by the Short Physical Performance Battery (SPPB), and balance using evaluation on a foam surface, with closed eyes, in the Modified Clinical Test of Sensory Integration. The SARC-F scale translated to Spanish and the consensus panels' criteria from European, international, and Asian sarcopenia working groups were applied to evaluate sarcopenia. The Spanish language version of the SARC-F scale showed reliability (Cronbach alfa = 0.641. All items in the scale correlated to the scale's total score, rho = 0.43 to 0.76), temporal consistency evaluated by test-retest (CCI = 0.80), criterion validity when compared to the consensus panels' criteria (high specificity and negative predictive values). The scale was also correlated to other measures related to sarcopenia (such as age, quality of life, self-rated health status, cognition, dependence in activities of daily living, nutritional status, depression, gait speed, grip strength, peak torque and power for knee extension, SPPB, balance, SMI, and frailty). The SARC-F scale was successfully adapted to

  19. The development of coke smelting and the industrial revolution

    OpenAIRE

    Macfarlane, Alan

    2004-01-01

    Abraham Darby and the origins of the industrial revolution in Britain. Alan Macfarlane talks to John about the reasons for the area near Birmingham becoming the epi-centre of the industrial development, and the development of coke furnaces and iron smelting.

  20. 31 CFR 101.5 - Payment of smelting costs.

    Science.gov (United States)

    2010-07-01

    ... FORFEITURE OF COUNTERFEIT GOLD COINS § 101.5 Payment of smelting costs. The petitioner shall be required to pay all reasonable costs incurred in extracting the bullion from the counterfeit coins, as shall be determined by the Assistant Secretary. Payment must be made prior to the return of the gold bullion to the...

  1. Project Update: ZVI Used for Arsenic from Lead Smelting Facility

    Science.gov (United States)

    The U.S. EPA Office of Research and Development’s National Risk Management Research Laboratory (NRMRL) is conducting long-term monitoring of a granular iron permeable reactive barrier (PRB) for remediation of ground water contaminated with arsenic from a former lead smelting faci...

  2. Proceedings of the Annual Conference on Child Abuse and Neglect in the Mexican American Community (1st, Laredo, Texas, May 26-29, 1981).

    Science.gov (United States)

    Gibson, Guadalupe, Ed.,; Torres, Angelina Moreno

    The conference focused attention on the severe problems of abuse and neglect among Mexican American children, particularly among migrant children. The welcome address discussed the plight and hardship endured by the Mexican American migrant worker and family. The keynote address emphasized the fact that minority families, who are usually poor, and…

  3. The Binational Civic and Political Engagement of Mexican Migrant Hometown Associations and Federations in the United States

    Directory of Open Access Journals (Sweden)

    Xóchitl Bada

    2014-06-01

    Full Text Available This article focuses on the history and current situation of Mexican hometown associations (HTAs in the United States with a special emphasis on Chicago-based Mexican hometown associations and federations. It presents empirical evidence of new forms of binational engagement among Mexican migrant communities in the United States leading to the creation of a Mexican migrant civil society.

  4. Sewing Empowerment: Examining Multiple Identity Shifts as a Mexican Immigrant Woman Develops Expertise in a Sewing Cooperative Community of Practice

    Science.gov (United States)

    Vickers, Caroline H.; Deckert, Sharon K.

    2013-01-01

    This article demonstrates how one woman's identity changed as she was empowered through her participation in a sewing cooperative community of practice. A community of practice framework allows examination of participation in ongoing negotiated interactions in which people construct expert and novice identities as they work together. Identity, as…

  5. Transferable Training Modules: Building Environmental Education Opportunities With and for Mexican Community Health Workers (Promotores de Salud).

    Science.gov (United States)

    Ramírez, Denise Moreno; Vea, Lourdes; Field, James A; Baker, Paul B; Gandolfi, A Jay; Maier, Raina M

    Community health workers (promotores de salud) have the ability to empower communities to mitigate negative health outcomes. Current training efforts in environmental topics are lacking. This project addressed this gap by developing 4 transferable training modules on environmental health. By applying a series of surveys, interviews, and trainings, we evaluated their relevance. Partners provided favorable feedback for 3 of the 4 modules. It was also learned that the development method could be improved by engaging technically trained promotores de salud in the role of co-creators. This project has implications for environmental justice communities as it can lessen information disparities.

  6. Reproduction and community structure of fish from winter catch sites from industrial shrimp bycatch from the northeast and southeast Mexican Pacific

    Directory of Open Access Journals (Sweden)

    Jorge de Jesus Tirado-Ibarra

    2018-03-01

    Full Text Available The shrimp fishery is one of the most important fisheries in the world, although the low selectivity from trawling nets has led to the capture of a large number of non-target species. Shrimp-bycatch species include a large number of fish and invertebrate species, of which fish species are the most abundant. The present study aims to determine the community structure as well as the average sizes at first maturity of the fish species from shrimp-bycatch caught from industrial fisheries in the Mexican Pacific from Sinaloa to Guerrero, from January to March 2015. The shrimp-bycatch fish diversity value was found to be 2.22. A total of 37 species of finfish were found, of which five were considered rare. The fish species with the highest Importance Value Index (IVI levels were Pseudupeneus grandisquamis, Paralichthys woolmani, Lutjanus peru and Diapterus peruvianus. The average size at first maturity was calculated for all species. Of the analysed organisms, 90% were in the juvenile stage, including species with riverine and artisanal fisheries. The present study demonstrates the risk within marine populations to different non-target species due to the poor selectivity of shrimp trawls.

  7. Optimization of suspension smelting technology by computer simulation

    Energy Technology Data Exchange (ETDEWEB)

    Lilius, K; Jokilaakso, A; Ahokainen, T; Teppo, O; Yongxiang, Yang [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Materials Processing and Powder Metallurgy

    1997-12-31

    An industrial-scale flash smelting furnace and waste-heat boilers have been modelled by using commercial Computational-Fluid-Dynamics software. The work has proceeded from cold gas flow to heat transfer, combustion, and two-phase flow simulations. In the present study, the modelling task has been divided into three sub-models: (1) the concentrate burner, (2) the flash smelting furnace (reaction shaft and uptake shaft), and (3) the waste-heat boiler. For the concentrate burner, the flow of the process gas and distribution air together with the concentrate or a feed mixture was simulated. Eulerian - Eulerian approach was used for the carrier gas-phase and the dispersed particle-phase. A large parametric study was carried out by simulating a laboratory scale burner with varying turbulence intensities and then extending the simulations to the industrial scale model. For the flash smelting furnace, the simulation work concentrated on gas and gas-particle two-phase flows, as well as the development of combustion model for sulphide concentrate particles. Both Eulerian and Lagrangian approaches have been utilised in describing the particle phase and the spreading of the concentrate in the reaction shaft as well as the particle tracks have been obtained. Combustion of sulphides was first approximated with gaseous combustion by using a built-in combustion model of the software. The real oxidation reactions of the concentrate particles were then coded as a user-defined sub-routine and that was tested with industrial flash smelting cases. For the waste-heat boiler, both flow and heat transfer calculations have been carried out for an old boiler and a modified boiler SULA 2 Research Programme; 23 refs.

  8. Nonmetallic inclusions in carbon steel smelted in plasma furnace

    Energy Technology Data Exchange (ETDEWEB)

    Shengelaya, I B; Kostyakov, V N; Nodiy, T K; Imerlishvili, V G; Gavisiani, A G [AN Gruzinskoj SSR, Tbilisi. Inst. Metallurgii

    1979-01-01

    A complex investigation on nonmetallic inclusions in carbon cast iron, smelted in plasma furnace in argon atmosphere and cast partly in the air and partly in argon atmosphere, has been carried out. As compared to open-hearth furnace carbon steel, the test metal was found to contain more oxide inclusions and nitrides; besides, in chromium-containing metal, chromium nitrides form the larger part of nitrides.

  9. Optimization of suspension smelting technology by computer simulation

    Energy Technology Data Exchange (ETDEWEB)

    Lilius, K.; Jokilaakso, A.; Ahokainen, T.; Teppo, O.; Yang Yongxiang [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Materials Processing and Powder Metallurgy

    1996-12-31

    An industrial-scale flash smelting furnace and waste-heat boilers have been modelled by using commercial Computational-Fluid-Dynamics software. The work has proceeded from cold gas flow to heat transfer, combustion, and two-phase flow simulations. In the present study, the modelling task has been divided into three sub-models: (1) the concentrate burner, (2) the flash smelting furnace (reaction shaft and uptake shaft), and (3) the waste-heat boiler. For the concentrate burner, the flow of the process gas and distribution air together with the concentrate or a feed mixture was simulated. Eulerian - Eulerian approach was used for the carrier gas-phase and the dispersed particle-phase. A large parametric study was carried out by simulating a laboratory scale burner with varying turbulence intensities and then extending the simulations to the industrial scale model. For the flash smelting furnace, the simulation work concentrated on gas and gas-particle two-phase flows, as well as the development of combustion model for sulphide concentrate particles. Both Eulerian and Lagrangian approaches have been utilised in describing the particle phase and the spreading of the concentrate in the reaction shaft as well as the particle tracks have been obtained. Combustion of sulphides was first approximated with gaseous combustion by using a built-in combustion model of the software. The real oxidation reactions of the concentrate particles were then coded as a user-defined sub-routine and that was tested with industrial flash smelting cases. For the waste-heat boiler, both flow and heat transfer calculations have been carried out for an old boiler and a modified boiler SULA 2 Research Programme; 23 refs.

  10. Design requirements for a metal-smelting facility

    International Nuclear Information System (INIS)

    Williams, L.C.; Mack, J.E.

    1982-01-01

    Functional requirements for the smelting of metal scrap contaminated with low-enriched uranium in a Metal Smelting Faclity (MSF) have been determined. The process will be designed to smelt ferrous metal scrap that has accumulated at the Oak Ridge Gaseous Diffusion Plant (ORGDP) into one-ton ingots at a rate of 40 ingots per day (10,000 tons/year). Total scrap inventories at the ORGDP are currently estimated at 28,000 tons. The diffusion plant scrap is primarily contaminated with 100 to 200 ppm U at an enrichment of 0.5 to 1.5% 235 U. The scrap is considered special nuclear material (SNM) and cannot be handled by commercial smelters without specific licensing. Slagging will be performed to remove contaminants from the metal and concentrate them in the slag. Process systems will include scrap handling, size reduction, preheating and charging, melting and slagging, ingot casting and storage, and fume exhaust. The MSF has been proposed for FY 1984 line item funding

  11. Extracting phosphoric iron under laboratorial conditions smelting bog iron ores

    International Nuclear Information System (INIS)

    Török, B; Thiele, A

    2013-01-01

    In recent years it has been indicated by archaeometric investigations that phosphoric-iron (P-iron, low carbon steel with 0,5-1,5wt% P), which is an unknown and unused kind of steel in the modern industry, was widely used in different parts of the world in medieval times. In this study we try to explore the role of phosphorus in the arhaeometallurgy of iron and answer some questions regarding the smelting bog iron ores with high P-content. XRF analyses were performed on bog iron ores collected in Somogy county. Smelting experiments were carried out on bog iron ores using a laboratory model built on the basis of previously conducted reconstructed smelting experiments in copies of excavated furnaces. The effect of technological parameters on P-content of the resulted iron bloom was studied. OM and SEM-EDS analyses were carried out on the extracted iron and slag samples. On the basis of the material analyses it can be stated that P-iron is usually extracted but the P-content is highly affected by technological parameters. Typical microstructures of P-iron and of slag could also be identified. It could also be established that arsenic usually solved in high content in iron as well

  12. Directly smelted lead-tin alloys: A historical perspective

    Science.gov (United States)

    Dube, R. K.

    2010-08-01

    This paper discusses evidence related to the genesis and occurrence of mixed lead-tin ore deposit consisting of cassiterite and the secondary minerals formed from galena. These evidences belong to a very long time period ranging from pre-historic to as late as the nineteenth century a.d. This type of mixed ore deposits was smelted to prepare lead-tin alloys. The composition of the alloy depended on the composition of the starting ore mixture. A nineteenth century evidence for the production of directly smelted lead-tin alloys in southern Thailand is discussed. A unique and rather uncommon metallurgical terminology in Sanskrit language— Nāgaja—was introduced in India for the tin recovered from impure lead. This suggests that Indians developed a process for recovering tin from lead-tin alloys, which in all probability was based on the general principle of fire refining. It has been shown that in the context of India the possibility of connection between the word Nāgaja and the directly smelted lead-tin alloys cannot be ruled out.

  13. Designing of Synergistic Waste Mixtures for Multiphase Reactive Smelting

    Directory of Open Access Journals (Sweden)

    Vaso Manojlović

    2016-06-01

    Full Text Available Electric arc furnace (EAF dust, together with a mill scale and coke were smelted in a laboratory electric arc furnace. These metallurgical wastes consist of a many different phases and elements, making the reaction process complex. Thermo-chemical analysis of the reactions in metal, slag, and gas phases was done, and used for modeling of the mixture composition and energy consumption required for smelting. Modelling was performed with the software named RikiAlC. The crude ZnO, slag, and metal phase were analyzed using the atomic absorption spectrometry (AAS, the optical emission spectrometry with inductively coupled plasma (ICP-OES, the X-ray diffraction (XRD, the scanning electron microscopy (SEM equipped with energy dispersive spectrometry (EDS, and reflected and transmitted light microscopy. Also, in order to follow the behavior of this process the exhausted gases were monitored. The synergetic effects of the designed mixture may be recognized in minimizing energy consumption for the smelting process, improving the product yield efficiency, and reducing the negative environmental effects.

  14. Tu Salud, ¡Si Cuenta!: Exposure to a community-wide campaign and its associations with physical activity and fruit and vegetable consumption among individuals of Mexican descent.

    Science.gov (United States)

    Reininger, Belinda M; Mitchell-Bennett, Lisa; Lee, MinJae; Gowen, Rose Z; Barroso, Cristina S; Gay, Jennifer L; Saldana, Mayra Vanessa

    2015-10-01

    Mexican Americans along the US-Mexico border have been found to be disproportionately affected by chronic diseases particularly related to lack of physical activity and healthful food choices. A community-wide campaign (CWC) is an evidence-based strategy to address these behaviors but with few examples of implementation in Mexican descent populations facing profound health disparities. We examined exposure to a CWC, titled Tu Salud ¡Sí Cuenta!, and its association with meeting the recommended minutes of moderate and vigorous physical activity weekly and consuming more portions of fruits and vegetables daily. A cross-sectional sample of 1438 Mexican descent participants was drawn from a city-wide, randomly-selected cohort interviewed between the years 2008 and 2012. Multivariable comparisons of participants exposed and not exposed to the CWC and meeting physical activity guidelines or their fruit and vegetable consumptions using mixed effects models were conducted. The community-wide campaign components included different forms of mass media and individually-focused components such as community health worker (CHW) home visits. After adjusting for gender, age, marital status, educational attainment, language preference, health insurance, and diabetes diagnosis, the strongest association was found between meeting physical activity guidelines and exposure to both CHW discussions and radio messages (adjusted OR = 3.83; 95% CI = [1.28, 6.21]; p = 0.0099). Participants who reported exposure to both radio and TV messages consumed more portions of fruits and vegetables than those who reported no exposure (adjusted RR = 1.30; 95% CI = [1.02, 1.66]; p = 0.0338). This study provides insights into the implementation and behavioral outcomes associated with exposure to a community-wide campaign, a potential model for addressing lifestyle modifications in populations affected by health disparities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Mercury distribution characteristics in primary manganese smelting plants

    International Nuclear Information System (INIS)

    Back, Seung-Ki; Sung, Jin-Ho; Moon, Young-Hoon; Kim, Young-Hee; Seok, Kwang-Seol; Song, Geum-Ju; Seo, Yong-Chil

    2017-01-01

    The mercury (Hg) distribution characteristics were investigated in three primary manganese smelting plants in Korea for the assessment of anthropogenic Hg released. Input and output materials were sampled from each process, and Hg concentrations in the samples were analyzed. Among the input materials, the most mercury was found in the manganese ore (83.1–99.7%) and mercury was mainly released through fly ash or off gas, depending on the condition of off gas cleaning system. As off gas temperature decreases, proportion and concentration of emitted gaseous elemental mercury (Hg 0 ) in off gas decreases. Based on mass balance study from these three plants and national manganese production data, the total amount of mercury released from those Korean plants was estimated to 644 kg/yr. About half of it was emitted into the air while the rest was released to waste as fly ash. With the results of this investigation, national inventory for Hg emission and release could be updated for the response to Minamata Convention on Mercury. - Graphical abstract: 1. Lack of data on mercury (Hg) distribution in manganese smelters. 2. Mass distribution of Hg released from 3 plants (as normalized values) were made as follows by measurements. 3. Information of distribution of Hg in Manganese smelters would be used for emission in to air and releases to other streams for the nation and globe in UNEP mercury report. - Highlights: • The mass balance study by on-site measurement from primary manganese smelting plants was made at first time in the world. • Hg distribution and main input and release pathways of Hg from primary manganese smelting plants could be found as the first time. • Gas temperature in bag filter affects Hg behavior and speciation changes in APCDs. • National inventory of Hg emssion has been updated with new data. - Mercury distribution in manganese smelting plant was investigated as the first measurements at commercial plants in the world. National Hg release

  16. Mexican Parenting Questionnaire (MPQ)

    Science.gov (United States)

    Halgunseth, Linda C.; Ispa, Jean M.

    2012-01-01

    The present study was conducted in four phases and constructed a self-report parenting instrument for use with Mexican immigrant mothers of children aged 6 to 10. The 14-item measure was based on semistructured qualitative interviews with Mexican immigrant mothers (N = 10), was refined by a focus group of Mexican immigrant mothers (N = 5), and was…

  17. VNTR polymorphisms of the IL-4 and IL-1RN genes and their relationship with frailty syndrome in Mexican community-dwelling elderly.

    Science.gov (United States)

    Pérez-Suárez, Thalía Gabriela; Gutiérrez-Robledo, Luis Miguel; Ávila-Funes, José Alberto; Acosta, José Luis; Escamilla-Tilch, Mónica; Padilla-Gutiérrez, Jorge Ramón; Torres-Carrillo, Norma; Torres-Castro, Sara; López-Ortega, Mariana; Muñoz-Valle, José Francisco; Torres-Carrillo, Nora Magdalena

    2016-10-01

    Inflammation is a key event that is closely associated with the pathophysiology of frailty. The relationship of genetic polymorphisms into inflammatory cytokines with frailty remains poorly understood. The aim of this study was to investigate the association between VNTR polymorphisms of the IL-4 and IL-1RN genes with the risk of frailty. We included a sample of 630 community-dwelling elderly aged 70 and older. Both IL-4 and IL-1RN VNTR polymorphisms were genotyped by the polymerase chain reaction (PCR) method. Mean age was 77.7 years (SD = 6.0) and 52.5 % were women. The participants classified as frail were more likely to be older, had lower MMSE score (p VNTR polymorphism did not show significant differences between study groups (p > 0.05). However, we just observed a significant difference in the allelic frequencies for the A2 allele of the IL-1RN VNTR polymorphism between frail and nonfrail groups (OR 1.84, 95 % CI 1.08-3.12, p = 0.02). In addition, we analyzed the combined effect of the IL-4 and IL-1RN VNTR polymorphisms and their possible association with frailty, where the combined IL-4 (low) -IL-1Ra (high) genotype was identified as a marker of risk to frailty syndrome (OR 7.86, 95 % CI 1.83-33.69, p = 0.006). Our results suggest that both A2 allele and the combined IL-4 (low) -IL-1Ra (high) genotype might be genetic markers of susceptibility to frailty in Mexican elderly.

  18. "American" Abjection: "Chicanos," Gangs, and Mexican/Migrant Transnationality in Chicago

    Science.gov (United States)

    De Genova, Nicholas

    2008-01-01

    Crime and street violence often evoke racialized discourses about urban space. In this ethnographic research in Chicago, however, the disdain that many Mexican migrants articulated about street gangs principally concerned issues "internal" to the Mexican/Chicano community, notably a profound ambivalence about U.S.-born Mexicans and a…

  19. Come bien, camina y no se preocupe--eat right, walk, and do not worry: selective biculturalism during pregnancy in a Mexican American community.

    Science.gov (United States)

    Laganá, Kathleen

    2003-04-01

    Mexican American childbearing women appear to offer a healthy model for pregnancy. However, statistics suggest that they may be at increased risk for poor birth outcome as they acculturate to a U.S. lifestyle. An ethnographic study in Watsonville, California, examined the influence of acculturation on pregnancy beliefs and practices of 29 Mexican American childbearing women. Data from formal semi-structured interviews were submitted to content analysis. During pregnancy, women balanced well-documented, traditional Mexican cultural beliefs with the individualistic beliefs common to Anglo-Americans. Selective biculturalism emerged as a protective approach to stress reduction and health promotion. Stress reduction interventions as part of routine prenatal care have potential benefit for all pregnant women. Future research on cultural barriers to family-based social support during pregnancy is needed.

  20. Ecological factors affecting Rainbow Smelt recruitment in the main basin of Lake Huron, 1976-2010

    Science.gov (United States)

    O'Brien, Timothy P.; Taylor, William W.; Roseman, Edward F.; Madenjian, Charles P.; Riley, Stephen C.

    2014-01-01

    Rainbow Smelt Osmerus mordax are native to northeastern Atlantic and Pacific–Arctic drainages and have been widely introduced throughout North America. In the Great Lakes region, Rainbow Smelt are known predators and competitors of native fish and a primary prey species in pelagic food webs. Despite their widespread distribution, importance as a prey species, and potential to negatively interact with native fish species, there is limited information concerning stock–recruitment relationships for Rainbow Smelt. To better understand recruitment mechanisms, we evaluated potential ecological factors determining recruitment dynamics for Rainbow Smelt in Lake Huron using data from bottom trawl catches. We specifically evaluated influence of stock size, environmental factors (water temperature, lake levels, and precipitation), and salmonine predation on the production of age-0 recruits from 1976 to 2010. Rainbow Smelt recruitment was negatively related to stock size exceeding 10 kg/ha, indicating that compensatory, density-dependent mortality from cannibalism or intraspecific competition was an important factor related to the production of age-0 recruits. Recruitment was positively related to spring precipitation suggesting that the amount of stream-spawning habitat as determined by precipitation was important for the production of strong Rainbow Smelt recruitment. Additionally, density of age-0 Rainbow Smelt was positively related to Lake Trout Salvelinus namaycush abundance. However, spawning stock biomass of Rainbow Smelt, which declined substantially from 1989 to 2010, was negatively associated with Lake Trout catch per effort suggesting predation was an important factor related to the decline of age-2 and older Rainbow Smelt in Lake Huron. As such, we found that recruitment of Rainbow Smelt in Lake Huron was regulated by competition with or cannibalism by older conspecifics, spring precipitation influencing stream spawning habitats, and predation by Lake Trout on

  1. Human papillomavirus 13 in a Mexican Mayan community with multifocal epithelial hyperplasia: could saliva be involved in household transmission?

    Science.gov (United States)

    Lopez-Villanueva, Maria Eugenia; Conde-Ferráez, Laura; Ayora-Talavera, Guadalupe; Cerón-Espinosa, Jose D; González-Losa, Maria del Refugio

    2011-01-01

    Multifocal epithelial hyperplasia (MEH) is a disease of the oral mucosa. Human papillomaviruses 13 and 32 have been detected in these lesions. We describe the epidemiology and clinical characteristics of patients with MEH in a rural community in the Mayan area of Mexico with 53 cases and 54 controls. Clinical and epidemiological data were collected through a direct interview. Oral cell samples were collected with a cytobrush. Subjects collected their own saliva sample in a sterile bottle. All samples were tested for HPV 13 and 32 by polymerase chain reaction using specific primers. Of the 53 patients and 54 healthy subjects, 56% were < 12 years old, 25% were males and 75% females. Evolution of the lesions was between two months and 17 years. The lesions affected lips, jugal mucosa, and tongue, 96% had multiple lesions. From 53 patients, fifty samples of oral cells and 31 samples of saliva were analyzed. HPV 13 was detected in 100% oral cell and 100% saliva samples studied. 16 healthy subjects were HVP 13 positive. A highly significant association of HPV 13 infection and MEH was found, as determined by chi square test (p = 0.00) Household transmission of HPV 13 may happen through saliva and the shared use of contaminated objects.

  2. Moessbauer study of ancient iron smelting slag in Japan

    International Nuclear Information System (INIS)

    Nakanishi, A.

    2008-01-01

    For an investigation of the ancient iron manufacturing technique, a reproducing experiment was carried out by archaeologists, where ancient type of iron smelting furnace was built and iron sand with high titanium contents was used as the raw material. During the operation of furnace, a large amount of slag flowed away from the furnace. In order to investigate the possibility for the estimation about the operative condition of furnace and the raw material, 57 Fe Moessbauer spectroscopy was applied for characterizing these slags and it was found that these slags mainly consisted of ferropseudobrookite (FeTi 2 O 5 ).

  3. State of the art of smelting lead-acid battery scrap

    Energy Technology Data Exchange (ETDEWEB)

    Melin, A

    1977-02-01

    A discussion is given of the economic importance of lead recovery and of scrap recycling in the battery industry. Various possibiliies of processing battery scrap, either by direct smelting or by smelting after preparaton are discussed, and the BBU, the Stolberger, and the Tonnolli methods are compared

  4. The Family Festival Prevention Model: Findings from a Pilot of a Teenage Pregnancy Prevention Programme Conceptualised by and for Mexican American Communities

    Science.gov (United States)

    Murphy-Erby, Yvette; Stauss, Kim; Koh, Eun

    2015-01-01

    Despite an overall reduction in teenage pregnancy rates in the USA, the decrease for young women of Mexican heritage in the USA has been less significant than the decrease for their White and African-American peers. Furthermore, the availability of teenage pregnancy prevention models that are conceptualised specifically for people of Mexican…

  5. Copper smelting and sediment pollution in Bronze Age China.

    Science.gov (United States)

    Zhang, S.; Dong, G.

    2017-12-01

    The emergence and diffusion of metallurgical technology had tremendous environmental consequence, however, the spatial-temporal consequences of the metallurgy during Bronze Age are not clear in China. Here, Xray fluorescence (XRF) measurement and principal component analysis (PCA) were conducted on heavy metal element (Cu, Ni, Pb, Zn, Cr and As) concentrations (HMEC) of natural and anthropogenic sediment samples systematically collected from 22 late Neolithic-Bronze Age sites in Hexi corridor to explore the potential for subcontinental-wide changes in soil geochemistry. We place this data within the context of the Cu concentrations in lacustrine sediments located near smelting and mining centers in Bronze Age China. Our results show that variation of HMEC in anthropogenic sediment in Hexi corridor is contemporaneous with the increases of the Cu concentrations in lacustrine sediment around 4000 BP. Comparative data suggests the metallurgical production diffused from the Hexi corridor to central and southwestern China around 3600 BP. We argue that sediment pollution is not an isolated phenomenon during the Bronze Age China, but rather occurred on regional scales and is closely related to the intensity of smelting activities.

  6. Preparation of Inconel 740 superalloy by electron beam smelting

    Energy Technology Data Exchange (ETDEWEB)

    You, Xiaogang [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Tan, Yi, E-mail: tanyi@dlut.edu.cn [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); You, Qifan; Shi, Shuang; Li, Jiayan [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Ye, Fei [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Wei, Xin [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China)

    2016-08-15

    A novel method, namely electron beam smelting (EBS) technology was used to prepare the Inconel 740 superalloy. The microstructures, hardness and oxidation behavior were characterized and compared with the traditionally prepared Inconel 740 superalloy. The results imply that the solution treatment gives rise to the coarsening of γ′ precipitates, with further aging treatment, the γ′ precipitates with size of less than 30 nm are distributed dispersively in the matrix, leading to a decreasing of the lattice parameters and an increasing of the misfit. The γ′ precipitates result in shearing mechanism of weakly pair coupling. The EBS 740 superalloy produces better properties than that prepared in the traditional method in both precipitation strengthening effect and oxidation resistance. - Highlights: • Electron beam smelting, a new method, was used to prepare the Inconel 740 superalloy. • The EBS 740 shows higher strengthening effect than 740 made in traditional method. • The EBS 740 shows better oxidation resistance than traditional 740. • It shows application prospect of EBS technology in preparing Ni-base superalloys.

  7. Mexican Society of Bioelectromagnetism

    International Nuclear Information System (INIS)

    Canedo, Luis

    2008-01-01

    In July 2007 physicians, biologists and physicists that have collaborated in previous meetings of the medical branch of the Mexican Physical Society constituted the Mexican Society of Bioelectromagnetism with the purpose of promote scientific study of the interaction of electromagnetic energy (at frequencies ranging from zero Hertz through those of visible light) and acoustic energy with biological systems. A second goal was to increase the contribution of medical and biological professionals in the meetings of the medical branch of the Mexican Physical Society. The following paragraphs summarize some objectives of the Mexican Society of Bioelectromagnetism for the next two years

  8. Enrichment of Gold in Antimony Matte by Direct Smelting of Refractory Gold Concentrate

    Science.gov (United States)

    Yang, Tianzu; Xie, Boyi; Liu, Weifeng; Zhang, Duchao; Chen, Lin

    2018-04-01

    Conventional cyanidation technology achieves low gold recovery when used to process refractory gold concentrate. Based on the geochemical characteristics of gold deposit mineralization, a new method is proposed herein for gold enrichment in antimony matte by smelting of refractory gold concentrate. The effects of the FeO/SiO2 and CaO/SiO2 ratios, smelting temperature, and smelting time on the gold recovery were investigated in detail. The optimum conditions were determined to be FeO/SiO2 ratio of 1.2, CaO/SiO2 ratio of 0.4, smelting temperature of 1200°C, and smelting time of 45 min. The gold content in antimony matte and smelting slag was 96.68 and 1.13 g/t, respectively. The gold, antimony, and arsenic recovery was 97.72%, 26.89%, and 6.56%, respectively, with most of the antimony and arsenic volatilized into dust. Mineral liberation analyzer results showed that the antimony matte mainly consisted of FeS and FeO, with three phases, viz. FeAs, SbAs, and AuSb, embedded between them, indicating that gold was easily enriched with antimony and arsenic during smelting of refractory gold concentrate.

  9. Enrichment of Gold in Antimony Matte by Direct Smelting of Refractory Gold Concentrate

    Science.gov (United States)

    Yang, Tianzu; Xie, Boyi; Liu, Weifeng; Zhang, Duchao; Chen, Lin

    2018-06-01

    Conventional cyanidation technology achieves low gold recovery when used to process refractory gold concentrate. Based on the geochemical characteristics of gold deposit mineralization, a new method is proposed herein for gold enrichment in antimony matte by smelting of refractory gold concentrate. The effects of the FeO/SiO2 and CaO/SiO2 ratios, smelting temperature, and smelting time on the gold recovery were investigated in detail. The optimum conditions were determined to be FeO/SiO2 ratio of 1.2, CaO/SiO2 ratio of 0.4, smelting temperature of 1200°C, and smelting time of 45 min. The gold content in antimony matte and smelting slag was 96.68 and 1.13 g/t, respectively. The gold, antimony, and arsenic recovery was 97.72%, 26.89%, and 6.56%, respectively, with most of the antimony and arsenic volatilized into dust. Mineral liberation analyzer results showed that the antimony matte mainly consisted of FeS and FeO, with three phases, viz. FeAs, SbAs, and AuSb, embedded between them, indicating that gold was easily enriched with antimony and arsenic during smelting of refractory gold concentrate.

  10. Explanatory Emotion Talk in Mexican Immigrant and Mexican American Families.

    Science.gov (United States)

    Cervantes, Christi A.

    2002-01-01

    Mother-child conversations during story-telling play were analyzed for patterns of emotion talk. Subjects were 48 Mexican immigrant and Mexican American mothers and their children aged 3-4. Contrary to previous findings, Mexican immigrant mothers used more explanations of emotions than labels. Mexican American mothers used both, equally. Results…

  11. Adaptive PCA based fault diagnosis scheme in imperial smelting process.

    Science.gov (United States)

    Hu, Zhikun; Chen, Zhiwen; Gui, Weihua; Jiang, Bin

    2014-09-01

    In this paper, an adaptive fault detection scheme based on a recursive principal component analysis (PCA) is proposed to deal with the problem of false alarm due to normal process changes in real process. Our further study is also dedicated to develop a fault isolation approach based on Generalized Likelihood Ratio (GLR) test and Singular Value Decomposition (SVD) which is one of general techniques of PCA, on which the off-set and scaling fault can be easily isolated with explicit off-set fault direction and scaling fault classification. The identification of off-set and scaling fault is also applied. The complete scheme of PCA-based fault diagnosis procedure is proposed. The proposed scheme is first applied to Imperial Smelting Process, and the results show that the proposed strategies can be able to mitigate false alarms and isolate faults efficiently. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  12. Mexican Perspectives on Mexican-U.S. Relations

    Science.gov (United States)

    1993-04-01

    while serving in the United States military, working in the Bracero program and in American factories. By working with Americans, Mexicans learned that...Mexican government blames the problem on the United States. During the history of the Bracero Program (1942 -1964) 4.6 million Mexicans traveled to...and became familiar to Mexican migrants.ŕ The termination of the Bracero Program did not discourage Mexican agricultural workers from entering the

  13. The Mexican oil industry

    International Nuclear Information System (INIS)

    Marcos-Giacoman, E.

    1991-01-01

    In the environment of growing domestic demand and enhanced international competitiveness, Petroleos Mexicanos (PEMEX)-the Mexican national oil company-faces the challenge of not only responding adequately to the rapid changes taking place in the Mexican economy, but making a significant contribution towards solid and stable growth. This paper reports that the relevant concern is how PEMEX is going to live up to these expectations. The Mexican oil industry, especially including the petrochemical sector, has great potential in terms of an ample domestic market as well as external foreign-currency-generating markets

  14. Delta smelt: Life history and decline of a once abundant species in the San Francisco Estuary

    Science.gov (United States)

    Moyle, Peter B.; Brown, Larry R.; Durand, John R; Hobbs, James A.

    2016-01-01

    This paper reviews what has been learned about Delta Smelt and its status since the publication of The State of Bay-Delta Science, 2008 (Healey et al. 2008). The Delta Smelt is endemic to the upper San Francisco Estuary. Much of its historic habitat is no longer available and remaining habitat is increasingly unable to sustain the population. As a listed species living in the central node of California’s water supply system, Delta Smelt has been the focus of a large research effort to understand causes of decline and identify ways to recover the species. Since 2008, a remarkable record of innovative research on Delta Smelt has been achieved, which is summarized here. Unfortunately, research has not prevented the smelt’s continued decline, which is the result of multiple, interacting factors. A major driver of decline is change to the Delta ecosystem from water exports, resulting in reduced outflows and high levels of entrainment in the large pumps of the South Delta. Invasions of alien species, encouraged by environmental change, have also played a contributing role in the decline. Severe drought effects have pushed Delta Smelt to record low levels in 2014–2015. The rapid decline of the species and failure of recovery efforts demonstrate an inability to manage the Delta for the “co-equal goals” of maintaining a healthy ecosystem and providing a reliable water supply for Californians. Diverse and substantial management actions are needed to preserve Delta Smelt.

  15. Patterns of recruitment of the sand smelt (Atherina presbyter on rocky intertidal habitats

    Directory of Open Access Journals (Sweden)

    Frederico Almada

    2015-11-01

    frequency of extremely cold events, becoming more common the occurrence of extremely hot events and fast temperature variations. As sand smelt is one of the most abundant cold/temperate fish species in temperate waters and a common prey item of many piscivorous species, a reduction of its reproductive success may unbalance food web relationships in temperate coastal communities and affect local fisheries economy.

  16. Study of the ancient iron-smelting sites at Pantaki, Tsauni and Samaru-west, Nigeria, using neutron activation analysis

    International Nuclear Information System (INIS)

    Oladipupo, M.D.; OIadipo, M.O.A.; Mallam, S.P.; Akpa, T.C.

    2010-01-01

    Neutron activation analysis was used to obtain concentrations of some elements in samples of potsherds and furnaces obtained from Pantaki, Tsauni and Samaru-west ancient iron-smelting sites. Using WARD method, cluster analysis of the elements was carried out to establish the relationship between the archaeological samples in term of similarity in elemental concentrations. It was found that there is some level of similarity among the potsherd samples from the three sites. Also, most of furnace samples display some similarity. It was established that there was cultural linkage between the iron-smelters at the different sites. The similarity between the samples lead to a conclusion that pot makers and furnace makers could have existed, who obtained clays from common sources, made and sold the products to users in different communities.

  17. Mercury distribution characteristics in primary manganese smelting plants.

    Science.gov (United States)

    Back, Seung-Ki; Sung, Jin-Ho; Moon, Young-Hoon; Kim, Young-Hee; Seok, Kwang-Seol; Song, Geum-Ju; Seo, Yong-Chil

    2017-08-01

    The mercury (Hg) distribution characteristics were investigated in three primary manganese smelting plants in Korea for the assessment of anthropogenic Hg released. Input and output materials were sampled from each process, and Hg concentrations in the samples were analyzed. Among the input materials, the most mercury was found in the manganese ore (83.1-99.7%) and mercury was mainly released through fly ash or off gas, depending on the condition of off gas cleaning system. As off gas temperature decreases, proportion and concentration of emitted gaseous elemental mercury (Hg 0 ) in off gas decreases. Based on mass balance study from these three plants and national manganese production data, the total amount of mercury released from those Korean plants was estimated to 644 kg/yr. About half of it was emitted into the air while the rest was released to waste as fly ash. With the results of this investigation, national inventory for Hg emission and release could be updated for the response to Minamata Convention on Mercury. Copyright © 2017. Published by Elsevier Ltd.

  18. The Diffusion of Mexican Immigrants During the 1990s: Explanations and Impacts

    OpenAIRE

    David Card; Ethan G. Lewis

    2005-01-01

    Mexican immigrants were historically clustered in a few cities, mainly in California and Texas. During the past 15 years, however, arrivals from Mexico established sizeable immigrant communities in many "new" cities. We explore the causes and consequences of the widening geographic diffusion of Mexican immigrants. A combination of demand-pull and supply push factors explains most of the inter-city variation in inflows of Mexican immigrants over the 1990s, and also illuminates the most importa...

  19. An updated conceptual model of Delta Smelt biology: Our evolving understanding of an estuarine fish

    Science.gov (United States)

    Baxter, Randy; Brown, Larry R.; Castillo, Gonzalo; Conrad, Louise; Culberson, Steven D.; Dekar, Matthew P.; Dekar, Melissa; Feyrer, Frederick; Hunt, Thaddeus; Jones, Kristopher; Kirsch, Joseph; Mueller-Solger, Anke; Nobriga, Matthew; Slater, Steven B.; Sommer, Ted; Souza, Kelly; Erickson, Gregg; Fong, Stephanie; Gehrts, Karen; Grimaldo, Lenny; Herbold, Bruce

    2015-01-01

    The main purpose of this report is to provide an up-to-date assessment and conceptual model of factors affecting Delta Smelt (Hypomesus transpacificus) throughout its primarily annual life cycle and to demonstrate how this conceptual model can be used for scientific and management purposes. The Delta Smelt is a small estuarine fish that only occurs in the San Francisco Estuary. Once abundant, it is now rare and has been protected under the federal and California Endangered Species Acts since 1993. The Delta Smelt listing was related to a step decline in the early 1980s; however, population abundance decreased even further with the onset of the “pelagic organism decline” (POD) around 2002. A substantial, albeit short-lived, increase in abundance of all life stages in 2011 showed that the Delta Smelt population can still rebound when conditions are favorable for spawning, growth, and survival. In this report, we update previous conceptual models for Delta Smelt to reflect new data and information since the release of the last synthesis report about the POD by the Interagency Ecological Program for the San Francisco Estuary (IEP) in 2010. Specific objectives include:

  20. Reaction Mechanism and Distribution Behavior of Arsenic in the Bottom Blown Copper Smelting Process

    Directory of Open Access Journals (Sweden)

    Qinmeng Wang

    2017-08-01

    Full Text Available The control of arsenic, a toxic and carcinogenic element, is an important issue for all copper smelters. In this work, the reaction mechanism and distribution behavior of arsenic in the bottom blown copper smelting process (SKS process were investigated and compared to the flash smelting process. There are obvious differences of arsenic distribution in the SKS process and flash process, resulting from the differences of oxygen potentials, volatilizations, smelting temperatures, reaction intensities, and mass transfer processes. Under stable production conditions, the distributions of arsenic among matte, slag, and gas phases are 6%, 12%, and 82%, respectively. Less arsenic is reported in the gas phase with the flash process than with the SKS process. The main arsenic species in gas phase are AsS (g, AsO (g, and As2 (g. Arsenic exists in the slag predominantly as As2O3 (l, and in matte as As (l. High matte grade is harmful to the elimination of arsenic to gas. The changing of Fe/SiO2 has slight effects on the distributions of arsenic. In order to enhance the removal of arsenic from the SKS smelting system to the gas phase, low oxygen concentration, low ratios of oxygen/ore, and low matte grade should be chosen. In the SKS smelting process, no dust is recycled, and almost all dust is collected and further treated to eliminate arsenic and recover valuable metals by other process streams.

  1. Mathematical model of whole-process calculation for bottom-blowing copper smelting

    Science.gov (United States)

    Li, Ming-zhou; Zhou, Jie-min; Tong, Chang-ren; Zhang, Wen-hai; Li, He-song

    2017-11-01

    The distribution law of materials in smelting products is key to cost accounting and contaminant control. Regardless, the distribution law is difficult to determine quickly and accurately by mere sampling and analysis. Mathematical models for material and heat balance in bottom-blowing smelting, converting, anode furnace refining, and electrolytic refining were established based on the principles of material (element) conservation, energy conservation, and control index constraint in copper bottom-blowing smelting. Simulation of the entire process of bottom-blowing copper smelting was established using a self-developed MetCal software platform. A whole-process simulation for an enterprise in China was then conducted. Results indicated that the quantity and composition information of unknown materials, as well as heat balance information, can be quickly calculated using the model. Comparison of production data revealed that the model can basically reflect the distribution law of the materials in bottom-blowing copper smelting. This finding provides theoretical guidance for mastering the performance of the entire process.

  2. The Relation between Maternal and Child Depression in Mexican American Families

    Science.gov (United States)

    Corona, Marissa; McCarty, Carolyn; Cauce, Ana Mari; Robins, Richard W.; Widaman, Keith F.; Conger, Rand D.

    2012-01-01

    In an effort to better understand possible pathways that lead to a relatively high incidence of depressive symptoms among Mexican American youth, an interpersonal stress model of depression was tested using a community sample of 674 Mexican American mothers and their 5th grade children. Structural equation analyses revealed that maternal…

  3. Chicano-Mexican Cultural Assimilation and Anglo-Saxon Cultural Dominance.

    Science.gov (United States)

    Menchaca, Martha

    1989-01-01

    Examines cultural assimilation in a Mexican and Chicano community in Santa Paula, California. Argues that the assumption of Anglo-Saxon superiority ascribed inferior social positions to Mexican-origin groups and generated conflict among these groups at times, but promoted intergroup unity when social conditions became intolerable. Contains 39…

  4. Reproductive habitus, psychosocial health, and birth weight variation in Mexican immigrant and Mexican American women in south Texas.

    Science.gov (United States)

    Fleuriet, K Jill; Sunil, T S

    2015-08-01

    The Latina Paradox, or persistent, unexplained variation in low birth weight rates in recently immigrated Mexican women and the trend toward higher rates in subsequent generations of Mexican American women, is most often attributed to unidentified sociocultural causes. We suggest herein that different disciplinary approaches can be synthesized under the constructs of reproductive habitus and subjective social status to identify influences of sociocultural processes on birth weight. Reproductive habitus are "modes of living the reproductive body, bodily practices, and the creation of new subjects through interactions between people and structures" (Smith-Oka, 2012: 2276). Subjective social status infers comparison of self to others based on community definitions of status or socioeconomic status (Adler 2007). We present results from a prospective study of low-income Mexican immigrant and Mexican American women from south Texas that tested the ability of reproductive habitus and subjective social status to elucidate the Latina Paradox. We hypothesized that reproductive habitus between Mexican immigrant women and Mexican American women inform different subjective social statuses during pregnancy, and different subjective social statuses mediate responses to psychosocial stressors known to correlate with low birth weight. Six hundred thirty-one women were surveyed for psychosocial health, subjective social status, and reproductive histories between 2011 and 2013. Eighty-three women were interviewed between 2012 and 2013 for status during pregnancy, prenatal care practices, and pregnancy narratives and associations. Birth weight was extracted from medical records. Results were mixed. Subjective social status and pregnancy-related anxiety predicted low birth weight in Mexican immigrant but not Mexican American women. Mexican immigrant women had significantly lower subjective social status scores but a distinct reproductive habitus that could explain improved psychosocial

  5. Smelting reduction of MgO in molten slag by liquid ferrosilicon

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Q.; Gao, J.; Chen, X.; Wei, X.

    2016-10-01

    The smelting reduction of magnesium oxide was researched in this paper. The effect of molten slag composition and reduction temperature on percent reduction of magnesium oxide were discussed, and kinetics of smelting reduction of magnesium oxide in molten slag was studied. The results showed that the reduction extent of magnesium oxide increased by increasing either one of the following factors: the initial mass ratio of Al{sub 2}O{sub 3}/SiO{sub 2}, the addition of CaF{sub 2}, the initial molar ratio of Si/2MgO, and reaction temperature. The overall smelting reduction was controlled by mass transfer in slag with an apparent activation energy 586 kJ mol{sup -}1. (Author)

  6. Development and Application of SKSSIM Simulation Software for the Oxygen Bottom Blown Copper Smelting Process

    Directory of Open Access Journals (Sweden)

    Qinmeng Wang

    2017-10-01

    Full Text Available The oxygen bottom blown copper smelting process (SKS process is a newly developed intense smelting process, which has been widely applied to copper production in China. A multiphase equilibrium model for the SKS process was established based on its mechanism characteristics and the principle of Gibbs energy minimization, and an efficient simulation software—SKSSIM (SKS Simulation—was developed based on the model. Industrial data from the SKS process were used to compare with the calculated data from the SKSSIM software. The calculated data on the compositions of slag and matte as well as the distribution ratios of minor elements (such as Pb, Zn, As, Sb and Bi among the slags, mattes and off-gases were in good agreement with the actual plant data. Accordingly, the SKSSIM simulation software has the potentail to be used for the prediction of smelting production and for optimizing the operating parameters of the SKS process.

  7. Energy Consumption in Copper Smelting: A New Asian Horse in the Race

    Science.gov (United States)

    Coursol, P.; Mackey, P. J.; Kapusta, J. P. T.; Valencia, N. Cardona

    2015-05-01

    After a marked improvement in energy consumption in copper smelting during the past few decades, technology development has been slowing down in the Americas and in Europe. Innovation, however, is still required to further reduce energy consumption while complying with stringent environmental regulations. The bottom blowing smelting technology being developed in China shows success and promise. The general configuration of the bath smelting vessel, the design of high-pressure injectors, and the concentrate addition system are described and discussed in this article with respect to those used in other technologies. The bottom blowing technology is shown to be operating at a temperature in the range of 1160-1180°C, which is the lowest reported temperature range for a modern copper smelting process. In this article, it is suggested that top feeding of filter cake concentrate, which is also used in other technologies, has a positive effect in reducing the oxidation potential of the slag ( p(O2)) while increasing the FeS solubility in slag. This reduction in p(O2) lowers the magnetite liquidus of the slag, while the increased solubility of FeS in slag helps toward reaching very low copper levels in flotation slag tailings. The application of high-pressure injectors allows for the use of high levels of oxygen enrichment with no requirements for punching. Using a standard modeling approach from the authors' previous studies, this article discusses these aspects and compares the energy consumption of the bottom blowing technology with that of other leading flash and bath smelting technologies, namely: flash smelting, Noranda/Teniente Converter, TSL (Isasmelt [Glencore Technology Pty. Ltd., Brisbane, Queensland, Australia]/Outotec), and the Mitsubishi Process (Mitsubishi Materials Corporation, Tokyo, Japan).

  8. A study on the smelting of electrolytically reduced spent fuel by using surrogates

    International Nuclear Information System (INIS)

    Hur, Jin-Mok; Jeong, Myoung-Soo; Cho, Soo-Haeng; Seo, Chung-Seok; Park, Seong-Won

    2005-01-01

    A smelting as a part of the advanced spent fuel conditioning process (ACP) was studied by using surrogate materials. Residual salts including LiCl-Li 2 O were successfully separated from the metal components by an evaporation at 950degC. The melting of the metal was characterized, especially by considering the oxidation of the fine metal particles. The operation procedure of the smelting was set up as 1) removal of residual salts, 2) melting of the metal powder, and 3) a solidification of the melted mass to an ingot. (author)

  9. Turbidity and salinity affect feeding performance and physiological stress in the endangered delta smelt.

    Science.gov (United States)

    Hasenbein, Matthias; Komoroske, Lisa M; Connon, Richard E; Geist, Juergen; Fangue, Nann A

    2013-10-01

    Coastal estuaries are among the most heavily impacted ecosystems worldwide with many keystone fauna critically endangered. The delta smelt (Hypomesus transpacificus) is an endangered pelagic fish species endemic to the Sacramento-San Joaquin Estuary in northern California, and is considered as an indicator species for ecosystem health. This ecosystem is characterized by tidal and seasonal gradients in water parameters (e.g., salinity, temperature, and turbidity), but is also subject to altered water-flow regimes due to water extraction. In this study, we evaluated the effects of turbidity and salinity on feeding performance and the stress response of delta smelt because both of these parameters are influenced by water flows through the San Francisco Bay Delta (SFBD) and are known to be of critical importance to the completion of the delta smelt's life cycle. Juvenile delta smelt were exposed to a matrix of turbidities and salinities ranging from 5 to 250 nephelometric turbidity units (NTUs) and 0.2 to 15 parts per thousand (ppt), respectively, for 2 h. Best statistical models using Akaike's Information Criterion supported that increasing turbidities resulted in reduced feeding rates, especially at 250 NTU. In contrast, best explanatory models for gene transcription of sodium-potassium-ATPase (Na/K-ATPase)-an indicator of osmoregulatory stress, hypothalamic pro-opiomelanocortin-a precursor protein to adrenocorticotropic hormone (expressed in response to biological stress), and whole-body cortisol were affected by salinity alone. Only transcription of glutathione-S-transferase, a phase II detoxification enzyme that protects cells against reactive oxygen species, was affected by both salinity and turbidity. Taken together, these data suggest that turbidity is an important determinant of feeding, whereas salinity is an important abiotic factor influencing the cellular stress response in delta smelt. Our data support habitat association studies that have shown greater

  10. Notes from the Field: Acute Mercury Poisoning After Home Gold and Silver Smelting--Iowa, 2014.

    Science.gov (United States)

    Koirala, Samir; Leinenkugel, Kathy

    2015-12-18

    In March 2014, a man, aged 59 years, who lived alone and had been using different smelting techniques viewed on the Internet to recover gold and silver from computer components, was evaluated at a local emergency department for shortness of breath, tremors, anorexia, and generalized weakness. During the smelting processes, he had used hydrogen peroxide, nitric acid, muriatic acid, and sulfuric acid purchased from local stores or Internet retailers. For protection, he wore a military gas mask of unknown type. The mask was used with filter cartridges, but their effectiveness against chemical fumes was not known.

  11. What's Values Got to Do with It? Thriving among Mexican/Mexican American College Students

    Science.gov (United States)

    Morgan Consoli, Melissa L.; Llamas, Jasmín; Consoli, Andrés J.

    2016-01-01

    The authors examined traditional Mexican/Mexican American and perceived U.S. mainstream cultural values as predictors of thriving. One hundred twenty-four (37 men, 87 women) self-identified Mexican/Mexican American college students participated in the study. The traditional Mexican/Mexican American cultural values of family support and religion…

  12. Mexican Folkart for Children.

    Science.gov (United States)

    Dominguez, Graciela; And Others

    Directions, suggested materials, and illustrations are given for making paper mache pinatas and masks, cascarones, Ojos de Dios, maracas, dresser scarf embroidery, burlap murals, yarn designs, paper plate trays, paper cut designs, the poppy, sarape aprons, and paper Mexican dolls. Filled with candy and broken, the pinata is used on most Mexican…

  13. Migration of diadromous and landlocked smelt populations studies by otolith geochemistry

    NARCIS (Netherlands)

    Phung, A.T.; Tulp, I.Y.M.; Baeyens, W.; Elskens, M.; Leermakers, M.; Gao, Y.

    2015-01-01

    Laser ablation inductively coupled mass spectrometry (LA-ICPMS) was used to determine Sr and Ba profiles along the growth axis of otholiths of European smelt caught in the Wadden Sea, the IJsselmeer and the Markermeer and to investigate the migration behaviour of the fish between the freshwater

  14. RISK ASSESSMENT AND REMEDIATION OF SOILS CONTAMINATED BY MINING AND SMELTING OF LEAD, ZINC AND CADMIUM

    Science.gov (United States)

    Mining nd smelting of Pb, Zn and Cd ores have caused widespread soil contamination in many countries. In locations with severe soil contamination, and strongly acidic soil or mine waste, ecosystems are devastated. Research has shown that An phytotoxicity, Pb-induced phosphate def...

  15. Reductive-sulfurizing smelting treatment of smelter slag for copper and cobalt recovery

    Directory of Open Access Journals (Sweden)

    Li Y.

    2018-01-01

    Full Text Available Recovery of copper and cobalt from smelter slag using reductive-sulfurizing smelting method was performed in this study. The effects of reductive agent (coke, sulfurizing agent (pyrite, slag modifier (CaO and smelting temperature and duration on the extractive efficiencies of Cu, Co and Fe were discussed. The phase compositions and microstructure of the materials, copper-cobalt matte and cleaned slag were determined. The results showed that copper and cobalt contents in cleaned slag could decrease averagely to 0.18% and 0.071% respectively after cleaning. 91.99% Cu and 92.94% Co and less than 38.73% Fe were recovered from the smelter slag under the optimum conditions: 6 wt.% coke, 20 wt.% pyrite and 6 wt.% CaO addition to the smelter slag, smelting temperature of 1350°C and smelting duration of 3h. The addition of CaO can increase the selectivity of Co recovery. The cleaning products were characterized by XRD and SEM-EDS analysis. The results showed that the main phases of copper-cobalt matte were iron sulfide (FeS, geerite (Cu8S5, iron cobalt sulfide (Fe0.92Co0.08S and Fe-Cu-Co alloy. The cleaned slag mainly comprised fayalite (Fe2SiO4, hedenbergite (CaFe(Si2O6 and magnetite (Fe3O4.

  16. Effects of a reducer type on copper flash smelting slag decopperisation

    Directory of Open Access Journals (Sweden)

    B. Oleksiak

    2015-01-01

    Full Text Available In the paper, results of investigations on coke dust, anthracite dust and coal flotation concentrate application in the technology of copper flash smelting slag processing are presented. The results show that the selected reducers can be used as substitutes for the conventional coke.

  17. [Limiting factors of waste land revegetation in indigenous zinc smelting areas of western Guizhou].

    Science.gov (United States)

    Lin, Wen-Jie; Xiao, Tang-Fu; Ao, Zi-Qiang; Xing, Jun; Ma, Huan-Cheng; Hu, Ting-Xing

    2007-03-01

    With indigenous zinc smelting waste residue, contaminated soil and background soil as test substrates, a pot experiment was conducted to study the growth characteristics of Lolium perenne and Trifolium pretense on these substrates. The results showed that the major limiting factors of waste land revegetation in indigenous zinc smelting areas of western Guizhou were the salt-alkali stress and the lower contents of organic matter, total N, available N and total K. The heavy metals in waste residue had a high concentration, but their available forms only occupied a small proportion, with low toxicity to plant but having potential harmful risk. Contaminated soil had lower concentrations of heavy metals than waste residue, but its contained heavy metals were more in available form. The constraints of revegetation on contaminated soil were the toxicity of heavy metals and the low contents of available P and K. Mixing contaminated soil with zinc smelting waste residue could be one of the effective approaches for the substrate amendment in indigenous zinc smelting areas.

  18. Land-use and land-cover assessment for the study of lifestyle change in a rural Mexican community: The Maycoba Project

    Directory of Open Access Journals (Sweden)

    Giraldo Mario A

    2012-07-01

    Full Text Available Abstract Background In 1995, a study was conducted to identify the effects of traditional and westernized environments on the prevalence of type 2 diabetes in Pima Indians (Pimas in Mexico and the United States. The study concluded that the more traditional lifestyle in Mexico had a protective effect against this metabolic disorder. In the ensuing 15 years, the environmental circumstances of the Mexican Pimas changed, and a follow-up study was conducted to determine the role environmental change plays in the development of diabetes in this genetically susceptible population. A major element of environmental transition relates to land-use and land-cover (LULC changes that could affect physical activity and promote an obesogenic environment. This study examined changes in the region’s LULC to determine whether there have been transitions in agricultural land use and urbanization that would be consistent with a more sedentary lifestyle. Changes were assessed from 1994 aerial photographs and 2007 satellite images. Results The land-cover analysis showed that mixed vegetation and dense trees cover most of the study area. It suggested a rural environment that includes a low percentage of impermeable areas, and it indicated that the area experiencing human intervention covers 7% of the total area. The land-use-change findings showed a decrease or no change in agricultural or ranching areas and a decrease in farmland due to reforestation or revegetation. Three variables from the land-use-change analysis were examined as proxies for lifestyle change: urban development, dwelling-unit density, and variation in the road network. Two of the measures –the amount of urbanization and the number and density of dwelling units—showed increases, most notably in the town of Maycoba. There were only minor changes in the road network: most of the road segments are short and concentrated in Maycoba where most of the buildings, points of interest (e.g., church

  19. The Mexican Committee against Racism and What It Reveals about Relations between Mexican and American Jews

    Directory of Open Access Journals (Sweden)

    Ariela Katz Gugenheim

    2012-10-01

    Full Text Available This work reconstructs the origin, organization, development, and disappearance of the Mexican Committee against Racism (Comité Mexicano contra el Racismo, CMR, active in Mexico City from 1944 to 1946, inthe context of the relations between a leading Jewish organization in the United States and a Mexican Jewish institution. The CMR appears in historiography as a Mexican anti-fascist institution, but this research reveals that it was conceived, implemented, financed, and supervised by the American Jewish Committee (AJC, a Jewish social action organization based in the United States, with the aim of fighting against racist and anti-Semitic prejudices, creating a friendly climate towards Jewish-refugee immigration, and quelling anti-American feelings in Mexico. The AJC's involvement was kept a secret for Mexicans in general and for the Jewish community in Mexico. Drawing on archives in Mexico and the United States, this work details the reasons that led to its organization, describes its implementation, explains why the AJC's involvement was kept a secret, and why the CMR failed to prosper and eventually disappeared.

  20. Distribution and health risk assessment to heavy metals near smelting and mining areas of Hezhang, China.

    Science.gov (United States)

    Briki, Meryem; Zhu, Yi; Gao, Yang; Shao, Mengmeng; Ding, Huaijian; Ji, Hongbing

    2017-08-19

    Mining and smelting areas in Hezhang have generated a large amount of heavy metals into the environment. For that cause, an evaluative study on human exposure to heavy metals including Co, Ni, Cu, Zn, Cr, As, Cd, Pb, Sb, Bi, Be, and Hg in hair and urine was conducted for their concentrations and correlations. Daily exposure and non-carcinogenic and carcinogenic risk were estimated. Sixty-eight scalp hair and 66 urine samples were taken from participants of different ages (6-17, 18-40, 41-60, and ≥ 65 years) living in the vicinity of an agricultural soil near mine and smelting areas. The results compared to the earlier studies showed an elevated concentration of Pb, Be, Bi, Co, Cr, Ni, Sb, and Zn in hair and urine. These heavy metals were more elevated in mining than in smelting. Considering gender differences, females were likely to be more affected than male. By investigating age differences in this area, high heavy metal concentrations in male's hair and urine existed in age of 18-40 and ≥ 66, respectively. However, females did not present homogeneous age distribution. Hair and urine showed a different distribution of heavy metals in different age and gender. In some cases, significant correlation was found between heavy metals in hair and urine (P > 0.05 and P > 0.01) in mining area. The estimated average daily intake of heavy metals in vegetables showed a great contribution compared to the soil and water. Non-carcinogenic and carcinogenic risk values of total pathways in mining and smelting areas were higher than 1 and exceeded the acceptable levels. Thus, the obtained data might be useful for further studies. They can serve as a basis of comparison and assessing the effect of simultaneous exposure from heavy metals in mining and smelting areas, and potential health risks from exposure to heavy metals in vegetables need more consideration.

  1. Interactions between hatch dates, growth rates, and mortality of Age-0 native Rainbow Smelt and nonnative Alewife in Lake Champlain

    Science.gov (United States)

    Parrish, Donna; Simonin, Paul W.; Rudstam, Lars G.; Pientka, Bernard; Sullivan, Patrick J.

    2016-01-01

    Timing of hatch in fish populations can be critical for first-year survival and, therefore, year-class strength and subsequent species interactions. We compared hatch timing, growth rates, and subsequent mortality of age-0 Rainbow Smelt Osmerus mordax and Alewife Alosa pseudoharengus, two common open-water fish species of northern North America. In our study site, Lake Champlain, Rainbow Smelt hatched (beginning May 26) almost a month earlier than Alewives (June 20). Abundance in the sampling area was highest in July for age-0 Rainbow Smelt and August for age-0 Alewives. Late-hatching individuals of both species grew faster than those hatching earlier (0.6 mm/d versus 0.4 for Rainbow Smelt; 0.7 mm/d versus 0.6 for Alewives). Mean mortality rate during the first 45 d of life was 3.4%/d for age-0 Rainbow Smelt and was 5.5%/d for age-0 Alewives. Alewife mortality rates did not differ with hatch timing but daily mortality rates of Rainbow Smelt were highest for early-hatching fish. Cannibalism is probably the primary mortality source for age-0 Rainbow Smelt in this lake. Therefore, hatching earlier may not be advantageous because the overlap of adult and age-0 Rainbow Smelt is highest earlier in the season. However, Alewives, first documented in Lake Champlain in 2003, may increase the mortality of age-0 Rainbow Smelt in the summer, which should favor selection for earlier hatching.

  2. Effect of acculturation and mutuality on family loyalty among Mexican American caregivers of elders.

    Science.gov (United States)

    Kao, Hsueh-Fen S; An, Kyungeh

    2012-06-01

    Informal family care for elders is conventional in Mexican American communities despite increasing intergenerational gaps in filial values. In our study, we explored whether acculturation and dyadic mutuality, as perceived by Mexican American family caregivers, explain the caregivers' expectations of family loyalty toward elderly relatives. A nonexperimental, correlational design with convenience sampling was used in El Paso, Texas, from October 2007 to January 2008. Three bilingual promotoras collected data from 193 Mexican American adult caregivers of community-dwelling elders using three scales designed for Mexican Americans: the Acculturation Rating Scale for Mexican Americans II-Short Form, the Mutuality Scale, and the Expectations of Family Loyalty of Children Toward Elderly Relatives Scale. Confirmatory factor analysis was used to analyze the data. Acculturation had a marginal effect (r = .21, p loyalty toward elderly relatives. There was no significant correlation between acculturation and mutuality (r = .05). Although Mexican American caregivers with strong Mexican orientation may have high expectations of family loyalty toward elderly relatives, mutuality exhibits more significant effects on expectations. Among Mexican Americans, mutuality between the caregiving dyad, as perceived by caregivers, may be a better predictor of filial values than caregivers' acculturation alone. It may be useful to incorporate the dual paradigm of acculturation and mutuality into immigrant family care for elderly relatives. © 2012 Sigma Theta Tau International.

  3. Contaminated Mexican steel incident

    International Nuclear Information System (INIS)

    1985-01-01

    This report documents the circumstances contributing to the inadvertent melting of cobalt 60 (Co-60) contaminated scrap metal in two Mexican steel foundries and the subsequent distribution of contaminated steel products into the United States. The report addresses mainly those actions taken by US Federal and state agencies to protect the US population from radiation risks associated with the incident. Mexico had much more serious radiation exposure and contamination problems to manage. The United States Government maintained a standing offer to provide technical and medical assistance to the Mexican Government. The report covers the tracing of the source to its origin, response actions to recover radioactive steel in the United States, and return of the contaminated materials to Mexico. The incident resulted in significant radiation exposures within Mexico, but no known significant exposure within the United States. Response to the incident required the combined efforts of the Nuclear Regulatory Commission (NRC), Department of Energy, Department of Transportation, Department of State, and US Customs Service (Department of Treasury) personnel at the Federal level and representatives of all 50 State Radiation Control Programs and, in some instances, local and county government personnel. The response also required a diplomatic interface with the Mexican Government and cooperation of numerous commercial establishments and members of the general public. The report describes the factual information associated with the event and may serve as information for subsequent recommendations and actions by the NRC. 8 figures

  4. Community level patterns in diverse systems: A case study of litter fauna in a Mexican pine-oak forest using higher taxa surrogates and re-sampling methods

    Science.gov (United States)

    Moreno, Claudia E.; Guevara, Roger; Sánchez-Rojas, Gerardo; Téllez, Dianeis; Verdú, José R.

    2008-01-01

    Environmental assessment at the community level in highly diverse ecosystems is limited by taxonomic constraints and statistical methods requiring true replicates. Our objective was to show how diverse systems can be studied at the community level using higher taxa as biodiversity surrogates, and re-sampling methods to allow comparisons. To illustrate this we compared the abundance, richness, evenness and diversity of the litter fauna in a pine-oak forest in central Mexico among seasons, sites and collecting methods. We also assessed changes in the abundance of trophic guilds and evaluated the relationships between community parameters and litter attributes. With the direct search method we observed differences in the rate of taxa accumulation between sites. Bootstrap analysis showed that abundance varied significantly between seasons and sampling methods, but not between sites. In contrast, diversity and evenness were significantly higher at the managed than at the non-managed site. Tree regression models show that abundance varied mainly between seasons, whereas taxa richness was affected by litter attributes (composition and moisture content). The abundance of trophic guilds varied among methods and seasons, but overall we found that parasitoids, predators and detrivores decreased under management. Therefore, although our results suggest that management has positive effects on the richness and diversity of litter fauna, the analysis of trophic guilds revealed a contrasting story. Our results indicate that functional groups and re-sampling methods may be used as tools for describing community patterns in highly diverse systems. Also, the higher taxa surrogacy could be seen as a preliminary approach when it is not possible to identify the specimens at a low taxonomic level in a reasonable period of time and in a context of limited financial resources, but further studies are needed to test whether the results are specific to a system or whether they are general

  5. Motivations and Implications of Community Service Provision by La Familia Michoacána / Knights Templar and other Mexican Drug Cartels

    Directory of Open Access Journals (Sweden)

    Shawn T. Flanigan

    2014-10-01

    Full Text Available Research demonstrates that service provision by violent organizations can be an effective strategy for coercing the local community to accept and conceal a group’s violent activities, and for creating loyalty to these groups. This has been most frequently explored among political organizations such as terrorist groups, with organizations like Hezbollah and Hamas very visibly engaged in providing social welfare in addition to their violent activities. Recent reports indicate that criminal organizations in Mexico also are involved in instances of public service provision in local communities. This article explores the extent to which drug cartels operating in Mexico are involved in public service provision to members of communities where they operate, and considers possible motivations and implications for public service provision by these criminal organizations, with specific attention to the organization La Familia Michoacána/ Knights Templar. The article also gives attention to the consequences to citizenship and government of service provision by violent nonstate actors, and the ways such service provision may disrupt the social contract between the citizen and the state.

  6. Prevalence of Bruxism among Mexican Children with Down Syndrome

    Science.gov (United States)

    Lopez-Perez, Ruben; Lopez-Morales, Patricia; Borges-Yanez, S. Aida; Maupome, Gerardo; Pares-Vidrio, Gustavo

    2007-01-01

    This study sought to determine the prevalence of bruxism in a Mexican community of children with Down syndrome, and to evaluate bruxism's relationship with age, sex, intellectual disability level, and type of chromosomal abnormality of trisomy 21. Using a cross-sectional design, 57 boys and girls (3 to 14 years old) were examined. Three approaches…

  7. Educación ambiental popular para el manejo sustentable de recursos naturales en una localidad rural del subtrópico mexicano / Popular environmental education for natural resources sustainable management at a rural community in the mexican subtropics

    Directory of Open Access Journals (Sweden)

    Etztli Morales Reyes

    2016-09-01

    steps were established: 1 Research, in which will be indentified the learning needs of the community, and issues of interest to the community, 2 Education, in which a curriculum proposal for environmental education was conducted, through two programs offered means by workshops, 3 Action, popular environmental education experiences were developed through twelve workshops with three groups: children, women and men, 4 Action-Reflection-Action, in which the results of environmental education experiences were evaluated. As a result, it was observed that the participants were able to define, model and propose alternatives for natural sustainable resource management at their community. Keywords: Popular Environmental Education, Sustainable Management, Natural Resources , Rural Community, Mexican Subtropics.

  8. Age, growth and sex composition of the American smelt Osmerus mordax(Mitchill), of western Lake Superior

    Science.gov (United States)

    Bailey, Merryll M.

    1964-01-01

    This study is based on 4,561 smelt collected in Chequamegon Bay, the Apostle Islands, the Brule River, and Superior Harbor, all in western Lake Superior. Commercial production in the Great Lakes (U.S. and Canada combined) reached a peak of nearly 16 million pounds in 1960. Production in Lake Superior has generally been small but increased during the 1950's to reach 948,000 pounds in 1960. All O-group and spring I-group smelt had scales with sufficient sculpturing to permit detection of the first annulus. Annulus formation began after 6 June in 1960. In 1961, all smelt had completed the annulus by 24 August. The body-scale relation is a straight line with an intercept of -0.9 inch on the axis of fish length. The weight of western Lake Superior smelt increased as the 2.952 power of the length. A large range of length in each age group and resulting overlap of age-groups II-VI made length a poor index of age. Female smelt grew faster than males after the second year and dominated strongly in age-groups IV-VII. Both sexes made their best annual growth in length (3.3 inches) during their second year of life; the largest weight increments (0.74 ounce, males; 0.85 ounce, females) came in the third year. Best production from a commercial pound net in 1961 occurred when the sex ratios of spawning smelt were nearest 50:50. Spawning male smelt were consistently shorter than females and the average lengths of both sexes decreased as the spawning season progressed. Shortest mature smelt of each sex were 5.0 to 5.2 inches but the males are probably the first to reach 100 percent maturity. All year-old smelt were immature. Among 2-year-old fish, 40.7 per cent of the males and 17.7 percent of the females had reached maturity. All smelt more than 2 years old were mature. Ovaries of 10 smelt contained an average of 31,338 eggs for fish 7.3 to 8.8 inches long.

  9. Critical Assessment of the Delta Smelt Population in the San Francisco Estuary, California

    Directory of Open Access Journals (Sweden)

    William A Bennett

    2005-09-01

    Full Text Available The delta smelt (Hypomesus transpacificus is a small and relatively obscure fish that has recently risen to become a major focus of environmental concern in California. It was formally abundant in the low-salinity and freshwater habitats of the northeastern San Francisco Estuary, but is now listed as threatened under the Federal and California State Endangered Species Acts. In the decade following the listings scientific understanding has increased substantially, yet several key aspects of its biology and ecological relationships within the highly urbanized estuary remain uncertain. A key area of controversy centers on impacts to delta smelt associated with exporting large volumes of freshwater from the estuary to supply California’s significant agricultural and urban water demands. The lack of appropriate data, however, impedes efforts to resolve these issues and develop sound management and restoration alternatives. Delta smelt has an unusual life history strategy relative to many fishes. Some aspects of its biology are similar to other coastal fishes, particularly salmonids. Smelts in the genus, Hypomesus, occur throughout the Pacific Rim, have variable life history strategies, and are able to adapt rapidly to local environments. By comparison, delta smelt has a tiny geographic range being confined to a thin margin of low salinity habitat in the estuary. It primarily lives only a year, has relatively low fecundity, and pelagic larvae; life history attributes that are unusual when compared with many fishes worldwide. A small proportion of delta smelt lives two years. These individuals are relatively highly fecund but are so few in number that their reproductive contribution only may be of benefit to the population after years of extremely poor spawning success and survival. Provisioning of reproductive effort by these older fish may reflect a bet-hedging tactic to insure population persistence. Overall, the population persists by maximizing

  10. Mexican experience on migration and development 1990-2013

    Directory of Open Access Journals (Sweden)

    Rodolfo García Zamora

    Full Text Available After 40 years of a long rising emigration from Mexico to the United States, the number of Mexicans increased to 12 million in 2006, while the increased input of remittances reached $26 million dollars in 2007. Yet, the increasing migration and remittances mainly in Zacatecas and Michoacan states do not achieve economic and social development because of the persistent backwardness, unemployment and marginalization. It demands the need for new Policies of Development, Migration and Human Rights that allow exercising the right to not emigrate in a medium term. Positive products of this long migration are the Mexican Migrant Clubs and their Federations that elaborated the concrete development proposals. Whereas, the possibility that these proposals can become a Development, Migration and Human Rights, Comprehensive and Long Term State Policy will depend on the capacity and participation of Mexican Civil Society and the Transnational Communities in both countries.

  11. Men of Mexican Origin Who Abuse Women: A Qualitative Study.

    Science.gov (United States)

    Montalvo-Liendo, Nora; Matthews, Debra W; Gilroy, Heidi; Nava, Angeles; Gangialla, Christyn

    2018-03-01

    Current literature indicates that intimate partner violence is a complex phenomenon that exists worldwide. However, little is known about why some men of Mexican origin abuse women. This descriptive study was conducted to understand the experiences of men of Mexican origin who abuse their intimate partners. A qualitative research design was used to conduct this study in a south Texas border community adjacent to the United States-Mexico border. This study builds on existing research and furthers the knowledge related to the factors contributing to intimate partner violence, including cultural factors. The results also reinforce the negative impacts of intimate partner violence on children and the family structure. Further research is needed to support the development of a culturally appropriate prevention and intervention program for men of Mexican origin who abuse women and their families.

  12. Larval nematodes in stomach wall granulomas of smelt Osmerus eperlanus from the German North Sea coast

    OpenAIRE

    Obiekezie, A. I.; Lick, Roland R.; Kerstan, Susanne L.; Möller, Heino

    1992-01-01

    Occurrence of stomach wall granulomas in European smelt was studled at 6 locations along the German North Sea coast. Identification of larval nematodes inhabiting these granulomas is provided for the first time. Three species, isolated by pepsin-HC1 digestion, are involved: Hysterothylacium cf. cornutum, Cosmocephalus obvelatus and Paracuaria tridentata. 72% of all stomachs examined were affected. The ratio of number of granulomas to number of the 3 larval species free in the mesentery was 1:...

  13. The Effect Of Local Coal And Smelting Sponge Iron On Iron Content Of Pig Iron

    Science.gov (United States)

    Oediyani, Soesaptri; Juwita Sari, Pramita; Hadi P, Djoko

    2018-03-01

    The new regulation on mineral resources was announced by Ministry of Energy and Mineral resources (ESDM) of Indonesia at 2014 which it called Permen ESDM No 1/2014. Therefore, this research was conducted to add the value of local iron ores by using smelting technology. The objective of the research is to produce pig iron that meet the requirement of the new regulation of mineral resources such as 90% Fe. First, iron ores and coal mixed together with lime as a flux, then smelted in a Electric Arc Furnace at 1800°C. The process variables are (1; 1.25; 1.5; 1.75; 2.0) and the composition of coal (0.8%, 1.6%, 3.0%). The type of coal that used in this research was bituminous coal from Kalimantan and also the iron ores from Kalimantan. The products of the smelting technology are Pig iron and slag. Both pig iron and slag then analyzed by SEM-EDS to measure the iron content. The result shows that the maximum iron content on pig iron is about 95.04% meanwhile the minimum iron content on slag is about 3.66%. This result achieved at 1.6% coal and 2.0.

  14. Aspects of energy reduction by autogenous copper production in the copper smelting plant Bor

    International Nuclear Information System (INIS)

    Najdenov, Ivan; Raić, Karlo T.; Kokeza, Gordana

    2012-01-01

    This work presents a comparative analysis of the energy consumption during copper production by the “standard” procedure (roasting in a fluo–solid reactor and smelting in a reverberatory furnace) in the Smelting Plant in Bor with modern autogenous procedures. All forms of expended energy were reduced to primary energy or to the same energy form, i.e., to the energy equivalent of the process (EEP), the raw material and the process materials. In addition, the energy equivalent of the process and waste products (water vapour, thermal energy and similar) were balanced. To complete the consumption of all energy generating products in copper production, they were reduced to conditional fuel (coal equivalent = 29.3 MJ/kg). Additionally, this study suggests replacement of the existing technology by an appropriate autogenous procedure and considers the prospects for further development of mining and metallurgy in Bor. Estimates of development perspectives for copper production should be comprehensive, based on complete and relevant data, as well as on real considerations of future development in world production. -- Highlights: ► “Standard” autogenous copper production in the Smelting Plant, Bor, Serbia. ► Comparation of energy consumption in “standard” with other autogenous procedures. ► All forms of energy are reduced to energy equivalent and conditional fuel. ► Replacement of existing technology with the appropriate autogenous procedure. ► Perspectives of further development of mining and metallurgy in Bor.

  15. Inverse boundary design of a radiative smelting furnace with ablative phase change phenomena

    International Nuclear Information System (INIS)

    Farzan, H.; Hosseini Sarvari, S.M.; Mansouri, S.H.

    2016-01-01

    Highlights: • The ablation phenomenon in a reverberatory smelting furnace is simulated numerically. • The results are verified by comparing with exact analytic solution. • Inverse design problem is solved to construct the desired melting rate. • The conjugate gradient method is used to solve the inverse phase change problem. - Abstract: An inverse analysis is employed to control the time rate of heaters in a 2-D smelting furnace to provide the specified radiative heat flux across the design surface to establish a desired melting rate. The design surface in the smelting furnace is the melting surface of the metal concentrate bank, and the melting process is considered to occur as an ablation phenomenon. The net radiation method is used to determine the radiation exchange between the elements of the furnace surfaces and the melting surface. The conjugate gradient method is employed to minimize the objective function, which is the sum of square residuals between the estimated and the desired heat fluxes over the design surface. It is shown that the proposed inverse technique is reliable and accurate for predicting the heater power distribution.

  16. Mexican renewable electricity law

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Mendoza, B.J.; Sheinbaum-Pardo, C. [Institute of Engineering of the National Autonomous University of Mexico, Circuito Exterior s/n, Edificio 12 Bernardo Quintana, Piso 3, Cubiculo 319, Ciudad Universitaria, Delegacion Coyoacan, CP 04510, Mexico D.F. (Mexico)

    2010-03-15

    Two renewable electricity bills have been proposed in Congress since 2005 in Mexico. The first one was rejected by the Senate and the second one was approved by both the House of Representatives and the Senate in October 2008. Our objective is to explain the nature of both bills and to analyze each of them bearing in mind the Mexican electricity sector management scheme. In the Mexican electricity sector single-buyer scheme, the state-owned companies (Comision Federal de Electricidad and Luz y Fuerza del Centro) are responsible of the public services and the private sector generates electricity under six modalities: self-supply, cogeneration, independent production, small production, export, and import, which are not considered a public service. This scheme has caused controversies related to the constitutionality of the 1992 Power Public Services Law that allowed this scheme to be implemented. Both bills, the rejected one and the approved one, were formulated and based on that controversial law and their objectives are linked precisely more to the controversial issues than to the promotion of renewable electricity technologies; consequently, the gap among environmental, economic and social issues related with sustainability notion is wider. (author)

  17. Mexican renewable electricity law

    International Nuclear Information System (INIS)

    Ruiz-Mendoza, B.J.; Sheinbaum-Pardo, C.

    2010-01-01

    Two renewable electricity bills have been proposed in Congress since 2005 in Mexico. The first one was rejected by the Senate and the second one was approved by both the House of Representatives and the Senate in October 2008. Our objective is to explain the nature of both bills and to analyze each of them bearing in mind the Mexican electricity sector management scheme. In the Mexican electricity sector single-buyer scheme, the state-owned companies (Comision Federal de Electricidad and Luz y Fuerza del Centro) are responsible of the public services and the private sector generates electricity under six modalities: self-supply, cogeneration, independent production, small production, export, and import, which are not considered a public service. This scheme has caused controversies related to the constitutionality of the 1992 Power Public Services Law that allowed this scheme to be implemented. Both bills, the rejected one and the approved one, were formulated and based on that controversial law and their objectives are linked precisely more to the controversial issues than to the promotion of renewable electricity technologies; consequently, the gap among environmental, economic and social issues related with sustainability notion is wider. (author)

  18. Structure and diversity of ground mesofauna inUlmus and Populus consortia in the industrial areas of mining and smelting complex of krivyi rig basin

    Directory of Open Access Journals (Sweden)

    V. V. Kachinskaya

    2010-05-01

    Full Text Available The structure and biological diversity of ground mesofauna on a consortium level of organisation of ecosystems are considered. Indicators of structural organisation and biodiversity of ground mesofauna were analised in Ulmus and Populus consortia in the conditions of industrial territories of mining and smelting complex of Krivyi Rig Basin. It is established that taxonomical structure of ground mesofauna is characterised by insignificant number and quantity of taxonomical groups. Prevalence of hortobionts and herpetobionts in morpho-ecological structure of the community testifies to their attachment to consortium’s determinants and influence of steppe climate on its structure. Dominance of phytophages and polyphages in trophic structure is caused by a combination of consortium determinants specificity and «a zone source» of the fauna formations. The structural organisation of ground mesofauna in consortia of Ulmus and Populus in the conditions of industrial sites is characterised by simplified taxonomical structure with low biodiversity at all levels.

  19. Thallium transformation and partitioning during Pb–Zn smelting and environmental implications

    International Nuclear Information System (INIS)

    Liu, Juan; Wang, Jin; Chen, Yongheng; Xie, Xiaofan; Qi, Jianying; Lippold, Holger; Luo, Dinggui; Wang, Chunlin; Su, Longxiao; He, Lucheng; Wu, Qiwei

    2016-01-01

    Thallium (Tl) is a toxic and non-essential heavy metal. Raw Pb–Zn ores and solid smelting wastes from a large Pb–Zn smelting plant – a typical thallium (Tl) pollution source in South China, were investigated in terms of Tl distribution and fractionation. A modified IRMM (Institute for Reference Materials and Measurement, Europe) sequential extraction scheme was applied on the samples, in order to uncover the geochemical behavior and transformation of Tl during Pb–Zn smelting and to assess the potential environmental risk of Tl arising from this plant. Results showed that the Pb–Zn ore materials were relatively enriched with Tl (15.1–87.7 mg kg"−"1), while even higher accumulation existed in the electrostatic dust (3280–4050 mg kg"−"1) and acidic waste (13,300 mg kg"−"1). A comparison of Tl concentration and fraction distribution in different samples clearly demonstrated the significant role of the ore roasting in Tl transformation and mobilization, probably as a result of alteration/decomposition of related minerals followed by Tl release and subsequent deposition/co-precipitation on fine surface particles of the electrostatic dust and acidic waste. While only 10–30% of total Tl amounts was associated with the exchangeable/acid-extractable fraction of the Pb–Zn ore materials, up to 90% of total Tl was found in this fraction of the electrostatic dust and acidic waste. Taking into account the mobility and bioavailability of this fraction, these waste forms may pose significant environmental risk. - Highlights: • Geo-chemical partitioning of Tl in Pb–Zn ores and smelting wastes was investigated. • Significant differences were shown in Tl contents and chemical fractionation. • Over 100-fold enrichment of Tl was found in electrostatic dust and acidic waste. • Ore roasting played a key role in Tl transformation and mobilization. • Tl was mainly bound in the labile fraction of electrostatic dust and acidic waste. - Geo

  20. Contamination and human health risk of lead in soils around lead/zinc smelting areas in China.

    Science.gov (United States)

    Lei, Kai; Giubilato, Elisa; Critto, Andrea; Pan, Huiyun; Lin, Chunye

    2016-07-01

    Pb/Zn smelting, an important economic activity in China, has led to heavy environmental pollution. This research reviewed studies on soil Pb contamination at Pb/Zn smelting sites in China published during the period of 2000 to 2015 to clarify the total levels, spatial changes, and health risks for Pb contamination in soils at local and national scales. The results show that Pb contents in surface soils at 58 Pb/Zn smelting sites in China ranged from 7 to 312,452 mg kg(-1) with an arithmetic average, geometric average, and median of 1982, 404, and 428 mg kg(-1), respectively (n = 1011). Surface soil Pb content at these smelting sites decreased from an average of 2466 to 659 mg kg(-1), then to 463 mg kg(-1) as the distance from the smelters increased from 2000 m. With respect to variation with depth, the average soil Pb content at these sites gradually decreased from 986 mg kg(-1) at 0- to 20-cm depth to 144 mg kg(-1) at 80- to 100-cm depth. Approximately 78 % of the soil samples (n = 1011) at the 58 Pb/Zn smelting sites were classified as having high Pb pollution levels. Approximately 34.2 and 7.7 % of the soil samples (n = 1011) at the 58 Pb/Zn smelting sites might pose adverse health effects and high chronic risks to children, respectively. The Pb/Zn smelting sites in the southwest and southeast provinces of China, as well as Liaoning province, were most contaminated and thus should receive priority for remediation.

  1. San Pedro Martir Telescope: Mexican design endeavor

    Science.gov (United States)

    Toledo-Ramirez, Gengis K.; Bringas-Rico, Vicente; Reyes, Noe; Uribe, Jorge; Lopez, Aldo; Tovar, Carlos; Caballero, Xochitl; Del-Llano, Luis; Martinez, Cesar; Macias, Eduardo; Lee, William; Carramiñana, Alberto; Richer, Michael; González, Jesús; Sanchez, Beatriz; Lucero, Diana; Manuel, Rogelio; Segura, Jose; Rubio, Saul; Gonzalez, German; Hernandez, Obed; García, Mary; Lazaro, Jose; Rosales-Ortega, Fabian; Herrera, Joel; Sierra, Gerardo; Serrano, Hazael

    2016-08-01

    The Telescopio San Pedro Martir (TSPM) is a new ground-based optical telescope project, with a 6.5 meters honeycomb primary mirror, to be built in the Observatorio Astronomico Nacional on the Sierra San Pedro Martir (OAN-SPM) located in Baja California, Mexico. The OAN-SPM has an altitude of 2830 meters above sea level; it is among the best location for astronomical observation in the world. It is located 1830 m higher than the atmospheric inversion layer with 70% of photometric nights, 80% of spectroscopic nights and a sky brightness up to 22 mag/arcsec2. The TSPM will be suitable for general science projects intended to improve the knowledge of the universe established on the Official Mexican Program for Science, Technology and Innovation 2014-2018. The telescope efforts are headed by two Mexican institutions in name of the Mexican astronomical community: the Universidad Nacional Autonoma de Mexico and the Instituto Nacional de Astrofisica, Optica y Electronica. The telescope has been financially supported mainly by the Consejo Nacional de Ciencia y Tecnologia (CONACYT). It is under development by Mexican scientists and engineers from the Center for Engineering and Industrial Development. This development is supported by a Mexican-American scientific cooperation, through a partnership with the University of Arizona (UA), and the Smithsonian Astrophysical Observatory (SAO). M3 Engineering and Technology Corporation in charge of enclosure and building design. The TSPM will be designed to allow flexibility and possible upgrades in order to maximize resources. Its optical and mechanical designs are based upon those of the Magellan and MMT telescopes. The TSPM primary mirror and its cell will be provided by the INAOE and UA. The telescope will be optimized from the near ultraviolet to the near infrared wavelength range (0.35-2.5 m), but will allow observations up to 26μm. The TSPM will initially offer a f/5 Cassegrain focal station. Later, four folded Cassegrain and

  2. "Adiós soccer, here comes fútbol!": transnacionalização de comunidades esportivas mexicanas nos Estados Unidos "Adiós soccer, here comes fútbol!": transnationalization of the Mexican sports communities in the U.S.

    Directory of Open Access Journals (Sweden)

    Ingrid Kummels

    2011-12-01

    Full Text Available Este artigo discute a dinâmica esportiva de comunidades mexicanas nos Estados Unidos no contexto do futebol. A partir da análise de grupos mexicanos que imigraram para o território americano e de suas práticas futebolísticas (de resistência, esta pesquisa se questiona se estaríamos presenciando uma "latino-americanização" esportiva dos EUA através do futebol. Como contrarresposta a uma homogeneização e subordinação, os mexicanos-americanos (e, por extensão, os latinos em geral criaram novas práticas culturais (e, dentre elas, as práticas esportivas que amalgamam tradições mexicanas com valores da sociedade estadunidense, constituindo, assim, um terceiro espaço (a third space que transpõe as fronteiras de ambos os Estados nacionais. O presente artigo, portanto, analisa por que um crescente número de imigrantes reforça as relações com suas comunidades de origem no México através da (recriação de um universo futebolístico próprio, expressando, com isso, uma "mexicanidade transnacional" que não é "harmônica", mas é marcada por linhas de conflito. Nessa "nova mexicanidade" manifestam-se conflitos de gênero, de classe e étnicos, locais e nacionais, que se dão simultaneamente nos EUA e no México, e que se influenciam mutuamente.This article discusses the sport dynamics of the Mexican communities in the United States in the context of soccer. From the analysis of Mexican groups which immigrated to the American territory, and from their soccer practices (of resistance, this research questions whether we would be witnessing a sportive "latinoamericanization" of the U.S. through the soccer practices. As a counter-response to a homogenization and subordination, the Mexican Americans (and, by extension, the Latinos in general have created new cultural practices (and, among them sportive ones that put together Mexican traditions with American values of society constituting, in that way, "a third space", which extends

  3. Smelting reduction of MgO in molten slag by liquid ferrosilicon

    Directory of Open Access Journals (Sweden)

    Tang, Qifeng

    2016-06-01

    Full Text Available The smelting reduction of magnesium oxide was researched in this paper. The effect of molten slag composition and reduction temperature on percent reduction of magnesium oxide were discussed, and kinetics of smelting reduction of magnesium oxide in molten slag was studied. The results showed that the reduction extent of magnesium oxide increased by increasing either one of the following factors: the initial mass ratio of Al2O3/SiO2, the addition of CaF2, the initial molar ratio of Si/2MgO, and reaction temperature. The overall smelting reduction was controlled by mass transfer in slag with an apparent activation energy 586 kJ mol-1.En este trabajo se estudia la reducción de óxido de magnesio. La influencia de la composición de las escorias y de la temperatura de reducción sobre el porcentaje de reducción de óxido de magnesio han sido discutidas, y asimismo se ha estudiado la cinética de la reducción del óxido de magnesio en escorias fundidas. Los resultados muestran que la reducción se incrementa al aumentar alguno de los siguientes factores: la proporción de Al2O3/SiO2, la adición de CaF2, la proporción molar de Si/2MgO y la temperatura de reacción. En general la reducción fue controlada por la transferencia de masa en la escoria con una energía aparente de 586 kJ mol-1.

  4. Thallium transformation and partitioning during Pb-Zn smelting and environmental implications.

    Science.gov (United States)

    Liu, Juan; Wang, Jin; Chen, Yongheng; Xie, Xiaofan; Qi, Jianying; Lippold, Holger; Luo, Dinggui; Wang, Chunlin; Su, Longxiao; He, Lucheng; Wu, Qiwei

    2016-05-01

    Thallium (Tl) is a toxic and non-essential heavy metal. Raw Pb-Zn ores and solid smelting wastes from a large Pb-Zn smelting plant - a typical thallium (Tl) pollution source in South China, were investigated in terms of Tl distribution and fractionation. A modified IRMM (Institute for Reference Materials and Measurement, Europe) sequential extraction scheme was applied on the samples, in order to uncover the geochemical behavior and transformation of Tl during Pb-Zn smelting and to assess the potential environmental risk of Tl arising from this plant. Results showed that the Pb-Zn ore materials were relatively enriched with Tl (15.1-87.7 mg kg(-1)), while even higher accumulation existed in the electrostatic dust (3280-4050 mg kg(-1)) and acidic waste (13,300 mg kg(-1)). A comparison of Tl concentration and fraction distribution in different samples clearly demonstrated the significant role of the ore roasting in Tl transformation and mobilization, probably as a result of alteration/decomposition of related minerals followed by Tl release and subsequent deposition/co-precipitation on fine surface particles of the electrostatic dust and acidic waste. While only 10-30% of total Tl amounts was associated with the exchangeable/acid-extractable fraction of the Pb-Zn ore materials, up to 90% of total Tl was found in this fraction of the electrostatic dust and acidic waste. Taking into account the mobility and bioavailability of this fraction, these waste forms may pose significant environmental risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Environmental impact of early Basque mining and smelting recorded in a high ash minerogenic peat deposit

    International Nuclear Information System (INIS)

    Monna, F.; Galop, D.; Carozza, L.; Tual, M.; Beyrie, A.; Marembert, F.; Chateau, C.; Dominik, J.; Grousset, F.E.

    2004-01-01

    More than four metres of core, covering almost 5000 years of deposition, were collected in a high ash minerogenic peat deposit located in the High Aldudes valley (Basque country), an area well known for its mineral abundance, exploited from Roman Times at least. Although minerogenic peatlands are not generally considered as the best archives to reconstruct past atmospheric metal deposition history, lead isotopic geochemistry demonstrates the integrity of the Pb record at least within the three upper meters; that is to say over the last four millennia. Zn, Cd and Cu may have been widely redistributed either by biological cycling, advective groundwater movements, or diffusional processes. Anthropogenic lead input phases are clearly pinpointed by positive shifts in Pb/Sc ratios with concomitant sharp drops in 206 Pb/ 207 Pb ratios. They are often accompanied by significant declines in tree taxa, interpreted as increasing demand for wood to supply energy for local mining and/or metallurgical operations. Periods of mining and/or smelting activity are identified during Antiquity and Modern Times, and are also confirmed by textual and field evidence. Inputs from the Rio Tinto (Southern Spain), often invoked as a major lead contributor to the European atmosphere during Roman Times, were not detected here. This remote source was probably masked by local inputs. Other mining and/or smelting phases, only suspected by archaeologists, are here identified as early as the Bronze Age. Although the durations of these phases are possibly overestimated because of detrital inputs consequent to the release of lead from polluted soils over a long period of time after major pollutant inputs, the periods at which pollution peaks occur are in good agreement with archaeological knowledge and palaeo-botanical data. The combination of geochemical and palaeo-botanical techniques with field archaeology, therefore provides a powerful tool in studying the interaction of early human societies with

  6. Ecotoxicological damage from zinc smelting at Palmerton, Pennsylvania

    Science.gov (United States)

    Beyer, W. Nelson; Storm, Gerald L.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John

    1995-01-01

    The two zinc smelters at Palmerton, PA emitted huge amounts of contaminants ( 260,000 t of Zn, 3,300 t of Cd, 6,800 t of Pb) to the air and severely damaged the forest on Blue Mountain. The high Zn concentrations in soil killed tree seedlings by inhibiting root elongation. The result was a forest with too few young trees. When natural stresses such as fire challenged the forest, the forest failed to regenerate, and the exposed soil eroded down the steep slopes. Tree species that could sprout were favored over those that developed from seeds. As a result of high zinc concentrations, the lichen and moss communities were depauperate for at least 20 km along Blue Mountain. The denuded areas are in the process of being reclaimed with the addition of a mixture of fly ash and sewage sludge, which is seeded with grasses tolerant to the harsh conditions. In preliminary experiments, the fly ash and sewage sludge mixture was stable, despite the steepness of the slopes of the reclaimed sites on Blue Mountain. Zinc emissions reduced the decomposition rate of plant material on Blue Mountain. The partially decomposed litter, in particular, accumulated on the surface of the mineral soil. The populations of both microorganisms and arthropods were greatly reduced in soils near the smelters. Samples of litter collected from sites spanning 30 km were toxic to woodlice, and Zn was shown to be the toxic factor. A white-tailed deer examined had a very high renal Zn concentration and an articular lesion in one of its hind legs that closely resembled the lesions reported in Zn-poisoned horses. Zinc concentrations were regulated in wildlife tissues and were not reliable indicators of exposure, except in extreme cases. Two songbirds, a shrew, and several rabbits contained Pb concentrations that were suggested to be toxic. Shrews and ground-feeding songbirds accumulated relatively high concentrations of Pb. Exposure to Pb seemed to be related to the amount of soil that an animal ingests. Some

  7. Distinguishing between native and smelted coppers using PIXE spectrometry: a case history from early colonial America

    International Nuclear Information System (INIS)

    Fleming, S.J.; Swann, C.P.

    2000-01-01

    During the recent excavation of a native American village at Governor's Land, in Virginia, two burials were unearthed, each of which contained a jumble of human bones, some fabric and a large number of copper tube beads. PIXE analysis of a representative group of these beads showed that about one-third of them were shaped from pieces of native copper, while the remainder were fashioned from scraps of smelted copper. Since the latter must have come from Europe, these data place the village's occupation in the decade either side of A.D. 1607, when the English first settled at nearby Jamestown

  8. Reduction electric smelting of ferriferrous-titanium concentrates from Gremyakha-Vyrmes deposit

    International Nuclear Information System (INIS)

    Morozov, A.A.

    2002-01-01

    Substantial composition of ilmenite and titanium-magnetite concentrates from Gremyaha-Vyrmes deposit is studied and their reducibility is examined as compared with other similar kids of raw materials. Thermal-physical properties of slag melts (such as toughness and melting ability), formed in reduction smelting of the above-mentioned concentrates for different reduction degree, are determined. These properties characterize the electric thermal transformation process of concentrates as hi-tech one. Features of chemical composition of metal, which is naturally alloyed with vanadium and is produced at the same time are noted. This metal expands the possibilities of complex used of the concentrates of this deposit [ru

  9. Fate of recovery boiler smelt nitrogen in the recovery cycle; Soodakattilan sulan typpiyhdisteitten kaeyttaeytyminen talteenottoprosessissa

    Energy Technology Data Exchange (ETDEWEB)

    Hupa, M.; Forssen, M.; Backman, R.; Ek, P.; Hulden, S.G.; Kilpinen, P.; Kymaelaeinen, M.; Malm, H. [Aabo Akademi, Turku (Finland). Combustion Chemistry Research Group

    1997-10-01

    The purpose of this project is to study the fate of the nitrogen bound in the inorganic smelt after it enters the dissolving tank. Of special interest is to find in what form this nitrogen can be found further down in the recovery process and especially in what form it can be removed from the process. The aim is to clarify if the nitrogen can be a potential problem in the process or if it can become a potential emission. The work is divided into choosing methods for the analysis of different nitrogen species, collection and analysis of mill samples, laboratory studies and theoretical studies on nitrogen chemistry in alkaline solutions and reporting

  10. Towards an Informed Mexican and Mexican-American Citizenry: Bridging the Gap to Increase Human Capacity and Information Dissemination

    Science.gov (United States)

    Ramirez, M. D.; Ramirez, D. M.

    2008-12-01

    The research translation and community outreach goal of The University of Arizona's (UA) Superfund Basic Research Program and U.S.-Mexico Binational Center for Environmental Sciences and Toxicology is to increase human capacity and information dissemination to diverse stakeholders, including federal, state, and local government agencies as well as northern Mexican and border community stakeholders. Due to Arizona's demographic characteristics and the UA's proximity to the U.S. - Mexico border, activities target primarily Mexican and Mexican-American populations. With this in mind, a model has been established that pulls from human capital, community-based participatory research and public participation theories. The theories applied to our target population have resulted in the creation of a successful model that is used in both research translation and community outreach work. The model contains four components: community needs (participation), science translation (information), engagement (outreach), and training (education). Examples of how this model operates for various stakeholders involved in environmental science and health issues will be discussed. A case in point of how this model has been applied effectively is the partnership with promotoras (community health advocates) to do environmental science and health trainings to increase the knowledge base of specific populations disproportionately exposed to contaminants of concern. Additional case studies and methodologies used to develop innovative communicative tools (that takes into consideration cultural idiosyncrasies) for stakeholders at all levels in Arizona, the border, and Mexico will be highlighted, such as: 1) information sheets regarding local environmental issues for communities neighboring contaminated sites, 2) SciTransfer Bulletins targeting professional level stakeholders such as Project Managers, Community Involvement Coordinators and the general public, 3) coordinating technical and

  11. El Arte Culinario Mexicano (Mexican Culinary Art).

    Science.gov (United States)

    Card, Michelle

    This unit in Mexican cooking can be used in Junior High School home economics classes to introduce students to Mexican culture or as a mini-course in Spanish at almost any level. It is divided into two parts. Part One provides historical background and information on basic foods, the Mexican market, shopping tips, regional cooking and customs.…

  12. A Place to Call Home: A Synthesis of Delta Smelt Habitat in the Upper San Francisco Estuary

    Directory of Open Access Journals (Sweden)

    Ted Sommer

    2013-06-01

    Full Text Available We used a combination of published literature and field survey data to synthesize the available information about habitat use by delta smelt Hypomesus transpacificus, a declining native species in the San Francisco Estuary. Delta smelt habitat ranges from San Pablo and Suisun bays to their freshwater tributaries, including the Sacramento and San Joaquin rivers. In recent years, substantial numbers of delta smelt have colonized habitat in Liberty Island, a north Delta area that flooded in 1997. The species has a more upstream distribution during spawning as opposed to juvenile rearing periods. Post-larvae and juveniles tend to have a more downstream distribution during wetter years. Delta smelt are most common in low-salinity habitat (<6 psu with high turbidities (>12 NTU and moderate temperatures (7 °C to 25 °C. They do not appear to have strong substrate preferences, but sandy shoals are important for spawning in other osmerids. The evidence to date suggests that they generally require at least some tidal flow in their habitats. Delta smelt also occur in a wide range of channel sizes, although they seem to be rarer in small channels (<15 m wide. Nonetheless, there is some evidence that open water adjacent to habitats with long water-residence times (e.g. tidal marsh, shoal, low-order channels may be favorable. Other desirable features of delta smelt habitat include high calanoid copepod densities and low levels of submerged aquatic vegetation (SAV and the toxic algae Microcystis. Although enough is known to plan for large-scale pilot habitat projects, these efforts are vulnerable to several factors, most notably climate change, which will change salinity regimes and increase the occurrence of lethal temperatures. We recommend restoration of multiple geographical regions and habitats coupled with extensive monitoring and adaptive management. An overall emphasis on ecosystem processes rather than specific habitat features is also likely to be

  13. Machismo sustains health and illness beliefs of Mexican American men.

    Science.gov (United States)

    Sobralske, Mary

    2006-08-01

    To inform nurse practitioners (NPs) about Mexican American men's health and illness beliefs and the ways in which these are influenced by their masculine identity and how they view themselves as men in their culture. The data sources used were based on a selected review of the literature about Mexican American men's health and illness beliefs and the concept of machismo. Several studies, including the author's study on Mexican American men's healthcare-seeking beliefs and behaviors and experience in providing primary health care to men across cultures, contributed new data. The meaning of manhood in the Mexican American culture is critical in understanding how men perceive health and illness and what they do when they are ill. Machismo enhances men's awareness of their health because they have to be healthy to be good fathers, husbands, brothers, sons, workers, and community members. Pain and disability are motivating factors in finding ways to regain their health. Men's health beliefs across cultures need further investigation by nurse researchers and NPs. How culture influences healthcare delivery to men should be better understood. If NPs are aware of men's views on masculinity, they are better prepared to understand and assist men in becoming more aware of their health status and to seek health care when appropriate.

  14. Cold-rolled sheets production of stainless martensite-ageing steel smelted by vacuum arc and electroslag techniques

    Energy Technology Data Exchange (ETDEWEB)

    Rivkin, A A; Grishkov, A I; Suslin, A P; Nesterenko, A A; Lola, V N [Tsentral' nyj Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii, Moscow (USSR)

    1975-05-01

    In cooperation with a number of metallurgical works the production of a high strength sheet stainless maraging steel EHP678 (000KH11N10M2T) has been tested by rolling cylindrical ingots of vacuum arc smelting at the blooming (the mass of rough ingots was 5.1 to 6.0 t, that of cleaned ingots - 3.8 to 5.1 t) or rectangular ingots of electroslag smelting (13 t) at the slabbing. The recommended regimes of heating and deformation are much similar to those used for the steel-KH18N10T. The output of valid cold-rolled sheets proved to be rather low (0.24 t/t for the vacuum arc smelting and 0.30 t/t for the electroslag smelting) mainly due to the losses on cleaning and a considerable portion of wrong-size slabs. The data are presented on the steel-EHP678 properties after various heat treatments. For the production of wide cold-rolled sheets of the steel EHP678 it is recommended to use steelmaking procedure with electroslag smelting including open-hearth melting in arc furnaces, rolling of ingots at the slabbing with heating up to 1260-1280 deg C (hold-up of 4.5 to 5 hrs); electroslag smelting for rectangular section slabs, rolling of ingots of electroslag smelting at the slabbing with their heating up to 1250 deg C (hold-up of 5.5 to 6 hrs), rolling at the 1680-type mill with heating up to 1250-1260 deg C (hold-up of 4 to 4.5 hrs ensuring the rolling temperature after a rough group not below 1100 deg C), quenching of hot-rolled sheets heating up to 920-940 deg C (hold-up of 3 to 3.5 min/mm), shot peening of sheets for descaling (provided the respective equipment is available) with a subsequent short-time pickling in an acid solution and cold rolling with a summary deformation of 35 to 45 %. The steelmaking with the electroslag smelting is much more profitable as regards to the fine technology of number of the main procedures, convenient cooperation of the works and a considerably greater output of the final products out of one ton of the steel produced.

  15. Sodium Silicate Gel Effect on Cemented Tailing Backfill That Contains Lead-Zinc Smelting Slag at Early Ages

    OpenAIRE

    Guo, Lijie; Li, Wenchen; Yang, Xiaocong; Xu, Wenyuan

    2018-01-01

    This paper presents the results of an experimental study on the priming effect of sodium silicate gel (SS) on cemented tailing backfill (CTB) that contains lead-zinc smelting slag. CTB and cemented paste (CP) containing lead-zinc smelting slag samples with SS of 0 and 0.4% of the mass of the slag were prepared and cured at 20°C for 1, 3, 7, and 28 days. Mechanical test and pore structure analyses were performed on the studied CTB samples, microstructural analyses (X-ray diffraction analysis a...

  16. Mexican and Cuban Composers in New York City circa 1880-1920

    Directory of Open Access Journals (Sweden)

    John Koegel

    2006-10-01

    Full Text Available Cuban musicians active in New  York in the 1860s through the 1890s such as Ignacio Cervantes, Emilio Agramonte, and Rosalia Chalia assisted in the struggle for Cuban independence from Spain from the vantage point of New York's Cuban émigré community, and they also established  a strong  presence in the city's musical life.  Important Mexican musicians such as Miguel Lerdo  de Tejada and Carlos Curti intermittently visited New York or were long-term residents there. This was especially true during the late- nineteenth century, when the forced political stability during the Porfiriato made possible the extended visits of Mexican musicians and ensembles to North American cities such as New York. The Mexican Revolution also sent Mexican musicians to the United States in search of political freedom as well as economic and artistic opportunities that were temporarily closed to them in Mexico.

  17. Investigation of the particulate derived from indigenous zinc smelting using the nuclear analytical technique

    International Nuclear Information System (INIS)

    Zhu Guanghua

    1995-12-01

    The air particulate samples at the site of indigenous zinc smelting in south of China, using an 8-stage cascade impactor have been collected. The elemental concentrations of the samples were analyzed by PIXE (Particle Induced X-ray Emission) method. As a result, the mass concentrations of more than 17 elements and their size distribution spectra were obtained. Then the data were analyzed by the absolute principal component analysis (APCA) to evaluate principal components and the percent variance explained by them. From the elemental size distribution spectra, three kinds of patterns were found that they corresponded to the tree principal components and suggested that they were from ore vapor, coal burning and soil dust. Based on the elemental size distribution spectra and a deposit model the deposited amounts for several elements in a human's lung during a day were calculated and compared with that of other places. It is shown that the air quality was heavily degraded at the site of indigenous zinc smelting. (5 refs., 3 figs., 2 tabs.)

  18. Modelling of chalcopyrite oxidation reactions in the Outokumpu flash smelting process

    Energy Technology Data Exchange (ETDEWEB)

    Ahokainen, T.; Jokilaakso, A. [Helsinki Univ. of Technology, Otaniemi (Finland)

    1996-12-31

    A mathematical model for simulating oxidation reactions of chalcopyrite particles together with momentum, heat and mass transfer between particle and gas phase in a flash smelting furnace reaction shaft is presented. In simulation, the equations governing the gas flow are solved numerically with a commercial fluid flow package, Phoenics. The particle phase is introduced into the gas flow by a Particle Source In Cell (PSIC) - technique, where a number of discrete particles is tracked in a gas flow and the relevant source terms for momentum, mass, and heat transfer are added to the gas phase equations. The gas phase equations used are elliptic in nature and the fluid turbulence is described by the (k-{epsilon}) -model. Thermal gas phase radiation is simulated with a six-flux radiation model. The chemical reactions of concentrate particles are assumed to happen at two sharp interfaces, and a shrinking core model is applied to describe the mass transfer of chemical species through the reaction product layer. In a molten state, the oxygen consumption is controlled by a film penetration concept. The reacting concentrate particles are a mixture of chalcopyrite and silica. Also a certain amount of pure inert silica is fed to the process as flux. In the simulations the calculation domain includes the concentrate burner and a cylindrical reaction shaft of an industrial scale flash smelting furnace. Some examples about the simulations carried out by the combustion model are presented. (author)

  19. Synthesis of cobalt alloy through smelting method and its characterization as prosthesis bone implant

    International Nuclear Information System (INIS)

    Aminatun,; Putri, N.S Efinda; Indriani, Arista; Himawati, Umi; Hikmawati, Dyah; Suhariningsih

    2014-01-01

    Cobalt-based alloys are widely used as total hip and knee replacements because of their excellent properties, such as corrosion resistance, fatigue strength and biocompatibility. In this work, cobalt alloys with variation of Cr (28.5; 30; 31.5; 33, and 34.5% wt) have been synthesized by smelting method began with the process of compaction, followed by smelting process using Tri Arc Melting Furnace at 200A. Continued by homogenization process at recrystallization temperature (1250° C) for 3 hours to allow the atoms diffuses and transform into γ phase. The next process is rolling process which is accompanied by heating at 1200° C for ± 15 minutes and followed by quenching. This process is repeated until the obtained thickness of ± 1 mm. The evaluated material properties included microstructure, surface morphology, and hardness value. It was shown that microstructure of cobalt alloys with variation of Cr is dominant by γ phase, thus making the entire cobalt alloys have high hardness. It was also shown from the surface morphology of entire cobalt alloys sample indicated the whole process of synthesis that had good solubility were at flat surface area. Hardness value test showed all of cobalt alloys sample had high hardness, just variation of 33% Cr be in the range of ASTMF75, it were 345,24 VHN which is potential to be applied as an implant prosthesis

  20. Smelting of high-quality boiler steel in large-load arc furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Kablukovskij, A F; Breus, V M; Tyurin, E I; Khristich, V D; Dumchev, Ya P [Tsentral' nyj Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii, Moscow (USSR)

    1975-02-01

    High-grade steel can be obtained in large-capacity furnaces if the smelting technology used takes account of the size of the aggregates, the course of the metal fusion process, interaction with slag, furnace atmosphere, reducing agents, and other process characteristics. 12Kh1MF boiler steel smelted in a 100-ton electric arc furnace by an oxidizing process with oxygen bath blow and cast by the siphon method into 6.5-ton ingots using a slag-forming mixture (240 mm diameter billets and 219 to 245 mm diameter tubes) is satisfactory with regard to macro and microstructure, oxygen and nonmetallic oxide inclusion content, and mechanical properties. The stress rupture strength of 10/sup 5/ h at 570/sup 0/C is similar to that of open-hearth steel. Sulfides larger than a 3.5 spheroid have been detected in it. The nitrogen content of the electric steel is 0.0090 to 0.0120%, which is somewhat greater than usual in open-hearth metal. Of the oxygen inclusions in the steel, spinel-alumina predominates. Large inclusions were represented mainly by brittle silicates which appeared to be of exogenous origin.

  1. Application of PAH concentration profiles in lake sediments as indicators for smelting activity.

    Science.gov (United States)

    Warner, Wiebke; Ruppert, Hans; Licha, Tobias

    2016-09-01

    The ability of lake sediment cores to store long-term anthropogenic pollution establishes them as natural archives. In this study, we focus on the influence of copper shale mining and smelting in the Mansfeld area of Germany, using the depth profiles of two sediment cores from Lake Süßer See. The sediment cores provide a detailed chronological deposition history of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in the studied area. Theisen sludge, a fine-grained residue from copper shale smelting, reaches the lake via deflation by wind or through riverine input; it is assumed to be the main source of pollution. To achieve the comparability of absolute contaminant concentrations, we calculated the influx of contaminants based on the sedimentation rate. Compared to the natural background concentrations, PAHs are significantly more enriched than heavy metals. They are therefore more sensitive and selective for source apportionment. We suggest two diagnostic ratios of PAHs to distinguish between Theisen sludge and its leachate: the ratio fluoranthene to pyrene ~2 and the ratio of PAH with logKOW5.7 converging to an even lower value than 2.3 (the characteristic of Theisen sludge) to identify the particulate input in lake environments. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Modelling of chalcopyrite oxidation reactions in the Outokumpu flash smelting process

    Energy Technology Data Exchange (ETDEWEB)

    Ahokainen, T; Jokilaakso, A [Helsinki Univ. of Technology, Otaniemi (Finland)

    1997-12-31

    A mathematical model for simulating oxidation reactions of chalcopyrite particles together with momentum, heat and mass transfer between particle and gas phase in a flash smelting furnace reaction shaft is presented. In simulation, the equations governing the gas flow are solved numerically with a commercial fluid flow package, Phoenics. The particle phase is introduced into the gas flow by a Particle Source In Cell (PSIC) - technique, where a number of discrete particles is tracked in a gas flow and the relevant source terms for momentum, mass, and heat transfer are added to the gas phase equations. The gas phase equations used are elliptic in nature and the fluid turbulence is described by the (k-{epsilon}) -model. Thermal gas phase radiation is simulated with a six-flux radiation model. The chemical reactions of concentrate particles are assumed to happen at two sharp interfaces, and a shrinking core model is applied to describe the mass transfer of chemical species through the reaction product layer. In a molten state, the oxygen consumption is controlled by a film penetration concept. The reacting concentrate particles are a mixture of chalcopyrite and silica. Also a certain amount of pure inert silica is fed to the process as flux. In the simulations the calculation domain includes the concentrate burner and a cylindrical reaction shaft of an industrial scale flash smelting furnace. Some examples about the simulations carried out by the combustion model are presented. (author)

  3. Thermodynamic Analysis of Oxygen-Enriched Direct Smelting of Jamesonite Concentrate

    Science.gov (United States)

    Zhang, Zhong-Tang; Dai, Xi; Zhang, Wen-Hai

    2017-12-01

    Thermodynamic analysis of oxygen-enriched direct smelting of jamesonite concentrate is reported in this article. First, the occurrence state of lead, antimony and other metallic elements in the smelting process was investigated theoretically. Then, the verification test was carried out. The results indicate that lead and antimony mainly exist in the alloy in the form of metallic lead and metallic antimony. Simultaneously, lead and antimony were also oxidized into the slag in the form of lead-antimony oxide. Iron and copper could be oxidized into the slag in the form of oxides in addition to combining with antimony in the alloy, while zinc was mainly oxidized into the slag in the form of zinc oxide. The verification test indicates that the main phases in the alloy contain metallic lead, metallic antimony and a small amount of Cu2Sb, FeSb2 intermetallic compounds, and the slag is mainly composed of kirschsteinite, fayalite and zinc oxide, in agreement with the thermodynamic analysis.

  4. Two-Dimensional Physical and CFD Modelling of Large Gas Bubble Behaviour in Bath Smelting Furnaces

    Directory of Open Access Journals (Sweden)

    Yuhua Pan

    2010-09-01

    Full Text Available The behaviour of large gas bubbles in a liquid bath and the mechanisms of splash generation due to gas bubble rupture in high-intensity bath smelting furnaces were investigated by means of physical and mathematical (CFD modelling techniques. In the physical modelling work, a two-dimensional Perspex model of the pilot plant furnace at CSIRO Process Science and Engineering was established in the laboratory. An aqueous glycerol solution was used to simulate liquid slag. Air was injected via a submerged lance into the liquid bath and the bubble behaviour and the resultant splashing phenomena were observed and recorded with a high-speed video camera. In the mathematical modelling work, a two-dimensional CFD model was developed to simulate the free surface flows due to motion and deformation of large gas bubbles in the liquid bath and rupture of the bubbles at the bath free surface. It was concluded from these modelling investigations that the splashes generated in high-intensity bath smelting furnaces are mainly caused by the rupture of fast rising large gas bubbles. The acceleration of the bubbles into the preceding bubbles and the rupture of the coalescent bubbles at the bath surface contribute significantly to splash generation.

  5. ""Una Persona Derechita" (Staying Right in the Mind)": Perceptions of Spanish-Speaking Mexican American Older Adults in South Texas "Colonias"

    Science.gov (United States)

    Sharkey, Joseph R.; Sharf, Barbara F.; St. John, Julie A.

    2009-01-01

    Purpose: This study describes the perceptions of brain health among older Spanish-speaking Mexican Americans who reside in colonia areas of the Lower Rio Grande Valley of Texas. Design and Methods: In 2007, 33 Mexican American older adults (9 men and 24 women) were recruited by "promotoras" (community health workers) from clusters of…

  6. Community

    Science.gov (United States)

    stability Science & Innovation Collaboration Careers Community Environment Science & Innovation Recruitment Events Community Commitment Giving Campaigns, Drives Economic Development Employee Funded neighbor pledge: contribute to quality of life in Northern New Mexico through economic development

  7. AIDS in Mexican prisons.

    Science.gov (United States)

    Olivero, J M; Roberts, J B

    1995-01-01

    The human rights organization Americas Watch, which toured Mexican prisons, reported in 1991 that all prisoners with HIV infection in the Mexico City area were housed in a single AIDS ward in Santa Marta Prison. In 1991, the 16-bed facility had 15 patients; in 1993, this number had increased by 5. In Mexico City, with 3 prisons holding over 2000 male adults each, there were only 20 known infected prisoners in the AIDS ward at Santa Marta. In 1991, authorities at Matamoros, in the state of Tamaulipas, insisted that none of their inmates had ever been diagnosed as infected with HIV. The prison physician at Reynosa indicated that only 2 inmates since 1985 had ever been diagnosed as infected. In 1992, the prison in Saltillo, in the state of Coahuila, reported that here had yet to be a single positive test for HIV. The prison at Reynosa held 1500 people and only 2 inmates were diagnosed as having AIDS between 1985 and 1991. Prisons at Matamoros and Saltillo held similar numbers but had no experience of infected inmates. A survey of 2 prisons in the state of Tamaulipas indicates that around 12% of the population may use IV drugs, and 9% indicate sharing needles. It is possible for prisoners to die of diseases like pneumonia, associated with AIDS, without the connection to AIDS being diagnosed. Each state, and possibly each prison in Mexico, has its own particular AIDS policies. Santa Marta was the single facility in Mexico City used to house AIDS-infected prisoners, who were segregated. Finally, the prison at Saltillo required all women entering the facility to have a medical examination, including a test for HIV. High-level prison personnel have demonstrated ignorance and fear of AIDS and intolerance of infected prisoners. Mexico must reassess the need to provide adequate medical care to offenders who are sick and dying behind bars.

  8. Mexican agencies reach teenagers.

    Science.gov (United States)

    Brito Lemus, R; Beamish, J

    1992-08-01

    The Gente Joven project of the Mexican Foundation for Family Planning (MEXFAM) trains young volunteers in 19 cities to spread messages about sexually transmitted diseases and population growth to their peers. They also distribute condoms and spermicides. It also uses films and materials to spread its messages. The project would like to influence young men's behavior, but the Latin image of machismo poses a big challenge. It would like to become more responsible toward pregnancy prevention. About 50% of adolescents have sexual intercourse, but few use contraceptives resulting in a high adolescent pregnancy rate. Many of these pregnant teenagers choose not to marry. Adolescent pregnancy leads to girls leaving school, few marketable skills, and rearing children alone. Besides women who began childbearing as a teenager have 1.5 times more children than other women. Male involvement in pregnancy prevention should improve these statistics. As late as 1973, the Health Code banned promotion and sales of contraceptives, but by 1992 about 50% of women of reproductive age use contraceptives. The Center for the Orientation of Adolescents has organized 8 Young Men's Clubs in Mexico City to involve male teenagers more in family planning and to develop self-confidence. It uses a holistic approach to their development through discussions with their peers. A MEXFAM study shows that young men are not close with their fathers who tend to exude a machismo attitude, thus the young men do not have a role model for responsible sexual behavior. MEXFAM's work is cut out for them, however, since the same study indicates that 50% of the young men believe it is fine to have 1 girlfriend and 33% think women should earn more than men. A teenager volunteer reports, however, that more boys have been coming to him for contraception and information than girls in 1992 while in other years girls outnumbered the boys.

  9. Sampling uncharted waters: Examining rearing habitat of larval Longfin Smelt (Spirinchus thaleichthys) in the upper San Francisco Estuary

    Science.gov (United States)

    Grimaldo, Lenny; Feyrer, Frederick; Burns, Jillian; Maniscalco, Donna

    2017-01-01

    The southern-most reproducing Longfin Smelt population occurs in the San Francisco Estuary, California, USA. Long-term monitoring of estuarine habitat for this species has generally only considered deep channels, with little known of the role shallow waters play in supporting their early life stage. To address the need for focused research on shallow-water habitat, a targeted study of Longfin Smelt larvae in littoral habitat was conducted to identify potential rearing habitats during 2013 and 2014. Our study objectives were to (1) determine if larval densities vary between littoral habitats (tidal slough vs. open-water shoal), (2) determine how larval densities in littoral habitats vary with physicochemical and biological attributes, (3) determine if larval densities vary between littoral habitats and long-term monitoring channel collections, and (4) determine what factors predict larval rearing distributions from the long-term monitoring channel collections. Larval densities did not vary between littoral habitats but they did vary between years. Water temperature, salinity, and chlorophyll a were found important in predicting larval densities in littoral habitats. Larval densities do not vary between littoral and channel surveys; however, the analysis based on channel data suggests that Longfin Smelt are hatching and rearing in a much broader region and under higher salinities (∼2–12 psu) than previously recognized. Results of this study indicate that conservation efforts should consider how freshwater flow, habitat, climate, and food webs interact as mechanisms that influence Longfin Smelt recruitment in estuarine environments.

  10. The recovery of Zn and Pb and the manufacture of lightweight bricks from zinc smelting slag and clay.

    Science.gov (United States)

    Hu, Huiping; Deng, Qiufeng; Li, Chao; Xie, Yue; Dong, Zeqin; Zhang, Wei

    2014-04-30

    Novel lightweight bricks have been produced by sintering mixes of zinc smelting slag and clay. A two-stage sintered process has been proposed to recovery of Zn and Pb and reutilization of the zinc smelting slag. In the first stage of the process, called reduction and volatilization procedure, zinc and lead were reduced by the carbon contained in the zinc smelting slag and volatilized into the dust, and the dust can be used as a secondary zinc resource. In the second stage of the process, called oxidation sintering procedure, a lightweight brick was produced. Samples containing up to 60 wt.% zinc smelting slag and 40 wt.% kaolin clay were reduced at 1050°C for 6h, and then sintered at 1050°C for 4h. The recoveries of Zn and Pb from the brick are 94.5 ± 0.6% and 97.6 ± 0.2%, respectively. Low bulk density (1.42 g cm(-3)) and relatively high compressive strength (2 2MPa) sintered bricks were produced, and the leaching toxicity of the sintered bricks was below the regulatory thresholds of Chinese National Standards. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Karyotype and chromosomal characteristics of Ag-NOR sites and 5S rDNA in European smelt, Osmerus eperlanus

    Czech Academy of Sciences Publication Activity Database

    Ocalewicz, K.; Hliwa, P.; Krol, J.; Rábová, Marie; Stabinski, R.; Ráb, Petr

    2007-01-01

    Roč. 131, - (2007), s. 29-35 ISSN 0016-6707 R&D Projects: GA AV ČR IAA6045405; GA MŠk LC06073 Institutional research plan: CEZ:AV0Z50450515 Keywords : chromosome banding * cytotaxonomy of smelt * fish cytogenetics Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.396, year: 2007

  12. La Artesania Mexicana (Mexican Handicrafts).

    Science.gov (United States)

    Steele, Bettina

    This booklet contains instructions in English and Spanish for making eleven typical Mexican craft articles. The instructions are accompanied by pen-and-ink drawings. The objects are (1) "La Rosa" (The Rose); (2) "El Crisantemo" (The Chrysanthemum); (3) "La Amapola" (The Poppy); (4) "Ojos de Dios" (God's Eyes); (5) "Ojitos con dos caras" (Two-Sided…

  13. Historical aspects of Mexican psychiatry.

    Science.gov (United States)

    Bayardo, Sergio Javier Villaseñor

    2016-04-01

    Mexican psychiatry initiated since pre-Hispanic times. Historically, treatments were a mixture of magic, science and religion. Ancient Nahuas had their own medical concepts with a holistic view of medicine, considering men and cosmos as a whole. The first psychiatric hospital appeared in 1566 and a more modern psychiatric asylum emerged until 1910. International exchanges of theoretical approaches started in the National University with the visit of Pierre Janet. There were other important figures that influenced Mexican psychiatry, such as Erich Fromm, Henri Ey, Jean Garrabé and Yves Thoret. Regarding Mexican psychiatrists, some of the most important contributors to Mexican psychiatry were José Luis Patiño Rojas, Manuel Guevara Oropeza and Ramón de la Fuente Muñiz. This article includes excerpts from "Clinical Psychiatry", a book by Patiño Rojas where he tries to understand and describe the inner world experienced by patients with schizophrenia; also, the thesis conducted by Guevara Oropeza ("Psychoanalisis"), which is a critical comparison between the theories of Janet and Freud. Finally, we include "The study of consciousness: current status" by Ramón de la Fuente, which leads us through the initial investigations concerning consciousness, its evolution, and the contributions made by psychology, philosophy and neurobiology.

  14. The Mexican Axolotl in Schools

    Science.gov (United States)

    Thomas, R. M.

    1976-01-01

    Suggests and describes laboratory activities in which the Mexican axolotl (Ambystoma mexicanum Shaw) is used, including experiments in embryology and early development, growth and regeneration, neoteny and metamorphosis, genetics and coloration, anatomy and physiology, and behavior. Discusses care and maintenance of animals. (CS)

  15. Proverbs in Mexican American Tradition.

    Science.gov (United States)

    Arora, Shirley L.

    1982-01-01

    Examines proverb use among 304 Mexican Americans (aged 16-85) of Los Angeles (California), assembling information on how or where particular proverbs were learned, with whom or what kind of individual their use is associated, the occasions on which they are used, and general attitudes toward the use of proverbs. (LC)

  16. Diet, Prey Selection, and Body Condition of Age-0 Delta Smelt, Hypomesus transpacificus, in the Upper San Francisco Estuary

    Directory of Open Access Journals (Sweden)

    Steven B. Slater

    2014-09-01

    Full Text Available Steven B. Slater and Randall D. Baxterdoi: http://dx.doi.org/10.15447/sfews.2014v12iss3art1The Delta Smelt, an endangered fish, has suffered a long-term decline in abundance, believed to result from, in part, to changes in the pelagic food web of the upper San Francisco Estuary. To investigate the current role of food as a factor in Delta Smelt well-being, we developed reference criteria for gut fullness and body condition based on allometric growth. We then examined monthly diet, prey selectivity, and gut fullness of larvae and juvenile Delta Smelt collected April through September in 2005 and 2006 for evidence of feeding difficulties leading to reduced body condition. Calanoid copepods Eurytemora affinis and Pseudodiaptomus forbesi remained major food items during spring and from early summer through fall, respectively. Other much larger copepods and macroinvertebrates contributed in lesser numbers to the diet of older juvenile fish from mid-summer through fall. In fall, juvenile Delta Smelt periodically relied heavily on very small prey and prey potentially associated with demersal habitat, suggesting typical pelagic food items were in short supply. We found a strong positive selection for E. affinis and P. forbesi, neutral to negative selection for evasive calanoid Sinocalanus doerrii, and neutral to negative selection for the small cyclopoid copepod Limnoithona tetraspina and copepod nauplii, which were consumed only when extremely numerous in the environment. Feeding incidence was significantly higher in 2006, but among successfully feeding fish we found no between year difference in gut fullness. However, we did detect differences in fullness across months in both years. We found no difference in body condition of Delta Smelt between years yet our sample sizes were low in September when Delta Smelt reverted to feeding on very small organisms and fullness declined, so the longer-term effect remains unknown. Our findings suggest that: Delta

  17. Trace element partitioning and soil particle characterisation around mining and smelting areas at Tharsis, Riotinto and Huelva, SW Spain

    Energy Technology Data Exchange (ETDEWEB)

    Chopin, E.I.B. [School of Human and Environmental Sciences, University of Reading (United Kingdom)]. E-mail: edith.chopin@univ-reims.fr; Alloway, B.J. [School of Human and Environmental Sciences, University of Reading (United Kingdom)

    2007-02-15

    Trace elements may present an environmental hazard in the vicinity of mining and smelting activities. However, the factors controlling trace element distribution in soils around ancient and modern mining and smelting areas are not always clear. Tharsis, Riotinto and Huelva are located in the Iberian Pyrite Belt in SW Spain. Tharsis and Riotinto mines have been exploited since 2500 B.C., with intensive smelting taking place. Huelva, established in 1970 and using the Flash Furnace Outokumpu process, is currently one of the largest smelter in the world. Pyrite and chalcopyrite ore have been intensively smelted for Cu. However, unusually for smelters and mines of a similar size, the elevated trace element concentrations in soils were found to be restricted to the immediate vicinity of the mines and smelters, being found up to a maximum of 2 km from the mines and smelters at Tharsis, Riotinto and Huelva. Trace element partitioning (over 2/3 of trace elements found in the residual immobile fraction of soils at Tharsis) and soil particles examination by SEM-EDX showed that trace elements were not adsorbed onto soil particles, but were included within the matrix of large trace element-rich Fe silicate slag particles (i.e. 1 mm o at least 1 wt.% As, Cu and Zn, and 2 wt.% Pb). Slag particle large size (1 mm o) was found to control the geographically restricted trace element distribution in soils at Tharsis, Riotinto and Huelva, since large heavy particles could not have been transported long distances. Distribution and partitioning indicated that impacts to the environment as a result of mining and smelting should remain minimal in the region.

  18. Polychlorinated dibenzo-p-dioxin and dibenzofuran and polychlorinated biphenyl emissions from different smelting stages in secondary copper metallurgy.

    Science.gov (United States)

    Hu, Jicheng; Zheng, Minghui; Nie, Zhiqiang; Liu, Wenbin; Liu, Guorui; Zhang, Bing; Xiao, Ke

    2013-01-01

    Secondary copper production has received much attention for its high emissions of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) reported in previous studies. These studies focused on the estimation of total PCDD/F and polychlorinated biphenyl (PCB) emissions from secondary copper smelters. However, large variations in PCDD/F and PCB emissions reported in these studies were not analyzed and discussed further. In this study, stack gas samples at different smelting stages (feeding-fusion, oxidation and deoxidization) were collected from four plants to investigate variations in PCDD/F and PCB emissions and characteristics during the secondary copper smelting process. The results indicate that PCDD/F emissions occur mainly at the feeding-fusion stage and these emissions contribute to 54-88% of the total emissions from the secondary copper smelting process. The variation in feed material and operating conditions at different smelting stages leads to the variation in PCDD/F emissions during the secondary copper smelting process. The total PCDD/F and PCB discharge (stack gas emission+fly ash discharge) is consistent with the copper scrap content in the raw material in the secondary copper smelters investigated. On a production basis of 1 ton copper, the total PCDD/F and dl-PCB discharge was 102, 24.8 and 5.88 μg TEQ t(-1) for the three plants that contained 100%, 30% and 0% copper scrap in their raw material feed, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Riders on the storm: selective tidal movements facilitate the spawning migration of threatened delta smelt in the San Francisco Estuary

    Science.gov (United States)

    Bennett, W.A.; Burau, Jon R.

    2015-01-01

    Migration strategies in estuarine fishes typically include behavioral adaptations for reducing energetic costs and mortality during travel to optimize reproductive success. The influence of tidal currents and water turbidity on individual movement behavior were investigated during the spawning migration of the threatened delta smelt, Hypomesus transpacificus, in the northern San Francisco Estuary, California, USA. Water current velocities and turbidity levels were measured concurrently with delta smelt occurrence at sites in the lower Sacramento River and San Joaquin River as turbidity increased due to first-flush winter rainstorms in January and December 2010. The presence/absence of fish at the shoal-channel interface and near the shoreline was quantified hourly over complete tidal cycles. Delta smelt were caught consistently at the shoal-channel interface during flood tides and near the shoreline during ebb tides in the turbid Sacramento River, but were rare in the clearer San Joaquin River. The apparent selective tidal movements by delta smelt would facilitate either maintaining position or moving upriver on flood tides, and minimizing advection down-estuary on ebb tides. These movements also may reflect responses to lateral gradients in water turbidity created by temporal lags in tidal velocities between the near-shore and mid-channel habitats. This migration strategy can minimize the energy spent swimming against strong river and tidal currents, as well as predation risks by remaining in turbid water. Selection pressure on individuals to remain in turbid water may underlie population-level observations suggesting that turbidity is a key habitat feature and cue initiating the delta smelt spawning migration.

  20. Mexican journals of educational research towards mainstream dissemination of science

    Directory of Open Access Journals (Sweden)

    Cabrera-Flores, Mayer

    2014-08-01

    Full Text Available The purpose of this study is to analyze the Electronic Journal of Educational Research (REDIE on its path towards the common manner of scientific dissemination. This research presents the evolution of Mexican policy with regards to the journals, the situation of the Educational Research Mexican journals, and its profundity relating to REDIE. In its evolution, there were three moments that stood out the most: the standardization of quality criteria, the digitalization and open access of the scientific journals, those that came together with REDIE like REDALYC and LATINDEX , and the individual initiatives of those journals that motivated the development of the scientific dissemination in Mexico. The investigation concludes with the realization of the necessity of achieving agreement on the efforts of various principal actors: governmental bodies, institutions, and academic communities.

  1. Undocumented immigration status and diabetes care among Mexican immigrants in two immigration "sanctuary" areas.

    Science.gov (United States)

    Iten, A Elizabeth; Jacobs, Elizabeth A; Lahiff, Maureen; Fernández, Alicia

    2014-04-01

    The objective of this study is to investigate the relationship between immigration status and the patient experience of health care, diabetes self-management, and clinical outcomes among Mexican immigrants with diabetes receiving health care in two immigration sanctuary cities. We used data from the Immigration, Culture and Health Care study, a cross-sectional survey and medical record study of low-income patients with diabetes recruited from public hospitals and community clinics in the San Francisco Bay Area and Chicago. Undocumented Mexican, documented Mexican immigrants, and US-born Mexican-Americans' health care experiences, diabetes self-management, and clinical outcomes were compared using multivariate linear and logistic regressions. We found no significant differences in reports of physician communication, or in measures of diabetes management between undocumented and documented immigrants. All three groups had similar clinical outcomes in glycemic, systolic blood pressure, and lipid control. These results indicate that, at least in some settings, undocumented Mexican immigrants with diabetes can achieve similar clinical outcomes and report similar health care experiences as documented immigrants and US-born Mexican-Americans.

  2. Age at migration and disability-free life expectancy among the elder Mexican-origin population

    Directory of Open Access Journals (Sweden)

    Marc Garcia

    2016-12-01

    Full Text Available Background: Migration selectivity is thought to shape the health profiles of Mexican immigrants. Objective: This study examines how the experience of Mexican migration to the United States affects the health process and the quality of life in old age by age at migration, specific to sex. Methods: We use 20 years of data from the Hispanic Established Populations for the Epidemiologic Study of the Elderly to estimate the proportion of life spent disability-free prior to death across eight subgroups by sex, nativity, and age at migration among Mexican-origin elderly in the United States. Results: Female migrants are at a significant disadvantage in terms of IADL disability-free life expectancy relative to US-born women, particularly late-life migrants. Conversely, mid- and late-life male migrants exhibit an advantage in ADL disability-free life expectancy compared to their US-born counterparts. Conclusions: Foreign-born Mexican elders are not a homogeneous group. This issue merits special attention in the development of community-based long-term care programs in order to appropriately target the specific needs of different subgroups of older Mexican individuals entering their last decades of life. Contribution: This study contributes to immigrant health literature by providing a more comprehensive documentation of nativity differentials, by distinguishing subgroups of Mexican elderly by sex, nativity, and age at migration.

  3. Trace elements in rainwater and dry deposition around a smelting complex

    Energy Technology Data Exchange (ETDEWEB)

    Beavington, F

    1977-06-01

    A number of plastic raingauges were set up at various distances around a smelting complex (copper smelter and steelworks) in Wollongong, Australia, to determine the pattern of total atmospheric deposition (rainwater and dry deposition) of copper, zinc, lead, cadmium, iron and manganese. At the site nearest the smelter, total deposition of these metals (6N HCl soluble) in kg/ha over a period of twelve months was 30.7 copper, 8.4 zinc, 4.7 lead, 0.19 cadmium, 42.6 iron and 1.5 manganese. These levels were considerably higher than at a distant rural site where background levels were similar to those reported for the United Kingdom. The pattern of deposition of metals over Wollongong accords with levels of metals previously reported in surface soil, herbage and leaf vegetables.

  4. Lance for fuel and oxygen injection into smelting or refining furnace

    Science.gov (United States)

    Schlichting, Mark R.

    1994-01-01

    A furnace 10 for smelting iron ore and/or refining molten iron 20 is equipped with an overhead pneumatic lance 40, through which a center stream of particulate coal 53 is ejected at high velocity into a slag layer 30. An annular stream of nitrogen or argon 51 enshrouds the coal stream. Oxygen 52 is simultaneously ejected in an annular stream encircling the inert gas stream 51. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus 84 to react with carbon monoxide gas rising from slag layer 30, thereby adding still more heat to the furnace.

  5. Statistical modeling of copper losses in the silicate slag of the sulfide concentrate smelting process

    Directory of Open Access Journals (Sweden)

    Savic Marija V.

    2015-09-01

    Full Text Available This article presents the results of the statistical modeling of copper losses in the silicate slag of the sulfide concentrates smelting process. The aim of this study was to define the correlation dependence of the degree of copper losses in the silicate slag on the following parameters of technological processes: SiO2, FeO, Fe3O4, CaO and Al2O3 content in the slag and copper content in the matte. Multiple linear regression analysis (MLRA, artificial neural networks (ANNs and adaptive network based fuzzy inference system (ANFIS were used as tools for mathematical analysis of the indicated problem. The best correlation coefficient (R2 = 0.719 of the final model was obtained using the ANFIS modeling approach.

  6. Community.

    Science.gov (United States)

    Grauer, Kit, Ed.

    1995-01-01

    Art in context of community is the theme of this newsletter. The theme is introduced in an editorial "Community-Enlarging the Definition" (Kit Grauer). Related articles include: (1) "The Children's Bridge is not Destroyed: Heart in the Middle of the World" (Emil Robert Tanay); (2) "Making Bridges: The Sock Doll…

  7. Geochemical Study on an Abandoned Copper Smelting Plant Using Rare Earth Elements

    Science.gov (United States)

    Sun, S. H.

    2017-12-01

    The Shuei Nan Dong Copper Smelting Plant smelting is located on the northern coast of New Taipei City, Taiwan. The plant built in 1906 for but has been shut down since 1987. However, the watershed is continuing to discharge acid mine water into the sea; and, the acid mine drainage releases high amounts of sulfate, heavy metals without any treatment. In this study, the water samples were sequentially collected along the main channel and its tributaries in the watershed. The results of hydrochemical analysis show that the untreated inflow water can be characterized with low pH value of 80% of the total variance and almost all chemical components have high loadings in the PC. Therefore, the hydrochemical properties in the watershed are mainly dominated by the mixing process between main channel and the major tributary but the geochemical reactions during flow down the channel is insignificant. Rare earth elements (REE) are an excellent tracer, which can indicate sources of chemical components and geochemical reactions in water. The analysis results demonstrate two distinct REE patterns. The water with low REE can be characterized by prominent Eu positive anomaly and Ce negative anomaly, which may result from the alteration of Na-plagioclase in sandstone and oxidation reaction when contact with air, respectively. On the contrary, the water with high REE shows only minor Ce negative anomaly and insignificant Eu positive anomaly. In addition, there is an enrichment of middle REE in high-REE water, which is quite different with the REE pattern of pyrite. According to the Grawunder's study (2014), it corresponds to the complexation to sulphite during pyrite oxidation. It is worth noting that REE show no considerable fractionation along the channel and confirms the results from PCA. It can be derived that the water may not reached equilibrium condition. A simple aerated retention pool could dramatically reduce the pollutants due to coprecipitation of iron oxide and aluminum

  8. PROFAM expands Mexican family planning clinics.

    Science.gov (United States)

    1983-01-01

    Mexico's private, nonprofit social marketing company, known as PROFAM, intends to expand its family planning clinics to marginal urban areas. The clinics are part of PROFAM's push to diversify social marketing outlets for contraceptive products and other birth control methods. PROFAM expects to establish 3 new clinics, possibly including a pregnancy test laboratory, a small 1-doctor clinic, and a large clinic housing an operating room. 1 clinic will be located outside the Mexico City area, the program's traditional boundaries. The company currently runs 2 small clinics and a pregnancy testing laboratory in Ciudad Netzahualcoyti, a community of 3.5 million on Mexico City's outskirts. PROFAM recently obtaine d government approval to sell condoms in food stores, which should increase distribtuion and sales. Currently, the company sells over 1 million high quality, lubricated condoms each month, accounting for over half of the Mexican market. Distribution covers 85% of the country's drugstore. Program setbacks occurred in 1981, when the Mexican government cancelled PROFAM's sales permits for all contraceptive products except condoms. Cancelled products included an oral contraceptive and 3 vaginal spermicides. These 4 products had provided nearly 100,000 couple years of protection in 1979 and an estimated 120,000 CYP 1980. During 1979 and 1980, condoms provided about 27,000 and 60,000 CYP, respectively. PROFAM had relied heavily on the pill and spermicides because its early studies showed condoms had a negative image in Mexico, due largely to the product's association with extramarital affairs. To counter this, PROFAM launched a widespread, free product sampling program in 1979, along with a continuing educational and advertising drive. Subsequent consumer surveys revealed a marked increase in product acceptance, with PROFAM's condom becoming the most widely known brand available in Mexico.

  9. New tariffs confuse Mexican market

    International Nuclear Information System (INIS)

    Coeyman, M.

    1992-01-01

    Indelpro - the Grupo Alfa/Himont joint venture 150,000-m.t./year polypropylene (PP) plant in Altamira, Mexico - has been working to find its place in the Mexican market since coming onstream in March. At the same time, that market has been complicated by the imposition of import and export tariffs by the U.S. Department of Commerce early this fall. Commerce's accession to a 10% ad valorem tax on US PP exports to Mexico surprised some industry observers. The tariff is scheduled to be phased out within 10 years and is partly countermanded by a 5% tariff over a five-year period on Mexican PP exports to the US. But some market analysts say the arrangement is baffling

  10. NAFTA and the Mexican Economy

    Science.gov (United States)

    2008-11-04

    its loans. Then President Miguel de la Madrid took steps to open and liberalize the Mexican economy and initiated procedures to replace import...capita income in countries. 24 Lessons from NAFTA, 2005. 25 Economia , “NAFTA and Convergence in North America: High Expectations, Big Events, Little Time...Easterly, Norbert Fiess, and Daniel Lederman, Economia , “NAFTA and Convergence in North America: High Expectations, Big Events, Little Time,” Fall 2003. The

  11. Mexican Migrant and Seasonal Farmworker Culture, Gender, and Language Ideologies: Platicas de HIV/AIDS

    Science.gov (United States)

    Allison, Donald N.

    2013-01-01

    Lack of health access and limited health care services are major concerns for those who provide healthcare for marginalized Mexican migrant and seasonal farmworker communities (MMSF). Health risks related to several deadly illnesses generate a significant challenge in providing services to this transnational population. In the United States,…

  12. Consequences of Arizona's Immigration Policy on Social Capital among Mexican Mothers with Unauthorized Immigration Status

    Science.gov (United States)

    Valdez, Carmen R.; Padilla, Brian; Valentine, Jessa Lewis

    2013-01-01

    This study explores the consequences of increasingly restrictive immigration policies on social capital among Mexican mothers with unauthorized immigrant status in Arizona. Three focus groups conducted in Arizona explore how mothers' experiences with immigration policies have affected their neighborhood, community, and family ties. Focus group…

  13. Culturally Competent Diabetes Self-Management Education for Mexican Americans: The Starr County Border Health Initiative.

    Science.gov (United States)

    Brown, Sharon A.; Garcia, Alexandra A.; Kouzekanani, Kamiar; Hanis, Craig L.

    2002-01-01

    In a culturally competent diabetes self-management intervention in Starr County, Texas, bilingual Mexican American nurses, dieticians, and community workers provided weekly instruction on nutrition, self-monitoring, exercise and other self-care topics. A biweekly support group promoted behavior change. Interviews and examinations with 256 Mexican…

  14. Pollution level and inhalation exposure of ambient aerosol fluoride as affected by polymetallic rare earth mining and smelting in Baotou, north China

    Science.gov (United States)

    Zhong, Buqing; Wang, Lingqing; Liang, Tao; Xing, Baoshan

    2017-10-01

    Airborne fluoride associated with total suspended particles (TSP) and respirable particulate (PM10) in the rare earth mining and smelting areas were analyzed during August 2012 and March 2013. In March, average concentrations of fluoride bound to TSP in the mining and smelting areas were 0.598 ± 0.626 μg/m3 and 3.615 ± 4.267 μg/m3, respectively, whereas that in August were 0.699 ± 0.801 μg/m3 and 1.917 ± 2.233 μg/m3, respectively. TSP samples were classified into four categories by different sampling periods and locations using Kohonen's self-organizing map, which demonstrates that high airborne fluoride concentrations in March in the smelting area were probably attributed to industrial emissions from smelting activities and wind-blown dust from tailings pond, influenced by meteorologic parameters such as temperature, relative humidity, precipitation and wind speed. The mean daily amount of fluoride inhaled in the mining and smelting areas were estimated to be in the range of 2.77-57.61 μg/day and 3.39-64.32 μg/day, respectively. These results indicate the high potential exposure level of fluoride inhaled for local residents in the polymetallic mining and smelting areas.

  15. EAF smelting trials of waste-carbon briquettes at Avesta Works of Outokumpu Stainless AB for recycling oily mill scale sludge from stainless steel production

    Energy Technology Data Exchange (ETDEWEB)

    Yang Qixing; Bjoerkman, Bo [Div. of Process Metallurgy, Lulea Univ. of Tech., Lulea (Sweden); Holmberg, Nils [Raw Materials Handling, Avesta Works, Outokumpu Stainless AB, Avesta (Sweden)

    2009-06-15

    The EAF steel plant of Avesta Works, Outokumpu Stainless AB, has been used to perform smelting reduction trials of briquettes consisting of oily mill scale sludge, carbon and other wastes. A total of 7 briquette smelting trials were performed. The heats were processed smoothly smelting 3 t of briquettes or 3.4 mass-% of metal charges. The quantities of FeSi powder and O{sub 2} gas injected and electric energy supplied were increased to smelt briquettes of 6 t. No impacts were found on the analyses of the crude stainless steel tapped from the EAF during the trials. The results of the briquette smelting have been evaluated by referring to the data from the reference heats and results from earlier laboratory tests. The recovery of Cr, Ni and Fe elements from the briquettes was nearly complete and was found to occur mainly through carbon reduction. The slag masses were not increased in three trials as compared with the reference heats. There were moderate increases in the slag masses in four trial heats. The increases were, nevertheless, lower by 52-69% than the slag masses generated by Si-reduction of the briquette oxides. Afterwards, by referring results from the present trials, waste-carbon briquettes amounting to 1-3 t were smelted very smoothly in many of the EAF heats at Avesta Works to recycle the oily mill scale sludge and other wastes from stainless steel production. (orig.)

  16. Toxic metal levels in children residing in a smelting craft village in Vietnam: a pilot biomonitoring study.

    Science.gov (United States)

    Sanders, Alison P; Miller, Sloane K; Nguyen, Viet; Kotch, Jonathan B; Fry, Rebecca C

    2014-02-04

    In Vietnam, environmental pollution caused by small-scale domestic smelting of automobile batteries into lead ingot is a growing concern. The village of Nghia Lo is a smelting craft village located roughly 25 km southeast of Hanoi in the Red River Delta. Despite the concern of toxic metal exposure in the village, biomonitoring among susceptible populations, such as children, has not been previously conducted. The aim of this study was to determine the body burden of toxic metals in children residing in a smelting craft village. Twenty children from Nghia Lo, Vietnam, ages 18 months to four years were selected for capillary whole blood and toenail biomonitoring. Whole blood lead levels (BLLs) were measured using a portable lead analyzer, and toenail levels of arsenic, cadmium, chromium, lead, manganese, and mercury were analyzed with inductively coupled plasma-mass spectrometry. The findings show that all of the 20 children had detectable BLLs, and every child had levels that exceeded the Centers for Disease Control and Prevention guideline level of 5 μg/dL. Eighty percent of tested subjects had BLLs higher than 10 μg/dL. Five children (25%) had BLLs greater than 45 μg/dL, the level of recommended medical intervention. In addition to blood lead, all of the children had detectable levels of arsenic, cadmium, chromium, lead, manganese, and mercury in toenail samples. Notably, average toenail lead, manganese, and mercury levels were 157 μg/g, 7.41 μg/g, and 2.63 μg/g respectively, well above levels previously reported in children. Significant Spearman's rank correlations showed that there were relationships between blood and toenail lead levels (r = 0.65, p craft villages in Vietnam are co-exposed to toxic metals. There is an urgent need for mitigation to control metal exposure related to domestic smelting.

  17. Business opportunities in the Mexican dairy industry

    NARCIS (Netherlands)

    Wijnands, J.H.M.; Armenta Gutierrez, B.M.; Poelarends, J.J.; Valk, van der O.M.C.

    2010-01-01

    This study explores the Mexican and Dutch business opportunities in the dairy industry in Mexico. The report discusses first the external environment of the Mexican dairy sector: the economic developments, the country's overall competitiveness, and the economic and agricultural policies. Next, it

  18. Stress Resilience among Border Mexican American Women

    Science.gov (United States)

    Guinn, Bobby; Vincent, Vern; Dugas, Donna

    2009-01-01

    The purpose of this study was to identify factors distinguishing Mexican American women living near the U.S.-Mexican border who are resilient to the experience of stress from those who are not. The study sample consisted of 418 participants ranging in age from 20 to 61 years. Data were gathered through a self-report survey instrument composed of…

  19. Mexican Women, Migration and Sex Roles.

    Science.gov (United States)

    Baca, Reynaldo; Dexter, Bryan

    1985-01-01

    Compares Mexican women involved in migration to understand how their sex roles and status have been affected. Uses data from two separate studies: ethnography on migrants' wives left at home in a Mexican village and a survey of unauthorized immigrants in the Los Angeles area. (SA)

  20. A Turnover Model for the Mexican Maquiladoras.

    Science.gov (United States)

    Maertz, Carl P.; Stevens, Michael J.; Campion, Michael A.

    2003-01-01

    From interviews with 47 Mexican maquiladora workers, a model of voluntary turnover was created and compared with models from the United States, Canada, England, and Australia. Despite similarities, the cultural and economic environment affected the precise content of antecedents in the Mexican model. (Contains 63 references.) (SK)

  1. Implications for future survival of delta smelt from four climate change scenarios for the Sacramento–San Joaquin Delta, California

    Science.gov (United States)

    Brown, Larry R.; Bennett, William A.; Wagner, R. Wayne; Morgan-King, Tara; Knowles, Noah; Feyrer, Frederick; Schoellhamer, David H.; Stacey, Mark T.; Dettinger, Mike

    2013-01-01

    Changes in the position of the low salinity zone, a habitat suitability index, turbidity, and water temperature modeled from four 100-year scenarios of climate change were evaluated for possible effects on delta smelt Hypomesus transpacificus, which is endemic to the Sacramento–San Joaquin Delta. The persistence of delta smelt in much of its current habitat into the next century appears uncertain. By mid-century, the position of the low salinity zone in the fall and the habitat suitability index converged on values only observed during the worst droughts of the baseline period (1969–2000). Projected higher water temperatures would render waters historically inhabited by delta smelt near the confluence of the Sacramento and San Joaquin rivers largely uninhabitable. However, the scenarios of climate change are based on assumptions that require caution in the interpretation of the results. Projections like these provide managers with a useful tool for anticipating long-term challenges to managing fish populations and possibly adapting water management to ameliorate those challenges.

  2. Effect of smelting method on the austenite grain size and properties of heat-resisting pearlitic steel

    International Nuclear Information System (INIS)

    Balakhovskaya, M.B.; Khusainova, N.A.; Davlyatova, L.N.

    1975-01-01

    Influence of smelting method on austenite grain size and properties of refractory perlite steel were studied. An opportunity was found to increase the steel refractoriness without deteriorating its other properties. The steel 12Kh1MF of electric or common open-hearth smelting was used. The dependence of kinetics of austenite grain growth on the smelting method was studied in the temperature range 950 deg - 1200 deg C with 1 hour exposure. The grain size of austenite in steel is supposedly determined by aluminium nitrides and vanadium carbides. In tests of normalized (kept for 20 minutes at 950-980 deg C) and tempered (kept for 3 hours at 730 deg C) transverse (tangential) pipe cross-section samples the electric steel had higher impact viscosity than the open-hearth metal. At working temperatures (540 deg -580 deg C) the difference in viscosity has its minimum. Viscosity of both steels 12Kh1MF begins to sharply decrease from 20 deg C. However, electric steel has rather high viscosity even at - 40 deg C, while the open-hearth one becomes brittle as early as at - 20 deg C. Long-term strength tests at 580 deg C under stresses 10-14 kG/mm 2 show that the coarse-grain steel is more refractory, i.e. time till fracture of open-hearth steel samples is twice as long as that of electric steel samples

  3. Effect of smelting method on the austenite grain size and properties of heat-resisting pearlitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Balakhovskaya, M B; Khusainova, N A; Davlyatova, L N [Vsesoyuznyj Nauchno-Issledovatel' skij Teplotekhnicheskij Inst., Moscow (USSR)

    1975-12-01

    Influence of smelting method on austenite grain size and properties of refractory perlite steel were studied. An opportunity was found to increase the steel refractoriness without deteriorating its other properties. The steel 12Kh1MF of electric or common open-hearth smelting was used. The dependence of kinetics of austenite grain growth on the smelting method was studied in the temperature range 950 deg - 1200 deg C with 1 hour exposure. The grain size of austenite in steel is supposedly determined by aluminium nitrides and vanadium carbides. In tests of normalized (kept for 20 minutes at 950-980 deg C) and tempered (kept for 3 hours at 730 deg C) transverse (tangential) pipe cross-section samples the electric steel had higher impact viscosity than the open-hearth metal. At working temperatures (540 deg -580 deg C) the difference in viscosity has its minimum. Viscosity of both steels 12Kh1MF begins to sharply decrease from 20 deg C. However, electric steel has rather high viscosity even at /sup -/40 deg C, while the open-hearth one becomes brittle as early as at /sup -/20 deg C. Long-term strength tests at 580 deg C under stresses 10-14 kG/mm/sup 2/ show that the coarse-grain steel is more refractory, i.e. time till fracture of open-hearth steel samples is twice as long as that of electric steel samples.

  4. Atmospheric thorium pollution and inhalation exposure in the largest rare earth mining and smelting area in China.

    Science.gov (United States)

    Wang, Lingqing; Zhong, Buqing; Liang, Tao; Xing, Baoshan; Zhu, Yifang

    2016-12-01

    Exposure to radionuclide thorium (Th) has generated widespread public concerns, mainly because of its radiological effects on human health. Activity levels of airborne 232 Th in total suspended particulate (TSP) were measured in the vicinity of the largest rare earth mine in China in August 2012 and March 2013. The mean activity concentrations of 232 Th in TSP ranged from 820μBqm -3 in a mining area in August 2012 to 39,720μBqm -3 in a smelting area in March 2013, much higher than the world reference of 0.5μBqm -3 . Multistatistical analysis and Kohonen's self-organizing maps suggested that 232 Th in TSP was mainly derived from rare earth mining and smelting practices. In addition, personal inhalation exposures to 232 Th associated with respirable particulate (PM 10 ) were also measured among local dwellers via personal monitoring. The mean dose values for different age groups in the smelting and mining areas ranged from 97.86 to 417μSvyear - 1 and from 101.03 to 430.83μSvyear -1 , respectively. These results indicate that people living in the study areas are exposed to high levels of widespread 232 Th. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Industrial activity, gas emissions and environmental urban management. Operative condition's diagnostic of smelting activities in Tandil, Argentina

    International Nuclear Information System (INIS)

    Soledad Sosa, Beatriz; Guerrero, Elsa Marcela; Banda Noriega, Roxana

    2013-01-01

    Amongst urban environmental problems, those associated to industry are of particular interest in environmental management. Tandil, a city in Argentina, owes its economic and urban growth to metalworking activity, especially to smelting. Despite the crisis in the sector, activity continues to be the axis of local economic and urban growth. The present research characterizes, in production, operative and environmental terms, local smelting industries and assesses operative conditions of gas emissions management during 2010. There were analyzed 25 industries over 30. The sample was representative of five productive processes: aluminum (Al), aluminum/iron (Al Fe), aluminum/bronze (Al Cu+Sn), aluminum/iron/bronze (Al Fe Cu+Sn), and iron (Fe). The variables analyzed were: primary fusion mater, oven used and industry size. To obtain production data we applied structured interviews, and for industry sizes we used surveys. It was possible to describe the productive prospect of the sector at a local level: for most industries the destination of their production is automotive sector. Taking into account the relation between the size and the type of industry, the aluminum smelting companies are small. Regarding iron industries, all three company sizes are present in the sample and exists a medium size industry that occupies between 51 and 230 employees. The operative conditions and their compliance with current legislation regarding control of gas emissions require to identify monitoring indicators for the melting stage that allow knowing precisely the resulting contaminants and their environmental effects.

  6. Sodium Silicate Gel Effect on Cemented Tailing Backfill That Contains Lead-Zinc Smelting Slag at Early Ages

    Directory of Open Access Journals (Sweden)

    Lijie Guo

    2018-01-01

    Full Text Available This paper presents the results of an experimental study on the priming effect of sodium silicate gel (SS on cemented tailing backfill (CTB that contains lead-zinc smelting slag. CTB and cemented paste (CP containing lead-zinc smelting slag samples with SS of 0 and 0.4% of the mass of the slag were prepared and cured at 20°C for 1, 3, 7, and 28 days. Mechanical test and pore structure analyses were performed on the studied CTB samples, microstructural analyses (X-ray diffraction analysis and thermal gravity analysis were performed on the studied CP samples, whereas the electrical conductivity of CTB was monitored. The results reveal that SS has a significant positive effect on cementitious activity of binder mixed by cement and lead-zinc smelting slag. This activation leads to the acceleration of binder hydration process, the formation of more cement hydration products in the CTBs, and the refinement of their pore structure, which is favorable for the strength development of CTB.

  7. Acculturative stress negatively impacts maternal depressive symptoms in Mexican-American women during pregnancy

    Science.gov (United States)

    D’Anna-Hernandez, Kimberly L.; Aleman, Brenda; Flores, Ana-Mercedes

    2015-01-01

    Background Mexican-American women exhibit high rates of prenatal maternal depressive symptoms relative to the general population. Though pregnant acculturated Mexican-American women experience cultural stressors such as acculturation, acculturative stress and discrimination that may contribute to elevated depressive symptoms, the contribution of these socio-cultural correlates to depressive symptomology is unknown. Method Ninety-eight pregnant women of Mexican descent were recruited from a community hospital clinic during their first trimester. Women completed surveys about acculturation, acculturative stress, perceived discrimination, general perceived stress, and maternal depressive symptoms as well as the potential protective factor of Mexican cultural values. Results Women who experienced greater acculturative and perceived stress, but not perceived discrimination or acculturation, reported significantly elevated depressive symptoms during pregnancy. Also, women who experienced greater acculturative stress identified with a mixture of Mexican and American cultural values. However, only the Mexican cultural value of respect was protective against maternal depressive symptoms while adhering to the Anglo value of independence and self-reliance was a risk factor. Limitations A limitation in the study is the cross-sectional and descriptive self-report nature of the work, underscoring the need for additional research. Moreover, physiological measures of stress were not analyzed in the current study. Conclusions Results point to acculturative stress, above other cultural stressors, as a potential intervention target in culturally competent obstetric care. These findings have implications for maternal mental health treatment during pregnancy, which likely affects maternal-fetal programming and may favorably affect perinatal outcomes in the vulnerable Mexican-American population. PMID:25699668

  8. Study on Apparent Kinetic Prediction Model of the Smelting Reduction Based on the Time-Series

    Directory of Open Access Journals (Sweden)

    Guo-feng Fan

    2012-01-01

    Full Text Available A series of direct smelting reduction experiment has been carried out with high phosphorous iron ore of the different bases by thermogravimetric analyzer. The derivative thermogravimetric (DTG data have been obtained from the experiments. One-step forward local weighted linear (LWL method , one of the most suitable ways of predicting chaotic time-series methods which focus on the errors, is used to predict DTG. In the meanwhile, empirical mode decomposition-autoregressive (EMD-AR, a data mining technique in signal processing, is also used to predict DTG. The results show that (1 EMD-AR(4 is the most appropriate and its error is smaller than the former; (2 root mean square error (RMSE has decreased about two-thirds; (3 standardized root mean square error (NMSE has decreased in an order of magnitude. Finally in this paper, EMD-AR method has been improved by golden section weighting; its error would be smaller than before. Therefore, the improved EMD-AR model is a promising alternative for apparent reaction rate (DTG. The analytical results have been an important reference in the field of industrial control.

  9. Antimony smelting process generating solid wastes and dust: characterization and leaching behaviors.

    Science.gov (United States)

    Guo, Xuejun; Wang, Kunpeng; He, Mengchang; Liu, Ziwei; Yang, Hailin; Li, Sisi

    2014-07-01

    A large amount of solid waste has been produced by the antimony smelting process in the "World Capital of Antimony", Xikuangshan area in China. This study comprehensively investigated the physical and chemical characteristics of the various solid wastes, as well as the leaching behavior of the solid wastes, which included water-quenched slag, arsenic-alkali residue, desulfurized slag and blast furnace dust. These four types of waste were enriched in a variety of heavy metals and metalloids and more specifically with As and Sb levels up to 8.6 × 10⁴ and 3.16×10⁵ mg/kg, respectively, in arsenic-alkali residue. For desulfurized slag and water-quenched slag, the leaching concentration of Sb significantly exceeded the acceptable limits during the leaching tests using the toxicity characteristic leaching procedure and the synthetic precipitation leaching procedure. In addition, As leaching in arsenic-alkali residue was extraordinarily hazardous, being three orders of magnitude higher than the regulatory level of As. According to the results of the extraction tests, all the tested wastes were classified as hazardous waste. Copyright © 2014. Published by Elsevier B.V.

  10. Questions about the reliability of recovery boilers of steel smelting units

    Energy Technology Data Exchange (ETDEWEB)

    Sazykin, Yu K; Mukhametzyanov, N K

    1979-01-01

    Because the main reason for failure of recovery boilers is contamination of the heating surfaces, the operational conditions of individual elements of boiler units, equipped with vibrational and pulsed cleaning are analyzed and the reliability of the cleaning systems in use today is evaluated. The recovery boilers from open hearth furnaces and two bath steel smelting units from the Magnitogorsk Metallurgic Combine were selected as the subjects of the study. It is established that the boiler heating surface cleaning system has a quite large number of failures. The vibrational cleaning readiness factor is rated at 0.9323 and that of the pulsed cleaning system, 0.9698. For the KU-100 recovery boilers with a mean productivity of 18-20 t/h, the losses caused by failures during operation with vibration and pulsed cleaning were 3,200 and 1,700 rubles per year, respectively. With reconstruction of the boilers, which is associated with an increase in their reliability, the vibration cleaning of the heating surface was replaced by pulsed cleaning.

  11. Nonlinear system identification of the reduction nickel oxide smelting process in electric arc furnace

    Science.gov (United States)

    Gubin, V.; Firsov, A.

    2018-03-01

    As the title implies the article describes the nonlinear system identification of the reduction smelting process of nickel oxide in electric arc furnaces. It is suggested that for operational control ratio of components of the charge must be solved the problem of determining the qualitative composition of the melt in real time. The use of 0th harmonic of phase voltage AC furnace as an indirect measure of the melt composition is proposed. Brief description of the mechanism of occurrence and nature of the non-zero 0th harmonic of the AC voltage of the arc is given. It is shown that value of 0th harmonic of the arc voltage is not function of electrical parameters but depends of the material composition of the melt. Processed industrial data are given. Hammerstein-Wiener model is used for description of the dependence of 0th harmonic of the furnace voltage from the technical parameters of melting furnace: the melt composition and current. Recommendations are given about the practical use of the model.

  12. Arsenic exposure levels in relation to different working departments in a copper mining and smelting plant

    Science.gov (United States)

    Sun, Qingshan; Song, Yingli; Liu, Shengnan; Wang, Fei; Zhang, Lin; Xi, Shuhua; Sun, Guifan

    2015-10-01

    The investigation was carried out to evaluate arsenic exposure and the urine metabolite profiles of workers with different working departments, including administration (Group1), copper ore mining (Group2), copper ore grinding (Group3), electrolytic procession (Group4) and copper smelting (Group5) in a Copper mining and processing plant in China. Information about characteristics of each subject was obtained by questionnaire and inorganic arsenic (iAs), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) in urine were determined. The highest urinary levels of iAs, MMA and DMA all were found in the Group 5. Group 4 workers had a higher iAs% and a lower PMI compared to Group 3. The urinary total As (TAs) levels of 54.7% subjects exceeded 50 μg/g Cr, and the highest percentage (93.3%) was found in Group 5, smelters. The results of the present study indicate that workers in copper production plant indeed exposed to As, especially for smelters and workers of electrolytic process.

  13. Influence of alumina on mineralogy and environmental properties of zinc-copper smelting slags

    Science.gov (United States)

    Mostaghel, Sina; Samuelsson, Caisa; Björkman, Bo

    2013-03-01

    An iron-silicate slag, from a zinc-copper smelting process, and mixtures of this slag with 5wt%, 10wt%, and 15wt% alumina addition were re-melted, semi-rapidly solidified, and characterized using scanning electron microscopy equipped with energy dispersive spectroscopy, and X-ray diffraction. The FactSage™6.2 thermodynamic package was applied to compare the stable phases at equilibrium conditions with experimental characterization. A standard European leaching test was also carried out for all samples to investigate the changes in leaching behaviour because of the addition of alumina. Results show that the commonly reported phases for slags from copper and zinc production processes (olivine, pyroxene, and spinel) are the major constituents of the current samples. A correlation can be seen between mineralogical characteristics and leaching behaviours. The sample with 10wt% alumina addition, which contains high amounts of spinels and lower amounts of the other soluble phases, shows the lowest leachabilities for most of the elements.

  14. Different Heavy Metal Accumulation Strategies of Epilithic Lichens Colonising Artificial Post-Smelting Wastes.

    Science.gov (United States)

    Rola, Kaja; Osyczka, Piotr; Kafel, Alina

    2016-02-01

    Lichens appear to be essential and effective colonisers of bare substrates including the extremely contaminated wastes of slag dumps. This study examines the metal accumulation capacity of epilithic lichens growing directly on the surface of artificial slag sinters. Four species representing different growth forms, i.e., crustose Candelariella aurella, Lecanora muralis, and Lecidea fuscoatra and fruticose Stereocaulon nanodes, were selected to evaluate the relationships between zinc, lead, cadmium, and nickel contents in their thalli and host substrates. Bioaccumulation factors of examined crustose lichens showed their propensity to hyperaccumulate heavy metals. Contrarily, concentrations of metals in fruticose thalli of S. nanodes were, as a rule, lower than in the corresponding substrates. This indicates that the growth form of thalli and degree of thallus adhesion to the substrate has a significant impact on metal concentrations in lichens colonising post-smelting wastes. Nonlinear regression models described by power functions show that at greater levels of Pb concentration in the substrate, the ability of C. aurella, L. muralis and L. fuscoatra to accumulate the metal experiences a relative decrease, whereas hyperbolic function describes a similar trend in relation to Ni content in S. nanodes. This phenomenon may be an important attribute of lichens that facilitates their colonisation of the surface of slag wastes.

  15. Environmental legacy of copper metallurgy and Mongol silver smelting recorded in Yunnan Lake sediments.

    Science.gov (United States)

    Hillman, Aubrey L; Abbott, Mark B; Yu, JunQing; Bain, Daniel J; Chiou-Peng, TzeHuey

    2015-03-17

    Geochemical measurements on well-dated sediment cores from Lake Er (Erhai) are used to determine the timing of changes in metal concentrations over 4500 years in Yunnan, a borderland region in southwestern China noted for rich mineral deposits but with inadequately documented metallurgical history. Our findings add new insight into the impacts and environmental legacy of human exploitation of metal resources in Yunnan history. We observe an increase in copper at 1500 BC resulting from atmospheric emissions associated with metallurgy. These data clarify the chronological issues related to links between the onset of Yunnan metallurgy and the advent of bronze technology in adjacent Southeast Asia, subjects that have been debated for nearly half a century. We also observe an increase from 1100 to 1300 AD in a number of heavy metals including lead, silver, zinc, and cadmium from atmospheric emissions associated with silver smelting. Culminating during the rule of the Mongols, known as the Yuan Dynasty (1271-1368 AD), these metal concentrations approach levels three to four times higher than those from industrialized mining activity occurring within the catchment today. Notably, the concentrations of lead approach levels at which harmful effects may be observed in aquatic organisms. The persistence of this lead pollution over time created an environmental legacy that likely contributes to known issues in modern day sediment quality. We demonstrate that historic metallurgical production in Yunnan can cause substantial impacts on the sediment quality of lake systems, similar to other paleolimnological findings around the globe.

  16. Cultural and social determinants of health among indigenous Mexican migrants in the United States.

    Science.gov (United States)

    Lee, Junghee; Donlan, William; Cardoso, Edgar Ezequiel Orea; Paz, Juan Jesus

    2013-01-01

    Despite growing numbers, indigenous Mexican migrants are relatively invisible to health practitioners who group them with nonindigenous, mestizo Mexican-origin populations. Associations between indigenous and mestizo cultural identifications with psychosocial characteristics and health indicators among indigenous Mexican migrants were examined. Results revealed gender differences in cultural identifications, perceived discrimination, self-esteem, self-efficacy, and various health indicators including depression severity, culture-bound syndromes, and self-rated health. Multivariate regression and structural equation path modeling demonstrated how indigenous cultural identification and perceived discrimination affects health. Findings suggest that interventions should utilize indigenous community-based activities designed to promote self-esteem and the value of indigenous culture, with a focus on females.

  17. Characterization of Mexican zeolite minerals

    International Nuclear Information System (INIS)

    Jimenez C, M.J.

    2005-01-01

    50% of the Mexican territory is formed by volcanic sequences of the Pliocene type, which appear extensively in the northwest states (Sonora, Sinaloa, Chihuahua, Durango) and west of Mexico (Jalisco and Nayarit), in central Mexico (Zacatecas, Guanajuato, San Luis Potosi, Queretaro, Hidalgo) and south of Mexico (Guerrero, Oaxaca); therefore, it is to be expected that in our country big locations of natural zeolites exist in its majority of the clinoptilolite type. The present study was focused toward the characterization of two Mexican natural zeolite rocks presumably of the clinoptilolite and filipsite types, one of them comes from the state of Chihuahua and the other of a trader company of non metallic minerals, due that these materials are not characterized, its are not known their properties completely and therefore, the uses that can be given to these materials. In this investigation work it was carried out the characterization of two Mexican zeolite rocks, one coming from the Arroyo zone, municipality of La Haciendita, in the state of Chihuahua; and the other one was bought to a trader company of non metallic minerals. The two zeolites so much in their natural form as conditioned with sodium; they were characterized by means of X-ray diffraction, scanning electron microscopy of high vacuum and elementary microanalysis (EDS), surface area analysis (BET), thermal gravimetric analysis. To differentiate the heulandite crystalline phase of the other clinoptilolite rock, its were carried out thermal treatments. The quantification of Al, Na, Ca, K, Mg, Fe was carried out in solution, by means of atomic absorption spectroscopy and the quantity of Si was determined by gravimetry. The zeolite rocks presented for the major part the crystalline heulandite and clinoptilolite phases for the most part, and it was found that the zeolite coming from the state of Chihuahua possesses a bigger content of heulandite and the denominated filipsite it is really a zeolite

  18. Acculturation and substance use in a Mexican American college student sample.

    Science.gov (United States)

    Mercado, Alfonso; Ramirez, Maria; Sharma, Rachita; Popan, Jason; Avalos Latorre, Maria Luisa

    2017-01-01

    Although the association between acculturation and substance use among Latino groups is important, it is often understudied, especially within specific Latino groups living in geographically distinct communities, such as the Mexican American population in South Texas. The researchers of this study aimed to better understand the effect of acculturation on substance use and alcohol dependence in a Mexican American college student population. This survey study investigated the correlation between acculturation and substance use and dependence by using the Vancouver Index of Acculturation (VIA), items related to substance use (nicotine, marijuana, and cocaine) in a Mexican American college student sample (N = 1,494), and the Short Alcohol Dependence Data Questionnaire (SADD; N = 715). The study was conducted in the Texas-Mexico border region. The results suggest that higher levels of acculturation do not predict increased drug use or alcohol dependence in the Mexican American college students. However, acculturation was found to be associated with lower use of cocaine and marijuana. The discussion examines commonalities and differences in drug use and dependence. Specifically, acculturation seems to have an inverse relationship to substance use and may serve as a protective factor to licit and illicit drug use among Mexican American college students.

  19. Reasons for self-medication and perceptions of risk among Mexican migrant farm workers.

    Science.gov (United States)

    Horton, Sarah; Stewart, Analisia

    2012-08-01

    Although the frequency of self-medication among Mexican migrants has been well-documented in the public health literature, the multiple reasons for this practice are poorly understood. Most studies point to migrants' cultural preferences for Mexican medications, their prior experiences in countries where antibiotics are loosely regulated, and their lack of access to health care as the primary factors behind their self-medication. Based on participant observation and in-depth interviews with 23 Mexican migrants in a farm working community in the interior of California, we argue that occupational vulnerability is an equally important factor that encourages self-medication. All 23 of our interviewees reported having engaged in some degree of self-medication, notable in this location 8 h from the US-Mexico border. Among interviewees, occupational vulnerability represented an even more important factor influencing self-medication than lack of health insurance or lack of legal documentation. While interviewees did express a preference for Mexican medications as more potent and effective, this did not necessarily translate to a preference for using them without a doctor's supervision. Finally, we show that rather than remaining unaware of the risks of following this custom "transported from Latin America", Mexican migrants devised an elaborate hierarchy of resort of the safest self-medication practices to follow.

  20. Dictionaries of Mexican Sexual Slang for NLP

    Directory of Open Access Journals (Sweden)

    Roberto Villarejo-Martínez

    2018-04-01

    Full Text Available Abstract: In this paper the creation of two relevant resources for the double entendre and humour recognition problem in Mexican Spanish is described: a morphological dictionary and a semantic dictionary. These were created from two sources: a corpus of albures (drawn from “Antología del albur” book and a Mexican slang dictionary (“El chilangonario”. The morphological dictionary consists of 410 forms of words that corresponds to 350 lemmas. The semantic dictionary consists of 27 synsets that are associated to lemmas of morphological dictionary. Since both resources are based on Freeling library, they are easy to implement for tasks in Natural Language Processing. The motivation for this work comes from the need to address problems such as double entendre and computational humour. The usefulness of these disciplines has been discussed many times and it has been shown that they have a direct impact on user interfaces and, mainly, in human-computer interaction. This work aims to promote that the scientific community generates more resources about informal language in Spanish and other languages.  Spanish Abstract: En este artículo se describe la creación de dos recursos relevantes para el reconocimiento del doble sentido y el humor en el español mexicano: un diccionario morfológico y un diccionario semántico. Éstos fueron creados a partir de dos fuentes: un corpus de albures (extraídos del libro "Antología del albur" y un diccionario de argot mexicano ("El chilangonario". El diccionario morfológico consiste en 410 formas de palabras que corresponden a 350 lemas. El diccionario semántico consiste en 27 synsets que están asociados a lemas del diccionario morfológico. Puesto que ambos recursos están basados en la biblioteca Freeling, son fáciles de implementar en tareas de Procesamiento del Lenguaje Natural. La motivación de este trabajo proviene de la necesidad de abordar problemas como el doble sentido y el humor

  1. Lead toxicosis in tundra swans near a mining and smelting complex in northern Idaho

    Science.gov (United States)

    Blus, L.J.; Henny, C.J.; Hoffman, D.J.; Grove, R.A.

    1991-01-01

    Die-offs of waterfowl have occurred in the Coeur d`Alene River system in northern Idaho since at least the early 1900`s. We investigated causes of mortality and lead and cadmium contamination of 46 tundra swans (Cygnus columbianus) from 1987 to 1989; an additional 22 swans found dead in 1990 were not examined. We necropsied 43 of the 46 birds found from 1987 to 1989; 38 of these were from the Coeur d`Alene River system, which has been contaminated with mining and smelting wastes for a century, and the other 5 were from a nearby, relatively uncontaminated area. Of the 36 livers of swans from the contaminated area that were analyzed, 32 contained lethal levels of lead (6 to 40 micrograms/g, wet weight) and all birds exhibited several symptoms of lead poisoning, notably enlarged gall bladders containing viscous, darkgreen bile. Only 13% of the lead-poisoned birds (10% when data were included from other studies of swans in the area) contained shot, compared to 95% of lead-poisoning swans in studies outside northern Idaho. Lead concentrations in blood samples from 16 apparently healthy swans (0.5 to 2.3 micrograms/g, and 4 leadpoisoned birds found moribund (1.3 to 9.6 micrograms/g) indicating that tundra swans accumulated high levels of lead from ingestion of sediment that contained up to 8,700 micrograms/g of lead and plants that contained up to 400 micrograms/g. The swans spend only a few weeks in the area staging during the spring migration. The five tundra swans from the uncontaminated area had low levels of lead and essentially no symptoms of lead poisoning.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Behavior of an indigenously fabricated transferred arc plasma furnace for smelting studies

    Science.gov (United States)

    A, K. MANDAL; R, K. DISHWAR; O, P. SINHA

    2018-03-01

    The utilization of industrial solid waste for metal recovery requires high-temperature tools due to the presence of silica and alumina, which is reducible at high temperature. In a plasma arc furnace, transferred arc plasma furnace (TAP) can meet all requirements, but the disadvantage of this technology is the high cost. For performing experiments in the laboratory, the TAP was fabricated indigenously in a laboratory based on the different inputs provided in the literature for the furnace design and fabrication. The observed parameters such as arc length, energy consumption, graphite electrode consumption, noise level as well as lining erosion were characterized for this fabricated furnace. The nitrogen plasma increased by around 200 K (200 °C) melt temperature and noise levels decreased by ∼10 dB compared to a normal arc. Hydrogen plasma offered 100 K (100 °C) higher melt temperature with ∼5 dB higher sound level than nitrogen plasma. Nitrogen plasma arc melting showed lower electrode and energy consumption than normal arc melting, whereas hydrogen plasma showed lower energy consumption and higher electrode consumption in comparison to nitrogen plasma. The higher plasma arc temperature resulted in a shorter meltdown time than normal arc with smoother arcing. Hydrogen plasma permitted more heats, reduced meltdown time, and lower energy consumption, but with increased graphite consumption and crucible wear. The present study showed that the fabricated arc plasma is better than the normal arc furnace with respect to temperature generation, energy consumption, and environmental friendliness. Therefore, it could be used effectively for smelting-reduction studies.

  3. Computational Fluid Dynamic Modeling of Zinc Slag Fuming Process in Top-Submerged Lance Smelting Furnace

    Science.gov (United States)

    Huda, Nazmul; Naser, Jamal; Brooks, Geoffrey; Reuter, Markus A.; Matusewicz, Robert W.

    2012-02-01

    Slag fuming is a reductive treatment process for molten zinciferous slags for extracting zinc in the form of metal vapor by injecting or adding a reductant source such as pulverized coal or lump coal and natural gas. A computational fluid dynamic (CFD) model was developed to study the zinc slag fuming process from imperial smelting furnace (ISF) slag in a top-submerged lance furnace and to investigate the details of fluid flow, reaction kinetics, and heat transfer in the furnace. The model integrates combustion phenomena and chemical reactions with the heat, mass, and momentum interfacial interaction between the phases present in the system. A commercial CFD package AVL Fire 2009.2 (AVL, Graz, Austria) coupled with a number of user-defined subroutines in FORTRAN programming language were used to develop the model. The model is based on three-dimensional (3-D) Eulerian multiphase flow approach, and it predicts the velocity and temperature field of the molten slag bath, generated turbulence, and vortex and plume shape at the lance tip. The model also predicts the mass fractions of slag and gaseous components inside the furnace. The model predicted that the percent of ZnO in the slag bath decreases linearly with time and is consistent broadly with the experimental data. The zinc fuming rate from the slag bath predicted by the model was validated through macrostep validation process against the experimental study of Waladan et al. The model results predicted that the rate of ZnO reduction is controlled by the mass transfer of ZnO from the bulk slag to slag-gas interface and rate of gas-carbon reaction for the specified simulation time studied. Although the model is based on zinc slag fuming, the basic approach could be expanded or applied for the CFD analysis of analogous systems.

  4. Atlas of Mexican Triatominae (Reduviidae: Hemiptera) and vector transmission of Chagas disease

    Science.gov (United States)

    Ramsey, Janine M; Peterson, A Townsend; Carmona-Castro, Oscar; Moo-Llanes, David A; Nakazawa, Yoshinori; Butrick, Morgan; Tun-Ku, Ezequiel; de la Cruz-Félix, Keynes; Ibarra-Cerdeña, Carlos N

    2015-01-01

    Chagas disease is one of the most important yet neglected parasitic diseases in Mexico and is transmitted by Triatominae. Nineteen of the 31 Mexican triatomine species have been consistently found to invade human houses and all have been found to be naturally infected with Trypanosoma cruzi. The present paper aims to produce a state-of-knowledge atlas of Mexican triatomines and analyse their geographic associations with T. cruzi, human demographics and landscape modification. Ecological niche models (ENMs) were constructed for the 19 species with more than 10 records in North America, as well as for T. cruzi. The 2010 Mexican national census and the 2007 National Forestry Inventory were used to analyse overlap patterns with ENMs. Niche breadth was greatest in species from the semiarid Nearctic Region, whereas species richness was associated with topographic heterogeneity in the Neotropical Region, particularly along the Pacific Coast. Three species, Triatoma longipennis, Triatoma mexicana and Triatoma barberi, overlapped with the greatest numbers of human communities, but these communities had the lowest rural/urban population ratios. Triatomine vectors have urbanised in most regions, demonstrating a high tolerance to human-modified habitats and broadened historical ranges, exposing more than 88% of the Mexican population and leaving few areas in Mexico without the potential for T. cruzi transmission. PMID:25993505

  5. ELECTROCARDIOGRAPHIC ABNORMALITIES AMONG MEXICAN AMERICANS: CORRELATIONS WITH DIABETES, OBESITY, AND THE METABOLIC SYNDROME.

    Science.gov (United States)

    Queen, Saulette R; Smulevitz, Beverly; Rentfro, Anne R; Vatcheva, Kristina P; Kim, Hyunggun; McPherson, David D; Hanis, Craig L; Fisher-Hoch, Susan P; McCormick, Joseph B; Laing, Susan T

    2012-04-01

    Resting ischemic electrocardiographic abnormalities have been associated with cardiovascular mortality. Simple markers of abnormal autonomic tone have also been associated with diabetes, obesity, and the metabolic syndrome in some populations. Data on these electrocardiographic abnormalities and correlations with coronary risk factors are lacking among Mexican Americans wherein these conditions are prevalent. This study aimed to evaluate the prevalent resting electrocardiographic abnormalities among community-dwelling Mexican Americans, and correlate these findings with coronary risk factors, particularly diabetes, obesity, and the metabolic syndrome. Study subjects (n=1280) were drawn from the Cameron County Hispanic Cohort comprised of community-dwelling Mexican Americans living in Brownsville, Texas at the United States-Mexico border. Ischemic electrocardiographic abnormalities were defined as presence of ST/T wave abnormalities suggestive of ischemia, abnormal Q waves, and left bundle branch block. Parameters that reflect autonomic tone, such as heart rate-corrected QT interval and resting heart rate, were also measured. Ischemic electrocardiographic abnormalities were more prevalent among older persons and those with hypertension, diabetes, obesity, and the metabolic syndrome. Subjects in the highest quartiles of QTc interval and resting heart rate were also more likely to be diabetic, hypertensive, obese, or have the metabolic syndrome. Among Mexican Americans, persons with diabetes, obesity, and the metabolic syndrome were more likely to have ischemic electrocardiographic abnormalities, longer QTc intervals, and higher resting heart rates. A resting electrocardiogram can play a complementary role in the comprehensive evaluation of cardiovascular risk in this minority population.

  6. Atlas of Mexican Triatominae (Reduviidae: Hemiptera and vector transmission of Chagas disease

    Directory of Open Access Journals (Sweden)

    Janine M Ramsey

    2015-05-01

    Full Text Available Chagas disease is one of the most important yet neglected parasitic diseases in Mexico and is transmitted by Triatominae. Nineteen of the 31 Mexican triatomine species have been consistently found to invade human houses and all have been found to be naturally infected with Trypanosoma cruzi. The present paper aims to produce a state-of-knowledge atlas of Mexican triatomines and analyse their geographic associations with T. cruzi, human demographics and landscape modification. Ecological niche models (ENMs were constructed for the 19 species with more than 10 records in North America, as well as for T. cruzi. The 2010 Mexican national census and the 2007 National Forestry Inventory were used to analyse overlap patterns with ENMs. Niche breadth was greatest in species from the semiarid Nearctic Region, whereas species richness was associated with topographic heterogeneity in the Neotropical Region, particularly along the Pacific Coast. Three species, Triatoma longipennis, Triatoma mexicana and Triatoma barberi, overlapped with the greatest numbers of human communities, but these communities had the lowest rural/urban population ratios. Triatomine vectors have urbanised in most regions, demonstrating a high tolerance to human-modified habitats and broadened historical ranges, exposing more than 88% of the Mexican population and leaving few areas in Mexico without the potential for T. cruzi transmission.

  7. Mexican participation in the AMS project

    Science.gov (United States)

    Menchaca-Rocha, A.; Buenerd, M.; Cabrera, J. I.; Canizal, C.; Esquivel, O.; Núñez, R.; Plascencia, J. C.; Reyes, T.; Villoro, M. F.

    2001-05-01

    Optical characterization of hydrophobic silica aerogel SP-25 for the RICH, and a scheme to generate particle-ID conditions on TOF and Tracker amplitude data are reported, as part of a Mexican effort to contribute to the AMS Project. .

  8. Mammagraphy Use by Older Mexican American Women

    National Research Council Canada - National Science Library

    Freeman, Jean

    1998-01-01

    The purpose of this study is to examine the determinants of mammographic screening in older Mexican- American women, particularly the influence of strong family relationships on promoting screening behavior...

  9. Can Silicon-Smelting Contribute to the Low O/Si Ratio on the Surface of Mercury?

    Science.gov (United States)

    McCubbin, F. M.; Vander Kaaden, K. E.; Hogancamp, J.; Archer, P. D., Jr.; Boyce, J. W.

    2018-01-01

    The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft collected data that provided important insights into the structure, chemical makeup, and compositional diversity of Mercury. Among the many discoveries about Mercury made by MESSENGER, several surprising compositional characteristics of the surface were observed. These discoveries include elevated sulfur abundances (up to 4 wt.%), elevated abundances of graphitic carbon (0-4.1 wt.% across the surface with an additional 1-3 wt.% graphite above the global average in low reflectance materials), low iron abundances (less than 2 wt.%), and low oxygen abundances (O/Si weight ratio of 1.20+/-0.1). These exotic characteristics likely have important implications for the thermochemical evolution of Mercury and point to a planet that formed under highly reducing conditions. In the present study, we focus specifically on the low O/Si ratio of Mercury, which is anomalous compared to all other planetary materials. A recent study that considered the geochemical implications of the low O/Si ratio reported that 12-20% of the surface materials on Mercury are composed of Si-rich, Si-Fe alloys. They further postulated that the origin of the metal is best explained by a combination of space weathering and graphite-induced smelting that was facilitated by interaction of graphite with boninitic and komatiitic parental liquids. The goal of the present study is to assess the plausibility of smelting on Mercury through experiments run at the conditions that McCubbin et al. indicated would be favorable for Si-smelting.

  10. NAFTA: The Mexican Economy, and Undocumented Migration

    Science.gov (United States)

    2011-10-28

    NAFTA contributed to modest increases in Mexican formal employment since 1994. Since employment constitutes one of the chief factors affecting poverty...any other provision of law , no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a...FINAL 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE NAFTA , the Mexican Economy, and Undocumented Migration 5a

  11. Generational Variations in Mexican-Origin Intermarriage

    OpenAIRE

    Cedillo, Rosalio

    2015-01-01

    This dissertation examines intermarriage across generations of the Mexican-origin population in order to better understand how this population is incorporating in U.S. society, and looks at parental migration status and parental nativity as factors that may impede or facilitate intermarriage incorporation. Using data from the Immigration and Intergenerational Mobility in Metropolitan Los Angeles (IIMMLA) survey the research shows that: the majority of intermarriages among the Mexican-origin ...

  12. Locomotion of Mexican jumping beans

    International Nuclear Information System (INIS)

    West, Daniel M; K Lal, Ishan; Leamy, Michael J; Hu, David L

    2012-01-01

    The Mexican jumping bean, Laspeyresia saltitans, consists of a hollow seed housing a moth larva. Heating by the sun induces movements by the larva which appear as rolls, jumps and flips by the bean. In this combined experimental, numerical and robotic study, we investigate this unique means of rolling locomotion. Time-lapse videography is used to record bean trajectories across a series of terrain types, including one-dimensional channels and planar surfaces of varying inclination. We find that the shell encumbers the larva's locomotion, decreasing its speed on flat surfaces by threefold. We also observe that the two-dimensional search algorithm of the bean resembles the run-and-tumble search of bacteria. We test this search algorithm using both an agent-based simulation and a wheeled Scribbler robot. The algorithm succeeds in propelling the robot away from regions of high temperature and may have application in biomimetic micro-scale navigation systems. (paper)

  13. Mexican gems as thermoluminescent dosimeters

    International Nuclear Information System (INIS)

    Azorin N, J.

    1979-01-01

    The possibility of using naturally ocurring mexican gems as thermoluminescent dosimeters (TLD) was investigated. Twelve types of gems were irradiated with X and gamma rays in order to determinate their dosimetric properties. Three of these gems showed favorable thermoluminescent characteristics compared with commercial thermoluminescent dosimeters. The plots of their thermoluminescent response as a function of gamma dose are straight lines on full log paper in the dose range 10 -2 to 10 2 Gy. The energy dependence is very strong to low energies of the radiation. Their fading was found to be about 5%/yr. and they may be annealed as reused without loss in sensitivity. Therefore, these gems can be used as X and gamma radiation dosimeters. (author)

  14. A Water Model Study on Mixing Behavior of the Two-Layered Bath in Bottom Blown Copper Smelting Furnace

    Science.gov (United States)

    Shui, Lang; Cui, Zhixiang; Ma, Xiaodong; Jiang, Xu; Chen, Mao; Xiang, Yong; Zhao, Baojun

    2018-05-01

    The bottom-blown copper smelting furnace is a novel copper smelter developed in recent years. Many advantages of this furnace have been found, related to bath mixing behavior under its specific gas injection scheme. This study aims to use an oil-water double-phased laboratory-scale model to investigate the impact of industry-adjustable variables on bath mixing time, including lower layer thickness, gas flow rate, upper layer thickness and upper layer viscosity. Based on experimental results, an overall empirical relationship of mixing time in terms of these variables has been correlated, which provides the methodology for industry to optimize mass transfer in the furnace.

  15. Effect of Copper and Iron Ions on the Sulphidizing Flotation of Copper Oxide in Copper Smelting Slag

    OpenAIRE

    Qing-qing Pan; Hui-qing Peng

    2018-01-01

    The treatment of smelting slag has attracted much attention nowadays. This study investigates the influence of Na2S, CuSO4, and FeCl3 on sulphidizing flotation of copper oxide. The results show that a proper Cu2+ concentration can increase the sulphidizing effect of copper oxide, while Fe3+ inhibits the sulphidizing effect. Further analysis shows that Cu2+ ions can reduce the surface potential, increase the S2− adsorption, then generate more polysulfide, and therefore promote the sulphidizing...

  16. Element Distribution in the Oxygen-Rich Side-Blow Bath Smelting of a Low-Grade Bismuth-Lead Concentrate

    Science.gov (United States)

    Yang, Tianzu; Xiao, Hui; Chen, Lin; Chen, Wei; Liu, Weifeng; Zhang, Duchao

    2018-03-01

    Oxygen-rich side-blow bath smelting (OSBS) technology offers an efficient method for processing complex bismuth-lead concentrates; however, the element distributions in the process remain unclear. This work determined the distributions of elements, i.e., bismuth, lead, silver, copper, arsenic and antimony, in an industrial-scale OSBS process. The feed, oxidized slag and final products were collected from the respective sampling points and analyzed. For the oxidative smelting process, 65% of bismuth and 76% of silver in the concentrate report to the metal alloy, whereas less lead reports to the metal ( 31%) than the oxidized slag ( 44%). Approximately 50% of copper enters the matte, while more than 63% of arsenic and antimony report to the slag. For the reductive smelting process, less than 4.5% of bismuth, lead, silver and copper in the oxidized slag enter the reduced slag, indicating high recoveries of these metal values.

  17. Comparative growth models of big-scale sand smelt (Atherina boyeri Risso, 1810 sampled from Hirfanll Dam Lake, Klrsehir, Ankara, Turkey

    Directory of Open Access Journals (Sweden)

    S. Benzer

    2017-06-01

    Full Text Available In this current publication the growth characteristics of big-scale sand smelt data were compared for population dynamics within artificial neural networks and length-weight relationships models. This study aims to describe the optimal decision of the growth model of big-scale sand smelt by artificial neural networks and length-weight relationships models at Hirfanll Dam Lake, Klrsehir, Turkey. There were a total of 1449 samples collected from Hirfanll Dam Lake between May 2015 and May 2016. Both model results were compared with each other and the results were also evaluated with MAPE (mean absolute percentage error, MSE (mean squared error and r2 (coefficient correlation data as a performance criterion. The results of the current study show that artificial neural networks is a superior estimation tool compared to length-weight relationships models of big-scale sand smelt in Hirfanll Dam Lake.

  18. Fair Start Program: Outreach to Mexican and Mexican American Farmworker Families.

    Science.gov (United States)

    Winters-Smith, Carol; Larner, Mary

    This presentation describes a home visiting health education program serving Mexican and Mexican-American migrant farmworkers in Florida. The purposes of the program were to educate farmworker families about pregnancy, childbirth, nutrition, and child development, and to encourage the use of preventive health care services. Home visitors were…

  19. Dynamic variation of histone H3 trimethyl Lys4 (H3K4me3) and heterochromatin protein 1 (HP1) with employment length in nickel smelting workers.

    Science.gov (United States)

    Zhao, Yanhong; Cheng, Ning; Dai, Min; Pu, Hongquan; Zheng, Tongzhang; Li, Haiyan; He, Jie; Bai, Yana

    2017-07-01

    To investigate the dynamic variation in H3K4me3 and HP1 with employment length in nickel smelting workers. Blood samples were collected from 140 nickel smelting workers and 140 age-matched office workers to test for H3K4me3, and HP1 levels. H3K4me3 was statistically significantly different (p exposure to nickel can induce oxidative damage, and increase H3K4me3 expression and inhibit HP1 expression.

  20. Effects of ocean acidification on the swimming ability, development and biochemical responses of sand smelt larvae

    International Nuclear Information System (INIS)

    Silva, Cátia S.E.; Novais, Sara C.; Lemos, Marco F.L.; Mendes, Susana; Oliveira, Ana P.; Gonçalves, Emanuel J.; Faria, Ana M.

    2016-01-01

    Ocean acidification, recognized as a major threat to marine ecosystems, has developed into one of the fastest growing fields of research in marine sciences. Several studies on fish larval stages point to abnormal behaviours, malformations and increased mortality rates as a result of exposure to increased levels of CO_2. However, other studies fail to recognize any consequence, suggesting species-specific sensitivity to increased levels of CO_2, highlighting the need of further research. In this study we investigated the effects of exposure to elevated pCO_2 on behaviour, development, oxidative stress and energy metabolism of sand smelt larvae, Atherina presbyter. Larvae were caught at Arrábida Marine Park (Portugal) and exposed to different pCO_2 levels (control: ~ 600 μatm, pH = 8.03; medium: ~ 1000 μatm, pH = 7.85; high: ~ 1800 μatm, pH = 7.64) up to 15 days, after which critical swimming speed (U_c_r_i_t), morphometric traits and biochemical biomarkers were determined. Measured biomarkers were related with: 1) oxidative stress — superoxide dismutase and catalase enzyme activities, levels of lipid peroxidation and DNA damage, and levels of superoxide anion production; 2) energy metabolism — total carbohydrate levels, electron transport system activity, lactate dehydrogenase and isocitrate dehydrogenase enzyme activities. Swimming speed was not affected by treatment, but exposure to increasing levels of pCO_2 leads to higher energetic costs and morphometric changes, with larger larvae in high pCO_2 treatment and smaller larvae in medium pCO_2 treatment. The efficient antioxidant response capacity and increase in energetic metabolism only registered at the medium pCO_2 treatment may indicate that at higher pCO_2 levels the capacity of larvae to restore their internal balance can be impaired. Our findings illustrate the need of using multiple approaches to explore the consequences of future pCO_2 levels on organisms. - Highlights: • Exposure to high pCO_2

  1. Effects of ocean acidification on the swimming ability, development and biochemical responses of sand smelt larvae

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cátia S.E. [MARE — Marine and Environmental Sciences Centre, ISPA − Instituto Universitário (Portugal); MARE — Marine and Environmental Sciences Centre, ESTM, Instituto Politécnico de Leiria (Portugal); Novais, Sara C.; Lemos, Marco F.L.; Mendes, Susana [MARE — Marine and Environmental Sciences Centre, ESTM, Instituto Politécnico de Leiria (Portugal); Oliveira, Ana P. [IPMA — Instituto Português do Mar e da Atmosfera, Algés (Portugal); Gonçalves, Emanuel J. [MARE — Marine and Environmental Sciences Centre, ISPA − Instituto Universitário (Portugal); Faria, Ana M., E-mail: afaria@ispa.pt [MARE — Marine and Environmental Sciences Centre, ISPA − Instituto Universitário (Portugal)

    2016-09-01

    Ocean acidification, recognized as a major threat to marine ecosystems, has developed into one of the fastest growing fields of research in marine sciences. Several studies on fish larval stages point to abnormal behaviours, malformations and increased mortality rates as a result of exposure to increased levels of CO{sub 2}. However, other studies fail to recognize any consequence, suggesting species-specific sensitivity to increased levels of CO{sub 2}, highlighting the need of further research. In this study we investigated the effects of exposure to elevated pCO{sub 2} on behaviour, development, oxidative stress and energy metabolism of sand smelt larvae, Atherina presbyter. Larvae were caught at Arrábida Marine Park (Portugal) and exposed to different pCO{sub 2} levels (control: ~ 600 μatm, pH = 8.03; medium: ~ 1000 μatm, pH = 7.85; high: ~ 1800 μatm, pH = 7.64) up to 15 days, after which critical swimming speed (U{sub crit}), morphometric traits and biochemical biomarkers were determined. Measured biomarkers were related with: 1) oxidative stress — superoxide dismutase and catalase enzyme activities, levels of lipid peroxidation and DNA damage, and levels of superoxide anion production; 2) energy metabolism — total carbohydrate levels, electron transport system activity, lactate dehydrogenase and isocitrate dehydrogenase enzyme activities. Swimming speed was not affected by treatment, but exposure to increasing levels of pCO{sub 2} leads to higher energetic costs and morphometric changes, with larger larvae in high pCO{sub 2} treatment and smaller larvae in medium pCO{sub 2} treatment. The efficient antioxidant response capacity and increase in energetic metabolism only registered at the medium pCO{sub 2} treatment may indicate that at higher pCO{sub 2} levels the capacity of larvae to restore their internal balance can be impaired. Our findings illustrate the need of using multiple approaches to explore the consequences of future pCO{sub 2} levels on

  2. Allocation and source attribution of lead and cadmium in maize (Zea mays L.) impacted by smelting emissions

    International Nuclear Information System (INIS)

    Bi Xiangyang; Feng Xinbin; Yang Yuangen; Li Xiangdong; Shin, Grace P.Y.; Li Feili; Qiu Guangle; Li Guanghui; Liu Taoze; Fu Zhiyou

    2009-01-01

    Plants grown in contaminated areas may accumulate trace metals to a toxic level via their roots and/or leaves. In the present study, we investigated the distribution and sources of Pb and Cd in maize plants (Zea mays L.) grown in a typical zinc smelting impacted area of southwestern China. Results showed that the smelting activities caused significantly elevated concentrations of Pb and Cd in the surrounding soils and maize plants. Pb isotope data revealed that the foliar uptake of atmospheric Pb was the dominant pathway for Pb to the leaf and grain tissues of maize, while Pb in the stalk and root tissues was mainly derived from root uptake. The ratio of Pb to Cd concentrations in the plants indicated that Cd had a different behavior from Pb, with most Cd in the maize plants coming from the soil via root uptake. - The sources and pathways of Pb and Cd accumulated in maize were assessed using Pb isotopes and Pb/Cd ratios

  3. Bioleaching mechanism of Zn, Pb, In, Ag, Cd and As from Pb/Zn smelting slag by autotrophic bacteria.

    Science.gov (United States)

    Wang, Jia; Huang, Qifei; Li, Ting; Xin, Baoping; Chen, Shi; Guo, Xingming; Liu, Changhao; Li, Yuping

    2015-08-15

    A few studies have focused on release of valuable/toxic metals from Pb/Zn smelting slag by heterotrophic bioleaching using expensive yeast extract as an energy source. The high leaching cost greatly limits the practical potential of the method. In this work, autotrophic bioleaching using cheap sulfur or/and pyrite as energy matter was firstly applied to tackle the smelting slag and the bioleaching mechanisms were explained. The results indicated autotrophic bioleaching can solubilize valuable/toxic metals from slag, yielding maximum extraction efficiencies of 90% for Zn, 86% for Cd and 71% for In, although the extraction efficiencies of Pb, As and Ag were poor. The bioleaching performance of Zn, Cd and Pb was independent of leaching system, and leaching mechanism was acid dissolution. A maximum efficiency of 25% for As was achieved by acid dissolution in sulfursulfur oxidizing bacteria (S-SOB), but the formation of FeAsO4 reduced extraction efficiency in mixed energy source - mixed culture (MS-MC). Combined works of acid dissolution and Fe(3+) oxidation in MS-MC was responsible for the highest extraction efficiency of 71% for In. Ag was present in the slag as refractory AgPb4(AsO4)3 and AgFe2S3, so extraction did not occur. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Allocation and source attribution of lead and cadmium in maize (Zea mays L.) impacted by smelting emissions

    Energy Technology Data Exchange (ETDEWEB)

    Bi Xiangyang [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Key Laboratory of Biogeology and Environmental Geology, Ministry of Education, China University of Geosciences, Wuhan 430074 (China); Feng Xinbin [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China)], E-mail: fengxinbin@vip.skleg.cn; Yang Yuangen [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China); Li Xiangdong; Shin, Grace P.Y. [Department of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Li Feili [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Qiu Guangle; Li Guanghui; Liu Taoze; Fu Zhiyou [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 (China)

    2009-03-15

    Plants grown in contaminated areas may accumulate trace metals to a toxic level via their roots and/or leaves. In the present study, we investigated the distribution and sources of Pb and Cd in maize plants (Zea mays L.) grown in a typical zinc smelting impacted area of southwestern China. Results showed that the smelting activities caused significantly elevated concentrations of Pb and Cd in the surrounding soils and maize plants. Pb isotope data revealed that the foliar uptake of atmospheric Pb was the dominant pathway for Pb to the leaf and grain tissues of maize, while Pb in the stalk and root tissues was mainly derived from root uptake. The ratio of Pb to Cd concentrations in the plants indicated that Cd had a different behavior from Pb, with most Cd in the maize plants coming from the soil via root uptake. - The sources and pathways of Pb and Cd accumulated in maize were assessed using Pb isotopes and Pb/Cd ratios.

  5. High-Temperature Oxidation and Smelt Deposit Corrosion of Ni-Cr-Ti Arc-Sprayed Coatings

    Science.gov (United States)

    Matthews, S.; Schweizer, M.

    2013-08-01

    High Cr content Ni-Cr-Ti arc-sprayed coatings have been extensively applied to mitigate corrosion in black liquor recovery boilers in the pulp and paper industry. In a previous article, the effects of key spray parameters on the coating's microstructure and its composition were investigated. Three coating microstructures were selected from that previous study to produce a dense, oxidized coating (coating A), a porous, low oxide content coating (coating B), and an optimized coating (coating C) for corrosion testing. Isothermal oxidation trials were performed in air at 550 and 900 °C for 30 days. Additional trials were performed under industrial smelt deposits at 400 and 800 °C for 30 days. The effect of the variation in coating microstructure on the oxidation and smelt's corrosion response was investigated through the characterization of the surface corrosion products, and the internal coating microstructural developments with time at high temperature. The effect of long-term, high-temperature exposure on the interaction between the coating and substrate was characterized, and the mechanism of interdiffusion was discussed.

  6. Transnational Mexican-Origin Families' Ways of Knowing: A Framework toward Bridging Understandings in U.S. Schools

    Science.gov (United States)

    Kasun, G. Sue

    2016-01-01

    Transnational students and families are those who cross real and metaphoric borders, spanning countries, to engage family and community in meaningful ways. Based on a three-year, multi-sited ethnographic study, I show the distinct ways of knowing of four Mexican-origin, working class families and how the U.S. schools where the children from these…

  7. Two Decades of Mexican Particle Physics at Fermilab

    International Nuclear Information System (INIS)

    Rubinstein, R.

    2003-01-01

    This report is a view from Fermilab of Mexican particle physics at the Laboratory since about 1980; it is not intended to be a history of Mexican particle physics: that topic is outside the expertise of the writer. The period 1980 to the present coincides with the growth of Mexican experimental particle physics from essentially no activity to its current state where Mexican groups take part in experiments at several of the world's major laboratories

  8. Green Medicine: Traditional Mexican-American Herbal Remedies.

    Science.gov (United States)

    Torres, Eliseo

    Traditional Mexican American herbal potions and remedies and their history are explained in an introductory book for the general reader. The importance of curanderismo, or green medicine, in Mexican and Mexican American cultures is explored. A brief history traces the herbal aspects of curanderismo through Mayan and Aztec cultures, the Spanish…

  9. Mexican energy policy and sustainability indicators

    International Nuclear Information System (INIS)

    Sheinbaum-Pardo, Claudia; Ruiz-Mendoza, Belizza Janet; Rodríguez-Padilla, Víctor

    2012-01-01

    The authors analyze the Mexican energy policy taking as reference the methodological framework for sustainable energy development proposed by the Economic Commission for Latin America and the Caribbean. This methodology takes eight related indicators to the social, environmental and economic dimensions in order to calculate a general sustainability indicator for the energy sector. In this methodology, the weight of each dimension is different; namely, the social and environmental issues have less relevance than the economic issues. The authors use this methodology because government institutions as the Department of Energy and the Department of Environment and Natural Resources have used some indicators from such a methodology to propose plans, programs, projects and bills. Authors know of the existence of other methodologies about sustainability. Nonetheless, opting for the Economic Commission for Latin America and the Caribbean's methodology is convenient because this organization is a respectable authority for civil servants from the Mexican institutions. Our objective is just to contrast the sustainability grade of the energy sector between 1990 and 2008 for Mexico whose government started reforms in the 1990s. It concludes that those reforms did not bring about a higher sustainability level for the energy sector. - Highlights: ► We used the OLADE, CEPAL and GTZ's methodology to calculate sustainability indicators for the Mexican energy sector. ► We studied the Mexican energy policy from 1990 to date and presented it. ► Currently, the Mexican energy sector is less sustainable than in 1990.

  10. Recirculation effect of Chilean copper smelting dust with high impurities contents on the impurity distributions during smelting process; Efecto de la recirculacion de polvo de fundicion de cobre de Chile con altos contenidos de impurezas en la distribucion de impurezas durante el proceso de fusion

    Energy Technology Data Exchange (ETDEWEB)

    Montenegro, V.; Sano, H.; Fujisawa, T.

    2010-07-01

    Usually, dust generated during the copper smelting process by the Teniente Converter and the Flash Smelting Furnaces in Chile, contains high concentrations of copper, zinc, arsenic, antimony and other metals. In general, the dust is recirculated to the smelting process or it is directed to hydrometallurgical process for recovery and stabilization. However, in recent years the generation of dust has increased because of the degradation of the quality of the concentrate. In addition, the environmental regulations have become stricter. It is therefore desirable to understand the behavior of those elements, when the smelting process operates with recirculation of dust. In this study, the effect of dust recirculation to smelting process on the distribution among the matte, slag and gas phases was evaluated, as a function of matte grade, amount of recirculated dust, oxygen enrichment and temperature. It was found that the concentration in the matte of the impurities such as arsenic, antimony and bismuth, increased slightly with recirculation of dust. On the other hand, the concentration of lead and zinc depend of the direct recirculation of dust to the process. Additionally, it was found that high concentrations of arsenic and antimony in the dust may lead to the formation and precipitation of copper arsenates and other metals (speiss), which may generates important operational problems. (Author) 15 refs.

  11. Size-resolved dust and aerosol contaminants associated with copper and lead smelting emissions: Implications for emission management and human health

    Energy Technology Data Exchange (ETDEWEB)

    Csavina, Janae [Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, AZ 85721 (United States); Taylor, Mark P. [Environmental Science, Faculty of Science, Macquarie University, North Ryde, Sydney, NSW 2109 (Australia); Félix, Omar [Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, AZ 85721 (United States); Rine, Kyle P. [Department of Atmospheric Sciences, The University of Arizona, Tucson, AZ 85721 (United States); Eduardo Sáez, A., E-mail: esaez@email.arizona.edu [Department of Chemical and Environmental Engineering, The University of Arizona, Tucson, AZ 85721 (United States); Betterton, Eric A., E-mail: betterton@atmo.arizona.edu [Department of Atmospheric Sciences, The University of Arizona, Tucson, AZ 85721 (United States)

    2014-09-15

    Mining operations, including crushing, grinding, smelting, refining, and tailings management, are a significant source of airborne metal and metalloid contaminants such as As, Pb and other potentially toxic elements. In this work, we show that size-resolved concentrations of As and Pb generally follow a bimodal distribution with the majority of contaminants in the fine size fraction (< 1 μm) around mining activities that include smelting operations at various sites in Australia and Arizona. This evidence suggests that contaminated fine particles (< 1 μm) are the result of vapor condensation and coagulation from smelting operations while coarse particles are most likely the result of windblown dust from contaminated mine tailings and fugitive emissions from crushing and grinding activities. These results on the size distribution of contaminants around mining operations are reported to demonstrate the ubiquitous nature of this phenomenon so that more effective emission management and practices that minimize health risks associated with metal extraction and processing can be developed. - Highlights: • Lead and copper smelting produce significant atmospheric concentrations of lead and arsenic. • Atmospheric lead and arsenic concentrations depend on particle size. • Lead isotopic analysis can be used to assess source of atmospheric contamination from smelters.

  12. Non-stationary recruitment dynamics of rainbow smelt: the influence of environmental variables and variation in size structure and length-at-maturation

    Science.gov (United States)

    Feiner, Zachary S.; Bunnell, David B.; Hook, Tomas O.; Madenjian, Charles P.; Warner, David M.; Collingsworth, Paris D.

    2015-01-01

    Fish stock-recruitment dynamics may be difficult to elucidate because of nonstationary relationships resulting from shifting environmental conditions and fluctuations in important vital rates such as individual growth or maturation. The Great Lakes have experienced environmental stressors that may have changed population demographics and stock-recruitment relationships while causing the declines of several prey fish species, including rainbow smelt (Osmerus mordax). We investigated changes in the size and maturation of rainbow smelt in Lake Michigan and Lake Huron and recruitment dynamics of the Lake Michigan stock over the past four decades. Mean lengths and length-at-maturation of rainbow smelt generally declined over time in both lakes. To evaluate recruitment, we used both a Ricker model and a Kalman filter-random walk (KF-RW) model which incorporated nonstationarity in stock productivity by allowing the productivity term to vary over time. The KF-RW model explained nearly four times more variation in recruitment than the Ricker model, indicating the productivity of the Lake Michigan stock has increased. By accounting for this nonstationarity, we were able identify significant variations in stock productivity, evaluate its importance to rainbow smelt recruitment, and speculate on potential environmental causes for the shift. Our results suggest that investigating mechanisms driving nonstationary shifts in stock-recruit relationships can provide valuable insights into temporal variation in fish population dynamics.

  13. Craniofacial Secular Change in Recent Mexican Migrants.

    Science.gov (United States)

    Spradley, Katherine; Stull, Kyra E; Hefner, Joseph T

    2016-01-01

    Research by economists suggests that recent Mexican migrants are better educated and have higher socioeconomic status (SES) than previous migrants. Because factors associated with higher SES and improved education can lead to positive secular changes in overall body form, secular changes in the craniofacial complex were analyzed within a recent migrant group from Mexico. The Mexican group represents individuals in the act of migration, not yet influenced by the American environment, and thus can serve as a starting point for future studies of secular change in this population group. The excavation of a historic Hispanic cemetery in Tucson, Arizona, also allows for a comparison between historic Hispanics and recent migrants to explore craniofacial trends over a broad time period, as both groups originate from Mexico. The present research addresses two main questions: (1) Are cranial secular changes evident in recent Mexican migrants? (2) Are historic Hispanics and recent Mexican migrants similar? By studying secular changes within a migrant population group, secular trends may be detected, which will be important for understanding the biological variation of the migrants themselves and will serve as a preliminary investigation of secular change within Mexican migrants. The comparison of a sample of recent Mexican migrants with a historic Hispanic sample, predominantly of Mexican origin, allows us to explore morphological similarities and differences between early and recent Mexicans within the United States. Vault and face size and a total of 82 craniofacial interlandmark distances were used to explore secular changes within the recent Mexican migrants (females, n = 38; males, n = 178) and to explore the morphological similarities between historic Hispanics (females, n = 54; males, n = 58) and recent migrants. Sexes were separated, and multivariate adaptive regression splines and basis splines (quadratic with one knot) were used to assess the direction and magnitude

  14. Early Childhood Internalizing Problems in Mexican- and Dominican-Origin Children: The Role of Cultural Socialization and Parenting Practices

    Science.gov (United States)

    Calzada, Esther; Barajas-Gonzalez, R. Gabriela; Huang, Keng-Yen; Brotman, Laurie

    2015-01-01

    This study examined mother- and teacher-rated internalizing behaviors (i.e., anxiety, depression and somatization symptoms) among young children using longitudinal data from a community sample of 661 Mexican and Dominican families, and tested a conceptual model in which parenting (mother’s socialization messages and parenting practices) predicted child internalizing problems 12 months later. Children evidenced elevated levels of mother-rated anxiety at both time points. Findings also supported the validity of the proposed parenting model for both Mexican and Dominican families. Though there were different pathways to child anxiety, depression and somatization among Mexican and Dominican children, socialization messages and authoritarian parenting were positively associated with internalizing symptoms for both groups. PMID:26042610

  15. The significance of protecting domestic native corn from genetically modified seeds: a perspective from local Mexican NGOs

    Directory of Open Access Journals (Sweden)

    Juanamaria Vazquez

    2016-12-01

    Full Text Available During the last decades, there has been an ongoing global discussion about the use of genetically modified organisms (GMO and their insertion in geographic regions where there is a vast pool of native landraces such as Mexican corn, Indian rice, Peruvian potato. This discussion takes place between those who defend native landraces along with traditional farming knowledge (TK and those who defend genetic engineering products (GMO, turning the discussion into a running social confrontation between large corporations and domestic NGO’s network. Both sides are accompanied by leading scientific communities.Based on the Political Economy perspective of K. Polanyi and his analytical categories, this paper examines the case of the Mexican GMO controversy between predominantly US agroindustry and Mexican NGOs. It shows the performance of NGO’s in trying to avoid the insertion of GM corn in México through a legal injunction that is banning the commercialization of this GM corn in the whole territory.

  16. Childhood asthma, air quality, and social suffering among Mexican Americans in California's San Joaquin Valley: "Nobody talks to us here".

    Science.gov (United States)

    Schwartz, Norah Anita; Pepper, David

    2009-10-01

    Nearly one in five Mexican American children residing in California's San Joaquin Valley (the Valley) in 2007 had an asthma attack at some point in their life. Numerous epidemiological studies have suggested that compared with other ethnic groups and Latino subgroups residing in the United States, Mexican origin children have the lowest rates of pediatric asthma. Ethnographic research conducted in central California, however, suggests otherwise. Known for its agricultural produce, extreme poverty, and poor air quality, the Valley is a magnet for the Mexican immigrant farm worker population. We conducted an exploratory ethnographic study to examine health disparities, social suffering, and childhood asthma in the Valley. Many Valley residents believe that their children's health concerns are being ignored. Open-ended interviews uncovered a largely rural community suffering not only from the effects of childhood asthma but the inability to have their experiences taken seriously.

  17. Early Childhood Internalizing Problems in Mexican- and Dominican-Origin Children: The Role of Cultural Socialization and Parenting Practices.

    Science.gov (United States)

    Calzada, Esther; Barajas-Gonzalez, R Gabriela; Huang, Keng-Yen; Brotman, Laurie

    2017-01-01

    This study examined mother- and teacher-rated internalizing behaviors (i.e., anxiety, depression, and somatization symptoms) among young children using longitudinal data from a community sample of 661 Mexican and Dominican families and tested a conceptual model in which parenting (mother's socialization messages and parenting practices) predicted child internalizing problems 12 months later. Children evidenced elevated levels of mother-rated anxiety at both time points. Findings also supported the validity of the proposed parenting model for both Mexican and Dominican families. Although there were different pathways to child anxiety, depression, and somatization among Mexican and Dominican children, socialization messages and authoritarian parenting were positively associated with internalizing symptoms for both groups.

  18. Nervios and dysphoria in Mexican American widows.

    Science.gov (United States)

    Kay, M; Portillo, C

    1989-01-01

    One hundred widows participating in experimental research entitled Efficacy of Support Groups for Mexican American Widows were studied to learn how they express the loss of their husbands. Mourning practices, acknowledged symptoms of dysphoria, and somatic reactions were studied to learn if the syndrome of nervios subsumes their reaction to bereavement. In addition, their responses to instruments designed to measure depression, the Spanish version of the Beck Depression Inventory and the Center for Epidemiologic Studies Depression Scale, were examined for correlation with nervios and relationships to Mexican American acculturation. Nervios seems to be a manifestation of dysphoria rather than a specific syndrome for these women.

  19. Mexican oil industry: Shifting to difficult oil

    Energy Technology Data Exchange (ETDEWEB)

    Bazan G., Gerardo; Gonzalez, Cristobal J.

    2010-09-15

    Mexico has stepped into an important transition of declining oil fields and new challenging oil projects. The aim of this paper is to show a new perspective of the oil resources that have been exploited throughout the Mexican territory, as well as the remaining resources yet to be exploited. We have developed a resources/production-costs chart that illustrates the historical and future development of the Mexican oil industry, showing the shift that the industry will face in the coming years; this chart was taken from a model already in use by the most prestige energy agencies in the world.

  20. Invisible Infantry: Mexicans in World War II

    Directory of Open Access Journals (Sweden)

    Enrique Plasencia de la Parra

    2003-04-01

    Full Text Available This paper analyses the  participation of Mexican  and  Mexican- American troops in the United States army during World War II. Recruiting, discrimination, their  role  in the  armed forces  and their reinsertion into society once the war ended, are examined. Special emphasis is placed  on the  Hispanics  fight for their  civil and political rights that was carried on very actively by many War veterans.

  1. Employers mexican migrants in the United States

    Directory of Open Access Journals (Sweden)

    Eduardo Fernández Guzmán

    2013-09-01

    Full Text Available You might think that by definition the migrant labor plays in less profitable niches and meager social mobility. However, a large group of migrants in different economically developed countries have successfully launched businesses of diverse nature and volume. This is why entrepreneurship of migrants is an issue that has received increasing attention in recent years. Compared to other immigrant groups in the United States, Mexicans show low levels of entrepreneurial activity. The aim of this paper is to, through a general literature review of official statistical data, a preliminary analysis of mexican migrant entrepreneurship in the United States, that is to say in recent years has been growing in importance.

  2. Breaking the Silence: Sexual Harassment of Mexican Women Farmworkers.

    Science.gov (United States)

    Kim, Nicole Jung-Eun; Vásquez, Victoria Breckwich; Torres, Elizabeth; Nicola, R M Bud; Karr, Catherine

    2016-01-01

    The purpose of this study was to understand Mexican women farmworkers' perceptions of workplace sexual harassment, its related factors and consequences, and potential points of intervention. This community-based participatory research study conducted focus groups with 20 women farmworkers in rural Washington. Four coders analyzed and gleaned interpretations from verbatim transcripts. Three main themes were identified. It was learned that women farmworkers: (1) frequently experienced both quid pro quo and hostile work environment forms of sexual harassment; (2) faced employment and health consequences due to the harassment; and (3) felt that both individual- and industry-level changes could prevent the harassment. Based on these findings, the authors identified three sets of risk factors contributing to workplace sexual harassment and recommend using a multilevel approach to prevent future harassment in the agriculture industry.

  3. The timing is never right: Mexican views of condom use.

    Science.gov (United States)

    McQuiston, C; Gordon, A

    2000-06-01

    Unprotected sex is a critical issue in the Hispanic community, with the incidence of new Hispanic acquired immune deficiency syndrome (AIDS) cases three times that of non-Hispanic Whites. The researchers used focus groups to examine: (a) whether newly immigrated Mexican men and women in the Southeast United States discussed human immunodeficiency virus (HIV)/sexually transmitted disease (STD) prevention with each other, and (b) how condom use was discussed. For the women, communication was safe sex, and for the men, trust was safe sex. Both communication and trust were dependent on timing in the relationship. Participants could not discuss condoms in a new or established relationship because of issues of trust. This study highlights the complexity of HIV/STD prevention and suggests that trust and timing should be considered within the cultural context of condom introduction.

  4. Risk behaviours for HIV infection among traveling Mexican migrants: The Mexico-US border as a contextual risk factor

    Science.gov (United States)

    Zhang, Xiao; Martinez-Donate, Ana P.; Simon, Norma-Jean E.; Hovell, Melbourne F.; Rangel, Maria Gudelia; Magis-Rodriguez, Carlos; Sipan, Carol L.

    2016-01-01

    The Mexico-US border region is a transit point in the trajectory of Mexican migrants traveling to and from the U.S. and a final destination for domestic migrants from other regions in Mexico. This region also represents a high-risk environment that may increase risk for HIV among migrants and the communities they connect. We conducted a cross-sectional, population-based survey, in Tijuana, Mexico, and compared Mexican migrants with a recent stay on the Mexico-US border region (Border, n=553) with migrants arriving at the border from Mexican sending communities (Northbound, n=1077). After controlling for demographics and migration history, border migrants were more likely to perceive their risk for HIV infection as high in this region and regard this area as a liberal place for sexual behaviours compared to Northbound migrants reporting on their perceptions of the sending communities (pmigrants were more likely to engage in sex, and have unprotected sex, with female sex workers during their recent stay on the border compared to other contexts (rate ratio= 3.0 and 6.6, respectively, pmigrants should be deployed in the Mexican border region to address migration related HIV transmission in Mexico and the U.S. PMID:26878494

  5. Risk behaviours for HIV infection among travelling Mexican migrants: The Mexico-US border as a contextual risk factor.

    Science.gov (United States)

    Zhang, Xiao; Martinez-Donate, Ana P; Simon, Norma-Jean E; Hovell, Melbourne F; Rangel, Maria Gudelia; Magis-Rodriguez, Carlos; Sipan, Carol L

    2017-01-01

    The Mexico-US border region is a transit point in the trajectory of Mexican migrants travelling to and from the USA and a final destination for domestic migrants from other regions in Mexico. This region also represents a high-risk environment that may increase risk for HIV among migrants and the communities they connect. We conducted a cross-sectional, population-based survey, in Tijuana, Mexico, and compared Mexican migrants with a recent stay on the Mexico-US border region (Border, n = 553) with migrants arriving at the border from Mexican sending communities (Northbound, n = 1077). After controlling for demographics and migration history, border migrants were more likely to perceive their risk for HIV infection as high in this region and regard this area as a liberal place for sexual behaviours compared to Northbound migrants reporting on their perceptions of the sending communities (p migrants were more likely to engage in sex, and have unprotected sex, with female sex workers during their recent stay on the border compared to other contexts (rate ratio = 3.0 and 6.6, respectively, p migrants should be deployed in the Mexican border region to address migration related HIV transmission in Mexico and the USA.

  6. Thermodynamics Calculation and Experimental Study on Separation of Bismuth from a Bismuth Glance Concentrate Through a Low-Temperature Molten Salt Smelting Process

    Science.gov (United States)

    Yang, Jian-Guang; He, De-Wen; Tang, Chao-Bo; Chen, Yong-Ming; Sun, Ya-Hui; Tang, Mo-Tang

    2011-08-01

    The main purpose of this study is to characterize and separate bismuth from a bismuth glance concentrate through a low-temperature, sulfur-fixing smelting process. This article reports on a study conducted on the optimization of process parameters, such as Na2CO3 and zinc oxide wt pct in charging, smelting temperature, smelting duration on the bismuth yield, resultant crude bismuth grade, and sulfur-fixing rate. A maximum bismuth recovery of 97.31 pct, crude bismuth grade of 96.93 pct, and 98.23 pct sulfur-fixing rate are obtained when a charge (containing 63.50 wt pct of Na2CO3 and 22.50 wt pct of bismuth glance, as well as 5 pct in excess of the stoichiometric requirement of zinc oxide dosage) is smelted at 1000 K (727 °C) for 150 minutes. This smelting operation is free from atmospheric pollution because zinc oxide is used as the sulfur-fixing agent, which can capture sulfur from bismuth sulfide and form the more thermodynamic-stable compound, zinc sulfide. The solid residue is subjected to a mineral dressing operation to obtain suspension, which is filtered to produce a cake, representing the solid particles of zinc sulfide. Based on the results of the chemical content analysis of the as-resultant zinc sulfide, more than 93 pct zinc sulfide can be recovered, and the recovered zinc sulfide grade can reach 60.20 pct. This material can be sold as zinc sulfide concentrate or roasted to be regenerated as zinc oxide.

  7. A Covered Cod-End and Tow-Path Evaluation of Midwater Trawl Gear Efficiency for Catching Delta Smelt (Hypomesus transpacificus

    Directory of Open Access Journals (Sweden)

    Lara Mitchell

    2017-12-01

    Full Text Available https://doi.org/10.15447/sfews.2017v15iss4art3For nearly 50 years, the California Department of Fish and Wildlife has used a midwater trawl to intensively monitor fish populations in the San Francisco Estuary during the fall, sampling over 100 locations each month. The data collected have been useful for calculating indices of fish abundance and for detecting and documenting the decline of the endangered fish species delta smelt (Hypomesus transpacificus. However, efforts to calculate estimates of absolute abundance have been hampered by the lack of information on gear efficiency, in particular questions about contact selectivity and the effect of tow method on catches. To answer these questions we conducted a study that used a covered cod end on a net towed either near the surface, referred to as a surface tow, or throughout the water column, referred to as an oblique tow. A contact selectivity model was fit to estimate the probability that a delta smelt that has come into contact with the net is retained in the cod end of the net conditional on its body length. Full retention of delta smelt was found to occur around 60 mm fork length. Delta smelt catch densities for the surface tows were an order of magnitude greater than densities in the oblique tows, suggesting a surface orientation at the sub-adult life stage. These results represent an important step in being able to calculate absolute abundance estimates of the delta smelt population size using decades’ worth of monitoring data.

  8. Rapid Microwave Digestion Procedures for the Elemental Analysis of Alloy and Slag Samples of Smelted Ocean Bed Polymetallic Nodules

    Directory of Open Access Journals (Sweden)

    Kumari Smita

    2013-01-01

    Full Text Available The use of microwave digester for digestion of alloy and slag samples of smelted ocean bed polymetallic nodules has permitted the complete digestion of samples, thereby replacing the tedious classical methods of digestion of samples. The digestion procedure includes two acid-closed digestions of samples in a microwave oven. Owing to the hazardous nature of perchloric acid, it was not used in developed digestion procedure. Digested sample solutions were analyzed for concentrations of various radicals and the effectiveness of the developed digestion methodology was tested using certified reference materials. It was found that the developed method is giving results comparable with that obtained from conventionally digested samples. In this digestion procedure, time required for digestion of samples was reduced to about 1 hour only from 8-9 hours of conventional digestion.

  9. Preparation of Cementitious Material Using Smelting Slag and Tailings and the Solidification and Leaching of Pb2+

    Directory of Open Access Journals (Sweden)

    Dan Zhang

    2015-01-01

    Full Text Available The composite cementitious materials were prepared with lead-zinc tailings, lead-zinc smelting slag, and cement clinker. The effect of material ratio on the mechanical properties, the phase analysis, and microstructures were investigated. The effect of the pH and stripping time on the leaching amount of lead ion was discussed. The results show that the additive amount of the tailings should be minimized for the cementitious materials meeting the strength requirements, controlled within 10%. The leaching amount of cementitious materials remains low in a larger range of pH, which can effectively reduce the leaching of heavy metal lead. The leaching kinetics of lead ions in the three kinds of samples could be better described by the pseudo-second-model.

  10. Effect of Copper and Iron Ions on the Sulphidizing Flotation of Copper Oxide in Copper Smelting Slag

    Directory of Open Access Journals (Sweden)

    Qing-qing Pan

    2018-01-01

    Full Text Available The treatment of smelting slag has attracted much attention nowadays. This study investigates the influence of Na2S, CuSO4, and FeCl3 on sulphidizing flotation of copper oxide. The results show that a proper Cu2+ concentration can increase the sulphidizing effect of copper oxide, while Fe3+ inhibits the sulphidizing effect. Further analysis shows that Cu2+ ions can reduce the surface potential, increase the S2− adsorption, then generate more polysulfide, and therefore promote the sulphidizing flotation. However, Fe3+ ions would increase the surface potential, reduce the S2− adsorption, generate more sulfur element, and therefore inhibit the sulphidizing flotation.

  11. Huelga Schools in Houston: Community-Based Education in the Struggle for Legal Recognition, 1970

    Science.gov (United States)

    San Miguel, Guadalupe, Jr.

    2016-01-01

    This essay provides an overview of the huelga schools established in Houston, Texas, in 1970. For 2 years, from 1970 to 1972, the Mexican American community opposed the Houston Independent School District's plan to integrate the schools by pairing so-called White Mexican Americans with African American students. While they protested this decision,…

  12. The Smell of Memories. A Mexican Migrant’s Search for Emotional Sustainability through Mexican Films.

    OpenAIRE

    Gabriela Coronado

    2011-01-01

    For more than 10 years living as a Mexican migrant, between two countries (Mexico and Australia), two cities (Mexico City and Sydney), and two social worlds (Mexican and multicultural Australian ‘families-friends’), I have been immersed in a systematic process of self observation and self reflection on my life in my country of destination. During this time I have explored my memories of place and their relationship with my emotional experiences, looking for strategies to continue to be connec...

  13. Subjective Social Status, Mental and Psychosocial Health, and Birth Weight Differences in Mexican-American and Mexican Immigrant Women.

    Science.gov (United States)

    Fleuriet, K Jill; Sunil, T S

    2015-12-01

    Recent Mexican immigrant women on average have an unexpectedly low incidence of low birth weight (LBW). Birth weights decline and LBW incidence increases in post-immigrant generations. This pilot project tested the hypothesis that subjective social status (SSS) of pregnant women predicts variation in birth weight between Mexican immigrant and Mexican-American women. 300 low-income pregnant Mexican immigrant and Mexican-American women in South Texas were surveyed for SSS, depression, pregnancy-related anxiety, perceived social stress and self-esteem and subsequent birth weight. No significant difference in SSS levels between pregnant Mexican immigrant and Mexican-American women were found. However, SSS better predicted variation in birth weight across both groups than mental and psychosocial health variables. Results suggest distinct relationships among SSS, mental and psychosocial health that could impact birth weight. They underscore the relevance of a multilevel, biopsychosocial analytical framework to studying LBW.

  14. Mexican-Americans in the Southwest.

    Science.gov (United States)

    Galarza, Ernesto; And Others

    With findings as presented in this 1969 book, a 2-year field study conducted by a 3-member team analyzed the economic, cultural, political, and educational conditions of Mexican Americans in the Southwest (California, Arizona, New Mexico, Colorado, and Texas) with some reference to braceros and the situation in Mexico. An overview of 8 geographic…

  15. Barreda, Vasconcelos, and Mexican Educational Reforms.

    Science.gov (United States)

    Skirius, John

    1983-01-01

    Reviews the contributions to Mexican education of Gabino Barredas' positivism between 1867-1898 and the contributions of Jose Vasconcelos during the 1920s. Discusses the secondary curriculum reforms of Barreda's era and the vocational education and the education for women and adults during the Vasconcelos era. (SB)

  16. Weight Preoccupation in Female Mexican American Adolescents.

    Science.gov (United States)

    Guinn, Bobby; Jorgensen, Layne; Semper, Tom; Vincent, Vern

    2002-01-01

    Investigated the contribution of body size, self-esteem, age, mainstream acculturation, and athletic status to concern or preoccupation about weight among female Mexican American adolescents. Students had low acculturation, high body fatness, and moderate self-esteem. There was little difference between athletes and non-athletes. Greater body size…

  17. New offshore platform in the Mexican Gulf

    Energy Technology Data Exchange (ETDEWEB)

    Beisel, T.

    1982-04-01

    After a construction period of only 10 months, the second steel Offshore platform was recently completed in the Mexican Gulf. The pattern for this structure was the Cognac platform. The erection of the new platform, called the 'Cerveza' platform, is described in the article.

  18. Conflict Resolution between Mexican Origin Adolescent Siblings

    Science.gov (United States)

    Killoren, Sarah E.; Thayer, Shawna M.; Updegraff, Kimberly A.

    2008-01-01

    We investigated correlates of adolescents' sibling conflict resolution strategies in 246, two-parent Mexican origin families. Specifically, we examined links between siblings' conflict resolution strategies and sibling dyad characteristics, siblings' cultural orientations and values, and sibling relationship qualities. Data were gathered during…

  19. The Mexican American Woman and Mental Health.

    Science.gov (United States)

    Gibson, Guadalupe

    For a long time Chicanas have been self-denying, self sacrificing. Well, it is time that Mexican American women began thinking of themselves. It follows that if women love and cherish others, they must begin by loving and cherishing themselves. From the mental health perspective it is essential that they do so, not only for their sake, but for…

  20. Civic Engagement Patterns of Undocumented Mexican Students

    Science.gov (United States)

    Perez, William; Espinoza, Roberta; Ramos, Karina; Coronado, Heidi; Cortes, Richard

    2010-01-01

    This study examined the civic engagement of undocumented Mexican students. Civic engagement was defined as providing a social service, activism, tutoring, and functionary work. Survey data results (n = 126) suggest that despite high feelings of rejection because of their undocumented status, part-time employment, and household responsibilities,…

  1. Open Access to Mexican Academic Production

    Science.gov (United States)

    Adame, Silvia I.; Llorens, Luis

    2016-01-01

    This paper presents a description of the metadata harvester software development. This system provides access to reliable and quality educational resources, shared by Mexican Universities through their repositories, to anyone with Internet Access. We present the conceptual and contextual framework, followed by the technical basis, the results and…

  2. The Mexican-American and Dramatic Literature.

    Science.gov (United States)

    Serrano, Hector M.

    In the area of the arts, the Mexican American has discovered a rich cultural heritage which gives him a strong sense of pride and a deep feeling of satisfaction. A new interest in the literature of Mexico and the Southwestern states of Texas, Arizona, New Mexico, Colorado, and California has started the Chicano people reading classic and modern…

  3. Decision Profiles of Mexican-Descent Families.

    Science.gov (United States)

    Baker, Georgianne

    An exploratory study of decision-making in families of Mexican heritage was carried out in Phoenix, Arizona. A Normative model of decision rationality and measurement (Family Problem Instrument-FPI) was adapted from previous research. Tape-recorded data were provided by 27 families. Husbands and wives responded separately to family decision…

  4. Racial Identity and Racial Treatment of Mexican Americans.

    Science.gov (United States)

    Ortiz, Vilma; Telles, Edward

    2012-04-01

    How racial barriers play in the experiences of Mexican Americans has been hotly debated. Some consider Mexican Americans similar to European Americans of a century ago that arrived in the United States with modest backgrounds but were eventually able to participate fully in society. In contrast, others argue that Mexican Americans have been racialized throughout U.S. history and this limits their participation in society. The evidence of persistent educational disadvantages across generations and frequent reports of discrimination and stereotyping support the racialization argument. In this paper, we explore the ways in which race plays a role in the lives of Mexican Americans by examining how education, racial characteristics, social interactions, relate to racial outcomes. We use the Mexican American Study Project, a unique data set based on a 1965 survey of Mexican Americans in Los Angeles and San Antonio combined with surveys of the same respondents and their adult children in 2000, thereby creating a longitudinal and intergenerational data set. First, we found that darker Mexican Americans, therefore appearing more stereotypically Mexican, report more experiences of discrimination. Second, darker men report much more discrimination than lighter men and than women overall. Third, more educated Mexican Americans experience more stereotyping and discrimination than their less-educated counterparts, which is partly due to their greater contact with Whites. Lastly, having greater contact with Whites leads to experiencing more stereotyping and discrimination. Our results are indicative of the ways in which Mexican Americans are racialized in the United States.

  5. Friendship Factors and Suicidality: Common and Unique Patterns in Mexican- and European-American Youth

    Science.gov (United States)

    Winterrowd, Erin; Canetto, Silvia Sara; Chavez, Ernest L.

    2010-01-01

    Research suggests a link between friendships and suicidality among U.S. youth but this link has not been confirmed across ethnicities. This study examined the relationship between friendships and suicidality among Mexican- and European-American adolescents. Specifically, the role of friendship problems (i.e., social isolation, poor quality friendships) and problematic friends (i.e., friends who were disconnected from school, delinquent friends) was explored. Participants were 648 community youth. Friends’ school disconnection was related to Mexican-American girls’ suicidal ideation while friends’ delinquency was associated with European-American youth suicidal behavior. Friendship factors were no longer associated with suicidality after controlling for suicidality correlates such as depression. These findings indicate that the relationship between friendships and suicidality varies by gender and ethnicity. They also suggest a dominant role of depression. PMID:21309824

  6. Trajectories of Mexican American and mainstream cultural values among Mexican American adolescents.

    Science.gov (United States)

    Knight, George P; Basilio, Camille D; Cham, Heining; Gonzales, Nancy A; Liu, Yu; Umaña-Taylor, Adriana J

    2014-12-01

    Mexican Americans are one of the largest and fastest growing ethnic groups in the United States, yet we have limited knowledge regarding changes (i.e., developmental trajectories) in cultural orientation based upon their exposure to the Mexican American and mainstream cultures. We examined the parallel trajectories of Mexican American and mainstream cultural values in a sample of 749 Mexican American adolescents (49 % female) across assessments during the fifth grade (approximately 11 years of age), the seventh grade (approximately 13 years of age) and the tenth grade (approximately 16 years of age). We expected that these values would change over this developmental period and this longitudinal approach is more appropriate than the often used median split classification to identify distinct types of acculturation. We found four distinct acculturation trajectory groups: two trajectory groups that were increasing slightly with age in the endorsement of mainstream cultural values, one of which was relatively stable in Mexican American cultural values while the other was declining in their endorsement of these values; and two trajectory groups that were declining substantially with age in their endorsement of mainstream cultural values, one of which was also declining in Mexican American cultural values and the other which was stable in these values. These four trajectory groups differed in expected ways on a number of theoretically related cultural variables, but were not highly consistent with the median split classifications. The findings highlight the need to utilize longitudinal data to examine the developmental changes of Mexican American individual's adaptation to the ethnic and mainstream culture in order to understand more fully the processes of acculturation and enculturation.

  7. Toward a Mexican eddy covariance network for carbon cycle science

    Science.gov (United States)

    Vargas, Rodrigo; Yépez, Enrico A.

    2011-09-01

    First Annual MexFlux Principal Investigators Meeting; Hermosillo, Sonora, Mexico, 4-8 May 2011; The carbon cycle science community has organized a global network, called FLUXNET, to measure the exchange of energy, water, and carbon dioxide (CO2) between the ecosystems and the atmosphere using the eddy covariance technique. This network has provided unprecedented information for carbon cycle science and global climate change but is mostly represented by study sites in the United States and Europe. Thus, there is an important gap in measurements and understanding of ecosystem dynamics in other regions of the world that are seeing a rapid change in land use. Researchers met under the sponsorship of Red Temática de Ecosistemas and Consejo Nacional de Ciencia y Tecnologia (CONACYT) to discuss strategies to establish a Mexican eddy covariance network (MexFlux) by identifying researchers, study sites, and scientific goals. During the meeting, attendees noted that 10 study sites have been established in Mexico with more than 30 combined years of information. Study sites span from new sites installed during 2011 to others with 9 to 6 years of measurements. Sites with the longest span measurements are located in Baja California Sur (established by Walter Oechel in 2002) and Sonora (established by Christopher Watts in 2005); both are semiarid ecosystems. MexFlux sites represent a variety of ecosystem types, including Mediterranean and sarcocaulescent shrublands in Baja California; oak woodland, subtropical shrubland, tropical dry forest, and a grassland in Sonora; tropical dry forests in Jalisco and Yucatan; a managed grassland in San Luis Potosi; and a managed pine forest in Hidalgo. Sites are maintained with an individual researcher's funds from Mexican government agencies (e.g., CONACYT) and international collaborations, but no coordinated funding exists for a long-term program.

  8. Hard X-ray Sources for the Mexican Synchrotron Project

    International Nuclear Information System (INIS)

    Reyes-Herrera, Juan

    2016-01-01

    One of the principal tasks for the design of the Mexican synchrotron was to define the storage ring energy. The main criteria for choosing the energy come from studying the electromagnetic spectrum that can be obtained from the synchrotron, because the energy range of the spectrum that can be obtained will determine the applications available to the users of the future light source. Since there is a public demand of hard X-rays for the experiments in the synchrotron community users from Mexico, in this work we studied the emission spectra from some hard X-ray sources which could be the best options for the parameters of the present Mexican synchrotron design. The calculations of the flux and the brightness for one Bending Magnet and four Insertion Devices are presented; specifically, for a Superconducting Bending Magnet (SBM), a Superconducting Wiggler (SCW), an In Vacuum Short Period Undulator (IV-SPU), a Superconducting Undulator (SCU) and for a Cryogenic Permanent Magnet Undulator (CPMU). Two commonly available synchrotron radiation programs were used for the computation (XOP and SRW). From the results, it can be concluded that the particle beam energy from the current design is enough to have one or more sources of hard X-rays. Furthermore, a wide range of hard X-ray region can be covered by the analyzed sources, and the choice of each type should be based on the specific characteristics of the X-ray beam to perform the experiments at the involved beamline. This work was done within the project Fomix Conacyt-Morelos ”Plan Estrategico para la construccion y operación de un Sincrotron en Morelos” (224392). (paper)

  9. Hard X-ray Sources for the Mexican Synchrotron Project

    Science.gov (United States)

    Reyes-Herrera, Juan

    2016-10-01

    One of the principal tasks for the design of the Mexican synchrotron was to define the storage ring energy. The main criteria for choosing the energy come from studying the electromagnetic spectrum that can be obtained from the synchrotron, because the energy range of the spectrum that can be obtained will determine the applications available to the users of the future light source. Since there is a public demand of hard X-rays for the experiments in the synchrotron community users from Mexico, in this work we studied the emission spectra from some hard X-ray sources which could be the best options for the parameters of the present Mexican synchrotron design. The calculations of the flux and the brightness for one Bending Magnet and four Insertion Devices are presented; specifically, for a Superconducting Bending Magnet (SBM), a Superconducting Wiggler (SCW), an In Vacuum Short Period Undulator (IV-SPU), a Superconducting Undulator (SCU) and for a Cryogenic Permanent Magnet Undulator (CPMU). Two commonly available synchrotron radiation programs were used for the computation (XOP and SRW). From the results, it can be concluded that the particle beam energy from the current design is enough to have one or more sources of hard X-rays. Furthermore, a wide range of hard X-ray region can be covered by the analyzed sources, and the choice of each type should be based on the specific characteristics of the X-ray beam to perform the experiments at the involved beamline. This work was done within the project Fomix Conacyt-Morelos ”Plan Estrategico para la construccion y operación de un Sincrotron en Morelos” (224392).

  10. Losses of Sacramento River Chinook Salmon and Delta Smelt to Entrainment in Water Diversions in the Sacramento–San Joaquin Delta

    Directory of Open Access Journals (Sweden)

    Wim J. Kimmerer

    2008-06-01

    Full Text Available Pumping at the water export facilities in the southern Sacramento-San Joaquin Delta kills fish at and near the associated fish-salvage facilities. Correlative analyses of salvage counts with population indices have failed to provide quantitative estimates of the magnitude of this mortality. I estimated the proportional losses of Sacramento River Chinook salmon (Oncorhynchus tshawytscha and delta smelt (Hypomesus transpacificus to place these losses in a population context. The estimate for salmon was based on recoveries of tagged smolts released in the upper Sacramento River basin, and recovered at the fish-salvage facilities in the south Delta and in a trawling program in the western Delta. The proportion of fish salvaged increased with export flow, with a mean value around 10% at the highest export flows recorded. Mortality was around 10% if pre-salvage losses were about 80%, but this value is nearly unconstrained. Losses of adult delta smelt in winter and young delta smelt in spring were estimated from salvage data (adults corrected for estimated pre-salvage survival, or from trawl data in the southern Delta (young. These losses were divided by population size and accumulated over the respective seasons. Losses of adult delta smelt were 1–50% (median 15% although the highest value may have been biased upward. Daily losses of larvae and juveniles were 0–8%, and seasonal losses accumulated were 0–25% (median 13%. The effect of these losses on population abundance was obscured by subsequent 50-fold variability in survival from summer to fall.

  11. The relationship between Mexican American cultural values and resilience among Mexican American college students: a mixed methods study.

    Science.gov (United States)

    Morgan Consoli, Melissa L; Llamas, Jasmin D

    2013-10-01

    The current study investigated the role of cultural values in the resilience of Mexican American college students. Utilizing mixed methodology, 124 self-identified Mexican American college students were asked to complete an online survey, including a demographic questionnaire, the Resilience Scale, Mexican American Cultural Values Scale, and 2 open-ended questions concerning overcoming adversity and cultural values. As hypothesized, Mexican American traditional cultural values (Familismo, Respeto, Religiosidad, and Traditional Gender Roles) predicted resilience, with Familismo accounting for the majority of the variance. Consensual qualitative research (Hill, Thompson, & Nutt Williams, 1997) was used to identify emergent domains and themes within the open-ended question responses. Traditional Mexican American Value themes included Familismo, Ethnic Identity, Religiosidad, Perseverance, and Respeto. Results highlight the important role that certain Mexican American cultural values play in providing strength for overcoming adversities.

  12. Alkaline pretreatment of Mexican pine residues for bioethanol ...

    African Journals Online (AJOL)

    Alkaline pretreatment of Mexican pine residues for bioethanol production. ... Keywords: Lignocellulosic biomass, alkaline pretreatment, enzymatic hydrolysis, fermentable sugars, fermentation. African Journal of Biotechnology Vol. 12(31), pp.

  13. Seizing Community Participation in Sustainable Development

    DEFF Research Database (Denmark)

    Balslev Clausen, Helene; Gyimóthy, Szilvia

    2015-01-01

    and cultural sustainability defined in the Mexican national tourism program Pueblos Mágicos are put into practice. The analysis is focused on how citizenship, local participation and democracy are operationalized and what are the local consequences of this governmental program in the community of Álamos...... migrant community in shaping sustainable tourism development as cultural brokers, social entrepreneurs and mediators of market knowledge. The paper criticizes the notion of homogenous local communities as an instrumental condition of sustainable and participatory development....

  14. 3. Mexican school of nuclear physics

    International Nuclear Information System (INIS)

    Chavez L, E.R.; Hess, P.O.; Martinez Q, E.

    2002-01-01

    The III Mexican School of Nuclear Physics which is directed to those post graduate in Sciences and those of last semesters students of the Physics career or some adjacent career was organized by the Nuclear Physics Division of the Mexican Physics Society, carrying out at November 18-29, 2002 in the installations of the Institute of Physics and the Institute of Nuclear Sciences both in the UNAM, and the National Institute of Nuclear Research (ININ). In this as well as the last version its were offered 17 courses, 9 of them including laboratory practices and the rest were of theoretical character only. This book treats about the following themes: Nuclear physics, Electrostatic accelerators, Cyclotrons, Thermonuclear reactions, Surface barrier detectors, Radiation detection, Neutron detection, Bonner sphere spectrometers, Radiation protection, Biological radiation effects, Particle kinematics, Nucleosynthesis, Plastics, Muons, Quadrupoles, Harmonic oscillators, Quantum mechanics among many other matters. (Author)

  15. Second Mexican School of Nuclear Physics: Notes

    International Nuclear Information System (INIS)

    Aguilera, E.F.; Chavez L, E.R.; Hess, P.O.

    2001-01-01

    The II Mexican School of Nuclear Physics which is directed to those last semesters students of the Physics career or post-graduate was organized by the Nuclear Physics Division of the Mexican Physics Society, carrying out at April 16-27, 2001 in the installations of the Institute of Physics and the Institute of Nuclear Sciences, both in the UNAM, and the National Institute of Nuclear Research (ININ). A first school of a similar level in Nuclear Physics, was carried out in Mexico at 1977 as Latin american School of Physics. This book treats about the following themes: Interactions of radiation with matter, Evaluation of uncertainty in experimental data, Particle accelerators, Notions of radiological protection and dosimetry, Cosmic rays, Basis radiation (environmental), Measurement of excitation functions with thick targets and inverse kinematics, Gamma ray technique for to measure the nuclear fusion, Neutron detection with Bonner spectrometer, Energy losses of alpha particles in nickel. It was held the practice Radiation detectors. (Author)

  16. Energy-urban transition: The Mexican case

    International Nuclear Information System (INIS)

    Paez, Armando

    2010-01-01

    In this paper I present a study regarding the institutional conditions of Mexican cities based on a post-petroleum urban model that considers transport, architecture, urban planning and land use, renewable energy sources, energy saving and efficiency, and urban metabolism issues. The model was constructed with recommendations of authors and organizations that have analysed the energy dimension of cities under an energy-availability, environmental or petroleum-independent view. To make the study I sent a questionnaire to some local governments of all the country. The information indicates that Mexican cities do not have institutional conditions to manage the urban-energy transition that signify the end of cheap oil and the peak of world oil production.

  17. PEMEX: The Mexican state petroleum agency

    International Nuclear Information System (INIS)

    1993-03-01

    An overview is presented of the Mexican state petroleum company PEMEX. The Mexican government created PEMEX through the expropriation of the largely foreign-dominated industry. Mexico is the world's fifth largest crude oil producer, and in 1992 PEMEX had proven reserves of 65.5 billion bbl, crude production of 2.668 million bbl/d, gas production of 3.6 billion cubic feet per day, refined product production of 1.57 million bbl/d and 18 million tonnes of petrochemical production per year. A background is presented of Mexico's economy, followed by discussion of PEMEX's market, the best sales prospects for foreign suppliers, a company profile, financial structure, exploration and production, refining, gas and basic petrochemicals, petrochemicals, transportation and distribution, research and development, recent activities, planned future activities, procurement, and market access. Extensive appendices supply relevant contacts and information. 30 tabs

  18. Electricity supply opportunities -- The Mexican door opens

    International Nuclear Information System (INIS)

    Holland, H.W.

    1993-01-01

    Anyone who assumes that the Mexican market for electrical capacity is just a matter of selling equipment and services is in for a shock. The astute neighbor to the south is exploring privatization in the power sector with a style and flair that is uniquely Mexican. While free market-market forces have, to some extent, already transformed the manner in which new generating capacity is added in the US, a Mexico equivalent will not develop over night. Mexico is no place for the faint of heart. You have to play hard in order to win against competition almost equivalent to that of the US market and have the staying power to be around long enough to reap the rewards. This work presents the author's views concerning the manner in which competition has been introduced within the electricity supply market of the neighbor to the south

  19. Research on the Characteristics and Mechanism of the Cumulative Release of Antimony from an Antimony Smelting Slag Stacking Area under Rainfall Leaching

    Science.gov (United States)

    Zhou, Yingying; Deng, Renjian

    2017-01-01

    We aimed to study the characteristics and the mechanism of the cumulative release of antimony at an antimony smelting slag stacking area in southern China. A series of dynamic and static leaching experiments to simulate the effects of rainfall were carried out. The results showed that the release of antimony from smelting slag increased with a decrease in the solid-liquid ratio, and the maximum accumulated release was found to be 42.13 mg Sb/kg waste and 34.26 mg Sb/kg waste with a solid/liquid ratio of 1 : 20; the maximum amount of antimony was released within 149–420 μm size fraction with 7.09 mg/L of the cumulative leaching. Also, the antimony release was the greatest and most rapid at pH 7.0 with the minimum release found at pH 4.0. With an increase in rainfall duration, the antimony release increased. The influence of variation in rainfall intensity on the release of antimony from smelting slag was small. PMID:28804669

  20. Transplantation of epiphytic bioaccumulators (Tillandsia capillaris) for high spatial resolution biomonitoring of trace elements and point sources deconvolution in a complex mining/smelting urban context

    Science.gov (United States)

    Goix, Sylvaine; Resongles, Eléonore; Point, David; Oliva, Priscia; Duprey, Jean Louis; de la Galvez, Erika; Ugarte, Lincy; Huayta, Carlos; Prunier, Jonathan; Zouiten, Cyril; Gardon, Jacques

    2013-12-01

    Monitoring atmospheric trace elements (TE) levels and tracing their source origin is essential for exposure assessment and human health studies. Epiphytic Tillandsia capillaris plants were used as bioaccumulator of TE in a complex polymetallic mining/smelting urban context (Oruro, Bolivia). Specimens collected from a pristine reference site were transplanted at a high spatial resolution (˜1 sample/km2) throughout the urban area. About twenty-seven elements were measured after a 4-month exposure, also providing new information values for reference material BCR482. Statistical power analysis for this biomonitoring mapping approach against classical aerosols surveys performed on the same site showed the better aptitude of T. Capillaris to detect geographical trend, and to deconvolute multiple contamination sources using geostatistical principal component analysis. Transplanted specimens in the vicinity of the mining and smelting areas were characterized by extreme TE accumulation (Sn > Ag > Sb > Pb > Cd > As > W > Cu > Zn). Three contamination sources were identified: mining (Ag, Pb, Sb), smelting (As, Sn) and road traffic (Zn) emissions, confirming results of previous aerosol survey.

  1. Geochemical and Pb isotopic evidence for sources and dispersal of metal contamination in stream sediments from the mining and smelting district of Pribram, Czech Republic

    International Nuclear Information System (INIS)

    Ettler, Vojtech; Mihaljevic, Martin; Sebek, Ondrej; Molek, Michael; Grygar, Tomas; Zeman, Josef

    2006-01-01

    Stream sediments from the mining and smelting district of Pribram, Czech Republic, were studied to determine the degree, sources and dispersal of metal contamination using a combination of bulk metal and mineralogical determinations, sequential extractions and Pb isotopic analyses. The highest metal concentrations were found 3-4 km downstream from the main polymetallic mining site (9800 mg Pb kg -1 , 26 039 mg Zn kg -1 , 316.4 mg Cd kg -1 , 256.9 mg Cu kg -1 ). The calculated enrichment factors (EFs) confirmed the extreme degree of contamination by Pb, Zn and Cd (EF > 40). Lead, Zn and Cd are bound mainly to Fe oxides and hydroxides. In the most contaminated samples Pb is also present as Pb carbonates and litharge (PbO). Lead isotopic analysis indicates that the predominant source of stream sediment contamination is historic Pb-Ag mining and primary Pb smelting ( 206 Pb/ 207 Pb = 1.16), while the role of secondary smelting (car battery processing) is negligible. - Pb isotopes properly complete traditional investigations of metal sources and dispersal in contaminated stream sediments

  2. Higher risk for obesity among Mexican-American and Mexican immigrant children and adolescents than among peers in Mexico.

    Science.gov (United States)

    Hernández-Valero, María A; Bustamante-Montes, L Patricia; Hernández, Mike; Halley-Castillo, Elizabeth; Wilkinson, Anna V; Bondy, Melissa L; Olvera, Norma

    2012-08-01

    We conducted a cross-sectional study among 1,717 children and adolescents of Mexican origin ages 5-19 years living in Mexico and Texas to explore the influence of country of birth and country of longest residence on their overweight and obesity status. Descriptive statistics were used to compare demographic and anthropometric characteristics of participants born and raised in Mexico (Mexicans), born in Mexico and raised in the United States (Mexican immigrants), and born and raised in the United States (Mexican-Americans). Univariate and multivariate nominal logistic regression was used to determine the demographic predictors of obesity adjusted by country of birth, country of residence, age, and gender. Almost half (48.8%) of the Mexican-Americans and 43.2% of the Mexican immigrants had body mass index at the 85th percentile or above, compared to only 29.3% of the Mexicans (P obese than their Mexican peers [Mexican-Americans: odds ratio (OR) = 2.5 (95% confidence interval [CI] 1.8-3.4); Mexican immigrants: OR = 2.2 (95% CI 1.6-3.0)]. In addition, males were more likely than females to be obese [OR = 1.6 (95% CI 1.2-2.1)], and adolescents 15-19 years of age were less likely than their younger counterparts [OR = 0.5 (95% CI 0.4-0.7)] to be obese. The high prevalence of obesity among children of Mexican origin in the United States is of great concern and underscores the urgent need to develop and implement obesity preventive interventions targeting younger children of Mexican origin, especially newly arrived immigrant children. In addition, future obesity research should take into consideration the country of origin of the study population to develop more culturally specific obesity interventions.

  3. Mexican Marine Corps in the Struggle for Scalable Security and Its Potential as a Guarantor of the Mexican Safety

    Science.gov (United States)

    2013-03-20

    53 G. Elena. Presidente Peña pide a militares a participar en la transformación de México. 1...security of the government of Mexico and the Mexican people until the civilian police is able to do so. 1S. SUBJECT TERMS MAGTF Concept;Mexican...to contribute better to the safety and security of the government of Mexico and the Mexican people until the civilian police is able to do so

  4. Mexican Trends: The Next Five Years,

    Science.gov (United States)

    1985-12-12

    either Argentina (60%) or Chile (75%) and far higher than Brazil (26%), whose total debt was around the same size. Second, of the aggregate Mexican...liberalization policies in Brazil, Argentina, and Chile were hammered into place not by politicians and political parties but by technocrats and...accident that violence has exploded in three border cities ( Agua ; Prieta, Piedras Negras, and San Luis) where the opposition had access to the U.S. media

  5. Narcocultura: A Threat to Mexican National Security?

    Science.gov (United States)

    2012-12-01

    Postcolony: The Zapatistas and Narcocultura,” PhD Essay , University of British Colombia: Department of Political Science, 2011, 18. 7 Rafael López...humorous lyrics or tones in some narcocorridos29 Edberg concludes by stating, “cultural images cross...provided inspiration for the lyrics of classical corridos.63 These original corridos became a source of Mexican national identity and a vehicle for

  6. The Mexican electricity industry - cogeneration potential

    International Nuclear Information System (INIS)

    Monroy, I.L.

    2000-01-01

    A brief history of Mexico's electric power industry is given. Diagrams show (i) the increase in primary energy production from 1990-1998; (ii) energy consumption by sector and (iii) the change in capacity between 1990 and 1998. The projected energy development for 1998-2007 is discussed. The Mexican government has chosen cogeneration to be an important contributor to future energy-efficient power production. Data on installed cogeneration capacity for years 2000 and 2001 are given according to sector

  7. 4. Mexican School of Nuclear Physics. Papers

    International Nuclear Information System (INIS)

    Aguilera, E.F.; Hernandez, E.; Hirsch, J.

    2005-01-01

    The IV Mexican School of Nuclear Physics, organized by the Nuclear Physics Division of the Mexican Physics Society, takes place from June 27 to July 8, 2005 in the Nuclear Sciences and of Physics Institutes of the UNAM and in the National Institute of Nuclear Research (ININ). This school, as the previous ones, it was guided the students of the last semesters of the career of Physics, of the Post grade of the same specialty, and of other adjacent careers. To give the students a current vision of some of the topics more important of the nuclear physics and their relationship with other near areas of the physics it was the objective of this School. The School covered a wide range of theoretical and experimental courses, imparted in its majority by Mexican expert professor-investigators in the matter to who we thank them the one effort and the quality of their presentations, reflected in the content of this document. The answer of the students to the convocation was excellent, 31 students presented application for admission coming from the following institutions: Meritorious Autonomous University de Puebla, National Institute of Nuclear Research, Technological Institute of Orizaba, National Polytechnic Institute, The University of Texas at Brownsville, Autonomous University of the State de Mexico, Autonomous University of the State of Morelos, Autonomous University of Baja California, Autonomous University of San Luis Potosi, University of Guadalajara, University of Guanajuato, National Autonomous University of Mexico, University of Texas, at El Paso and University Veracruzana. They were admitted to the 22 students with the higher averages qualifications of the list of applicants. The organizers of this school thank the financial support granted by the following sponsor institutions: Nuclear Sciences Institute, UNAM, Physics Institute of UNAM, Coordination of the Scientific Research UNAM, National Institute of Nuclear Research, Nuclear Physics Division of the Mexican

  8. 4. Mexican School of Nuclear Physics

    International Nuclear Information System (INIS)

    Aguilera, E.F.; Hernandez, E.; Hirsch, J.G. -mail: svp@nuclear.inin.mx

    2005-01-01

    The IV Mexican School of Nuclear Physics, organized by the Nuclear Physics Division of the Mexican Physics Society, taken place from June 27 to July 8, 2005 in the Institute of Nuclear Sciences and the Institute of Physics of the UNAM and in the National Institute of Nuclear Research (ININ). This school, as the previous ones, it was guided to the students of the last semesters of the career of Physics, of the Post grade of the same specialty, and of other adjacent careers. To give the students a current vision of some of the topics more important of the nuclear physics and their relationship with other near areas of the physics it was the objective of this School. The School covered a wide range of theoretical and experimental courses, imparted in its majority by Mexican expert professor-investigators in the subject to whom we thank them the one effort and the quality of their presentations, reflected in the content of this document. The answer of the students to the convocation was excellent, 31 students presented application for admission coming from the following institutions: Meritorious Autonomous University of Puebla, National Institute of Nuclear Research, Technological Institute of Orizaba, National Polytechnic Institute, The University of Texas at Brownsville, Autonomous University of the State de Mexico, Autonomous University of the State of Morelos, Autonomous University of Baja California, Autonomous University of San Luis Potosi, University of Guadalajara, University of Guanajuato, National Autonomous University of Mexico, University of Texas, at El Paso and University Veracruzana. They were admitted to those 22 students with the higher averages qualifications of the list of applicants. The organizers of this school thank the financial support granted by the following sponsor institutions: Institute of Nuclear Sciences, UNAM, Institute of Physics, UNAM, Coordination of the Scientific Research, UNAM, National Institute of Nuclear Research, Nuclear

  9. New Mexicans debate nuclear waste disposal

    International Nuclear Information System (INIS)

    Lepkowski, W.

    1979-01-01

    A brief survey of the background of the Waste Isolation Plant (WIPP) at Carlsbad, New Mexico and the forces at play around WIPP is presented. DOE has plans to establish by 1988 an underground repository for nuclear wastes in the salt formations near Carlsbad. Views of New Mexicans, both pro and con, are reviewed. It is concluded that DOE will have to practice public persuasion to receive approval for the burial of wastes in New Mexico

  10. Type 2 diabetes mortality at Mexican borders

    OpenAIRE

    Manzanares Rivera, José Luis

    2017-01-01

    Abstract:Objective: To analyze type II diabetes mortality rates geographic distribution and evolution in time across both Mexican border regions during the period 1998-2013.Methods: The work is based on exploratory and inferential data analysis conducted using death reports from the national health information system. The analysis considers social determinants of health as a theoretical paradigm and includes microdata on consumption patterns at household level for the US-Mexico and Mexico- Gu...

  11. Genetic analysis of Mexican Criollo cattle populations.

    Science.gov (United States)

    Ulloa-Arvizu, R; Gayosso-Vázquez, A; Ramos-Kuri, M; Estrada, F J; Montaño, M; Alonso, R A

    2008-10-01

    The objective of this study was to evaluate the genetic structure of Mexican Criollo cattle populations using microsatellite genetic markers. DNA samples were collected from 168 animals from four Mexican Criollo cattle populations, geographically isolated in remote areas of Sierra Madre Occidental (West Highlands). Also were included samples from two breeds with Iberian origin: the fighting bull (n = 24) and the milking central American Criollo (n = 24) and one Asiatic breed: Guzerat (n = 32). Genetic analysis consisted of the estimation of the genetic diversity in each population by the allele number and the average expected heterozygosity found in nine microsatellite loci. Furthermore, genetic relationships among the populations were defined by their genetic distances. Our data shows that Mexican cattle populations have a relatively high level of genetic diversity based either on the mean number of alleles (10.2-13.6) and on the expected heterozygosity (0.71-0.85). The degree of observed homozygosity within the Criollo populations was remarkable and probably caused by inbreeding (reduced effective population size) possibly due to reproductive structure within populations. Our data shows that considerable genetic differentiation has been occurred among the Criollo cattle populations in different regions of Mexico.

  12. The United Mexican States: an update.

    Science.gov (United States)

    Hakkert, R; Aguirre, E J

    1988-09-01

    Although the popular North American opinion of Mexico is one that paints a picture of a poor, disadvantaged country, South America sees Mexico has a richer more prosperous nation. It is observed that only in the Latin American countries of Venezuela, Suriname and Trinidad and Tobago do consumers have higher incomes than Mexican consumers. Moreover, while millions of Mexicans migrate to the United States to seek a better standard of living, several thousand Central American refugees illegally migrate to Mexico in search of a better life. This better life includes an increased age of lie expectancy from 51 years in the 1950s to 64 years in the late 1970s. There have also been improvements in health care and school enrollments and in the low cost availability of education. Tourism and the prospect of the manufacturing of energy are significant, positive factors working in favor of an improved Mexican economy and a higher overall quality of life. However, Mexico faces serious problems such as a mounting foreign debt. Also rising is Mexico's population which has doubled since 1964 and which continues to grow at a rate of 1.9%. Economic programs and reforms and family development planning have been instituted in response to the countries' current recession and population growth and have begun to show positive results.

  13. Participants in urban Mexican male homosexual encounters.

    Science.gov (United States)

    Carrier, J M

    1971-12-01

    Preliminary data are presented on 53 urban Mexican males interviewed during 1970-1971 in a study of homosexual encounters in a large Mexican city. These data are compared with data from recent studies in the United States and England of male homosexual behavior. Although preliminary and limited, the Mexican data indicate that cultural factors are important determinants of life styles and sex practices of homosexual males. Forty-eight of the 53 (90%) preferred and usually practiced anal intercourse, four preferred oral contacts, and one preferred mutual masturbation. Interviewees were also grouped according to major type of sex activity during the first sustained year of homosexual activity after puberty. One intragroup comparison indicates significant differences between anal active and anal passive interviewees. For example, as children anal passive subjects had significantly more homosexual contacts with adults; they also considered themselves more effeminate and as children were more involved with female sex-typed activities. Comparison of data from the English and United States studies with the present data suggests that preference for a particular sexual technique is not as developed in the former two countries; when there is a preference, it is not usually for anal intercourse.

  14. National Mexican Tourism Policy and North American Second Homeowners In Mexico: Local Tourism Development and Mexican Identity (Chapter 6)

    DEFF Research Database (Denmark)

    Clausen, Helene Balslev

    2018-01-01

    . Still the Mexican state does not seize the second home owners as a resource and ‘producers’ rather only as consumers of different Mexican objects, food etc. The chapter addresses this research gap and proposes rather than only perceive North American second home owners as part of tourism development...... participate in reshaping and reconfigure public policy and Mexican culture/identity construction. The purpose of the chapter is to explore the role of the North American second home owners and their impact on the planning and regulation of Mexican state policies, and how they might reconfigure practices and...

  15. Seasonal fish and invertebrate communities in three northern California estuaries

    OpenAIRE

    Osborn, Katherine

    2017-01-01

    The majority of Northern California estuaries are small, flooded, river valleys that are largely unstudied due to their small sizes and remote locations. Yet these estuaries serve as important nursery areas for many marine fish species including rockfish, flatfish, smelt, and herring, and they are vital to anadromous species such as Chinook Salmon (Oncorhynchus tshawytscha) and Steelhead (O. mykiss). I sampled the summer and winter fish and invertebrate communities of the Big, Mad, and Ten Mi...

  16. Long-term surveillance plan for the Mexican Hat disposal site Mexican Hat, Utah

    International Nuclear Information System (INIS)

    1997-06-01

    This long-term surveillance plan (LTSP) describes the U.S. Department of Energy's (DOE) long-term care program for the Uranium Mill Tailings Remedial Action (UMTRA) Project Mexican Hat, Utah, disposal site. This LSTP describes the long-term surveillance program the DOE will implement to ensure the Mexican Hat disposal site performs as designed and is cared for in a manner that protects the public health and safety and the environment. Before each disposal site is licensed for custody and long-term care, the Nuclear Regulatory Commission (NRC) requires the DOE to submit such a site-specific LTSP

  17. Living Outside the Gender Box in Mexico: Testimony of Transgender Mexican Asylum Seekers.

    Science.gov (United States)

    Cheney, Marshall K; Gowin, Mary J; Taylor, E Laurette; Frey, Melissa; Dunnington, Jamie; Alshuwaiyer, Ghadah; Huber, J Kathleen; Garcia, Mary Camero; Wray, Grady C

    2017-10-01

    To explore preimmigration experiences of violence and postimmigration health status in male-to-female transgender individuals (n = 45) from Mexico applying for asylum in the United States. We used a document review process to examine asylum declarations and psychological evaluations of transgender Mexican asylum seekers in the United States from 2012. We coded documents in 2013 and 2014 using NVivo, a multidisciplinary team reviewed them, and then we analyzed them for themes. Mexican transgender asylum applicants experienced pervasive verbal, physical, and sexual abuse from multiple sources, including family, school, community, and police. Applicants also experienced discrimination in school and in the workplace. Applicants immigrated to the United States to escape persistent assaults and threats to their life. Applicants suffered health and psychological effects from their experiences in Mexico that affected opportunities in the United States for employment, education, and social inclusion. Additional social protections for transgender individuals and antidiscrimination measures in Mexican schools and workplaces are warranted as are increased mental health assessment and treatment, job training, and education services for asylum seekers in the United States.

  18. Neighborhood and family intersections: prospective implications for Mexican American adolescents' mental health.

    Science.gov (United States)

    White, Rebecca M B; Roosa, Mark W; Zeiders, Katharine H

    2012-10-01

    We present an integrated model for understanding Mexican American youth mental health within family, neighborhood, and cultural contexts. We combined two common perspectives on neighborhood effects to hypothesize that (a) parents' perceptions of neighborhood risk would negatively impact their children's mental health by disrupting key parenting and family processes, and (b) objective neighborhood risk would alter the effect parent and family processes had on youth mental health. We further incorporated a cultural perspective to hypothesize that an ethnic minority group's culture-specific values may support parents to successfully confront neighborhood risk. We provided a conservative test of the integrated model by simultaneously examining three parenting and family process variables: maternal warmth, maternal harsh parenting, and family cohesion. The hypothesized model was estimated prospectively in a diverse, community-based sample of Mexican American adolescents and their mothers (N = 749) living in the southwestern United States. Support for specific elements of the hypothesized model varied depending on the parenting or family process variable examined. For family cohesion results were consistent with the combined neighborhood perspectives. The effects of maternal warmth on youth mental health were altered by objective neighborhood risk. For harsh parenting, results were somewhat consistent with the cultural perspective. The value of the integrated model for research on the impacts of family, neighborhood, and cultural contexts on youth mental health are discussed, as are implications for preventive interventions for Mexican American families and youth. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

  19. Neighborhood and Family Intersections: Prospective Implications for Mexican American Adolescents’ Mental Health

    Science.gov (United States)

    White, Rebecca M. B.; Roosa, Mark W.; Zeiders, Katharine H.

    2012-01-01

    We present an integrated model for understanding Mexican American youth mental health within family, neighborhood, and cultural contexts. We combined two common perspectives on neighborhood effects to hypothesize that (a) parents’ perceptions of neighborhood risk would negatively impact their children’s mental health by disrupting key parenting and family processes, and (b) objective neighborhood risk would alter the effect parent and family processes had on youth mental health. We further incorporated a cultural perspective to hypothesize that an ethnic minority group’s culture-specific values may support parents to successfully confront neighborhood risk. We provided a conservative test of the integrated model by simultaneously examining three parenting and family process variables: maternal warmth, maternal harsh parenting, and family cohesion. The hypothesized model was estimated prospectively in a diverse, community-based sample of Mexican American adolescents and their mothers (N = 749) living in the Southwestern, U.S. Support for specific elements of the hypothesized model varied depending on the parenting or family process variable examined. For family cohesion results were consistent with the combined neighborhood perspectives. The effects of maternal warmth on youth mental health were altered by objective neighborhood risk. For harsh parenting results were somewhat consistent with the cultural perspective. The value of the integrated model for research on the impacts of family, neighborhood, and cultural contexts on youth mental health are discussed, as are implications for preventive interventions for Mexican American families and youth. PMID:22866932

  20. The Diabetes Symptom Self-Care Inventory: development and psychometric testing with Mexican Americans.

    Science.gov (United States)

    García, Alexandra A

    2011-04-01

    Type 2 diabetes is prevalent throughout the world. In previous studies of Mexican Americans with type 2 diabetes, 95%-97% of those sampled reported having symptoms they believe were caused by diabetes and most self-treated their symptoms. To more accurately capture Mexican Americans' symptom prevalence and their self-treatments, the Diabetes Symptom Self-Care Inventory (DSSCI) was adapted from the Diabetes Self-Care Instrument. This article describes the modification process used to perfect the DSSCI for use in improving self-care among people with type 2 diabetes. This instrumentation study used qualitative and quantitative methods. The study was completed in four phases that used focus groups, cognitive interviews, and survey administration. Four convenience samples were drawn from community-dwelling Mexican American adults, aged 25-75 years, with type 2 diabetes in an urban area and a rural location in Texas. Phase I: Seven focus groups (n=45) generated data for revising items. Phase II: Cognitive interviews with 16 participants were used to evaluate four revisions of the questionnaire. Phase III: Surveys were administered to 81 participants. Total number of symptoms on the DSSCI correlated with scores on the Centers for Epidemiological Studies-Depression scale (r=0.65, PPerception Questionnaire-Revised Diabetes Symptom subscale (r=0.57, PAmericans' diabetes symptoms and the actions they take to address them. Copyright © 2011 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.

  1. Evaluation of the spoken knowledge in low literacy in diabetes scale for use with Mexican Americans.

    Science.gov (United States)

    Garcia, Alexandra A; Zuniga, Julie; Reynolds, Raquel; Cairampoma, Laura; Sumlin, Lisa

    2015-05-01

    This article evaluates the Spoken Knowledge in Low Literacy in Diabetes (SKILLD) questionnaire, a measure of essential knowledge for type 2 diabetes self-management, after it was modified for English- and Spanish-speaking Mexican Americans. We collected surveys (SKILLD, demographic, acculturation) and blood for A1C analysis from 72 community-recruited participants to analyze the SKILLD's internal consistency, interrater reliability, item analysis, and construct validity. Clinical experts evaluated content validity. The SKILLD demonstrated low internal consistency but high interrater reliability and content and construct validity. There were significant correlations in expected directions between SKILLD scores and acculturation, education, and A1C and significant differences in SKILLD scores between and within groups after an educational intervention and between high- and low-acculturated participants. The SKILLD generates useful information about Mexican Americans' diabetes knowledge. Lower SKILLD scores suggest less diabetes knowledge, lower health literacy, and participants' difficulties understanding items. Further modifications should improve use with low-acculturated Mexican Americans. © The Author(s) 2014.

  2. Comparison and evaluation of dietary quality between older and younger Mexican-American women.

    Science.gov (United States)

    Pignotti, Giselle A P; Vega-López, Sonia; Keller, Colleen; Belyea, Michael; Ainsworth, Barbara; Nagle Williams, Allison; Records, Kathie; Coonrod, Dean; Permana, Paska

    2015-10-01

    To compare and evaluate the dietary quality of young and older sedentary Mexican-American women. Understanding key dietary concerns, while considering developmental transition periods and cultural relevance, can provide insight for developing appropriate nutrition interventions. Cross-sectional dietary data were collected using unannounced 24 h diet recalls to assess nutrient intake adequacy (Estimated Average Requirement cut-point method) and dietary quality (Healthy Eating Index (HEI) 2010). Mujeres en Acción and Madres para la Salud, two community-based physical activity interventions. Participants were 139 young (28 (sd 6) years) and 124 older (55 (sd 7) years) overweight/obese sedentary Mexican-American women (BMI=25·0-35·0 kg/m2) of low socio-economic status. Older women consumed less Ca, Fe, folate, empty calories and energy from carbohydrate, but more fruit, vegetables, greens and beans, and fibre than younger women (all P<0·05). Over 60 % of all participants had an intake below recommendations for fibre, Ca, vitamin E, vitamin C and folate. Both groups had low total HEI-2010 scores (62 for older and 63 for younger women; NS), with 57 % of older and 48 % of younger women classified as having a poor diet. Despite differences in nutrient requirements according to developmental transition periods (childbearing v. perimenopausal), overall, older and younger Mexican-American women generally had low-quality diets and may benefit from dietary quality improvement.

  3. A conceptual framework for the study of social capital in new destination immigrant communities.

    Science.gov (United States)

    Bernosky de Flores, Catherine H

    2010-07-01

    Mexican immigration to the United States is an intragenerational phenomenon. Young adult Mexicans leave their families of origin in search of employment opportunities that pull them to new destination communities. A conceptual framework that defines and relates the concepts of human capital, personal networks, social capital, and resources is introduced. The influence of social capital on the capacity of immigrants to access resources is described. The framework informed the design of a study to examine the approaches used by Mexican immigrant women to access resources for healthy childbearing in the absence of traditional family support systems in a new destination community.

  4. Technogenic magnetic particles in soils as evidence of historical mining and smelting activity: A case of the Brynica River Valley, Poland

    Energy Technology Data Exchange (ETDEWEB)

    Magiera, Tadeusz, E-mail: tadeusz.magiera@ipis.zabrze.pl [Institute of Environmental Engineering, Polish Academy of Sciences, Skłodowskiej-Curie 34, Zabrze (Poland); Mendakiewicz, Maria; Szuszkiewicz, Marcin [Institute of Environmental Engineering, Polish Academy of Sciences, Skłodowskiej-Curie 34, Zabrze (Poland); Jabłońska, Mariola [Department of Geochemistry, Mineralogy and Petrology, Faculty of Earth Sciences, University of Silesia, Sosnowiec (Poland); Chróst, Leszek [Laboratory for Ecological Research, Ekopomiar, Gliwice (Poland)

    2016-10-01

    In the area of Brynica River basin (Upper Silesia, southern Poland) the exploitation and smelting of iron, silver and lead ores was historically documented since early Middle Ages. First investigations showed that metallurgy industry had a large impact from 9th century (AD) until the Second World War. The aim of the study was to use magnetic prospection to detect traces of past mining and ore smelting in Brynica River Valley located in Upper Silesia (southern Poland). The field screening was performed by measurement magnetic susceptibility (κ) on surface and in vertical profiles and was supported locally by gradiometric measurements. Vertical distribution of magnetic susceptibility values was closely associated with the type of soil use. Historical technogenic magnetic particles resulting from exploitation, processing, and smelting of iron, silver, and lead ores were accumulated in the soil layer at the depth 10 to 25 cm. They were represented by sharp-edged particles of slag, coke, as well as various mineralogical forms of iron minerals and aggregates composed of carbon particles, aluminosilicate glass, and single particles of metallic iron. The additional geochemical study in adjacent peat bog supported by radiocarbon dating was also performed. The application of integrated geochemical-magnetic methods to reconstruct the historical accumulation of pollutants in the studied peat bog was effective. The magnetic peak, which was pointed out by magnetic analyses, is consistent with the presence of charcoal and pollution from heavy metals, such as Ag, Cd, Cu, Fe, Pb, or Sn. The results of this work will be helpful for the further study of human's impact on the environment related to the historical and even pre-historical ore exploitation and smelting and also used for better targeting the archeological excavations on such areas. - Highlights: • Due to ferrimagnetic properties of historical slags magnetic prospection is an efficient tool for they localization.

  5. [Rare earth elements content in farmland soils and crops of the surrounding copper mining and smelting plant in Jiangxi province and evaluation of its ecological risk].

    Science.gov (United States)

    Jin, Shu-Lan; Huang, Yi-Zong; Wang, Fei; Xu, Feng; Wang, Xiao-Ling; Gao, Zhu; Hu, Ying; Qiao Min; Li, Jin; Xiang, Meng

    2015-03-01

    Rare earth elements content in farmland soils and crops of the surrounding copper mining and smelting plant in Jiangxi province was studied. The results showed that copper mining and smelting could increase the content of rare earth elements in soils and crops. Rare earth elements content in farmland soils of the surrounding Yinshan Lead Zinc Copper Mine and Guixi Smelting Plant varied from 112.42 to 397.02 mg x kg(-1) and 48.81 to 250.06 mg x kg(-1), and the average content was 254.84 mg x kg(-1) and 144.21 mg x kg(-1), respectively. The average contents of rare earth elements in soils in these two areas were 1.21 times and 0.68 times of the background value in Jiangxi province, 1.36 times and 0.77 times of the domestic background value, 3.59 times and 2.03 times of the control samples, respectively. Rare earth elements content in 10 crops of the surrounding Guixi Smelting Plant varied from 0.35 to 2.87 mg x kg(-1). The contents of rare earth elements in the leaves of crops were higher than those in stem and root. The contents of rare earth elements in Tomato, lettuce leaves and radish leaves were respectively 2.87 mg x kg(-1), 1.58 mg x kg(-1) and 0.80 mg x kg(-1), which were well above the hygienic standard limit of rare earth elements in vegetables and fruits (0.70 mg x kg(-1)). According to the health risk assessment method recommended by America Environmental Protection Bureau (USEPA), we found that the residents' lifelong average daily intake of rare earth elements was 17.72 mg x (kg x d)(-1), lower than the critical value of rare earth elements damage to human health. The results suggested that people must pay attention to the impact of rare earth elements on the surrounding environment when they mine and smelt copper ore in Jiangxi.

  6. Technogenic magnetic particles in soils as evidence of historical mining and smelting activity: A case of the Brynica River Valley, Poland

    International Nuclear Information System (INIS)

    Magiera, Tadeusz; Mendakiewicz, Maria; Szuszkiewicz, Marcin; Jabłońska, Mariola; Chróst, Leszek

    2016-01-01

    In the area of Brynica River basin (Upper Silesia, southern Poland) the exploitation and smelting of iron, silver and lead ores was historically documented since early Middle Ages. First investigations showed that metallurgy industry had a large impact from 9th century (AD) until the Second World War. The aim of the study was to use magnetic prospection to detect traces of past mining and ore smelting in Brynica River Valley located in Upper Silesia (southern Poland). The field screening was performed by measurement magnetic susceptibility (κ) on surface and in vertical profiles and was supported locally by gradiometric measurements. Vertical distribution of magnetic susceptibility values was closely associated with the type of soil use. Historical technogenic magnetic particles resulting from exploitation, processing, and smelting of iron, silver, and lead ores were accumulated in the soil layer at the depth 10 to 25 cm. They were represented by sharp-edged particles of slag, coke, as well as various mineralogical forms of iron minerals and aggregates composed of carbon particles, aluminosilicate glass, and single particles of metallic iron. The additional geochemical study in adjacent peat bog supported by radiocarbon dating was also performed. The application of integrated geochemical-magnetic methods to reconstruct the historical accumulation of pollutants in the studied peat bog was effective. The magnetic peak, which was pointed out by magnetic analyses, is consistent with the presence of charcoal and pollution from heavy metals, such as Ag, Cd, Cu, Fe, Pb, or Sn. The results of this work will be helpful for the further study of human's impact on the environment related to the historical and even pre-historical ore exploitation and smelting and also used for better targeting the archeological excavations on such areas. - Highlights: • Due to ferrimagnetic properties of historical slags magnetic prospection is an efficient tool for they localization.

  7. Cd, Pb, and Zn mobility and (bio)availability in contaminated soils from a former smelting site amended with biochar.

    Science.gov (United States)

    Lomaglio, Tonia; Hattab-Hambli, Nour; Miard, Florie; Lebrun, Manhattan; Nandillon, Romain; Trupiano, Dalila; Scippa, Gabriella Stefania; Gauthier, Arnaud; Motelica-Heino, Mikael; Bourgerie, Sylvain; Morabito, Domenico

    2017-07-20

    Biochar is a potential candidate for the remediation of metal(loid)-contaminated soils. However, the mechanisms of contaminant-biochar retention and release depend on the amount of soil contaminants and physicochemical characteristics, as well as the durability of the biochar contaminant complex, which may be related to the pyrolysis process parameters. The objective of the present study was to evaluate, in a former contaminated smelting site, the impact of two doses of wood biochar (2 and 5% w/w) on metal immobilization and/or phytoavailability and their effectiveness in promoting plant growth in mesocosm experiments. Different soil mixtures were investigated. The main physicochemical parameters and the Cd, Pb, and Zn contents were determined in soil and in soil pore water. Additionally, the growth, dry weight, and metal concentrations were analyzed in the different dwarf bean plant (Phaseolus vulgaris L.) organs tested. Results showed that the addition of biochar at two doses (2 and 5%) improved soil conditions by increasing soil pH, electrical conductivity, and water holding capacity. Furthermore, the application of biochar (5%) to metal-contaminated soil reduced Cd, Pb, and Zn mobility and availability, and hence their accumulation in the different P. vulgaris L. organs. In conclusion, the data clearly demonstrated that biochar application can be effectively used for Cd, Pb, and Zn immobilization, thereby reducing their bioavailability and phytotoxicity.

  8. Co-reduction of Copper Smelting Slag and Nickel Laterite to Prepare Fe-Ni-Cu Alloy for Weathering Steel

    Science.gov (United States)

    Guo, Zhengqi; Pan, Jian; Zhu, Deqing; Zhang, Feng

    2018-02-01

    In this study, a new technique was proposed for the economical and environmentally friendly recovery of valuable metals from copper smelting slag while simultaneously upgrading nickel laterite through a co-reduction followed by wet magnetic separation process. Copper slag with a high FeO content can decrease the liquidus temperature of the SiO2-Al2O3-CaO-MgO system and facilitate formation of liquid phase in a co-reduction process with nickel laterite, which is beneficial for metallic particle growth. As a result, the recovery of Ni, Cu, and Fe was notably increased. A crude Fe-Ni-Cu alloy with 2.5% Ni, 1.1% Cu, and 87.9% Fe was produced, which can replace part of scrap steel, electrolytic copper, and nickel as the burden in the production of weathering steel by an electric arc furnace. The study further found that an appropriate proportion of copper slag and nickel laterite in the mixture is essential to enhance the reduction, acquire appropriate amounts of the liquid phase, and improve the growth of the metallic alloy grains. As a result, the liberation of alloy particles in the grinding process was effectively promoted and the metal recovery was increased significantly in the subsequent magnetic separation process.

  9. Material and energy flows in rotary kiln-electric furnace smelting of ferronickel alloy with energy saving

    International Nuclear Information System (INIS)

    Liu, Peng; Li, Baokuan; Cheung, Sherman C.P.; Wu, Wenyuan

    2016-01-01

    Highlights: • Establish the synergy relationship of material and energy in key RKEF processes. • Develop an analysis model to study energy saving with internal cycling of energy. • Analyze material and energy flow parameters and assess its associated synergy effect. • A methodology to evaluate the synergy and design indices of RKEF processes. - Abstract: An energy saving strategy with two energy saving measures has been proposed for reducing energy loss in the rotary kiln-electric furnace (RKEF) for the smelting of ferronickel alloy. One of the measures is to recover the waste heat of exhaust gas from the rotary kiln for preheating and dehydrating the wet laterite ores in the rotary dryer. Another measure is to recycle the furnace gas from the electric furnace into the rotary kiln as fuel. Based on the mass conservation and energy conservation laws, an analysis model of material and energy flows has been developed to understand the potential energy saving with the internal cycling of material and energy in the RKEF process. The analysis model not only considers the energy efficiency but also assess the synergy degree of system. Furthermore, the model also predicts the ratio of raw materials and the energy flow distribution to investigate residual heat and energy and analyze the effects of nickel content on energy flow. Finally, the evaluation methodology of synergy and the technic indices are also presented. Through the investigation of the synergy effect, the performance of the RKEF process can be evaluated and quantified for performance optimization in future.

  10. [Evaluation and source analysis of the mercury pollution in soils and vegetables around a large-scale zinc smelting plant].

    Science.gov (United States)

    Liu, Fang; Wang, Shu-Xiao; Wu, Qing-Ru; Lin, Hai

    2013-02-01

    The farming soil and vegetable samples around a large-scale zinc smelter were collected for mercury content analyses, and the single pollution index method with relevant regulations was used to evaluate the pollution status of sampled soils and vegetables. The results indicated that the surface soil and vegetables were polluted with mercury to different extent. Of the soil samples, 78% exceeded the national standard. The mercury concentration in the most severely contaminated area was 29 times higher than the background concentration, reaching the severe pollution degree. The mercury concentration in all vegetable samples exceeded the standard of non-pollution vegetables. Mercury concentration, in the most severely polluted vegetables were 64.5 times of the standard, and averagely the mercury concentration in the vegetable samples was 25.4 times of the standard. For 85% of the vegetable samples, the mercury concentration, of leaves were significantly higher than that of roots, which implies that the mercury in leaves mainly came from the atmosphere. The mercury concentrations in vegetable roots were significantly correlated with that in soils, indicating the mercury in roots was mainly from soil. The mercury emissions from the zinc smelter have obvious impacts on the surrounding soils and vegetables. Key words:zinc smelting; mercury pollution; soil; vegetable; mercury content

  11. Lead in residential soil and dust in a mining and smelting district in northern Armenia: a pilot study

    International Nuclear Information System (INIS)

    Petrosyan, Varduhi; Orlova, Anna; Dunlap, Charles E.; Babayan, Emil; Farfel, Mark; Braun, Margrit von

    2004-01-01

    This pilot study of sources of lead exposure in residential settings was conducted in a mining and smelting district in northern Armenia. Samples of exterior soil and dust and interior house dust were collected in and around apartment buildings in Alaverdi where the country's largest polymetallic smelter is located, and in nearby mining towns of Aghtala and Shamlugh. The NITON XL-723 Multi-Element XRF analyzer was used for lead testing. Lead levels in samples from Alaverdi were higher than those in Shamlugh and Aghtala. In all three towns, the highest lead levels were found in loose exterior dust samples, and lead concentrations in yard soil were higher than those in garden soil. Many soil samples (34%) and the majority of loose dust samples (77%) in Alaverdi exceeded the US Environmental Protection Agency standard of 400 mg/kg for bare soil in children's play areas. In addition, 36% of floor dust samples from apartments in Alaverdi exceeded the US Environmental Protection Agency standard of 40 μg/ft 2 for lead loading in residential floor dust. The Armenian Ministry of Health and other interested agencies are being informed about the findings of the study so that they can consider and develop educational and preventive programs including blood lead screening among sensitive populations

  12. Numerical Investigation on the Impact of Anode Change on Heat Transfer and Fluid Flow in Aluminum Smelting Cells

    Science.gov (United States)

    Wang, Qiang; Gosselin, Louis; Fafard, Mario; Peng, Jianping; Li, Baokuan

    2016-04-01

    In order to understand the impact of anode change on heat transfer and magnetohydrodynamic flow in aluminum smelting cells, a transient three-dimensional (3D) coupled mathematical model has been developed. The solutions of the mass, momentum, and energy conservation equations were simultaneously implemented by the finite volume method with full coupling of the Joule heating and Lorentz force through solving the electrical potential equation. The volume of fluid approach was employed to describe the two-phase flow. The phase change of molten electrolyte (bath) as well as molten aluminum (metal) was modeled by an enthalpy-based technique, where the mushy zone is treated as a porous medium with a porosity equal to the liquid fraction. The effect of the new anode temperature on recovery time was also analyzed. A reasonable agreement between the test data and simulated results is obtained. The results indicate that the temperature of the bath under cold anodes first decreases reaching the minimal value and rises under the effect of increasing Joule heating, and finally returns to steady state. The colder bath decays the velocity, and the around ledge becomes thicker. The lowest temperature of the bath below new anodes increases from 1118 K to 1143 K (845 °C to 870 °C) with the new anode temperature ranging from 298 K to 498 K (25°C to 225°C), and the recovery time reduces from 22.5 to 20 hours.

  13. Geostatistical approach for assessing soil volumes requiring remediation: validation using lead-polluted soils underlying a former smelting works.

    Science.gov (United States)

    Demougeot-Renard, Helene; De Fouquet, Chantal

    2004-10-01

    Assessing the volume of soil requiring remediation and the accuracy of this assessment constitutes an essential step in polluted site management. If this remediation volume is not properly assessed, misclassification may lead both to environmental risks (polluted soils may not be remediated) and financial risks (unexpected discovery of polluted soils may generate additional remediation costs). To minimize such risks, this paper proposes a geostatistical methodology based on stochastic simulations that allows the remediation volume and the uncertainty to be assessed using investigation data. The methodology thoroughly reproduces the conditions in which the soils are classified and extracted at the remediation stage. The validity of the approach is tested by applying it on the data collected during the investigation phase of a former lead smelting works and by comparing the results with the volume that has actually been remediated. This real remediated volume was composed of all the remediation units that were classified as polluted after systematic sampling and analysis during clean-up stage. The volume estimated from the 75 samples collected during site investigation slightly overestimates (5.3% relative error) the remediated volume deduced from 212 remediation units. Furthermore, the real volume falls within the range of uncertainty predicted using the proposed methodology.

  14. Determination of the main parameters of the cyclone separator of the flue gas produced during the smelting of secondary aluminum

    Science.gov (United States)

    Matusov, Jozef; Gavlas, Stanislav

    2016-06-01

    One way how is possible to separate the solid particulate pollutants from the flue gas is use the cyclone separators. The cyclone separators are very frequently used separators due to the simplicity of their design and their low operating costs. Separation of pollutants in the form of solids is carried out using three types of forces: inertia force, centrifugal force, gravity force. The main advantage is that cyclone consist of the parts which are resistant to wear and have long life time, e.g. various rotating and sliding parts. Mostly are used as pre-separators, because they have low efficiency in the separation of small particles. Their function is to separate larger particles from the flue gases which are subsequently cleaned in the other device which is capable of removing particles smaller than 1 µm, which is limiting size of particle separation. The article will deal with the issue of calculating the basic dimensions and main parameters of the cyclone separator from flue gas produced during the smelting of secondary aluminum.

  15. Development Contexts, Psychological Distress, Social Self- Esteem and School Violence from a Gender Perspective in Mexican Adolescents

    Directory of Open Access Journals (Sweden)

    María Elena Villarreal-González

    2011-07-01

    Full Text Available The aim of this study was to analyze the relationships between three development contexts -family, school and community-, and school violence, examining psychological distress and social selfesteem from a gender perspective in Mexican adolescents. To test these relationships, 1,285 Mexican students between 12 and 18 years of age in secondary (n = 634 and high school (n = 651 were recruited. To analyze these relationships, Structural Equation Modeling With EQS was used. Results showed that familial context is directly related to school violence, and that school and community context is indirectly related to school violence through social self-esteem and psychological distress. Finally, results and their possible implications regarding gender are discussed.

  16. Prevalence of risk factors for HIV infection among Mexican migrants and immigrants: probability survey in the north border of Mexico

    Directory of Open Access Journals (Sweden)

    Gudelia Rangel M.

    2006-01-01

    Full Text Available OBJECTIVE: To estimate the prevalence of risk factors for HIV infection among Mexican migrants and immigrants (MMIs in different geographic contexts, including the sending communities in Mexico, the receiving communities in the United States (US, and the Mexican North border region. MATERIAL AND METHODS: We conducted a probability survey among MMIs traveling through key border crossing sites in the Tijuana (Baja California, Mexico-San Diego (California, US border region (N=1 429. RESULTS: The survey revealed substantial rates of reported sexually transmitted infections, needle-sharing and sexual risk practices in all migration contexts. CONCLUSIONS: The estimated levels of HIV risk call for further binational research and preventive interventions in all key geographic contexts of the migration experience to identify and tackle the different personal, environmental, and structural determinants of HIV risk in each of these contexts.

  17. Damage to the forest ecosystem on Blue Mountain from zinc smelting

    Science.gov (United States)

    Beyer, W.N.

    1988-01-01

    Emissions from two zinc smelters in Palmerton, Pennsylvania, have caused widespread destruction of the forest on Blue Mountain. There have been striking changes in the species composition and structure of the community of vascular plants, as well as population reductions of lichens, mosses, arthropods inhabiting the letter, and amphibians. Reductions in the populations of decomposers of organic matter have led to an accumulation of litter on the forest floor. Zinc poisoning was diagnosed in a white-tailed deer, and lead poisoning was diagnosed in a shrew. White-tailed deer also contained high concentrations of cadmium.

  18. Another Mexican birthweight paradox? The role of residential enclaves and neighborhood poverty in the birthweight of Mexican-origin infants.

    Science.gov (United States)

    Osypuk, Theresa L; Bates, Lisa M; Acevedo-Garcia, Dolores

    2010-02-01

    Examining whether contextual factors influence the birth outcomes of Mexican-origin infants in the US may contribute to assessing rival explanations for the so-called Mexican health paradox. We examined whether birthweight among infants born to Mexican-origin women in the US was associated with Mexican residential enclaves and exposure to neighborhood poverty, and whether these associations were modified by nativity (i.e. mother's place of birth). We calculated metropolitan indices of neighborhood exposure to Mexican-origin population and poverty for the Mexican-origin population, and merged with individual-level, year 2000 natality data (n=490,332). We distinguished between neighborhood exposure to US-born Mexican-origin population (i.e. ethnic enclaves) and neighborhood exposure to foreign-born (i.e. Mexico-born) Mexican-origin population (i.e. immigrant enclaves). We used 2-level hierarchical linear regression models adjusting for individual, metropolitan, and regional covariates and stratified by nativity. We found that living in metropolitan areas with high residential segregation of US-born Mexican-origin residents (i.e. high prevalence of ethnic enclaves) was associated with lower birthweight for infants of US-born Mexican-origin mothers before and after covariate adjustment. When simultaneously adjusting for exposure to ethnic and immigrant enclaves, the latter became positively associated with birthweight and the negative effect of the former increased, among US-born mothers. We found no contextual birthweight associations for mothers born in Mexico in adjusted models. Our findings highlight a differential effect of context by nativity, and the potential health effects of ethnic enclaves, which are possibly a marker of downward assimilation, among US-born Mexican-origin women. Copyright 2009 Elsevier Ltd. All rights reserved.

  19. Perceived social stress, pregnancy-related anxiety, depression and subjective social status among pregnant Mexican and Mexican American women in south Texas.

    Science.gov (United States)

    Fleuriet, K Jill; Sunil, T S

    2014-05-01

    The purpose of this study was to determine differences in subjective social status, perceived social stress, depressive symptoms, and pregnancy-related anxiety between pregnant Mexican American and Mexican immigrant women. Three hundred pregnant Mexican immigrant and Mexican American women in South Texas were surveyed for pregnancy-related anxiety, perceived social stress, depressive symptoms, and subjective social status. Pregnant Mexican immigrant women had higher levels of pregnancy-related anxiety and lower levels of depression and perceived social stress than pregnant Mexican American women. Change in these variables among Mexican immigrant women was relatively linear as time of residence in the United States increased. Mexican immigrant and Mexican American women had significantly different correlations between subjective social status, self-esteem and perceived social stress. Results indicate that subjective social status is an important psychosocial variable among pregnant Hispanic women. Results contribute to ongoing efforts to provide culturally responsive prenatal psychosocial support services.

  20. Women's Networks and the Social Needs of Mexican Immigrants.

    Science.gov (United States)

    O'Connor, Mary I.

    1990-01-01

    Reports on the persistence of a two-tiered economic and political system that routinely excludes Mexican immigrants. Focuses on the predominantly female employees of a wholesale nursery in Carpinteria (California), who have adapted the Mexican tradition of "confianza"-based relationships to form networks that facilitate communication and…

  1. Losing American Students, Mexican Universities Struggle against a Scary Image

    Science.gov (United States)

    Ambrus, Steven

    2012-01-01

    Like most Mexicans, Eugenio Yarce has been deeply affected by the violence between drug cartels and the Mexican army, which has filled news coverage with accounts of kidnappings, assassinations, and torture. But for Mr. Yarce, deputy rector for outreach here at the private Autonomous Popular University of the State of Puebla, or Upaep, the…

  2. Mexican-Origin Women's Employment Instability. Working Paper No. 51.

    Science.gov (United States)

    De Anda, Roberto M.

    This paper compares the causes and consequences of employment instability among Mexican-origin women, White women, and White men. Data came from the work experience supplement in the March 1995 file of the Current Population Survey for a sample that included 1,399 Mexican-origin women, 17,092 White women, and 24,440 White men. All were experienced…

  3. The Mexican American in Higher Education: Implications for Educators.

    Science.gov (United States)

    Muhs, William F.; And Others

    1979-01-01

    Literature reviews suggest that Mexican-American students place more emphasis on cooperation and group than on individual achievement. Education may be enhanced when teachers reinforce "successful behavior." Problems may arise using U.S.-based theories of "democratic" leadership styles because Mexican-American culture places emphasis on…

  4. Mexican Art and Architecture Databases: Needs, Achievements, Problems.

    Science.gov (United States)

    Barberena, Elsa

    At the international level, a lack of diffusion of Mexican art and architecture in indexes and abstracts has been detected. Reasons for this could be lack of continuity in publications, the use of the Spanish language, lack of interest in Mexican art and architecture, and sporadic financial resources. Nevertheless, even though conditions are not…

  5. Transformative, Mixed Methods Checklist for Psychological Research with Mexican Americans

    Science.gov (United States)

    Canales, Genevieve

    2013-01-01

    This is a description of the creation of a research methods tool, the "Transformative, Mixed Methods Checklist for Psychological Research With Mexican Americans." For conducting literature reviews of and planning mixed methods studies with Mexican Americans, it contains evaluative criteria calling for transformative mixed methods, perspectives…

  6. Storytelling in Mexican Homes: Connections between Oral and Literacy Practices

    Science.gov (United States)

    Reese, Leslie

    2012-01-01

    The study focuses on storytelling among Mexican families, documenting the frequency of storytelling in the homes of working- and middle-class Mexican families, the range of topics of the stories, characteristics and genres of stories, and intergenerational continuity of storytelling practices. Also examined are potential associations between…

  7. Parental Factors Associated with Mexican American Adolescent Alcohol Use

    Directory of Open Access Journals (Sweden)

    Cristina Mogro-Wilson

    2013-01-01

    Full Text Available The purpose of this study is to further the understanding of how parenting and the relationship between the parent and the youth influence adolescent alcohol use in Mexican American families, with particular attention to acculturation. Results indicated that parental warmth is a strong factor in predicting adolescent alcohol use among Mexican adolescents. The parent-youth relationship played an important role in lowering alcohol use for Mexican American youth. Acculturation has an impact on the level of warmth, control, and the parent-youth relationship for Mexican American families. Findings indicate that there are unique family mechanisms for Mexican American families that should be considered when developing prevention and treatment options.

  8. [Dichotic perception of Mandarin third tone by Mexican Chinese learners].

    Science.gov (United States)

    Wang, Hongbin

    2014-05-01

    To investigate the relationship between the advantage ear (cerebral hemisphere) of Spanish-speaking Mexican learners and the third Chinese tone. Third tone Chinese vowel syllables were used as experimental materials with dichotic listening technology to test the Spanish-speaking Mexican Chinese learners (20-32 years old) who studied Chinese about 20 h. In terms of error rates to identify the third Chinese tone, the Spanish-speaking Mexican Chinese learners's reaction to the third tone suggested that their left ears were the advantageous ear (the right cerebral hemisphere) (Z=-2.091, P=0.036). The verbal information of tones influenced the perception of Mexican Chinese learners' mandarin tones. In the process of learning mandarin tones, Mexican Chinese learners gradually formed the category of tones.

  9. Colonia development and land use change in Ambos Nogales, United States-Mexican border

    Science.gov (United States)

    Norman, Laura M.; Donelson, Angela; Pfeifer, Edwin; Lam, Alven H.

    2006-01-01

    This report outlines a planning approach taken by a Federal Government partnership that is meant to promote sustainable development in the future, integrating both sides of the United States-Mexican border. The twin-city area of Nogales, Ariz., and Nogales, Sonora, Mexico, known collectively as Ambos (both) Nogales, has a common borderland history of urban growth presumably based on changes in policy and economic incentives. We document changes over time in an attempt to identify colonia development and settlement patterns along the border, combining a community-participation approach with a remote-sensing analysis, to create an online mapping service.

  10. "Hospital utilization by Mexican migrants returning to Mexico due to health needs"

    OpenAIRE

    González-Block, Miguel A; de la Sierra-de la Vega, Luz A

    2011-01-01

    Abstract Background A total of 12.7 million Mexicans reside as migrants in the United States, of whom only 45% have health insurance in this country while access to health insurance by migrants in Mexico is fraught with difficulties. Health insurance has been shown to impact the use of health care in both countries. This paper quantifies hospitalizations by migrants who return from the US seeking medical care in public and private hospitals in the US-Mexico border area and in communities of o...

  11. Meeting a Binational Research Challenge: Substance Abuse Among Transnational Mexican Farmworkers in the United States

    Science.gov (United States)

    Garcia, Victor

    2011-01-01

    To help in understanding the manner in which community, individual, and other factors in the United States and Mexico contribute to drug use among transnational migrants, this paper introduces a binational social ecology model of substance abuse in this population. We draw on our 2 NIH-funded ethnographic studies—1 on problem drinking and the other on drug abuse—among transnational Mexican workers in the mushroom industry of southeastern Pennsylvania. Our model demonstrates that major reasons for substance abuse among transnational migrants include nontraditional living arrangements in labor camps and overcrowded apartments, the absence of kin and community deterrents to drug use, social isolation, the presence of drug use and binge drinking subcultures, the availability of drugs, family history of drugs, previous drug use or witnessing of drug use in Mexico, and drug use norms and drug availability in Mexico. It suggests the need for US and Mexican researchers to collaborate in binational teams and address factors on both sides of the border. Our binational social ecology model, together with our research recommendations, will assist alcohol and drug researchers to discover how community and individual factors in both the United States and abroad fit and interact beyond mere association and provide a more comprehensive research approach to substance abuse research among transnational migrants. PMID:18237326

  12. Diasporic Community Smartness: Saberes (Knowings) beyond Schooling and Borders

    Science.gov (United States)

    Urrieta, Luis, Jr.

    2016-01-01

    This article presents ethnographic data of US Mexican-indigenous heritage children's transnational experiences during return visits to Mexico. US-born children and youth's acquisition of transnational diasporic community knowledge, in this article, is studied as a form of "smartness." Diasporic community knowledge is defined as the…

  13. Engineering assessment of inactive uranium mill tailings: Mexican Hat Site, Mexican Hat, Utah

    International Nuclear Information System (INIS)

    1981-09-01

    Ford, Bacon and Davis Utah Inc. has reevaluated the Mexican Hat site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Mexican Hat, Utah. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 2.2 million tons of tailings at the Mexican Hat site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material to removal of the tailings to remote disposal sites and decontamination of the tailings site. Cost estimates for the four options range from about $15,200,000 for stabilization in place, to about $45,500,000 for disposal at a distance of about 16 mi. Three principal alternatives for the reprocessing of the Mexican Hat tailings were examined: heap leaching; treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $115/lb of U 3 O 8 whether by heap leach or conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Reprocessing the Mexican Hat tailings for uranium recovery is not economically attractive under present conditions

  14. Idioms of Distress Among Depressed White-Non-Mexican and Mexican-Origin Older Men.

    Science.gov (United States)

    Apesoa-Varano, Ester Carolina; Barker, Judith C; Unutzer, Jurgen; Aguilar-Gaxiola, Sergio; Johnson, Megan Dwight; Tran, Cindy; Guarnaccia, Peter; Hinton, Ladson

    2015-09-01

    Older men are less likely than older women to receive depression treatment. Latino older men in particular have been found to have significantly lower rates of depression treatment than their white-non-Mexican (WNM) counterparts. Prior research has shown that men are less likely than women to express overt affect and/or report depression symptoms that may prompt primary care physicians' inquiry about depression. Previous studies have overlooked the idioms of distress common among older men. This study investigates: a) the range of idioms of distress that emerge in the narratives of depressed older men, and b) the use of these idioms among depressed WNM and Mexican-origin older men. The present report is based on qualitative data collected through the Men's Health and Aging Study (MeHAS), a mixed-method study of clinically depressed WNM and Mexican-origin older (65 and above) men recruited in primary care settings. Qualitative analysis of 77 interviews led to identification of idioms of distress and informed idiom categories. Study findings show that: a) both groups of men utilized a range of idioms of distress that met current DSM criteria for depression, b) both groups were also likely to utilize idioms that feel outside clinical depression criteria, and c) there were similarities as well as differences between WNM and Mexican-origin men. This study provides a larger vocabulary that clinicians might consider in recognizing depression and initiating depression care for older men from diverse ethnic backgrounds. This is important to improve depression care among older men in general and those of Mexican-origin in particular.

  15. Prediabetes, undiagnosed diabetes, and diabetes among Mexican adults: findings from the Mexican Health and Aging Study.

    Science.gov (United States)

    Kumar, Amit; Wong, Rebeca; Ottenbacher, Kenneth J; Al Snih, Soham

    2016-03-01

    The purpose of the study was to examine the prevalence and determinants of prediabetes, undiagnosed diabetes, and diabetes among Mexican adults from a subsample of the Mexican Health and Aging Study. We examined 2012 participants from a subsample of the Mexican Health and Aging Study. Measures included sociodemographic characteristics, body mass index, central obesity, medical conditions, cholesterol, high-density lipoprotein cholesterol, hemoglobin A1c, and vitamin D. Logistic regression was performed to identify factors associated with prediabetes, undiagnosed diabetes, and self-reported diabetes. Prevalence of prediabetes, undiagnosed, and self-reported diabetes in this cohort was 44.2%, 18.0%, and 21.4%, respectively. Participants with high waist-hip ratio (1.61, 95% confidence interval [CI] = 1.05-2.45) and high cholesterol (1.85, 95% CI = 1.36-2.51) had higher odds of prediabetes. Overweight (1.68, 95% CI = 1.07-2.64), obesity (2.38, 95% CI = 1.41-4.02), and high waist circumference (1.60, 95% CI = 1.06-2.40) were significantly associated with higher odds of having undiagnosed diabetes. Those residing in a Mexican state with high U.S. migration had lower odds of prediabetes (0.61, 95% CI = 0.45-0.82) and undiagnosed diabetes (0.53, 95% CI = 0.41-0.70). Those engaged in regular physical activity had lower odds of undiagnosed diabetes (0.74, 95% CI = 0.57-0.97). There is a high prevalence of prediabetes and undiagnosed diabetes among Mexican adults in this subsample. Findings suggest the need for resources to prevent, identify, and treat persons with prediabetes and undiagnosed diabetes. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Engineering assessment of inactive uranium mill tailings: Mexican Hat site, Mexican Hat, Utah. Summary

    International Nuclear Information System (INIS)

    1981-09-01

    Ford, Bacon and Davis Utah Inc. has reevaluated the Mexican Hat site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Mexican Hat, Utah. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 2.2 million tons of tailings at the Mexican Hat site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material to removal of the tailings to remote disposal sites and decontamination of the tailings site. Cost estimates for the four options range from about $15,200,000 for stabilization in place, to about $45,500,000 for disposal at a distance of about 16 mi. Three principal alternatives for the reprocessing of the Mexican Hat tailings were examined: (a) heap leaching; treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $115/lb of U 3 O 8 whether by heap leach or conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Reprocessing the Mexican Hat tailings for uranium recovery is not economically attractive under present conditions

  17. Prevalence of metabolic syndrome among elderly Mexicans.

    Science.gov (United States)

    Ortiz-Rodríguez, María Araceli; Yáñez-Velasco, Lucía; Carnevale, Alessandra; Romero-Hidalgo, Sandra; Bernal, Demetrio; Aguilar-Salinas, Carlos; Rojas, Rosalba; Villa, Antonio; Tur, Josep A

    2017-11-01

    One of the most prevalent chronic diseases among elderly population is the Metabolic Syndrome (MetS). The aim of this study was to assess the prevalence of MetS and associated factors among Mexican elderly people. Cross-sectional survey carried out in Mexico (2007). A random sample (n=516) of the elderly population (≥65years; 277 female, 239 male) was interviewed. Anthropometric and analytical measurements, and a general questionnaire incorporating questions related to socio-demographic and life-style factors were used. MetS definition AHA/NHLBI/IDF was applied. The prevalence of MetS in the elderly (≥65years) was of 72.9% (75.7% men; 70.4% women). Participants with values above MetS cut-off points were 92.4% (hypertension), 77.8% (hypertriglyceridemia), 77.1% (low HDL-cholesterol), 71.1% (hyperglycaemia), and 65.4% (central obesity). People with MetS showed higher values of anthropometric and biochemical variables than those without MetS, except for the height, cholesterol and creatinine. Mid-high education level (9-12 years), no smokers and former smokers, and Central-Western inhabitants of Mexico were associated with MetS components. BMI status was the main determinant of MetS prevalence and MetS components. The reported prevalence of MetS among the elderly Mexican population was higher than those previously obtained in the geographical area, showing a major public health problem in Mexican elders. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. 60Co retention by Mexican montmorillonites

    International Nuclear Information System (INIS)

    Pacheco, G.; Martinez, V.; Bosch, P.; Bulbulian, S.

    1995-01-01

    Radioactive elements may be retained by clays. The ability of natural Mexican clays to retain radioactive Co from aqueous solutions, is discussed. Experiments were performed with solutions containing labeled cobalt. The effect of contact time on Co 2+ retention was studied. It was found that the Co 2+ uptake value in dehydrated montmorillonites is between 0.30 and 0.70 meq g -1 of clay. A sorption sequence was obtained for the various clays. The samples were characterized, before and after cobalt exchange, by X-ray diffraction. (author). 7 refs., 3 figs., 3 tabs

  19. Women writers and the Mexican Revolution

    OpenAIRE

    Thornton, Niamh

    2003-01-01

    The aim of this thesis is to explore how women are represented in novels written by women which have conflict as their central thematic concern. Consequently, it was necessary to examine the context in which these texts were written and how they compare to texts written by men based on the same period. As a result I studied the novela de la revolución as a genre in Mexico, accessing this material in Irish, British and Mexican libraries. Having established thematic predecessors, I approached t...

  20. Natural Variability of Mexican Forest Fires

    Science.gov (United States)

    Velasco-Herrera, Graciela; Velasco Herrera, Victor Manuel; Kemper-Valverdea, N.

    The purpose of this paper was 1) to present a new algorithm for analyzing the forest fires, 2) to discuss the present understanding of the natural variability at different scales with special emphasis on Mexico conditions since 1972, 3) to analyze the internal and external factors affecting forest fires for example ENSO and Total Solar Irradiance, and 4) to discuss the implications of this knowledge, on research and on restoration and management methods, which purpose is to enhance forest biodiversity conservation. 5) We present an estimate of the Mexican forest fires for the next decade. These results may be useful to minimize human and economic losses.

  1. Usual Vitamin Intakes by Mexican Populations.

    Science.gov (United States)

    Pedroza-Tobías, Andrea; Hernández-Barrera, Lucía; López-Olmedo, Nancy; García-Guerra, Armando; Rodríguez-Ramírez, Sonia; Ramírez-Silva, Ivonne; Villalpando, Salvador; Carriquiry, Alicia; Rivera, Juan A

    2016-09-01

    In the past several years, the consumption of high-energy, nutrient-poor foods has increased globally. Dietary intake data collected by the National Health and Nutrition Survey (ENSANUT) 2012 provide information to assess the quality of the Mexican diet and to guide food and nutrition policy. The aim was to describe the usual intake and the prevalence of inadequate intakes of vitamins for the overall Mexican population and by subgroups defined by sex, age, region, urban or rural areas, and socioeconomic status (SES). ENSANUT 2012 is a cross-sectional probabilistic survey representative of the Mexican population. Dietary information was collected by using the 24-h recall automated multiple-pass method (n = 10,096) with a repeated measurement on a subsample (n = 889) to permit adjustment for intraindividual variability with the use of the Iowa State University method. Mean usual intakes and the prevalence of inadequate intakes of thiamin, riboflavin, niacin, folate, and vitamins A, D, E, C, B-6, and B-12 were calculated for children aged 1-4 y (CH1-4y), children aged 5-11 y (CH5-11y), adolescents aged 12-19 y, and adults aged ≥20 y. In all of the age groups, prevalences of inadequate intakes of vitamins D and E were the highest (77-99% of adults and adolescents and 53-95% of CH5-11y and CH1-4y) and those of folate and vitamin A were intermediate (47-70% of adults and adolescents, 15-23% of CH5-11y and 8-13% of CH1-4y), whereas those of thiamin, riboflavin, niacin, and vitamins B-6, B-12, and C were the lowest (0-37% of adults, 1-27% of adolescents, and 0-2.4% of CH5-11y and CH1-4y). With few exceptions, the highest prevalences of inadequate intakes for vitamins were observed in the poorest populations (rural South region and the lowest tertile of SES). The intake of vitamins among Mexicans is inadequate overall. Information collected by ENSANUT can help target food assistance programs and develop strategies to prevent vitamin deficiencies. © 2016 American Society

  2. Mexican waves in an excitable medium.

    Science.gov (United States)

    Farkas, I; Helbing, D; Vicsek, T

    2002-09-12

    The Mexican wave, or La Ola, which rose to fame during the 1986 World Cup in Mexico, surges through the rows of spectators in a stadium as those in one section leap to their feet with their arms up, and then sit down again as the next section rises to repeat the motion. To interpret and quantify this collective human behaviour, we have used a variant of models that were originally developed to describe excitable media such as cardiac tissue. Modelling the reaction of the crowd to attempts to trigger the wave reveals how this phenomenon is stimulated, and may prove useful in controlling events that involve groups of excited people.

  3. Alcohol Use Disorders in National Samples of Mexicans and Mexican-Americans: The Mexican National Addiction Survey and the U.S. National Alcohol Survey

    Science.gov (United States)

    Borges, Guilherme; Medina-Mora, Maria Elena; Lown, Anne; Ye, Yu; Robertson, Marjorie J.; Cherpitel, Cheryl; Greenfield, Tom

    2006-01-01

    The authors show associations between immigration and alcohol disorders using data from the 1995 and 2000 U.S. National Alcohol Surveys and the 1998 Mexico National Household Survey on Addictions. The prevalence of alcohol dependence was 4.8% for the Mexicans, 4.2% for the Mexico-born immigrants, and 6.6% for the U.S.-born Mexican Americans. They…

  4. Delta smelt habitat in the San Francisco Estuary: A reply to Manly, Fullerton, Hendrix, and Burnham’s “Comments on Feyrer et al. Modeling the effects of future outflow on the abiotic habitat of an imperiled estuarine fish"

    Science.gov (United States)

    Feyrer, Frederick V.; Newman, Ken B.; Nobriga, Matthew; Sommer, Ted

    2016-01-01

    Manly et al. (2015) commented on the approach we (Feyrer et al. 2011) used to calculate an index of the abiotic habitat of delta smelt Hypomesus transpacificus. The delta smelt is an annual fish species endemic to the San Francisco Estuary (SFE) in California, USA. Conserving the delta smelt population while providing reliability to California’s water supply with water diverted from the SFE ecosystem is a major management and policy issue. Feyrer et al. (2011) evaluated historic and projected future abiotic habitat conditions for delta smelt. Manly et al. (2015) specifically commented regarding the following: (1) use of an independent abundance estimate, (2) spatial bias in the habitat index, and (3) application of the habitat index to future climate change projections. Here, we provide our reply to these three topics. While we agree that some of the concepts raised by Manly et al. (2015) have the potential to improve habitat assessments and their application to climate change scenarios as knowledge is gained, we note that the Feyrer et al. (2011) delta smelt habitat index is essentially identical to one reconstructed using Manly et al.’s (2015) preferred approach (their model 8), as shown here in Fig. 1.

  5. Effect of solution heat treatment on the precipitation behavior and strengthening mechanisms of electron beam smelted Inconel 718 superalloy

    Energy Technology Data Exchange (ETDEWEB)

    You, Xiaogang [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Tan, Yi, E-mail: tanyi@dlut.edu.cn [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Shi, Shuang [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China); Yang, Jenn-Ming [Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095 (United States); Wang, Yinong [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Li, Jiayan; You, Qifan [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116023 (China); Laboratory for New Energy Material Energetic Beam Metallurgical Equipment Engineering of Liaoning Province, Dalian 116024 (China)

    2017-03-24

    Inconel 718 superalloy was fabricated by electron beam smelting (EBS) technique. The effect of solution heat treatment on the precipitation behavior and mechanical properties of EBS 718 superalloys were studied, the strengthening mechanisms were analyzed and related to the mechanical properties. The results indicate that the optimized microstructures can be acquired by means of EBS, which is attributed to the rapid cooling rate of approximately 280 ℃/min. The solution heat treatment shows a great impact on the microstructures, precipitation behavior and mechanical properties of EBS 718 superalloy. The γ'' phase shows an apt to precipitate at relatively lower solution temperatures followed by aging, while the γ' precipitates are prone to precipitate at higher temperatures. When solution treated at 1150 ℃, the γ' precipitates are dispersively distributed in the matrix with size and volume fraction of 8.43 nm and 21.66%, respectively, a Vickers hardness of approximately 489 HV{sub 0.1} is observed for the aged superalloy. The precipitation strengthening effect of EBS 718 superalloy could be elucidated by considering the interaction between the dislocations and γ''/γ' precipitates. The shearing of γ' is resisted by the coherency strengthening and formation of antiphase boundary (APB), which shows equal effect as weakly coupled dislocation (WCD) model. And for γ'', the strengthening effect is much more prominent with the primary strengthening mechanism of ordering. Moreover, it is interestingly found that the strengthening mechanism of stacking fault (SF) shearing coexists with APB shearing, and SF shearing plays a major role in strengthening of EBS 718 superalloy.

  6. Cleaning of a copper matte smelting slag from a water-jacket furnace by direct reduction of heavy metals.

    Science.gov (United States)

    Maweja, Kasonde; Mukongo, Tshikele; Mutombo, Ilunga

    2009-05-30

    Cleaning experiments of a copper matte smelting slag from the water-jacket furnace was undertaken by direct reduction in a laboratory-scale electric furnace. The effects of coal-to-slag ratio, w, and the reduction time, t, were considered for two different coal/slag mixing procedures. In the first procedure, metallurgical coal was added to the molten slag, whereas in the second procedure, coal was premixed with the solid slag before charging into the furnace. The recovery of heavy metals (Cu, Co), and the fuming of Pb and Zn were investigated. Contamination of the metal phase by iron and the acidity index of the final slag were analysed as these may impede the economical viability of the process. The lower w value of 2.56% yielded a recovery rate of less than 60% for copper and less than 50% for cobalt, and around 70% for zinc. However, increasing w to 5% allowed the recovery of 70-90% for Cu, Co and Zn simultaneously after 30-60 min reduction of the molten slag. After reduction, the cleaned slags contained only small amounts of copper and cobalt (zinc was efficient as the %Pb of the residual slag dropped to levels lower than 0.04% after 30 min of reduction. Ninety percent of the lead was removed from the initial slag and collected in the dusts. The zinc content of the cleaned slags quickly dropped to between 1 and 3 wt% from the initial 8.2% after 30 min reduction for w value of 5 and after 60 min reduction for w value of 2.56. The dusts contained about 60% Zn and 10% Pb. Recovery of lead from fuming of the slag was higher than 90% in all the experimental conditions considered in this study.

  7. Remedial Action Plan for the codisposal and stabilization of the Monument Valley and Mexican Hat uranium mill tailings at Mexican Hat, Utah

    International Nuclear Information System (INIS)

    1993-02-01

    This document is a revision of the original Mexiacan Hat Remedial Action Plan (RAP) and RAP Modification submitted in July 1988 and January 1989, respectively, along with updated design documents. This RAP has been developed to serve a two-fold purpose. It presents the activities proposed by the Department of Energy (DOE) to accomplish long-term stabilization and control of the residual radioactive materials (RRM) from Monument Valley, Arizona, and Mexican Hat, Utah, at the Mexican Hat disposal site. It also serves to document the concurrence of both the Navajo Nation and the Nuclear Regulatory Commission (NRC) in the remedial action. This agreement, upon execution by DOE and the Navajo Nation and concurrence by the NRC, becomes Appendix B of the Cooperative Agreement. This document has been structured to provide a comprehensive understanding of the remedial action proposed for the Monument Valley and Mexican Hat sites. It includes specific design and construction requirements for the remedial action. Pertinent information and data are included with reference given to the supporting documents. Section 2.0 presents the EPA standards, including a discussion of their objectives. Section 3. 0 summarizes the present site characteristics and provides a definition of site-specific problems. Section 4.0 is the site design for the proposed action. Section 5.0 presents the water resources protection strategy. Section 6.0 summarizes the plan for ensuring health and safety protection for the surrounding community and the on- site workers. Section 7.0 lists the responsibilities of the project participants. Section 8.0 describes the features of the long-term surveillance and maintenance plan

  8. The offshore benthic fish community

    Science.gov (United States)

    Lantry, Brian F.; Lantry, Jana R.; Weidel, Brian C.; Walsh, Maureen; Hoyle, James A.; Schaner, Teodore; Neave, Fraser B.; Keir, Michael

    2014-01-01

    Lake Ontario’s offshore benthic fish community includes primarily slimy sculpin, lake whitefish, rainbow smelt, lake trout, burbot, and sea lamprey. Of these, lake trout have been the focus of an international restoration effort for more than three decades (Elrod et al. 1995; Lantry and Lantry 2008). The deepwater sculpin and three species of deepwater ciscoes (Coregonus spp.) that were historically important in the offshore benthic zone became rare or were extirpated by the 1960s (Christie 1973; Owens et al. 2003; Lantry et al. 2007b; Roth et al. 2013). Ecosystem changes continue to influence the offshore benthic fish community, including the effects of dreissenid mussels, the near disappearance of burrowing amphipods (Diporeia spp.) (Dermott et al. 2005; Watkins et al. 2007), and the increased abundance and expanded geographic distribution of round goby (see Nearshore Fish Community chapter) (Lantry et al. 2007b). The fish-community objectives for the offshore benthic fish community, as described by Stewart et al. (1999), are:

  9. Points for Improvement in Mexican Legislation on Safeguards

    International Nuclear Information System (INIS)

    Maciel Sánchez, S.; Carreño Padilla, A. L.

    2015-01-01

    The main goal of this paper is to underline the specific points needed still to be improved on safeguards in the Mexican legal framework. The problem: Mexico proposed the Tlatelolco Treaty which was before the TNP. So the Mexican legislation on safeguards should to be one of the best around the world, but there are still points to be improved, such as a specific regulation on the topic. Justification: Remembering that the exact sciences need of the law in order to be applied in a desirable way. I mean, the safeguards could be well conceived and well worked from the physics and mathematics point of view, but in order to be followed in any country, it is necessary the right legal framework. Hypothesis: What has Mexico now in its legislation on safeguards and what remains to be done (what is pending in the Mexican legal scope of the safeguards)? Objectives: – To propose legal solutions to correct the weakness of the Mexican legal framework on Safeguards; taking into account my own experience drafting the Mexican regulation on safeguards from 2008 for the Mexican Government in my nuclear law firm “Martínez and Maciel”. – To propose a legal framework on safeguards for Mexico as it is understood by the IAEA. – To update the legal frame work on safeguards in Mexico linking it to the Back end of the spent fuel. (Considering that sooner or later the Mexican Government will have to define its politic on this topic). (author)

  10. PREFACE: X Workshop of the Gravitation and Mathematical Physics Division, Mexican Physical Society

    Science.gov (United States)

    2014-11-01

    The collection of papers in this volume was presented during the X Workshop of the Gravitation and Mathematical Physics Division of the Mexican Physical Society (DGFM-SMF), which was held in Pachuca, Hidalgo, México, December 2-6, 2013. The Workshop is a bi-annual series of conferences sponsored by the DGFM-SMF that started in 1993 with the purposes of discussing and exchanging the research and experience of the gravitational and mathematical physics communities in Mexico. Each Mexican Workshop has been devoted to subjects of broad interest, so that students, in particular, can have access to specialized courses and talks that allow them to raise up their qualifications as professional researchers. Recurrent topics in the Mexican Workshop are supergravity, branes, black holes, the early Universe, observational cosmology, quantum gravity and cosmology and numerical relativity. Following our previous Workshops, distinguished researchers in the field, working in Mexico, were invited to give courses, whereas young researchers were invited for plenary lectures. More specialized talks were also presented in parallel sessions, with ample participation of researchers, and graduate and undergraduate students; most of the presentations have been included in these proceedings. The contributions in this volume have been peer-reviewed, and they represent most of the courses, plenary talks and contributed talks presented during our Workshop. We are indebted to the contributors of these proceedings, as well as to the other participants and organizers, all for making the event a complete success. We acknowledge the professionalism of our reviewers, who helped us to keep high quality standards in all manuscripts. Acknowledgments The organizing committee would like to acknowledge the financial support of the Mexican National Science and Technology Council (CONACyT), the Mexican Physical Society (SMF), as well as several Institutions including: Centro de Investigación y Estudios

  11. Conservation of Native Fishes of the San Francisco Estuary: Considerations for Artificial Propagation of Chinook Salmon, Delta Smelt, and Green Sturgeon

    Directory of Open Access Journals (Sweden)

    Joshua A. Israel

    2011-04-01

    Full Text Available Many native fishes in the San Francisco Estuary and its watersheds have reached all-time low abundances. Some of these declining species (e.g., Chinook salmon Oncorhynchus tschawytscha have been under artificial propagation for decades. For others (e.g., delta smelt, Hypomesus transpacificus, and green sturgeon, Acipenser medirostris, this management option is just beginning to be discussed and implemented. Propagation strategies, in which organisms spend some portion of their lives in captivity, pose well-documented genetic and ecological threats to natural populations. Negative impacts of propagation have been documented for all Central Valley Chinook salmon runs, but limited efforts have been made to adapt hatchery operations to minimize the genetic and ecological threats caused by propagated fishes. A delta smelt propagation program is undergoing intensive design and review for operations and monitoring. However, if limiting factors facing this species in its estuarine habitat are not effectively addressed, captive propagation may not be a useful conservation approach, regardless of how carefully the propagation activity is designed or monitored. Scientifically defensible, ecologically based restoration programs that include monitoring and research aimed at quantifying natural population vital rates should be fully implemented before there is any attempt to supplement natural populations of delta smelt. Green sturgeon are also likely to face risks from artificial propagation if a large–scale program is implemented before this species’ limiting factors are better understood. In each of these cases, restoring habitats, and reducing loss from human actions, are likely to be the best strategy for rebuilding and supporting self–sustaining populations.

  12. General overview of the Mexican energy sector

    International Nuclear Information System (INIS)

    Perez-Jacome, D.

    1999-01-01

    An overview of Mexico's energy sector was presented, with particular focus on the natural gas and electricity sectors. Mexico ranks fifth in oil production, eighth in proven oil reserves, and fourteenth in natural gas reserves. In 1998, the energy sector generated 3.3 per cent of Mexico's gross domestic product (GDP), and oil accounted for 7.5 per cent of total exports. National production of natural gas has been forecasted to grow at a rate of 5.2 per cent annually over the next 10 years. This will be largely due to the increased demand for natural gas to produce electricity. The Mexican government has also taken initiatives to restructure the Mexican energy sector with particular focus on increasing the competitiveness of the electric power industry. Electricity demand is also expected to grow at a rate of 6 per cent annually over the next six years. The objectives of energy reform are to promote more investment from all sectors in order to strengthen the development of the electric power industry and to provide a reliable, high quality service at competitive prices. 9 figs

  13. Mexican registry of pulmonary hypertension: REMEHIP.

    Science.gov (United States)

    Sandoval Zarate, Julio; Jerjes-Sanchez, Carlos; Ramirez-Rivera, Alicia; Zamudio, Tomas Pulido; Gutierrez-Fajardo, Pedro; Elizalde Gonzalez, Jose; Leon, Mario Seoane Garcia De; Gamez, Miguel Beltran; Abril, Francisco Moreno Hoyos; Michel, Rodolfo Parra; Aguilar, Humberto Garcia

    REMEHIP is a prospective, multicentre registry on pulmonary hypertension. The main objective will be to identify the clinical profile, medical care, therapeutic trends and outcomes in adult and pediatric Mexican patients with well-characterized pulmonary hypertension. REMEHIP a multicenter registry began in 2015 with a planned recruitment time of 12 months and a 4-year follow-up. The study population will comprise a longitudinal cohort study, collecting data on patients with prevalent and incident pulmonary hypertension. Will be included patients of age >2 years and diagnosis of pulmonary hypertension by right heart catheterization within Group 1 and Group 4 of the World Health Organization classification. The structure, data collection and data analysis will be based on quality current recommendations for registries. The protocol has been approved by institutional ethics committees in all participant centers. All patients will sign an informed consent form. Currently in Mexico, there is a need of observational registries that include patients with treatment in the everyday clinical practice so the data could be validated and additional information could be obtained versus the one from the clinical trials. In this way, REMEHIP emerges as a link among randomized clinical trials developed by experts and previous Mexican experience. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

  14. Emission and profile characteristic of volatile organic compounds emitted from coke production, iron smelt, heating station and power plant in Liaoning Province, China.

    Science.gov (United States)

    Shi, Jianwu; Deng, Hao; Bai, Zhipeng; Kong, Shaofei; Wang, Xiuyan; Hao, Jiming; Han, Xinyu; Ning, Ping

    2015-05-15

    107 kinds of C₂-C₁₂ volatile organic compound (VOC) mass concentrations and profiles for four types of coal-fired stationary sources in Liaoning Province were studied by a dilution sampling system and GC-MS analysis method, which are of significant importance with regard to VOC emissions in northeast of China. The results showed that there were some differences among these VOC source profiles. The total mass concentrations of analyzed 107 VOC species varied from 10,917 to 19,652 μg m(-3). Halogenated hydrocarbons exhibited higher mass percentages for the VOC source profiles of iron smelt (48.8%) and coke production plant (37.7%). Aromatic hydrocarbons were the most abundant in heating station plant (69.1%). Ketones, alcohols and acetates held 45.0% of total VOCs in thermal power plant. For non-methane hydrocarbons (NMHCs), which are demanded for photochemical assessment in the USA, toluene and n-hexane were the most abundant species in the iron smelt, coke production and thermal power plant, with the mass percentages of 64.8%, 52.7% and 38.6%, respectively. Trimethylbenzene, n-propylbenzene and o,m-ethyltoluene approximately accounted for 70.0% in heating station plant. NMHCs emitted from coke production, iron smelt, heating station and power plant listed above presented different chemical reactivities. The average OH loss rate of NMHCs from heating station, was 4 to 5.6 times higher than that of NMHCs from iron smelt, coke production and power plant, which implies that VOCs emitted from heating station in northeast of China should be controlled firstly to avoid photochemical ozone pollution and protect human health. There are significant variations in the ratios of benzene/toluene and m, p-xylene/ethylbenzene of these coal-fired source profiles. The representativeness of the coal-fired sources studied and the VOC samples collected should be more closely examined. The accuracy of VOC source profiles related to coal-fired processes is highly dependent on

  15. Post-depositional redistribution of trace metals in reservoir sediments of a mining/smelting-impacted watershed (the Lot River, SW France)

    International Nuclear Information System (INIS)

    Audry, Stephane; Grosbois, Cecile; Bril, Hubert; Schaefer, Joerg; Kierczak, Jakub; Blanc, Gerard

    2010-01-01

    Mining/smelting wastes and reservoir sediment cores from the Lot River watershed were studied using mineralogical (XRD, SEM-EDS, EMPA) and geochemical (redox dynamics, selective extractions) approaches to characterize the main carrier phases of trace metals. These two approaches permitted determining the role of post-depositional redistribution processes in sediments and their effects on the fate and mobility of trace metals. The mining/smelting wastes showed heterogeneous mineral compositions with highly variable contents of trace metals. The main trace metal-bearing phases include spinels affected by secondary processes, silicates and sulfates. The results indicate a clear change in the chemical partitioning of trace metals between the reservoir sediments upstream and downstream of the mining/smelting activities, with the downstream sediments showing a 2-fold to 5-fold greater contribution of the oxidizable fraction. This increase was ascribed to stronger post-depositional redistribution of trace metals related to intense early diagenetic processes, including dissolution of trace metal-bearing phases and precipitation of authigenic sulfide phases through organic matter (OM) mineralization. This redistribution is due to high inputs (derived from mining/smelting waste weathering) at the water-sediment interface of (i) dissolved SO 4 promoting more efficient OM mineralization, and (ii) highly reactive trace metal-bearing particles. As a result, the main trace metal-bearing phases in the downstream sediments are represented by Zn- and Fe-sulfides, with minor occurrence of detrital zincian spinels, sulfates and Fe-oxyhydroxides. Sequestration of trace metals in sulfides at depth in reservoir sediments does not represent long term sequestration owing to possible resuspension of anoxic sediments by natural (floods) and/or anthropogenic (dredging, dam flush) events that might promote trace metal mobilization through sulfide oxidation. It is estimated that, during a major

  16. [Mexican] Private-sector petroleum companies and agents

    International Nuclear Information System (INIS)

    1993-07-01

    An overview is presented of the Mexican petroleum sector. The sector is largely controlled by the state company PEMEX and is not completely open to foreign participation and supply, however the trend towards privatization and open competition, combined with the drive for competitiveness of PEMEX operations in particular, is creating market opportunities for foreign suppliers of petroleum equipment and services. Detailed profiles are provided of 50 Mexican companies and their primary products and services, specific areas of expertise, client base, international experience, interest in Canada, other relevant information, and a contact person. A less detailed list is also provided of additional Mexican contacts, petroleum industry associations and chambers of commerce

  17. Personality traits associated with success in Mexican exporter

    Directory of Open Access Journals (Sweden)

    Olga Leticia Gil Gaytan

    2017-06-01

    Full Text Available The objective of this research is to identify the personality traits associated with success in exporting by Mexican entrepreneurs in the Guadalajara metropolitan area. The main justification for carrying out this study is Mexico’s need to reduce its current dependence on manufacturing exports using foreign investment and increase the exports of Mexican companies. According to this study, there is association between export success and personality traits in successful Mexican exporters. With the spread of these findings, it is expected that both universities and business organizations will consider these results when selecting students for programs related to international venture.

  18. Problems Faced by Mexican Asylum Seekers in the United States

    OpenAIRE

    J. Anna Cabot

    2014-01-01

    Violence in Mexico rose sharply in response to President Felipe Calderón’s military campaign against drug cartels which began in late 2006. As a consequence, the number of Mexicans who have sought asylum in the United States has grown significantly. In 2013, Mexicans made up the second largest group of defensive asylum seekers (those in removal proceedings) in the United States, behind only China (EOIR 2014b). Yet between 2008 and 2013, the grant rate for Mexican asylum seekers in immigration...

  19. A cross-over in Mexican and Mexican-American fertility rates: Evidence and explanations for an emerging paradox

    Directory of Open Access Journals (Sweden)

    Patrick Heuveline

    2005-03-01

    Full Text Available Against a backdrop of two new developments in the fertility behavior of the Mexican- Origin population in the U.S., the present discussion will update contemporary Mexican-Origin fertility patterns and address several theoretical weaknesses in the current approach to minority group fertility. Data come from six national surveys (three from Mexico and three from the U.S. that cover a twenty-five year period (1975-2000. The findings demonstrate dramatic decreases in the fertility rates in Mexico at the same time that continuous increases have been documented in the fertility rates of third-or-later generation Mexican-Americans in the U.S., particularly at younger ages. These changes necessitate a reexamination of the ubiquitous theory that Mexican pronatalist values are responsible for the high fertility rates found within the Mexican-Origin population in the U.S. Instead, they point to the increasing relevance of framing the fertility behavior of the Mexican-Origin population within a racial stratification perspective that stresses the influence of U.S. social context on fertility behavior. As a step in this direction, the analysis examines fertility patterns within the Mexican-Origin population in the U.S. Special attention is given to the role of nativity/generational status in contributing to within group differences.

  20. The Mexican Revolution and health care or the health of the Mexican Revolution.

    Science.gov (United States)

    Horn, J J

    1985-01-01

    Despite a victorious social revolution, a self-proclaimed "revolutionary" government, and a significant post-war economic growth, Mexico has not achieved a just or equitable social system. The Mexican Revolution led to the emergence of a new bureaucratic class whose "trickle-down" development strategy sacrificed social welfare to capital accumulation. Mexican morbidity and mortality patterns resemble those of more impoverished developing nations without revolutionary experience. The patterns of health care in Mexico reflect inequities and contradictions in the society and economy at large and flow from the erosion of the egalitarian aims of the revolution concomitant with the expansion of capitalism and the concentration of the benefits of "modernization" in the hands of privileged elites. Mexico's health problems are symptomatic of a general socio-economic malaise which questions the legitimacy of the Revolution.

  1. Characterization of mtDNA haplogroups in 14 Mexican indigenous populations.

    Science.gov (United States)

    Peñaloza-Espinosa, Rosenda I; Arenas-Aranda, Diego; Cerda-Flores, Ricardo M; Buentello-Malo, Leonor; González-Valencia, Gerardo; Torres, Javier; Alvarez, Berenice; Mendoza, Irma; Flores, Mario; Sandoval, Lucila; Loeza, Francisco; Ramos, Irma; Muñoz, Leopoldo; Salamanca, Fabio

    2007-06-01

    In this descriptive study we investigated the genetic structure of 513 Mexican indigenous subjects grouped in 14 populations (Mixteca-Alta, Mixteca-Baja, Otomi, Purépecha, Tzeltal, Tarahumara, Huichol, Nahua-Atocpan, Nahua-Xochimilco, Nahua-Zitlala, Nahua-Chilacachapa, Nahua-Ixhuatlancillo, Nahua-Necoxtla, and Nahua-Coyolillo) based on mtDNA haplogroups. These communities are geographically and culturally isolated; parents and grandparents were born in the community. Our data show that 98.6% of the mtDNA was distributed in haplogroups A1, A2, B1, B2, C1, C2, D1, and D2. Haplotype X6 was present in the Tarahumara (1/53) and Huichol (3/15), and haplotype L was present in the Nahua-Coyolillo (3/38). The first two principal components accounted for 95.9% of the total variation in the sample. The mtDNA haplogroup frequencies in the Purépecha and Zitlala were intermediate to cluster 1 (Otomi, Nahua-Ixhuatlancillo, Nahua-Xochimilco, Mixteca-Baja, and Tzeltal) and cluster 2 (Nahua-Necoxtla, Nahua-Atocpan, and Nahua-Chilacachapa). The Huichol, Tarahumara, Mixteca-Alta, and Nahua-Coyolillo were separated from the rest of the populations. According to these findings, the distribution of mtDNA haplogroups found in Mexican indigenous groups is similar to other Amerindian haplogroups, except for the African haplogroup found in one population.

  2. Targeting the taqueria: implementing healthy food options at Mexican American restaurants.

    Science.gov (United States)

    Hanni, Krista D; Garcia, Elan; Ellemberg, Cheryl; Winkleby, Marilyn

    2009-04-01

    As part of a 5-year community-based intervention in Salinas, California, the Steps to a Healthier Salinas team developed a taqueria intervention addressing obesity and diabetes among Mexican Americans. The authors present: (a) a comparison of service/entrée options for Salinas taquerias (n = 35) and fast-food restaurants ( n = 38) at baseline, (b) a case study of one taqueria, (c) a description of a healthy nutrition tool kit tailored to taquerias, and (d) an evaluation of the intervention at Year 3. It was found that traditional Mexican American-style menu offerings at taquerias tended to be healthier than American-style fast-food restaurant offerings. In addition, the initial response to the intervention has shown positive changes, which include the taqueria owners promoting available healthy menu items and modifying other menu offerings to reduce fats and increase fruit and vegetable availability. This, in turn, has led to a transition of the owners' perceptions of themselves as gatekeepers for a healthy community.

  3. Diabetes is more lethal in Mexicans and Mexican Americans compared to non-Hispanic Whites

    Science.gov (United States)

    Hunt, Kelly J; Gonzalez, Maria Elena; Lopez, Ruy; Haffner, Steve M; Stern, Michael P; Gonzalez-Villalpando, Clicerio

    2012-01-01

    Purpose To examine the mortality risk associated with diabetes in the Mexico City Diabetes Study (MCDS) and the San Antonio Heart Study (SAHS). Methods Prospective cohorts conducted 1990-2007 in MCDS and 1979-2000 in SAHS. Mortality risk was examined using Cox proportional hazard models in 1,402 non-Hispanic whites (NHW), 1,907 U.S.-born Mexican Americans (MA), 444 Mexican-born MA, 2,281 Mexico City residents (MCR) between the ages of 35 and 64. Results Age- and sex-adjusted mortality HRs comparing U.S.-born MA, Mexican-born MA and MCR to NHW were 1.09 (95% CI: 0.86, 1.37), 1.23 (95% CI: 0.86, 1.76) and 0.97 (95% CI: 0.77, 1.23), respectively, in non-diabetic individuals; in contrast, mortality risk varied in diabetic individuals with respective HRs of 1.77 (95% CI: 1.20, 2.61), 1.08 (95% CI: 0.59, 1.97) and 2.27 (95% CI: 1.53, 3.35) (interaction p-value=0.0003). Excluding Mexican-born MA and non-diabetic individuals, controlling for medication use, insulin use, fasting glucose levels and duration of diabetes explained a significant proportion of the mortality differential (HRs relative to NHW were 1.31 (95% CI: 0.87, 1.98) in U.S.-born MA and 1.38 (95% CI: 0.89, 2.12) in MCR). Conclusions This study provides evidence that diabetes is more lethal in U.S.-born MA and MCR than in NHW. PMID:21840730

  4. The Smell of Memories. A Mexican Migrant’s Search for Emotional Sustainability through Mexican Films.

    Directory of Open Access Journals (Sweden)

    Gabriela Coronado

    2011-12-01

    Full Text Available For more than 10 years living as a Mexican migrant, between two countries (Mexico and Australia, two cities (Mexico City and Sydney, and two social worlds (Mexican and multicultural Australian ‘families-friends’, I have been immersed in a systematic process of self observation and self reflection on my life in my country of destination. During this time I have explored my memories of place and their relationship with my emotional experiences, looking for strategies to continue to be connected with my country of origin and my people. In this process I discovered films were especially significant in sustaining me emotionally. I benefited from the memory associations triggered by representations of Mexico in films produced by Mexicans or by filmmakers from other nationalities. By reflecting on my responses to those films, in this paper I explore how representations of their country of origin can impact on migrants’ emotional life. Using autoethnography, examining my own subjectivity as a way to arrive at a deeper grasp of these processes, I analyse the roles played by different senses in the process of recollection and in the emotional effects produced, which come to embody the experience. My particular focus in this article is the sense of smell triggered by complex interactions within the sensorium while watching films, producing associations and feelings through which I re-live my memories and maintain my emotional sustainability.

  5. Opportunities - oil and gas development in the Mexican market

    International Nuclear Information System (INIS)

    1997-01-01

    This review of business opportunities is intended as a guide for Alberta companies who are interested in investing or otherwise participating in the Mexican oil and gas industry. The guide provides a brief summary of Mexico, its political, legal and economic system, a brief review of the Mexican oil and gas industry, environmental legislation, the financial institutions, labour/management relations and overseas trade relations. Opportunities for Alberta firms in the Mexican resources industry are identified. Steps to follow for anyone contemplating business with Pemex, the state-owned oil company, are outlined and sources of assistance available to Alberta companies are reviewed. There are various lists of private consultants, Canadian banks in Mexico, accounting firms, customs brokers, freight forwarders and tips on Canadian and Mexican sources of financing. There is also a summary of commercial regulations between Pemex and its suppliers, and an organization chart of the Exploration and Production Branch of Petroleos Mexicanos. tabs., figs

  6. FastStats: Health of Mexican American Population

    Science.gov (United States)

    ... Submit Button NCHS Home Health of Mexican American Population Recommend on Facebook Tweet Share Compartir Data are ... Source: Summary Health Statistics Tables for the U.S. Population: National Health Interview Survey, 2015, Table P-1c [ ...

  7. Mexican immigration and the port-of-entry school.

    Science.gov (United States)

    Baca, R; Bryan, D; Mclean-bardwell, C; Gomez, F

    1989-01-01

    The results of an immigrant student census in a California port-of-entry school district are used to describe the educational backgrounds of Mexican immigrant students and to distinguish types of Mexican immigrant students by school entry patterns. Interviews with recently arrived Mexican immigrant parents reveal the educational and occupational expectations they hold for their children in the US. The study findings are used as a basis for raising policy questions and generating research issues. The most notable observation from the study is that the children of Mexican immigrants in La Entrada do not migrate once they are in school. Parents may be migrating back and forth between the US and Mexico, but children once in La Entrada do not leave the school to return to school in Mexico. The study suggests that the parents of immigrant students do not know how the US educational system works but they are interested in helping teachers educate their children.

  8. B Physics at the D0 experiment A Mexican review

    International Nuclear Information System (INIS)

    De La Cruz-Burelo, E.

    2010-01-01

    On April of 1992 a Mexican group from Cinvestav officially joined the D0 experiment, one of the two experiments in the Tevatron collider at Fermilab. The seed for this experimental group on high energy physics from Cinvestav was planted in Mexico in some measure by Augusto Garcia, to whom this workshop is in memorial. Augusto's efforts and support to groups dedicated to this area was clear and important. Some of these seeds have given origin to today's established Mexican groups on experimental high energy physics, one example of this is the Mexican group at D0. I present here a short review of some of the D0 results on which the Mexican group has contributed, emphasizing the last decade, which I have witnessed.

  9. United States -- Mexican joint ventures: A case history approach

    Energy Technology Data Exchange (ETDEWEB)

    Moore, N.L.; Chidester, R.J.; Hughes, K.R.; Fowler, R.A.

    1993-03-01

    Because the Mexican government has encouraged investment in Mexico by increasing the percentage of ownership of a Mexican business that a US company can hold, joint ventures are more attractive now than they had been in the past. This study provides preliminary information for US renewable energy companies who are interested in forming a joint venture with a Mexican company. This report is not intended to be a complete reference but does identifies a number of important factors that should be observed when forming a Mexican joint venture: (1)Successful joint ventures achieve the goals of each partner. (2)It is essential that all parties agree to the allocation of responsibilities. (3)Put everything in writing. (4)Research in depth the country or countries in which you are considering doing business.

  10. A refined ecological risk assessment for California red-legged frog, Delta smelt, and California tiger salamander exposed to malathion.

    Science.gov (United States)

    Clemow, Yvonne H; Manning, Gillian E; Breton, Roger L; Winchell, Michael F; Padilla, Lauren; Rodney, Sara I; Hanzas, John P; Estes, Tammara L; Budreski, Katherine; Toth, Brent N; Hill, Katie L; Priest, Colleen D; Teed, R Scott; Knopper, Loren D; Moore, Dwayne Rj; Stone, Christopher T; Whatling, Paul

    2018-03-01

    The California red-legged frog (CRLF), Delta smelt (DS), and California tiger salamander (CTS) are 3 species listed under the United States Federal Endangered Species Act (ESA), all of which inhabit aquatic ecosystems in California. The US Environmental Protection Agency (USEPA) has conducted deterministic screening-level risk assessments for these species potentially exposed to malathion, an organophosphorus insecticide and acaricide. Results from our screening-level analyses identified potential risk of direct effects to DS as well as indirect effects to all 3 species via reduction in prey. Accordingly, for those species and scenarios in which risk was identified at the screening level, we conducted a refined probabilistic risk assessment for CRLF, DS, and CTS. The refined ecological risk assessment (ERA) was conducted using best available data and approaches, as recommended by the 2013 National Research Council (NRC) report "Assessing Risks to Endangered and Threatened Species from Pesticides." Refined aquatic exposure models including the Pesticide Root Zone Model (PRZM), the Vegetative Filter Strip Modeling System (VFSMOD), the Variable Volume Water Model (VVWM), the Exposure Analysis Modeling System (EXAMS), and the Soil and Water Assessment Tool (SWAT) were used to generate estimated exposure concentrations (EECs) for malathion based on worst-case scenarios in California. Refined effects analyses involved developing concentration-response curves for fish and species sensitivity distributions (SSDs) for fish and aquatic invertebrates. Quantitative risk curves, field and mesocosm studies, surface-water monitoring data, and incident reports were considered in a weight-of-evidence approach. Currently, labeled uses of malathion are not expected to result in direct effects to CRLF, DS or CTS, or indirect effects due to effects on fish and invertebrate prey. Integr Environ Assess Manag 2018;14:224-239. © 2017 The Authors. Integrated Environmental Assessment and

  11. Assessment of heavy metal pollution from a Fe-smelting plant in urban river sediments using environmental magnetic and geochemical methods

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Chunxia, E-mail: cxzhang@mail.iggcas.ac.cn [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, No. 19 Bei Tucheng Xilu, Chaoyang Dist., Beijing 100029 (China); Qiao Qingqing [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, No. 19 Bei Tucheng Xilu, Chaoyang Dist., Beijing 100029 (China); Piper, John D.A. [Geomagnetism Laboratory, Department of Earth and Ocean Science, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Huang, Baochun [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, No. 19 Bei Tucheng Xilu, Chaoyang Dist., Beijing 100029 (China)

    2011-10-15

    Environmental magnetic proxies provide a rapid means of assessing the degree of industrial heavy metal pollution in soils and sediments. To test the efficiency of magnetic methods for detecting contaminates from a Fe-smelting plant in Loudi City, Hunan Province (China) we investigated river sediments from Lianshui River. Both magnetic and non-magnetic (microscopic, chemical and statistical) methods were used to characterize these sediments. Anthropogenic heavy metals coexist with coarse-grained magnetic spherules. It can be demonstrated that the Pollution Load Index of industrial heavy metals (Fe, V, Cr, Mo, Zn, Pb, Cd, Cu) and the logarithm of saturation isothermal remanent magnetization, a proxy for magnetic concentration, are significantly correlated. The distribution heavy metal pollution in the Lianshui River is controlled by surface water transport and deposition. Our findings demonstrate that magnetic methods have a useful and practical application for detecting and mapping pollution in and around modern industrial cities. - Highlights: > Assessment of heavy metal (HM) pollution in river sediment using magnetic and chemical methods. > HMs from an Fe-smelting plant coexist with coarse-grained magnetic spherules. > A linear correlation between the Pollution Load Index (PLI) of industrial HMs and a magnetic concentration parameter is demonstrated. > The distribution of HM pollution in river sediments is controlled by surface water flow and deposition. - Heavy metal (HM) contamination of river sediments from industrial input by surface water transport and deposition can be detected by using magnetic methods providing a convenient assessment of HM pollution in industrialized cities.

  12. Effects of Basicity and MgO in Slag on the Behaviors of Smelting Vanadium Titanomagnetite in the Direct Reduction-Electric Furnace Process

    Directory of Open Access Journals (Sweden)

    Tao Jiang

    2016-05-01

    Full Text Available The effects of basicity and MgO content on reduction behavior and separation of iron and slag during smelting vanadium titanomagnetite by electric furnace were investigated. The reduction behaviors affect the separation of iron and slag in the direct reduction-electric furnace process. The recovery rates of Fe, V, and Ti grades in iron were analyzed to determine the effects of basicity and MgO content on the reduction of iron oxides, vanadium oxides, and titanium oxides. The chemical compositions of vanadium-bearing iron and main phases of titanium slag were detected by XRF and XRD, respectively. The results show that the higher level of basicity is beneficial to the reduction ofiron oxides and vanadium oxides, and titanium content dropped in molten iron with the increasing basicity. As the content of MgO increased, the recovery rate of Fe increased slightly but the recovery rate of V increased considerably. The grades of Ti in molten iron were at a low level without significant change when MgO content was below 11%, but increased as MgO content increased to 12.75%. The optimum conditions for smelting vanadium titanomagnetite were about 11.38% content of MgO and quaternary basicity was about 1.10. The product, vanadium-bearing iron, can be applied in the converter steelmaking process, and titanium slag containing 50.34% TiO2 can be used by the acid leaching method.

  13. Assessment of heavy metal pollution from a Fe-smelting plant in urban river sediments using environmental magnetic and geochemical methods

    International Nuclear Information System (INIS)

    Zhang Chunxia; Qiao Qingqing; Piper, John D.A.; Huang, Baochun

    2011-01-01

    Environmental magnetic proxies provide a rapid means of assessing the degree of industrial heavy metal pollution in soils and sediments. To test the efficiency of magnetic methods for detecting contaminates from a Fe-smelting plant in Loudi City, Hunan Province (China) we investigated river sediments from Lianshui River. Both magnetic and non-magnetic (microscopic, chemical and statistical) methods were used to characterize these sediments. Anthropogenic heavy metals coexist with coarse-grained magnetic spherules. It can be demonstrated that the Pollution Load Index of industrial heavy metals (Fe, V, Cr, Mo, Zn, Pb, Cd, Cu) and the logarithm of saturation isothermal remanent magnetization, a proxy for magnetic concentration, are significantly correlated. The distribution heavy metal pollution in the Lianshui River is controlled by surface water transport and deposition. Our findings demonstrate that magnetic methods have a useful and practical application for detecting and mapping pollution in and around modern industrial cities. - Highlights: → Assessment of heavy metal (HM) pollution in river sediment using magnetic and chemical methods. → HMs from an Fe-smelting plant coexist with coarse-grained magnetic spherules. → A linear correlation between the Pollution Load Index (PLI) of industrial HMs and a magnetic concentration parameter is demonstrated. → The distribution of HM pollution in river sediments is controlled by surface water flow and deposition. - Heavy metal (HM) contamination of river sediments from industrial input by surface water transport and deposition can be detected by using magnetic methods providing a convenient assessment of HM pollution in industrialized cities.

  14. Distribution and transfer of potentially toxic metal(loid)s in Juncus effusus from the indigenous zinc smelting area, northwest region of Guizhou Province, China.

    Science.gov (United States)

    Peng, Yishu; Chen, Jun; Wei, Huairui; Li, Shibin; Jin, Tao; Yang, Ruidong

    2018-05-15

    We collected samples (i.e., the aerial parts and roots of Juncus effusus and their growth media) in the indigenous zinc smelting area in the northwest region of Guizhou Province, China, and we measured and analyzed potentially toxic metal(loid)s (arsenic, As; cadmium, Cd; chromium, Cr; copper, Cu; mercury, Hg; lead, Pb and zinc, Zn) in these samples. The results include the following: First, there is a high concentration of one or more potentially toxic metal(loid)s in the slag and surrounding soil in the research area. This situation might be caused by metal(loid) damage or contamination due to the circumstances. Additionally, Juncus effusus in the indigenous zinc smelting area are contaminated by some potentially toxic metal(loid)s; since they are used for Chinese medical materials, it is especially significant that their As, Cd and Pb concentrations are greater than their limited standard values. Finally, both the bioconcentration factors and transfer factors for most potentially toxic metal(loid)s in Juncus effusus are less than 1 in the study area. Therefore, we suggest that Juncus effusus could be used for phytostabilization or as a pioneer plant for phytoremediation of potentially toxic metal(loid)s because it has a tolerance and exclusion mechanism for these metal(loid)s in the research district. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Patterns of contraceptive use among Mexican-origin women

    Directory of Open Access Journals (Sweden)

    Kari White

    2013-06-01

    Full Text Available BACKGROUND Mexican women in the United States (US have higher rates of fertility compared to other ethnic groups and women in Mexico. Whether variation in women's access to family planning services or patterns of contraceptive use contributes to this higher fertility has received little attention. OBJECTIVE We explore Mexican women's contraceptive use, taking into account women's place in the reproductive life course. METHODS Using nationally representative samples from the US (National Survey of Family Growth and Mexico (Encuesta National de la Dinámica Demográfica, we compared the parity-specific frequency of contraceptive use and fertility intentions for non-migrant women, foreign-born Mexicans in the US, US-born Mexicans, and whites. RESULTS Mexican women in the US were less likely to use IUDs and more likely to use hormonal contraception than women in Mexico. Female sterilization was the most common method among higher parity women in both the US and Mexico, however, foreign-born Mexicans were less likely to be sterilized, and the least likely to use any permanent contraceptive method. Although foreign-born Mexicans were slightly less likely to report that they did not want more children, differences in method use remained after controlling for women's fertility intentions. CONCLUSIONS At all parities, foreign-born Mexicans used less effective methods. These findings suggest that varying access to family planning services may contribute to variation in women's contraceptive use. COMMENTS Future studies are needed to clarify the extent to which disparities in fertility result from differences in contraceptive access.

  16. Family Structure and Family Processes in Mexican American Families

    OpenAIRE

    Zeiders, Katharine H.; Roosa, Mark W.; Tein, Jenn-Yun

    2011-01-01

    Despite increases in single-parent families among Mexican Americans (MA), few studies have examined the association of family structure and family adjustment. Utilizing a diverse sample of 738 Mexican American families (21.7% single parent), the current study examined differences across family structure on early adolescent outcomes, family functioning, and parent-child relationship variables. Results revealed that early adolescents in single parent families reported greater school misconduct,...

  17. MEXICAN DRUG CARTELS AND TERRORIST ORGANIZATIONS, A NEW ALLIANCE

    Science.gov (United States)

    2016-02-16

    Nevertheless, existing studies provide little evidence to support the claim that a risk of collaboration exists between Mexican cartels and...of Defense (DoD) nor Department of Homeland Security (DHS) have a published definition for cartel. For purposes of this study it is important to note...commodities and real estate. According to National Drug Intelligence Center, Mexican and Colombian cartels launder between $18- $39 billion annually.15

  18. Sanitary and Phytosanitary Measures: The Case of Mexican Avocados

    OpenAIRE

    Bakshi, Nishita

    2003-01-01

    This thesis examines the effects on demand, supply, imports, and prices of partial easing of sanitary and phytosanitary (SPS) barriers to trade in the U.S. market in the case of Mexican avocados. The SPS Agreement plays a role in the avocado market studied here through its implications for negotiations between countries that have not utilized the formal channels of the WTO for resolving disputes. A quarantine in place from 1914 until very recently banned entry of Mexican avocados into the...

  19. Health perceptions of Mexican American women.

    Science.gov (United States)

    Mendelson, Cindy

    2002-07-01

    This article describes the health perceptions of a sample of moderately to highly acculturated Mexican American women. Using an ethnographic design, the author interviewed 13 women to determine their health perceptions. The interviews were guided by the domains of health described in the World Health Organization (WHO) definition of health. Three broad categories of health perceptions were identified: the physical body, the emotional component, and finding balance. With the addition of a spiritual component, the WHO definition was a useful tool for uncovering health perceptions. The process of in-depth ethnographic interviewing provided a contextual view of health in which the complexity of intrafamilial relationships was revealed, as were the importance of spirituality as a coping mechanism and the perception of health as an integrated, holistic experience.

  20. Area selection for conservation of Mexican mammals

    Directory of Open Access Journals (Sweden)

    Vázquez, L. B.

    2009-06-01

    Full Text Available Three sets of priority cells for mammal conservation in Mexico were identified using distributional data. A complementarity approach was implemented through linear integer programming. The minimum set of sites required for the representation of each mammal species varied between 38 (5.4% grid cells for at least one occurrence, 110 (15.6% grid cells for at least three occurrences, and 173 (24.5% grid cells for at least five occurrences. The complementary analyses mainly highlighted three regions of particular concern for mammal conservation in Mexico: (i the trans-Mexican Volcanic Belt and natural provinces of the Pacific Coast, (ii Sierra Madre del Sur and the Highlands of Chiapas, and (iii the northern portion of the Sierra Madre Occidental. The results reported here did not indicate absolute priority locations for conservation activities, but rather identified locations warranting further investigation at finer resolutions more appropriate to such activity

  1. [First Mexican Consensus of Vaccination in Adults].

    Science.gov (United States)

    Gutiérrez-Robledo, Luis Miguel; Caro-López, Elizabeth; Guerrero-Almeida, María de Lourdes; Dehesa-Violante, Margarita; Rodríguez-Noriega, Eduardo; García-Lara, Juan Miguel; Medina-López, Zaira; Báez-Saldaña, Renata; Díaz-López, Elsa; Avila-Fematt, Flor Maria de Guadalupe; Betancourt-Cravioto, Miguel; Garcia-Garcia, Lourdes

    2017-03-01

    For years our efforts have been focused on vaccination during childhood. Today we know that this is not enough to ensure health in the rest of the life. Childhood is as important as any other stage and, therefore, vaccination must be permanent and differentiated, according to our age, throughout life. Introducing a life course perspective in vaccination programs, with emphasis on adult vaccination, particularly in older adults, offers us the opportunity to review the performance of health programs, actions, and services in the field of immunization, as well as strengthening health promotion actions. In this context, the first Mexican Consensus on Adult Vaccination was carried out in a joint effort of the National Institute of Geriatrics, bringing together a group of specialists who worked on three central objectives: establishing vaccination guidelines throughout the life course, with emphasis on new vaccines; defining priority groups according to their risk factors; and contributing to the effort to promote healthy aging.

  2. Religiosity and Migration Aspirations among Mexican Youth.

    Science.gov (United States)

    Hoffman, Steven; Marsiglia, Flavio Francisco; Ayers, Stephanie L

    2015-02-01

    International migration has become an important topic of discussion from a policy and humanitarian perspective. Part of the debate includes a renewed interest in understanding the factors that influence decisions about migration to the US among Mexican youth still residing in their country of origin. The purpose of this study was to advance knowledge specifically about internal and external religiosity and their influence on youths' migration aspirations. The data for this study were collected in 2007 from students enrolled in an alternative high school program located in the state of Guanajuato, Mexico. The findings indicated that as external religiosity increases, the desire to work or live in the USA decreases. Furthermore, as internal religiosity increases, the desire to work or live in the USA and plans to migrate increase. The results are interpreted and discussed in light of previous research on religious and cultural norm adherence.

  3. Mexican geothermal development and the future

    International Nuclear Information System (INIS)

    Serrano, J.M.E.V.

    1998-01-01

    Geothermics in Mexico started in 1954, by drilling the first geothermal well in Pathe, State of Hidalgo, which reached a depth of 237 meters. In 1959 electrical generation from geothermal origin began, with an installed capacity of 3.5 MW. From 1959 to 1994 Mexico increased its installed capacity to 753 MW, by developing three geothermal fields: Cerro Prieto, Los Azufres, and Los Humeros. Currently, 177 wells produce steam at a rate of 36 tons per hour (t/h) each. Comision Federal de Electricidad (CFE, Federal Commission of Electricity) has planned to increase the geothermal-electric installed capacity through construction and installation of several projects. Repowering of operating units and development of new geothermal zones will also allow Mexican geothermal growth

  4. [Characterization of Mexican households with food insecurity].

    Science.gov (United States)

    Mundo-Rosas, Verónica; Méndez-Gómez Humarán, Ignacio; Shamah-Levy, Teresa

    2014-01-01

    To describe the sociodemographic and health characteristics associated with food insecurity (FI) in Mexican households. The study included information about 40 809 households from the National Health and Nutrition Survey 2012. The Latin American and Caribbean Scale Food Safety (ELCSA) was used to categorize households in terms of food insecurity. Classification and regression trees were used to identify the most significant characteristics in households with high prevalence of FI. The characteristics associated with higher prevalence of FI in homes were: lowest quintiles of welfare status, lack of education or walking or moving disability of household head, and not receiving money from social programmes, pension or remittances. Monitoring of the factors that favor the presence of FI is required to detect social groups being excluded from the right to food.

  5. Caloric beverage consumption patterns in Mexican children

    Directory of Open Access Journals (Sweden)

    Rivera Juan A

    2010-10-01

    Full Text Available Abstract Background Mexico has seen a very steep increase in child obesity level. Little is known about caloric beverage intake in this country as well as all other countries outside a few high income countries. This study examines overall patterns and trends in all caloric beverages from two nationally representative surveys from Mexico. Methods The two nationally representative dietary intake surveys (1999 and 2006 from Mexico are used to study caloric beverage intake in 17, 215 children. The volume (ml and caloric energy (kcal contributed by all beverages consumed by the sample subjects were measured. Results are weighted to be nationally representative. Results The trends from the dietary intake surveys showed very large increases in caloric beverages among pre-school and school children. The contribution of whole milk and sugar-sweetened juices was an important finding. Mexican pre-school children consumed 27.8% of their energy from caloric beverages in 2006 and school children consumed 20.7% of their energy from caloric beverages during the same time. The three major categories of beverage intake are whole milk, fruit juice with various sugar and water combinations and carbonated and noncarbonated sugared-beverages. Conclusion The Mexican government, greatly concerned about obesity, has identified the large increase in caloric beverages from whole milk, juices and soft drinks as a key target and is initiating major changes to address this problem. They have already used the data to shift 20 million persons in their welfare and feeding programs from whole to 1.5% fat milk and in a year will shift to nonfat milk. They are using these data to revise school beverage policies and national regulations and taxation policies related to an array of less healthful caloric beverages.

  6. Problems Faced by Mexican Asylum Seekers in the United States

    Directory of Open Access Journals (Sweden)

    J. Anna Cabot

    2014-12-01

    Full Text Available Violence in Mexico rose sharply in response to President Felipe Calderón’s military campaign against drug cartels which began in late 2006. As a consequence, the number of Mexicans who have sought asylum in the United States has grown significantly. In 2013, Mexicans made up the second largest group of defensive asylum seekers (those in removal proceedings in the United States, behind only China (EOIR 2014b. Yet between 2008 and 2013, the grant rate for Mexican asylum seekers in immigration court fell from 23 percent to nine percent (EOIR 2013, 2014b. This paper examines—from the perspective of an attorney who represented Mexican asylum seekers on the US-Mexico border in El Paso, Texas—the reasons for low asylum approval rates for Mexicans despite high levels of violence in and flight from Mexico from 2008 to 2013. It details the obstacles faced by Mexican asylum seekers along the US-Mexico border, including placement in removal proceedings, detention, evidentiary issues, narrow legal standards, and (effectively judicial notice of country conditions in Mexico. The paper recommends that asylum seekers at the border be placed in affirmative proceedings (before immigration officials, making them eligible for bond. It also proposes increased oversight of immigration judges.

  7. Improving collected rainwater quality in rural communities.

    Science.gov (United States)

    Garrido, S; Aviles, M; Ramirez, A; Gonzalez, A; Montellano, L; Gonzalez, B; de la Paz, J; Ramirez, R M

    2011-01-01

    The country of Mexico is facing serious problems with water quality and supply for human use and consumption in rural communities, mainly due to topographic and isolation. In Mexico the average annual precipitation is 1,500 cubic kilometers of water, if 3% of that amount were used, 13 million Mexicans could be supplied with drinking water that they currently do not have access. Considering the limited infrastructure and management in rural communities, which do not receive services from the centralized systems of large cities, a modified pilot multi-stage filtration (MMSF) system was designed, developed, and evaluated for treating collected rainwater in three rural communities, Ajuchitlan and Villa Nicolas Zapata (Morelos State) and Xacxamayo (Puebla State). The efficiencies obtained in the treatment system were: colour and turbidity >93%. It is worth mentioning that the water obtained for human use and consumption complies with the Mexican Standard NOM-127-SSA1-1994.

  8. Long-term effects of extreme weather events and eutrophication on the fish community of shallow Lake Peipsi (Estonia/Russia

    Directory of Open Access Journals (Sweden)

    Külli Kangur

    2013-06-01

    Full Text Available The fish kill in lake Peipsi (Estonia/Russia during the extraordinarily hot summer of 2010 evoked an investigation into the effects of environmental extremes and long-term eutrophication on the fish community of the lake. Current data on lake Peipsi indicate that temperature extremes and synergistic interactions with eutrophication have led to a radical restructuring of the fish community. Commercial landings of lake smelt, Osmerus eperlanus eperlanus m. spirinchus (Pallas, the previous dominant species of the fish community, have decreased dramatically since the 1930s, these declines being coupled with summer heat waves coinciding with low water levels. Gradual decline in smelt stock and catches was significantly related to a decline of near-bottom oxygen conditions and to a decrease in water transparency. The first documented fish kill in 1959 occurred only in the southern, most shallow and eutrophic lake (lake Pihkva. Recently, summer fish kill have become more frequent, involving larger areas of the lake. In addition to the cold-water species, e.g. smelt and vendace Coregonus albula (L., the abundance of bottom-dwelling fishes such as ruffe Gymnocephalus cernuus (L. and juvenile fish have significantly decreased after the 2010 heat wave probably due to hypoxia and warm water temperatures. This study showed that fish community structure in large shallow lakes may be very vulnerable to water temperature increases, especially temperature extremes in combination with eutrophication.

  9. Role of physical activity in reducing cognitive decline in older Mexican-American adults.

    Science.gov (United States)

    Ottenbacher, Allison J; Snih, Soham Al; Bindawas, Saad M; Markides, Kyriakos S; Graham, James E; Samper-Ternent, Rafael; Raji, Mukaila; Ottenbacher, Kenneth J

    2014-09-01

    The effect of physical activity on cognitive function in older adults from minority and disadvantaged populations is not well understood. This study examined the longitudinal association between physical activity and cognition in older Mexican Americans. The study methodology included a prospective cohort with longitudinal analysis of data from the Hispanic Established Populations for the Epidemiologic Study of the Elderly. General linear mixed models were used to assess the associations and interactions between physical activity and cognitive function over 14 years. Community-based assessments were performed in participants' homes. Physical activity was recorded for 1,669 older Mexican Americans using the Physical Activity Scale for the Elderly. Cognition was measured using the Mini-Mental State Examination (MMSE) and separated into memory and nonmemory components. A statistically significant positive association was observed between levels of physical activity and cognitive function after adjusting for age, sex, marital status, education, and comorbid health conditions. There was a statistically significant difference in MMSE scores over time between participants in the third (β = 0.11, standard error (SE) = 0.05) and fourth (β = 0.10, SE = 0.2) quartiles of physical activity and those in the first. The protective effect of physical activity on cognitive decline was evident for the memory component of the MMSE but not the nonmemory component after adjusting for covariates. Greater physical activity at baseline was associated with less cognitive decline over 14 years in older Mexican Americans. The reduction in cognitive decline appeared to be related to the memory components of cognitive function. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

  10. Mobility limitations and fear of falling in non-English speaking older Mexican-Americans.

    Science.gov (United States)

    James, Eric G; Conatser, Phillip; Karabulut, Murat; Leveille, Suzanne G; Hausdorff, Jeffrey M; Cote, Sarah; Tucker, Katherine L; Barton, Bruce; Bean, Jonathan F; Al Snih, Soham; Markides, Kyriakos S

    2017-10-01

    To determine whether older Mexican-Americans who cannot speak and/or understand spoken English have higher rates of mobility limitations or fear of falling than their English-speaking counterparts. We conducted a cross-sectional analysis of 1169 community-dwelling Mexican-Americans aged 72-96 years from the 2000-2001 wave of the Hispanic Established Population for the Epidemiological Study of the Elderly. Mobility limitations were defined as having a Short Physical Performance Battery score ≤9, and fear of falling by participant report of being somewhat, fairly, or very afraid of falling. We determined the rates and odds ratios, for having mobility limitations and fear of falling as a function of English ability in those who were 72-96, English 85.7% had mobility limitations and 61.6% were afraid of falling, compared to 77.6% and 57.5%, respectively, of English speakers. Before adjusting for covariates, participants who did not speak and/or understand spoken English were more likely to have mobility limitations (odds ratio: 1.7; 95% CI: 1.3-2.4) but not fear of falling, compared to English speakers. Among those aged ≥80 years, but not those English were more likely to have mobility limitations (odds ratio: 4.8; 95% CI:2.0-11.5) and fear of falling (odds ratio: 2.0; 95% CI:1.3-3.1). Older Mexican-Americans who do not speak or understand spoken English have a higher rate of mobility limitations and fear of falling than their English-speaking counterparts.

  11. Weight status of Mexican immigrant women: a comparison with women in Mexico and with US-born Mexican American women.

    Science.gov (United States)

    Guendelman, Sylvia D; Ritterman-Weintraub, Miranda L; Fernald, Lia C H; Kaufer-Horwitz, Martha

    2013-09-01

    We assessed the association between birthplace, residence, or years in the United States and actual weight (body mass index), perceived weight accuracy, or provider screens for overweight or obesity among Mexican immigrant women. We used linked data from Health and Nutrition Examination Survey waves 2001-2006 and 2006 National Mexican Health and Nutrition Survey to compare 513 immigrants with 9527 women in Mexico and 342 US-born Mexican American women. Immigrants were more likely than women in Mexico to be obese and to perceive themselves as overweight or obese after adjustment for confounders. Recent immigrants had similar weight-related outcomes as women in Mexico. Immigrants were less likely to be obese than were US-born Mexican Americans. Within the overweight or obese population, reported provider screens were higher among immigrants than among women in Mexico, but lower than among US-born Mexican Americans. US residency of at least 5 years but less than 20 years and reporting insufficient provider screens elevated obesity risk. Mexican-origin women in the United States and Mexico are at risk for overweight and obesity. We found no evidence of a "healthy immigrant" effect.

  12. Obesity and central adiposity in Mexican adults: results from the Mexican National Health and Nutrition Survey 2006.

    Science.gov (United States)

    Barquera, Simón; Campos-Nonato, Ismael; Hernández-Barrera, Lucía; Flores, Mario; Durazo-Arvizu, Ramón; Kanter, Rebecca; Rivera, Juan A

    2009-01-01

    To estimate the prevalence of overweight, obesity and central adiposity in Mexico, and to explore trends compared to the previous Mexican National Health Survey (ENSA 2000) and to Mexican-Americans. The Mexican National Health and Nutrition Survey 2006 (ENSANUT 2006) was used to describe overweight, obesity and central adiposity. Trends over time were assessed using the ENSA 2000 and by comparing the ENSANUT 2006 results to those of Mexican-Americans using the United States National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2005-2006. A total of 33023 adults > 20 years old were included; 39.7% were found to be overweight and 29.9% were found to be obese; 75.9% of all adults had abdominal obesity. In Mexico between 2000 and 2006, the combined prevalence of overweight and obesity in adults increased approximately 12%. Mexican-Americans showed a higher prevalence of morbid obesity compared to native Mexicans. Mexico has experienced a rapid increase in the number of adults who have experienced excess weight gain between the years 2000 and 2006.

  13. The aluminum smelting process.

    Science.gov (United States)

    Kvande, Halvor

    2014-05-01

    This introduction to the industrial primary aluminum production process presents a short description of the electrolytic reduction technology, the history of aluminum, and the importance of this metal and its production process to modern society. Aluminum's special qualities have enabled advances in technologies coupled with energy and cost savings. Aircraft capabilities have been greatly enhanced, and increases in size and capacity are made possible by advances in aluminum technology. The metal's flexibility for shaping and extruding has led to architectural advances in energy-saving building construction. The high strength-to-weight ratio has meant a substantial reduction in energy consumption for trucks and other vehicles. The aluminum industry is therefore a pivotal one for ecological sustainability and strategic for technological development.

  14. Familism, machismo and child rearing practices among Mexican Americans.

    Science.gov (United States)

    Tamez, E G

    1981-09-01

    Mexican Americans form the 2nd largest minority group in the US. Fertility is 50% higher than in any other ethnic group. Income levels are inordinately low. In 1970, 42% of Mexican Americans were indigent, making approxiamtely 4200 annually. The Mexican American poor can be categorized into newly arrived aliens or 2nd or 3rd generation American citizens. In the 1st instance, the couple is young and English is not spoken. 2nd or 3rd generation Mexican Americans speak English. The persistent socioeconomic status of the Mexican American relates directly to the level of education. 52% of all Mexican Americans do not finish high school. Paz and Remos described the Mexican in terms of Adler's inferiority model. Murillo stated that to an individual, the family--whether nuclear or extended--is the center of life. The inherent responsibility is that the individual behave properly lest the family be disgraced. The family provides emotional and material security. Familism was seen as a deterrant to utilization of health care services, although some studies claim opposing views. Familism and occupational stability related positively to seeking medical care when ill. Hayden believed that supreme male dominance, individualism, pride, wife beating, aversion to contraceptives, and other characteristics were attributable to machismo. A predominant pattern in Mexican American culture is that of elders' ordering young men and women to establish obedience and male dominance. The husband represents authority and the wife-mother maintains a role of complete devotion to her husband and children. Role differentiation is taught implicitly and explicitly from infancy. Studies on the psychological differences between the sexes indicated that females were oppressed and had lower self esteem than males. 18-24 year old Mexican Americans are becoming less insistent upon strict separation of sex roles and are beginning to reject the traditional Mexican notion of masculine superiority. The word

  15. Georeferenced Population Datasets of Mexico (GEO-MEX): Raster Based GIS Coverage of Mexican Population

    Data.gov (United States)

    National Aeronautics and Space Administration — The Raster Based GIS Coverage of Mexican Population is a gridded coverage (1 x 1 km) of Mexican population. The data were converted from vector into raster. The...

  16. Long-term surveillance plan for the Mexican Hat disposal site Mexican Hat, Utah

    International Nuclear Information System (INIS)

    1997-05-01

    This long-term surveillance plan (LTSP) describes the U.S. Department of Energy's (DOE) long-term care program for the Uranium Mill Tailings Remedial Action (UMTRA) Project Mexican Hat, Utah, disposal site. The U.S. Nuclear Regulatory Commission (NRC) has developed regulations for the issuance of a general license for the custody and long-term care of UMTRA Project disposal sites in 10 CFR Part 40. The purpose of this general license is to ensure that the UMTRA Project disposal sites will be cared for in a manner that protects the public health and safety and the environment. Before each disposal site is licensed, the NRC requires the DOE to submit a site-specific LTSP. The DOE prepared this LTSP to meet this requirement for the Mexican Hat disposal site. The general license becomes effective when the NRC concurs with the DOE's determination of completion of remedial action for the disposal site and the NRC formally accepts this LTSP. This LTSP describes the long-term surveillance program the DOE will implement to ensure that the Mexican Hat disposal site performs as designed. The program is based on two distinct types of activities: (1) site inspections to identify potential threats to disposal cell integrity, and (2) monitoring of selected seeps to observe changes in flow rates and water quality. The LTSP is based on the UMTRA Project long-term surveillance program guidance and meets the requirements of 10 CFR section 40.27(b) and 40 CFR section 192.03. 18 refs., 6 figs., 1 tab

  17. Molecular phylogenetics and species delimitation of leaf-toed geckos (Phyllodactylidae: Phyllodactylus) throughout the Mexican tropical dry forest.

    Science.gov (United States)

    Blair, Christopher; Méndez de la Cruz, Fausto R; Law, Christopher; Murphy, Robert W

    2015-03-01

    Methods and approaches for accurate species delimitation continue to be a highly controversial subject in the systematics community. Inaccurate assessment of species' limits precludes accurate inference of historical evolutionary processes. Recent evidence suggests that multilocus coalescent methods show promise in delimiting species in cryptic clades. We combine multilocus sequence data with coalescence-based phylogenetics in a hypothesis-testing framework to assess species limits and elucidate the timing of diversification in leaf-toed geckos (Phyllodactylus) of Mexico's dry forests. Tropical deciduous forests (TDF) of the Neotropics are among the planet's most diverse ecosystems. However, in comparison to moist tropical forests, little is known about the mode and tempo of biotic evolution throughout this threatened biome. We find increased speciation and substantial, cryptic molecular diversity originating following the formation of Mexican TDF 30-20million years ago due to orogenesis of the Sierra Madre Occidental and Mexican Volcanic Belt. Phylogenetic results suggest that the Mexican Volcanic Belt, the Rio Fuerte, and Isthmus of Tehuantepec may be important biogeographic barriers. Single- and multilocus coalescent analyses suggest that nearly every sampling locality may be a distinct species. These results suggest unprecedented levels of diversity, a complex evolutionary history, and that the formation and expansion of TDF vegetation in the Miocene may have influenced subsequent cladogenesis of leaf-toed geckos throughout western Mexico. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Effects of Functional Disability and Depressive Symptoms on Mortality in Older Mexican-American Adults with Diabetes Mellitus.

    Science.gov (United States)

    Mutambudzi, Miriam; Chen, Nai-Wei; Markides, Kyriakos S; Al Snih, Soham

    2016-11-01

    To examine the effect of co-occurring depressive symptoms and functional disability on mortality in older Mexican-American adults with diabetes mellitus. Longitudinal cohort study. Hispanic Established Populations for the Epidemiological Study of the Elderly (HEPESE) survey conducted in the southwestern United States (Texas, Colorado, Arizona, New Mexico, California). Community-dwelling Mexican Americans with self-reported diabetes mellitus participating in the HEPESE survey (N = 624). Functional disability was assessed using a modified version of the Katz activity of daily living scale. Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale. Mortality was determined by examining death certificates and reports from relatives. Cox proportional hazards regression analyses were used to examine the hazard of mortality as a function of co-occurring depressive symptoms and functional disability. Over a 9.2-year follow-up, 391 participants died. Co-occurring high depressive symptoms and functional disability increased the risk of mortality (hazard ratio (HR) = 3.02, 95% confidence interval (CI) = 2.11-4.34). Risk was greater in men (HR = 8.11, 95% CI = 4.34-16.31) than women (HR = 2.21, 95% CI = 1.42-3.43). Co-occurring depressive symptoms and functional disability in older Mexican-American adults with diabetes mellitus increases mortality risk, especially in men. These findings have important implications for research, practice, and public health interventions. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

  19. Long-term surveillance plan for the Mexican Hat disposal site, Mexican Hat, Utah

    International Nuclear Information System (INIS)

    1996-01-01

    This plan describes the long-term surveillance activities for the Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site at Mexican Hat, Utah. The US Department of Energy (DOE) will carry out these activities to ensure that the disposal site continues to function as designed. This long-term surveillance plan (LTSP) was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive material (RRM). This LTSPC documents the land ownership interests and details how the long-term care of the disposal site will be accomplished

  20. Deconstructive humour: subverting Mexican and Chicano stereotypes in ‘Un Día Sin Mexicanos’

    OpenAIRE

    Barrow, Sarah

    2012-01-01

    a long time, US cinema developed unshakeable stereotypes of Mexican ‘otherness’, with characters of Mexican cultural and ethnic heritage stigmatised as criminals or as sensual objects of desire. Filmmakers in Mexico, meanwhile, treated Mexican Americans as misfits who belonged nowhere, or ignored them and their complex experience completely. The emergence of a distinct ‘Chicano cinema’ in the 1960s allowed for the development of a more powerful set of images of Mexican Americans, exploiting t...

  1. Screening for depression among indigenous Mexican migrant farmworkers using the Patient Health Questionnaire-9.

    Science.gov (United States)

    Donlan, William; Lee, Junghee

    2010-04-01

    U.S. farmworkers include growing numbers of individuals from indigenous, pre-Columbian communities in southern Mexico with distinctive languages and cultures. Given the high stress these farmworkers experience in their challenging work environments, they are very susceptible to depression and other mental and emotional health disorders. The present study explores the Spanish version of the Patient Health Questionnaire-9 (PHQ-9) as a screen for the presence and severity of depression among 123 indigenous Mexican-origin, migrant farmworkers in Oregon. Factor structure and inter-item correlations of the PHQ-9 are examined, along with associations between depression and culture-bound syndromes, self-esteem, self-efficacy, acculturation stress, and other sample psychosocial characteristics. The PHQ-9 exhibited strong factor loadings and internal consistency, and its severity score significantly correlated with other indicators of health status that were observed in previous studies to be significantly associated with depression. The PHQ-9 appears to be culturally relevant for use with Mexicans coming from a variety of indigenous cultures and having very low education and literacy.

  2. Mexican-American perspectives on participation in clinical trials: A qualitative study

    Directory of Open Access Journals (Sweden)

    Mariana Arevalo

    2016-12-01

    Full Text Available Clinical trials are essential to advancing knowledge to reduce disease morbidity and mortality; however, ethnic and racial minorities remain under-represented in those studies. We explored knowledge and perceptions of clinical trials among Mexican-Americans in Texas. We conducted focus groups (N = 128 stratified by gender, language preference, and geographical location. This paper presents four emergent, primary themes: 1 knowledge and understanding of clinical trials, 2 fears and concerns about participating, 3 perceived benefits of participating, and 4 incentives to participate. Results suggest that lack of knowledge and understanding of clinical trials leads to misunderstanding about research, including fears and lack of trust. Participants indicated that fears related to perceived experimentation, harm, immigration status, and lack of clinical trial opportunities within their communities were barriers to participation. On the other hand, free healthcare access, helping family members in the future, and monetary incentives could facilitate participation. We also found differences across themes by language, gender, and place of residence. Findings from our study could inform the development of interventions to enhance recruitment of Mexican-American participants into clinical trials.

  3. Communication Interface for Mexican Spanish Dysarthric Speakers

    Directory of Open Access Journals (Sweden)

    Gladys Bonilla-Enriquez

    2012-03-01

    Full Text Available La disartria es una discapacidad motora del habla caracterizada por debilidad o poca coordinación de los músculos del habla. Esta condición puede ser causada por un infarto, parálisis cerebral, o por una lesión severa en el cerebro. Para mexicanos con esta condición hay muy pocas, si es que hay alguna, tecnologías de asistencia para mejorar sus habilidades sociales de interacción. En este artículo presentamos nuestros avances hacia el desarrollo de una interfazde comunicación para hablantes con disartria cuya lengua materna sea el español mexicano. La metodología propuesta depende de (1 diseño especial de un corpus de entrenamiento con voz normal y recursos limitados, (2 adaptación de usuario estándar, y (3 control de la perplejidad del modelo de lenguaje para lograr alta precisión en el Reconocimiento Automático del Habla (RAH. La interfaz permite al usuario y terapéuta el realizar actividades como adaptación dinámica de usuario, adaptación de vocabulario, y síntesis de texto a voz. Pruebas en vivo fueron realizadas con un usuario con disartria leve, logrando precisiones de 93%-95% para habla espontánea.Dysarthria is a motor speech disorder due to weakness or poor coordination of the speechmuscles. This condition can be caused by a stroke, cerebral palsy, or by a traumatic braininjury. For Mexican people with this condition there are few, if any, assistive technologies to improve their social interaction skills. In this paper we present our advances towards the development of a communication interface for dysarthric speakers whose native language is Mexican Spanish. We propose a methodology that relies on (1 special design of a training normal-speech corpus with limited resources, (2 standard speaker adaptation, and (3 control of language model perplexity, to achieve high Automatic Speech Recognition (ASR accuracy. The interface allows the user and therapist to perform tasks such as dynamic speaker adaptation, vocabulary

  4. The Mexican Health Paradox: Expanding the Explanatory Power of the Acculturation Construct

    Science.gov (United States)

    Horevitz, Elizabeth; Organista, Kurt C.

    2013-01-01

    The Mexican health paradox refers to initially favorable health and mental health outcomes among recent Mexican immigrants to the United States. The subsequent rapid decline in Mexican health outcomes has been attributed to the process of acculturation to U.S. culture. However, the construct of acculturation has come under significant criticism…

  5. Contact with the Dead, Religion, and Death Anxiety among Older Mexican Americans

    Science.gov (United States)

    Krause, Neal; Bastida, Elena

    2012-01-01

    The purpose of this study is to see if contact with the dead is associated with lower death anxiety among older Mexican Americans. The data come from a nationwide survey of older Mexican Americans (N = 1,005). The study model specifies that (a) older Mexican Americans who have experienced contact with the dead are more likely to see the…

  6. Contemporary Fertility Patterns and First-Birth Timing among Mexican-Origin Women

    Science.gov (United States)

    Batson, Christie D.

    2013-01-01

    This article examines first-birth timing among Mexican women in the United States over two birth cohorts. Currently, Mexican women are one of a small group that maintains above-replacement fertility in the United States, contributing to both Mexican population growth and overall national population growth. Yet, the fertility timing of Mexican…

  7. Parents' Promotion of Psychological Autonomy, Psychological Control, and Mexican-American Adolescents' Adjustment

    Science.gov (United States)

    Sher-Censor, Efrat; Parke, Ross D.; Coltrane, Scott

    2011-01-01

    Mexican-American adolescents are at an elevated risk for adjustment difficulties. In an effort to identify parenting practices that can affect the adjustment of Mexican-American youth, the current study examined parents' promotion of psychological autonomy and parents' psychological control as perceived by Mexican-American early adolescents, and…

  8. "Hospital utilization by Mexican migrants returning to Mexico due to health needs".

    Science.gov (United States)

    González-Block, Miguel A; de la Sierra-de la Vega, Luz A

    2011-04-18

    A total of 12.7 million Mexicans reside as migrants in the United States, of whom only 45% have health insurance in this country while access to health insurance by migrants in Mexico is fraught with difficulties. Health insurance has been shown to impact the use of health care in both countries. This paper quantifies hospitalizations by migrants who return from the US seeking medical care in public and private hospitals in the US-Mexico border area and in communities of origin. The proportion of bed utilization and the proportion of hospitalizations in Mexico out of the total expected by migrants in the US were estimated. The universe included 48 Ministry of Health and 47 private hospitals serving municipalities of high or very high migration in Mexico, where 17% of remittance-receiving households are located, as well as 15 public and 159 private hospitals in 10 Mexican cities along the border with the US. Hospitals were sampled through various methods to include 27% of beds. Patients and staff were interviewed and data triangulated to quantify migrants that returned to Mexico seeking medical care. Official hospital discharge statistics and secondary data from migration databases and published statistics were analyzed to identify bed occupancy, general migrant hospitalization rates and the size of the migrant population that maintains close relationships with households in communities of origin. Up to 1609 migrants were admitted to public hospitals (76.6%) and 492 to private hospitals (23.4%) serving municipalities of high and very high migration intensity in 2008. Up to 0.90% of public hospital capacity was used. In the border area up to 908 and 2416 migrants were admitted to public (27.3%) and private (72.7%) hospitals, respectively. Up to 1.18% of public hospital capacity was used. Between 2.4% and 20.4% of the expected hospitalization needs of migrants with dependent households are satisfied through these services. The most common diagnostic categories

  9. "Hospital utilization by Mexican migrants returning to Mexico due to health needs"

    Directory of Open Access Journals (Sweden)

    de la Sierra-de la Vega Luz A

    2011-04-01

    Full Text Available Abstract Background A total of 12.7 million Mexicans reside as migrants in the United States, of whom only 45% have health insurance in this country while access to health insurance by migrants in Mexico is fraught with difficulties. Health insurance has been shown to impact the use of health care in both countries. This paper quantifies hospitalizations by migrants who return from the US seeking medical care in public and private hospitals in the US-Mexico border area and in communities of origin. The proportion of bed utilization and the proportion of hospitalizations in Mexico out of the total expected by migrants in the US were estimated. Methods The universe included 48 Ministry of Health and 47 private hospitals serving municipalities of high or very high migration in Mexico, where 17% of remittance-receiving households are located, as well as 15 public and 159 private hospitals in 10 Mexican cities along the border with the US. Hospitals were sampled through various methods to include 27% of beds. Patients and staff were interviewed and data triangulated to quantify migrants that returned to Mexico seeking medical care. Official hospital discharge statistics and secondary data from migration databases and published statistics were analyzed to identify bed occupancy, general migrant hospitalization rates and the size of the migrant population that maintains close relationships with households in communities of origin. Results Up to 1609 migrants were admitted to public hospitals (76.6% and 492 to private hospitals (23.4% serving municipalities of high and very high migration intensity in 2008. Up to 0.90% of public hospital capacity was used. In the border area up to 908 and 2416 migrants were admitted to public (27.3% and private (72.7% hospitals, respectively. Up to 1.18% of public hospital capacity was used. Between 2.4% and 20.4% of the expected hospitalization needs of migrants with dependent households are satisfied through these

  10. Positive pregnancy outcomes in Mexican immigrants: what can we learn?

    Science.gov (United States)

    Page, Robin L

    2004-01-01

    To provide an integrated review of the literature of potential explanations for better than expected pregnancy outcomes in Mexican immigrants, focusing on socioeconomics, social support, desirability of pregnancy, nutrition, substance use, religion, acculturation, and prenatal care. Computerized searches of MEDLINE and CINAHL databases, as well as reference lists from published articles on low birth weight and prematurity in immigrants and acculturation in immigrants from January 1989 to December 2002. Search terms were Mexican immigrant women, childbearing, and pregnancy outcome, and only English-language articles were reviewed. Literature was selected from refereed publications in the areas of nursing, medicine, public health, family, and sociology. Data were extracted using keywords pertinent to pregnancy outcome in Mexican immigrants. Despite having many of the risk factors for poor pregnancy outcomes, Mexican immigrants have superior birth outcomes when compared to U.S.-born women. Social support, familism, healthy diet, limited use of cigarettes and alcohol, and religion may play a role in improved outcomes. The superior outcomes diminish with the process of acculturation as the individual adapts to her new culture. Low birth weight and prematurity are public health concerns in the United States. Through further study of the factors that lead to superior birth outcomes among Mexican immigrant women, rates of low birth weight and prematurity in the United States may be reduced.

  11. Mobility and International Collaboration: Case of the Mexican Scientific Diaspora.

    Directory of Open Access Journals (Sweden)

    Rafael Marmolejo-Leyva

    Full Text Available We use a data set of Mexican researchers working abroad that are included in the Mexican National System of Researchers (SNI. Our diaspora sample includes 479 researchers, most of them holding postdoctoral positions in mainly seven countries: USA, Great Britain, Germany, France, Spain, Canada and Brazil. Their research output and impact is explored in order to determine their patterns of production, mobility and scientific collaboration as compared with previous studies of the SNI researchers in the periods 1991-2001 and 2003-2009. Our findings confirm that mobility has a strong impact on their international scientific collaboration. We found no substantial influence among the researchers that got their PhD degrees abroad from those trained in Mexican universities. There are significant differences among the areas of knowledge studied: biological sciences, physics and engineering have better production and impact rates than mathematics, geosciences, medicine, agrosciences, chemistry, social sciences and humanities. We found a slight gender difference in research production but Mexican female scientists are underrepresented in our diaspora sample. These findings would have policy implications for the recently established program that will open new academic positions for young Mexican scientists.

  12. Mobility and International Collaboration: Case of the Mexican Scientific Diaspora.

    Science.gov (United States)

    Marmolejo-Leyva, Rafael; Perez-Angon, Miguel Angel; Russell, Jane M

    2015-01-01

    We use a data set of Mexican researchers working abroad that are included in the Mexican National System of Researchers (SNI). Our diaspora sample includes 479 researchers, most of them holding postdoctoral positions in mainly seven countries: USA, Great Britain, Germany, France, Spain, Canada and Brazil. Their research output and impact is explored in order to determine their patterns of production, mobility and scientific collaboration as compared with previous studies of the SNI researchers in the periods 1991-2001 and 2003-2009. Our findings confirm that mobility has a strong impact on their international scientific collaboration. We found no substantial influence among the researchers that got their PhD degrees abroad from those trained in Mexican universities. There are significant differences among the areas of knowledge studied: biological sciences, physics and engineering have better production and impact rates than mathematics, geosciences, medicine, agrosciences, chemistry, social sciences and humanities. We found a slight gender difference in research production but Mexican female scientists are underrepresented in our diaspora sample. These findings would have policy implications for the recently established program that will open new academic positions for young Mexican scientists.

  13. The Mexican mesozoic uranium province: its distribution and metallogeny

    International Nuclear Information System (INIS)

    Bazan B, S.

    1981-01-01

    The distribution of uranium scattered in sedimentary terrains of the continental jurassic such as those found in the Tlaxiaco-Guerrero Basin encourage the outlook for uncovering extensive new deposits of strato-bound uranium belonging to the Mexican mesozoic in other structurally similar intercratonic basins. Stratographic and paleographic structural references define the simultaneous evolution of five sedimentary basins during the Mexican geotechtonic cycle: 1. the Tlaxiaco-Guerrero basin, 2. the Huayacocotla basin, 3. the Gulf of Sabinas basin, 4. the Chihuahua basin and 5. the Sonora basin. From the various lithostratographic formations in them we favourably infer the presence of intermountainous mesozoic concentrations of uranium sediments leached from crystalline precambric packets and from nevadian plutonites and volcanic rocks. During the metallogeny process described under the techtonic evolution of the Mexican structural belt, the presence is established of extensive terciary hydrothermal uranium deposits in the districts of Aldama, Chihuahua; Coneto-El Rodeo, Durango; Vizarron de Montes, Queretaro; Tlaucingo, Puebla; Los Amoles, Sonora; El Picacho, Sonora; Amalia Margarita, Coahuila; etc., scattered in sandstones and sinters of the continental mesozoic and shifted during the postorogenic phase of the Mexican geotectonic cycle. The extensive mesozoic province defined within the Mexican territory favourable to large deposits of uranium, scattered and strato-bound in triassic, jurassic and cretaceous sandstone and sinters, could resolve future demands for energetics within a modified philosophy and resourceful policy of regional mining. (author)

  14. The North American Free Trade Agreement (NAFTA) and Mexican nursing.

    Science.gov (United States)

    Squires, Allison

    2011-03-01

    In the context of nurse migration, experts view trade agreements as either vehicles for facilitating migration or as contributing to brain-drain phenomena. Using a case study design, this study explored the effects of the North American Free Trade Agreement (NAFTA) on the development of Mexican nursing. Drawing results from a general thematic analysis of 48 interviews with Mexican nurses and 410 primary and secondary sources, findings show that NAFTA changed the relationship between the State and Mexican nursing. The changed relationship improved the infrastructure capable of producing and monitoring nursing human resources in Mexico. It did not lead to the mass migration of Mexican nurses to the United States and Canada. At the same time, the economic instability provoked by the peso crisis of 1995 slowed the implementation of planned advances. Subsequent neoliberal reforms decreased nurses' security as workers by minimizing access to full-time positions with benefits, and decreased wages. This article discusses the linkages of these events and the effects on Mexican nurses and the development of the profession. The findings have implications for nursing human resources policy-making and trade in services.

  15. Economic reform, energy, and development: the case of Mexican manufacturing

    International Nuclear Information System (INIS)

    Aguayo, Francisco; Gallagher, K.P.

    2005-01-01

    Given increasing concern over global climate change and national security there is a burgeoning interest in examining the relationship between economic growth and energy use in developed and developing countries. More specifically, decoupling energy use per unit of gross domestic product (GDP) has fast come to be seen as in the interests of national economies and the world as a whole. Recent attention has been paid to the dramatic decreases in the energy intensity of the Chinese economy, which fell by 55% between 1975 and 1995. Do other developing economies follow similar trajectories? This paper examines the energy intensity of the Mexican economy for the period 1988-1998. Although the long-term trend in Mexican energy intensity is rising, the energy intensity of the Mexican economy began to decline in 1988. This paper explores the factors that have contributed to this reduction. Diminishing Mexican energy use per unit of GDP has been driven by significant decreases in industrial energy intensity. We show that these changes have resulted from changes in the composition of Mexican industrial structure, and technological change

  16. A case study of the effects of social experiences on the science identity formation of Mexican American females in high school chemistry

    Science.gov (United States)

    Beeton, Renee P.

    Mexican Americans are a rapidly growing ethnic group in the United States. However, they are noticeably absent from physical science fields. Little research has explored the experiences of Mexican American girls in high school chemistry. The theories of identity based on communities of practice and multicultural feminism framed this year-long case study of nine Mexican American girls in a high school chemistry course. This study explored the social encounters and experiences that shaped the participants' identities and how their views of themselves affected their attitudes towards high school chemistry and future science careers. Data collection included a focus group and in-depth interviews with the participants, classroom observations, and teacher interviews. Five main identities influenced the participants' potential to become a scientist: ethnic, gender, science, student, and college. Mexican ethnic identity was the overarching identity; however gender also influenced the participants' other identities. The participants were aware of ethnic gender stereotypes that might hinder them from being successful in science. Also, ethnic factors, such as citizenship and abilities to receive financial aid limited their views of themselves as chemists. Participatory science, student, and school identities were all needed in order for the participants to be potential scientists. Family expectations, authentic relationships with teachers, and personal connections were important factors in the development of these participatory identities.

  17. The effect of smelting time and composition of palm kernel shell charcoal reductant toward extractive Pomalaa nickel laterite ore in mini electric arc furnace

    Science.gov (United States)

    Sihotang, Iqbal Huda; Supriyatna, Yayat Iman; Ismail, Ika; Sulistijono

    2018-04-01

    Indonesia is a country that is rich in natural resources. Being a third country which has a nickel laterite ore in the world after New Caledonia and Philippines. However, the processing of nickel laterite ore to increase its levels in Indonesia is still lacking. In the processing of nickel laterite ore into metal, it can be processed by pyrometallurgy method that typically use coal as a reductant. However, coal is a non-renewable energy and have high enough levels of pollution. One potentially replace is the biomass, that is a renewable energy. Palm kernel shell are biomass that can be used as a reductant because it has a fairly high fix carbon content. This research aims to make nickel laterite ores become metal using palm kernel shell charcoal as reductant in mini electric arc furnace. The result show that the best smelting time of this research is 60 minutes with the best composition of the reductant is 2,000 gram.

  18. Determination of the elemental composition of aerosol samples in the working environment of a secondary lead smelting company in Nigeria using EDXRF technique

    International Nuclear Information System (INIS)

    Obiajunwa, E.I.; Johnson-Fatokun, F.O.; Olaniyi, H.B.; Olowole, A.F.

    2002-01-01

    Energy dispersive X-ray fluorescence technique was employed to determine the concentrations of elements in aerosol samples collected in the working environment of a secondary lead smelting company in Nigeria. Sampling was done using Whatman-41 cellulose filters mounted in Negretti air samplers at 10 locations within the factory. The concentrations of eight elements (K, Ca, Ti, Mn, Fe, Cu, Zn and Pb) were determined. The TSP values ranged from 70 to 7963 μg/m 3 and the concentration of Pb was found to be between 2.98 and 538.47 μg/m 3 . The high Pb concentration is a danger signal to the health of the factory workers

  19. Standardization of the process of smelting for sands with self-forgeling resins in the Military Industry Santa Bárbara Factory

    Directory of Open Access Journals (Sweden)

    Lina Consuelo Carvajal-Fernández

    2014-12-01

    Full Text Available This article describes the standardization of the smelting process for sands with self-forgeling resins in the Military Industry Santa Barbara Factory. The molding process was studied in the Smelter for six months, to set standards for workforce and raw materials, so that would allow truthfully evaluate the costs per kilogram of casting. 41 pieces of civil and military sectors throughout the development of the project were worked. Finally both standards were evaluated, labor as raw material for different parts, with results was evidenced improved process, essentially in workforce, while in raw material standards did not show significantly change, in this case is corroborated that existing ones are applicable to the process

  20. [Mexican National Consensus on Assisted Reproduction Treatment].

    Science.gov (United States)

    Kably Ambe, Alberto; López Ortiz, Carlos Salazar; Serviere Zaragoza, Claudio; Velázquez Cornejo, Gerardo; Pérez Peña, Efrain; Santos Haliscack, Roberto; Luna Rojas, Martha; Valerio, Emilio; Santana, Héctor; Gaviño Gaviño, Fernando

    2012-09-01

    It is estimated that 15% of couples living in industrialized countries are infertile, ie have failed to conceive, reproductive age, after 12 months ormore of regular intercourse without contraception. During the past decade has increased the demand for fertility treatments because they believe are moreeffective now. To unify the therapeutic approach and service to patients and set a precedent for a Mexican Official Standard respect and support for the legislation of these procedures. Consensus by technical experts group panel with the participation of 34 national centers accredited for use in assisted reproduction. He organized seven workshops with the following themes: 1) selection of patients for assisted reproduction treatment, 2) schemes controlled ovarian stimulation for assisted reproduction techniques of high complexity, 3) preparation and egg retrieval technique, 4) transferembryo; 5) luteal phase supplementation; 6) indications and techniques of cryopreservation and 7) informed consent. Each table had a coordinator who wrote and presented the findings to the full, it made a number of observations until they reached unanimity of criteria, which are reflected in this document. Patient selection for assisted reproduction techniques is the first step of the process. Proper selection lead to success, in the same way that a bad pick up for failure. In the case of egg donation the most important recommendation is that only one to two embryos transferred in order to reduce multiple pregnancy rates and maintaining high pregnancy rates.

  1. Mexican demand for US natural gas

    International Nuclear Information System (INIS)

    Kanter, M.A.; Kier, P.H.

    1993-09-01

    This study describes the Mexican natural gas industry as it exists today and the factors that have shaped the evolution of the industry in the past or that are expected to influence its progress; it also projects production and use of natural gas and estimates the market for exports of natural gas from the United States to Mexico. The study looks ahead to two periods, a near term (1993--1995) and an intermediate term (1996--2000). The bases for estimates under two scenarios are described. Under the conservative scenario, exports of natural gas from the United States would decrease from the 1992 level of 250 million cubic feet per day (MMCF/d), would return to that level by 1995, and would reach about 980 MMCF/D by 2000. Under the more optimistic scenario, exports would decrease in 1993 and would recover and rise to about 360 MMCF/D in 1995 and to 1,920 MMCF/D in 2000

  2. The Mexican Fruit Fly Eradication Programme

    Energy Technology Data Exchange (ETDEWEB)

    Reyes F, Jesus; Santiago M, Guillermo; Hernandez M, Porfirio [Comision Nacional de Sanidad Agropecuaria (Mexico)

    2000-07-01

    The goal of the Mexican Fruit Fly Eradication Programme is to control, suppress or eradicate from Mexico four species of fruit flies of economic and quarantine importance (Anastrepha ludens Loew, A. obliqua Macquart, A. serpentina Wied. and A. striata Schiner). These pests cause damage amounting to US$710 million per year. In addition to this cost, there are other expenses from pest control actions and the loss of international markets, because fruit importing countries have established stringent quarantine measures to restrict the entry of these pests. For purposes of the programme's implementation, Mexico was divided into three working zones, defined by agro-ecological characteristics, the number of fruit fly species present and the size of fruit growing regions. In addition, a cost:benefit analysis was carried out which indicated that the rate of return, in a 12-year time frame, might be as much as 33:1 in Northern Mexico, and 17:1 in the rest of the country, for an area over 100,000 hectares. Eradication technology involves: 1) surveys of pest populations by trapping and host fruit harvesting to monitor the presence and density of fruit flies, 2) reduction of pest populations applying cultural practices and using selective bait sprays, 3) mass release of sterile flies and augmentative release of parasitoids to eliminate populations and, 4) enforcement of quarantine measures to protect fruit fly free areas.

  3. The Mexican Fruit Fly Eradication Programme

    International Nuclear Information System (INIS)

    Reyes F, Jesus; Santiago M, Guillermo; Hernandez M, Porfirio

    2000-01-01

    The goal of the Mexican Fruit Fly Eradication Programme is to control, suppress or eradicate from Mexico four species of fruit flies of economic and quarantine importance (Anastrepha ludens Loew, A. obliqua Macquart, A. serpentina Wied. and A. striata Schiner). These pests cause damage amounting to US$710 million per year. In addition to this cost, there are other expenses from pest control actions and the loss of international markets, because fruit importing countries have established stringent quarantine measures to restrict the entry of these pests. For purposes of the programme's implementation, Mexico was divided into three working zones, defined by agro-ecological characteristics, the number of fruit fly species present and the size of fruit growing regions. In addition, a cost:benefit analysis was carried out which indicated that the rate of return, in a 12-year time frame, might be as much as 33:1 in Northern Mexico, and 17:1 in the rest of the country, for an area over 100,000 hectares. Eradication technology involves: 1) surveys of pest populations by trapping and host fruit harvesting to monitor the presence and density of fruit flies, 2) reduction of pest populations applying cultural practices and using selective bait sprays, 3) mass release of sterile flies and augmentative release of parasitoids to eliminate populations and, 4) enforcement of quarantine measures to protect fruit fly free areas

  4. The boson and the Mexican hat

    International Nuclear Information System (INIS)

    Cohen-Tannoudji, Gilles; Spiro, Michel

    2013-01-01

    This document contains a brief presentation and the table of contents of a book in which the authors who reports the evolutions of the contemporary astrophysics theories, and the scientific, technological and human adventure of the CERN until the discovery of the Higgs boson by means of the LHC. The Mexican hat is the name given to the mechanism by which the boson reports the origin of the elementary particle masses. The first part reports the boson genealogy: the law of universal gravitation, the relativity and the limits of the rational mechanics, quantum mechanics, and particle physics at the end of the 1960's. The second part addresses the necessary existence of the boson: quantum electrodynamics, from the quark model to quantum chromo-dynamics, from intermediate bosons to the Brout, Englert and Higgs boson, the standard cosmology model. The third part deals with the perspectives opened by the existence and evidence of the boson: the search for physics theory and models beyond standard models

  5. Cobalt 60 cation exchange with mexican clays

    International Nuclear Information System (INIS)

    Nava Galve, R.G.

    1993-01-01

    Mexican clays can be used to remove radioactive elements from contaminated aqueous solutions. Cation exchange experiments were performed with 60 Co radioactive solution. In the present work the effect of contact time on the sorption of Co 2+ was studied. The contact time in hydrated montmorillonite was from 5 to 120 minutes and in dehydrated montmorillonite 5 to 1400 minutes. The Co 2+ uptake value was, in hydrated montmorillonite, between 0.3 to 0.85 m eq/g and in dehydrated montmorillonite, between 0.6 to 1.40 m eq/g. The experiments were done in a pH 5.1 to 5.7 and normal conditions. XRD patterns were used to characterize the samples. The crystallinity was determined by X-ray Diffraction and it was maintained before and after the cation exchange. DTA thermo grams showed the temperatures of the lost humidity and crystallization water. Finally, was observed that dehydrated montmorillonite adsorb more cobalt than hydrated montmorillonite. (Author)

  6. Cytotoxic activity of four Mexican medicinal plants.

    Science.gov (United States)

    Vega-Avila, Elisa; Espejo-Serna, Adolfo; Alarcón-Aguilar, Francisco; Velasco-Lezama, Rodolfo

    2009-01-01

    Ibervillea sonorae Greene, Cucurbita ficifolia Bouché, Tagetes lucida Cav and Justicia spicigera Scheltdd are Mexican native plants used in the treatment of different illnesses. The ethanolic extract of J. spicigera and T. lucida as well as aqueous extracts from I. sonorae, C. ficifolia, T. lucida and J. spicigera were investigated using sulforhodamine B assay. These extracts were assessed using two cell line: T47D (Human Breast cancer) and HeLa (Human cervix cancer). Colchicine was used as the positive control. Data are presented as the dose that inhibited 50% control growth (ED50). All of the assessed extracts were cytotoxic (ED50 < 20 microg/ml) against T47D cell line, meanwhile only the aqueous extract from T. lucida and the ethanolic extract from J. spicigera were cytotoxic to HeLa cell line. Ethanolic extract from J. spicigera presented the best cytotoxic effect. The cytotoxic activity of J. spicigera correlated with one of the popular uses, the treatment of cancer.

  7. Tobacco brand preference among Mexican adolescents.

    Science.gov (United States)

    West, Joshua H; Hall, P Cougar; Page, Randy M; Trinidad, Dennis R; Lindsay, Gordon B

    2012-01-01

    Advertising plays a major role in smoking behavior and forming brand preferences. Additionally, the most advertised tobacco brands have also been the most preferred. Maintaining brand loyalty in Latin America remains a priority for the tobacco industry. The purpose of this study was to explore tobacco brand preference trends from 2003 to 2006, and explore marketing and advertising factors that might be associated with these trends. Data for this study came from Mexican adolescents residing in cities that participated in the Global Youth Tobacco Survey in both 2003 and 2006 and reported smoking either Marlboro or Camel cigarettes in the past 30 days. Respondents reported the brand name of their preferred cigarette during the past 30 days. Multivariate regression analysis was used to determine differences by brand preference and exposure to tobacco marketing and advertising, which was assessed using six items. In 2003, most adolescents preferred Marlboro. By 2006, older boys preferred Camel cigarettes to Marlboro, while girls' preference for Camel was similar to their preference for Marlboro. Adolescents that preferred Camel cigarettes in 2003 also reported greater exposure to tobacco marketing and advertising. Findings indicate that there are ongoing shifts in youth brand preference in Mexico, and that these shifts might be related to marketing and advertising practices. There is an ongoing need for monitoring marketing and advertising practices in an effort to protect adolescents from tobacco company exploits.

  8. Resegmentation in the Mexican axolotl, Ambystoma mexicanum.

    Science.gov (United States)

    Piekarski, Nadine; Olsson, Lennart

    2014-02-01

    The segmental series of somites in the vertebrate embryo gives rise to the axial skeleton. In amniote models, single vertebrae are derived from the sclerotome of two adjacent somites. This process, known as resegmentation, is well-studied using the quail-chick chimeric system, but the presumed generality of resegmentation across vertebrates remains poorly evaluated. Resegmentation has been questioned in anamniotes, given that the sclerotome is much smaller and lacks obvious differentiation between cranial and caudal portions. Here, we provide the first experimental evidence that resegmentation does occur in a species of amphibian. Fate mapping of individual somites in the Mexican axolotl (Ambystoma mexicanum) revealed that individual vertebrae receive cells from two adjacent somites as in the chicken. These findings suggest that large size and segmentation of the sclerotome into distinct cranial and caudal portions are not requirements for resegmentation. Our results, in addition to those for zebrafish, indicate that resegmentation is a general process in building the vertebral column in vertebrates, although it may be achieved in different ways in different groups. Copyright © 2013 Wiley Periodicals, Inc.

  9. Mexican demand for US natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Kanter, M.A.; Kier, P.H.

    1993-09-01

    This study describes the Mexican natural gas industry as it exists today and the factors that have shaped the evolution of the industry in the past or that are expected to influence its progress; it also projects production and use of natural gas and estimates the market for exports of natural gas from the United States to Mexico. The study looks ahead to two periods, a near term (1993--1995) and an intermediate term (1996--2000). The bases for estimates under two scenarios are described. Under the conservative scenario, exports of natural gas from the United States would decrease from the 1992 level of 250 million cubic feet per day (MMCF/d), would return to that level by 1995, and would reach about 980 MMCF/D by 2000. Under the more optimistic scenario, exports would decrease in 1993 and would recover and rise to about 360 MMCF/D in 1995 and to 1,920 MMCF/D in 2000.

  10. Effect of Calcium Oxide on the Crushing Strength, Reduction, and Smelting Performance of High-Chromium Vanadium–Titanium Magnetite Pellets

    Directory of Open Access Journals (Sweden)

    Gongjin Cheng

    2017-05-01

    Full Text Available The effect of calcium oxide on the crushing strength, reduction, and smelting performance of high-chromium vanadium–titanium magnetite pellets (HCVTMP was studied in this work. The main characterization methods of an electronic universal testing machine (EUTM, X-ray fluorescent (XRF, inductively-coupled plasma-atomic emission spectroscopy (ICP-AES, X-ray diffraction (XRD, and scanning electron microscope-energy disperse spectroscopy (SEM-EDS were employed. The crushing strength was affected by the mineral phases generated during oxidative baking and the subsequently-formed pellet microstructures owing to CaO addition. The reduction and smelting properties of HCVTMP with different CaO additives were measured and characterized with different softening-melting-dripping indices. Although HCVTMP showed the highest crushing strength with CaO addition of ca. 2 wt %, more CaO addition may be needed to achieve high permeability of the furnace burdens and a good separation condition of the slag and melted iron. In the formation process of the slag and melted iron, it can be determined that CaO could have a relationship with the transformation behavior of Cr, V, and Ti to some extent, with respect to the predominant chemical composition analysis of ICP-AES and XRF. With the microscopic examination, the restraining formation of Ti(C,N and the promoting formation of CaTiO3 are in accordance with the improved melting-dripping indices, including the decrease of the maximum external static load and gas permeability, and the increase of the melting-dripping zone and dripping difficulty.

  11. Multi-criteria analysis of soil pollution by heavy metals in the vicinity of the Copper Smelting Plant in Bor (Serbia

    Directory of Open Access Journals (Sweden)

    NEVENKA PETROVIĆ

    2011-04-01

    Full Text Available This study highlights the consequences on soil pollution of one hund­red years of manufacturing in the Copper Mining and Smelting Complex RTB-Bor (Serbia. Soil sediments were taken via a probe from the surface layer of the soil at twelve different measuring points. The measuring points were all within 20 km of the smelting plant, which included both urban and rural zones. Soil sampling was performed using a soil core sampler in such way that a core of a soil of radius 5 cm and depth of 30 cm was removed. Subsequently, the samples were analyzed for pH and heavy metal concentrations (Cu, Pb, As, Cd, Mn, Ni and Hg using different spectrometric methods. The obtained results for the heavy metal contents in the samples show high values: 2,540 mg kg-1 Cu; 230 mg kg-1 Pb; 6 mg kg-1 Cd; 530 mg kg-1 Ni; 1,300 mg kg-1 Mn; 260 mg kg-1 As and 0.3 mg kg-1 Hg. In this study, critical zones of polluted soil were iden­tified and ranked according to their metal contents by the multi-criteria deci­sion method Preference Organization Method for Enrichment Evaluation/Geo­metrical Analysis for Interactive Assistance – PROMETHEE/GAIA, which is the preferred multivariate method commonly used in chemometric studies. The ranking results clearly showed that the most polluted zones are at locations holding the vital functions of the town. Therefore, due to the high bioavail­abi­lity of heavy metals through com­plex reactions with organic species in the sediments, consequences for human health could drastically emerge if these metals enter the food chain.

  12. PREFACE: The XI Mexican School on Particles and Fields

    Science.gov (United States)

    2005-01-01

    The XI Mexican School on Particles and Fields took place on 2-13 August 2004, in the city of Xalapa, Veracruz, México. The School continued with the tradition of promoting High Energy Physics among the younger generation in Mexico. Thus, it was aimed specifically at graduate students and postdocs. The School consisted of several courses delivered by international experts on subjects of current interest to the scientific community. The length of each course was of six to eight hours, English being the language of instruction. A novelty in this edition of the School was its total duration (two weeks as opposed to one), the number of hours assigned to one subject, and the addition of some experimental courses for the students to overcome their inhibitions of a direct encounter with the equipment and its usage. There were also a few overview talks delivered by local experts on the current status of some of the research fields actively pursued in Mexico. The XI-MSPF was organized by the Particles and Fields Division of the Mexican Physical Society. It was generously sponsored by several institutions: Universidad de Veracruz, Universidad Nacional Autónoma de México, Universidad Michoacana de San Nicolás de Hidalgo, Centro de Investigaciones y Estudios Avanzados del IPN (CINVESTAV) and Consejo Nacional de Ciencia y Tecnología (CONACyT). We are very grateful to Dr Raúl Arias Lovillo, Dr Víctor Manuel Alcaráz Romero, Dr Asdrúbal Flóres López and Mtro Walter Saiz González, head of the Academic Secretariat, Director and Subdirector of the Office of Scientific Research and Director of the Division of Exact Sciences of the University of Veracruz, respectively, for their invaluable support in all senses to our Summer School. We also appreciate the important and useful assistance provided by Dr Rubén Bernardo Morante López, Director of the Museum of Anthropology of Xalapa, and Dr Héctor Coronel Brizio of the Secretariat of Education and Culture of the state of

  13. Espanol mexicano y espanol chicano: Problemas y propuestas fundamentales (Mexican Spanish and Chicano Spanish: Fundamental Problems and Proposals).

    Science.gov (United States)

    Hidalgo, Margarita

    1987-01-01

    Discusses the rise of Mexican Spanish as a distinct variety of Spanish and describes the regional and social dialects of contemporary Mexican Spanish. Although countless similarities exist between Mexican Spanish and the Chicano Spanish spoken in the southwestern United States, Mexican Spanish shows greater variability. (GR)

  14. Moving In and Out of Bilingualism: Investigating Native Language Maintenance and Shift in Mexican-Descent Children. Research Report: 6.

    Science.gov (United States)

    Pease-Alvarez, Lucinda

    A study investigated patterns and influences in Mexican-American children's Spanish language maintenance and shift toward English dominance or monolingualism. Subjects were 64 Mexican-descent children, ages 8-9, of varying immigration backgrounds (Mexican-born, U.S.-born of Mexican-born parents, U.S.-born of U.S.-born parents), and their families…

  15. Occupy Public Education: A Community's Struggle for Educational Resources in the Era of Privatization

    Science.gov (United States)

    Cortez, Gabriel Alejandro

    2013-01-01

    This case study investigates globalization and its growing impact on public school services to disenfranchised urban communities. Using a combination of periodicals, internal documents, and observations from the author, the research provides a narrative analysis of relations between community leaders of a low-income, Mexican immigrant community…

  16. Cultural Health Capital on the margins: Cultural resources for navigating healthcare in communities with limited access.

    Science.gov (United States)

    Madden, Erin Fanning

    2015-05-01

    Communities struggling with access to healthcare in the U.S. are often considered to be disadvantaged and lacking in resources. Yet, these communities develop and nurture valuable strategies for healthcare access that are underrecognized by health scholars. Combining medical sociology and critical race theory perspectives on cultural capital, this paper examines the health-relevant cultural resources, or Cultural Health Capital, in South Texas Mexican American border communities. Ethnographic data collected during 2011-2013 in Cameron and Hidalgo counties on the U.S.-Mexico border provide empirical evidence for expanding existing notions of health-relevant cultural capital. These Mexican American communities use a range of cultural resources to manage healthcare exclusion and negotiate care in alternative healthcare spaces like community clinics, flea markets and Mexican pharmacies. Navigational, social, familial, and linguistic skills and knowledge are used to access doctors and prescription drugs in these spaces despite social barriers to mainstream healthcare (e.g. cost, English language skills, etc.). Cultural capital used in marginalized communities to navigate limited healthcare options may not always fully counteract healthcare exclusion. Nevertheless, recognizing the cultural resources used in Mexican American communities to facilitate healthcare challenges deficit views and yields important findings for policymakers, healthcare providers, and advocates seeking to capitalize on community resources to improve healthcare access. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Voices of Youth: Podcasting as a Means for Inquiry-Based Community Engagement

    Science.gov (United States)

    Bruce, Bertram; Lin, Ching-Chiu

    2009-01-01

    A youth community informatics (YCI) research project intersected an inquiry learning model with the making of audiovisual podcasts to foster personal growth and community engagement in a group of Mexican American youth enrolled in an afterschool program. Specifically, the article describes the cycle of inquiry together with the development of a…

  18. Acculturation and Life Satisfaction Among Immigrant Mexican Adults

    Directory of Open Access Journals (Sweden)

    Flavio F. Marsiglia

    2013-09-01

    Full Text Available The numbers of Mexican Americans living in the United States, many of whom are first generation immigrants, are increasing. The process of immigration and acculturation can be accompanied by stress, as an individual attempts to reconcile two potentially competing sets of norms and values and to navigate a new social terrain. However, the outcomes of studies investigating the relationship between levels of acculturation and well-being are mixed. To further investigate the dynamic of acculturation, this article will address the impact of acculturation and familismo, on reported life satisfaction and resilience among Mexican American adults living in the Southwest (N=307, the majority (89% of which are immigrants. The findings indicate that bilingual individuals report significantly higher levels of life satisfaction and resilience than their Spanish-speaking counterparts do. Speaking primarily English only predicted higher levels of resilience but not life satisfaction. Implications for social work practice with Mexican American immigrants are discussed.

  19. [Observational study of craniofacial growth and development in Mexican children].

    Science.gov (United States)

    Fijikami, T K; Cedeño Pacheco, E

    1991-01-01

    The election of a investigation about craniofacial growing and development in Mexican children, was done due to a lack of national information in this rubric and as a fundamental part of the "growing and development in the scholastic" module of the Universidad Autónoma Metropolitana-Xochimilco, which work hypothesis was that "craniofacial growing and development in Mexican, 6 to 12 children in Xochimilco area are due to nutritional deficiency, second dentition eruption delay and dental maloclution "which was totality confirmed in a 100 Mexican facial characteristic children field work study, with cephalometric studies which permit to determine the craniofacial growing standard. This study was corroborated with a 40 children, 4 years later follow up.

  20. Volunteer work in the church among older Mexican Americans.

    Science.gov (United States)

    Krause, Neal; Hayward, R David

    2012-07-01

    The purpose of this study is to identify the factors that influence the amount of volunteer work that older Mexican Americans perform in the place where they worship. The relationship between religion and volunteering is viewed from a social identity perspective. Data from a nationally representative sample of older Mexican Americans suggest that Evangelical/Pentecostal church members spend more time performing volunteer work at church than older Mexican Americans who affiliate with other denominations. Moreover, the findings indicate that the difference in the amount of volunteering between the two groups can largely be explained by differences in the nature of the spiritual support that Evangelical/Pentecostal receive from their fellow church members as well as depth of their commitment to their faith.

  1. Identifying Strategic Groups: An Assessment in Mexican Franchises

    Directory of Open Access Journals (Sweden)

    Cesario Armando Flores Villanueva

    2017-07-01

    Full Text Available The formation of strategic groups in the franchising sector has been previously documented in the context of different countries. Our proposal is the franchise industry in Mexico should be formed by groups of differentiated franchisors. The identification and analysis of the different strategic groups formed in the franchise system of the Mexican market is the objective of this research. Our evaluation was performed using the factor analysis technique in a sample of 167 franchises of national origin. Seven strategic dimensions supported by the theory of scarce resources and agency theory make up the existence of differentiated groups of franchisors in the Mexican market. Our research confirmed the identification of five strategic groups called: rapid growth, converters, experienced and international franchisors, high entry fees and expensive conservatives, which use differentiated strategies to compete in the Mexican market.

  2. Scale and scope economies in Mexican private medical units.

    Science.gov (United States)

    Keith, Jorge; Prior, Diego

    2014-01-01

    To evaluate technical efficiency and potential presence of scale and scope economies in Mexican private medical units (PMU) that will improve management decisions. We used data envelopment analysis methods with inputs and outputs for 2 105 Mexican PMU published in 2010 by the Instituto Nacional de Estadística y Geografía from the "Estadística de Unidades Médicas Privadas con Servicio de Hospitalización (PEC-6-20-A)" questionnaire. The application of the models used in the paper found that there is a marginal presence of economies of scale and scope in Mexican PMU. PMU in Mexico must focus to deliver their services on a diversified structure to achieve technical efficiency.

  3. Scale and scope economies in Mexican private medical units

    Directory of Open Access Journals (Sweden)

    Jorge Keith

    2014-07-01

    Full Text Available Objective. To evaluate technical efficiency and potential presence of scale and scope economies in Mexican private medical units (PMU that will improve management decisions. Materials and methods. We used data envelopment analysis methods with inputs and outputs for 2 105 Mexican PMU published in 2010 by the Instituto Nacional de Estadística y Geografía from the “Estadística de Unidades Médicas Privadas con Servicio de Hospitalización (PEC-6-20-A” questionnaire. Results. The application of the models used in the paper found that there is a marginal presence of economies of scale and scope in Mexican PMU. Conclusions. PMU in Mexico must focus to deliver their services on a diversified structure to achieve technical efficiency.

  4. Training in the Mexican company: a study of job training

    Directory of Open Access Journals (Sweden)

    Alma Lilia Sapién Aguilar

    2014-12-01

    Full Text Available The processes of training and instruction in a medium-sized Mexican company are not being understood as an investment that contributes to business success.The aim of this study was to analyze these processes. The methodological approach was exploratory and descriptive with a non-experimental or ex post facto design. The Mexican Business Information System was consulted and 17 medium-sized companies in the industrial sector were randomly chosen. The results indicated that in the median Mexican company decisive actions must be taken in order to achieve that training and instruction are no longer seen as an unnecessary expense. They need to be understood as the best investment one can make in human resources. Therefore, training and instruction must become a part of the work culture of any organization.

  5. A review of the Mexican national innovation system

    Directory of Open Access Journals (Sweden)

    Samantha Rullán

    2015-12-01

    Full Text Available Governments and business leaders are increasingly aware of the role that innovation plays in economic growth, development and competitiveness. There are imperative challenges for Latin American countries, among them, poverty, social inclusion, sustainable development, climate change, natural disasters, productivity, improve the quality of education and health. Innovations are essential to drive economic growth and prosperity in the region. According to the Global Innovation Index (2015, Mexico is ranked 57th. Most of the research on innovation performance is mostly focused on technological innovation. Therefore, the main variables used, such as patents and number of scientific publications, do not always reflect the other types of innovations (i.e. business model, organizational, etc. that are developing in emerging markets. The aim of this paper is to analyze the Mexican innovation system using a broad concept with a focus on other types of innovation including cultural aspects to identify the main characteristics that distinguish and determine how innovation in Mexico is formed. Although the Mexican government has improved its institutional structure for innovation and its support policies, they need to evaluate programs and adjust incentive schemes based on performance to improve their innovation policy. Purpose – The purpose of this paper is to examine the Mexican National Innovation System using a broad concept with a focus on other types of innovation and including cultural aspects to identify some of the main characteristics that determine how innovation in Mexico is formed. Design/methodology/approach – The national innovation systems framework is used to review the Mexican innovation policy.A review of relevant literature on national innovation systems and Mexican innovation policies with data from the Global Innovation Index and INEGI were used for this paper. Findings – Higher private investment in R&D is needed to enhance

  6. Employer Sanctions and the Wages of Mexican Immigrants

    Directory of Open Access Journals (Sweden)

    Peter Brownell

    2017-07-01

    Full Text Available Wage differences between authorized and unauthorized Mexican immigrants can be explained by human capital factors prior to the 1986 passage of employer sanctions, which prohibited knowingly hiring unauthorized aliens. However, a significant post-1986 wage differential has been interpreted as employers “passing along” expected costs of sanctions through lower wages for unauthorized immigrants. I test this explanation using administrative data on employer sanctions enforcement, finding employer sanctions enforcement levels are related to Mexican immigrants’ wages but have no statistically significant differential effect based on legal status. Estimated savings to employers due to the pay gap are orders of magnitude larger than actual fines.

  7. Social and cultural influences among Mexican border entrepreneurs.

    Science.gov (United States)

    Díaz Bretones, Francisco; Cappello, Héctor M; Garcia, Pedro A

    2009-06-01

    Social and cultural conditions (including U.S. border and inland influence, role models within the family, and educational background) which affect locus of control and achievement motivation among Mexican entrepreneurs were explored among 64 selected entrepreneurs in two Mexican towns, one on the Mexico-U.S. border, the other located inland. Analyses showed that the border subsample scored higher on External locus of control; however, in both subsamples the father was an important element in the locus of control variable and the entrepreneur status. No statistically significant mean difference was noted for achievement motivation. Practical applications and limitations are discussed.

  8. Immigration and Wage Dynamics: Evidence from the Mexican Peso Crisis

    OpenAIRE

    Monras , Joan

    2015-01-01

    How does the US labor market absorb low-skilled immigration? I address this question using the 1995 Mexican Peso Crisis, an exogenous push factor that raised Mexican migration to the US. In the short run, high-immigration states see their low-skilled labor force increase and native low-skilled wages decrease, with an implied local labor demand elasticity of -.7. Internal relocation dissipates this shock spatially. In the long run, the only lasting consequences are for low-skilled natives who ...

  9. Conservation of Mexican wetlands: role of the North American Wetlands Conservation Act

    Science.gov (United States)

    Wilson, M.H.; Ryan, D.A.

    1997-01-01

    Mexico's wetlands support a tremendous biological diversity and provide significant natural resource benefits to local communities. Because they are also critical stopover and wintering grounds for much of North America's waterfowl and other migratory birds, Mexico has become an important participant in continental efforts to conserve these resources through the North American Wetlands Conservation Act. Funding from the Act has supported partnerships in a number of Mexico's priority wetlands to conduct data analyses and dissemination, mapping, environmental education, wetland restoration, development of sustainable economic alternatives for local people, and reserve planning and management. These partnerships, with the close involvement of Mexico's Federal Government authority, the Instituto Nacional de Ecologia, have advanced conservation in a uniquely Mexican model that differs from that employed in the United States and Canada.

  10. Proceedings of the 4. National Congress of the Mexican Society of Radiological Safety C.A

    International Nuclear Information System (INIS)

    1991-01-01

    In these sessions it had the participation of personalities of diverse internationally grateful organizations, with exhibitions about the situation of the nuclear industry of power, the applications of the radiations and the radiological safety in the international context. Also its were presented works about Emergency plans in Nuclear facilities and plants, Nuclear medicine, Food processing, Thermal neutrons, Neutron dosimetry, Charged particles, Thermoluminescence, Industrial radiography, Radiation monitoring, all of them with the participation of specialists with international prestige. The 41 works that are presented in the technical sessions come from Spanish, Brazilian, Greek and Mexican grateful institutions. All they are a sample of the intense activity in investigation and development in the areas of the nuclear industry as of the radiological safety. This congress reveals the impulse that the nuclear community grants to the formation of human resources

  11. Study protocol: intervention in maternal perception of preschoolers' weight among Mexican and Mexican-American mothers.

    Science.gov (United States)

    Flores-Peña, Yolanda; He, Meizi; Sosa, Erica T; Avila-Alpirez, Hermelinda; Trejo-Ortiz, Perla M

    2018-05-30

    Childhood obesity is a public health issue negatively affecting children's physical and psychosocial health. Mothers are children's primary caregivers, thus key players in childhood obesity prevention. Studies have indicated that mothers underestimate their children's weight. If mothers are unaware of their children's weight problem, they are less likely to participate in activities preventing and treating excess weight. The "Healthy Change" intervention is designed to change maternal perception of child's weight (MPCW) through peer-led group health education in childcare settings. The "Healthy Change" is a multicenter two-arm randomized trial in four centers. Three centers are in Mexican States (Nuevo Leon, Tamaulipas, and Zacatecas). The fourth center is in San Antonio, Texas, USA. A total of 360 mother-child pairs (90 pairs per center) are to be randomly and evenly allocated to either the intervention or the control group. Intervention group will receive four-session group obesity prevention education. Control group will receive a four-session personal and food hygiene education. The education is delivered by trained peer-mother promotoras. Data will be collected using questionnaires and focus groups. The primary outcome is a change in proportion of mothers with accurate MPCW. Secondary outcomes include change in maternal feeding styles and practices, maternal self-efficacy and actions for managing child excessive weight gain. McNemar's Test will be used to test the primary outcome. The GLM Univariate procedure will be used to determine intervention effects on secondary outcomes. The models will include the secondary outcome measures as the dependent variables, treatment condition (intervention/control) as the fixed factor, and confounding factors (e.g., mother's education, children's gender and age) as covariates. Sub-analyses will be performed to compare intervention effects on primary and secondary outcomes between the samples from Mexico and Texas, USA

  12. Development of the Mexican electric power sector

    International Nuclear Information System (INIS)

    Escofet, A.

    1981-06-01

    In 1980 Mexico had a population of 68 million, mostly concentrated in a few cities with many other areas being practically unpopulated. The country is semi-industrialized, and in order to achieve better standards of living, economic growth will have to continue at about 7.5 percent or more, particularly if the population continues to increase at 2.9 percent per year. The total installed electrical capacity at the end of 1980 was 14 600 MW; the per capita consumption of electricity was 910 KWh. The present government has as a goal an 8 percent annual growth rate in gross domestic product until 1995, resulting in forecast of a 12.5 percent growth rate in the electric sector to about 410 TWh per year. Hydroelectric power could be used to produce 80 TWh a year by 2000 if capacity were quadrupled. The use of coal for the production of electricity is beginning, and it is planned to generate 40 TWh a year from this source by 2000. Geothermal power should yield 20 TWh by then. A goal has been set of 20 000 MW of installed nuclear capacity by the end of the century; this would produce about 130 TWh, leaving some 280 TWh to be generated by oil or gas. The planned nuclear program must include the development of a strong Mexican nuclear industry, so that in 20 years 80 percent of the nuclear plant components could be locally produced. Ultimately it is hoped that Mexico will have the capability of installing, with its own resources, five or six large nuclear plants per year

  13. The Mexican consensus on irritable bowel syndrome.

    Science.gov (United States)

    Carmona-Sánchez, R; Icaza-Chávez, M E; Bielsa-Fernández, M V; Gómez-Escudero, O; Bosques-Padilla, F; Coss-Adame, E; Esquivel-Ayanegui, F; Flores-Rendón, Á R; González-Martínez, M A; Huerta-Iga, F; López-Colombo, A; Méndez-Gutiérrez, T H; Noble-Lugo, A; Nogueira-de Rojas, J R; Raña-Garibay, R H; Remes-Troche, J M; Roesch-Dietlen, F; Schmulson, M J; Soto-Pérez, J C; Tamayo, J L; Uscanga, L F; Valdovinos, M Á; Valerio-Ureña, J; Zavala-Solares, M R

    2016-01-01

    Since the publication in 2009 of the Guidelines on the Diagnosis and Treatment of Irritable Bowel Syndrome of the Asociación Mexicana de Gastroenterología (2009 Guidelines), there have been significant advances in our knowledge of the epidemiology, pathophysiology, diagnosis, and treatment of this disease. To present a consensus review of the most current knowledge of IBS, updating the 2009 Guidelines by incorporating new internationally published scientific evidence, with a special interest in Mexican studies. The PubMed literature from January 2009 to March 2015 was reviewed and complemented through a manual search. Articles in English and Spanish were included and preference was given to consensuses, guidelines, systematic reviews, and meta-analyses. Statements referring to the different aspects of the disease were formulated and voted upon by 24 gastroenterologists employing the Delphi method. Once a consensus on each statement was reached, the quality of evidence and strength of recommendation were determined through the GRADE system. Forty-eight statements were formulated, updating the information on IBS and adding the complementary data that did not appear in the 2009 Guidelines regarding the importance of exercise and diet, diagnostic strategies, and current therapy alternatives that were analyzed with more stringent scientific vigor or that emerged within the last 5 years. We present herein a consensus review of the most relevant advances in the study of IBS, updating and complementing the 2009 Guidelines. Several studies conducted in Mexico were included. Copyright © 2016 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.

  14. Long-term surveillance plan for the Mexican Hat Disposal Site, Mexican Hat, Utah

    International Nuclear Information System (INIS)

    1996-02-01

    This plan describes the long-term surveillance activities for the Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site at Mexican Hat, Utah. The U.S. Department of Energy (DOE) will carry out these activities to ensure that the disposal site continues to function as designed. This long-term surveillance plan (LTSP) was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive material (RRM). This LTSP (based on the DOE's Guidance for Implementing the UMTRA Project Long-term Surveillance Program), documents the land ownership interests and details how the long-term care of the disposal site will be accomplished

  15. Environmental assessment of remedial action at the Mexican Hat uranium mill tailings site, Mexican Hat, Utah

    International Nuclear Information System (INIS)

    1987-10-01

    This document assesses the environmental impacts of the proposed remedial action at the Mexican Hat uranium mill tailings site located on the Navajo Reservation in southern Utah. The site covers 235 acres and contains 69 acres of tailings and several of the original mill structures. Remedial action must be performed in accordance with standards and with the concurrence of the US Nuclear Regulatory Commission and the Navajo Nation. The proposed action is to stabilize the tailings within the present tailings site by consolidating the tailings and associated contaminated soils into a recontoured pile. A radon barrier of compacted earth would be constructed over the pile, and various erosion control measures would be taken to assure the long-term stability of the pile. The no action alternative is also assessed in this document. 240 refs., 12 figs., 20 tabs

  16. EDITORIAL: XIII Mexican Workshop on Particles and Fields

    Science.gov (United States)

    Barranco, Juan; Contreras, Guillermo; Delepine, David; Napsuciale, Mauro

    2012-08-01

    Electroweak and Flavor Physics in whose classification we had Quark masses and mixing, Electroweak Symmetry Breaking, Heavy Quark Physics, Neutrinos, CP Violation, CKM and Rare Decays. The working group for this topic was formed by David Delepine, Lorenzo Díaz, Gerardo Herrera and Olga Félix Beltrán. The three topics included invited talks dedicated to reviewing theoretical and experimental aspects of the corresponding topic. We had also plenary topical sessions during the mornings and early afternoons and parallel thematic sessions were held late in the afternoons. The reviews sessions were delivered by invited speakers of international prestige on the corresponding subjects and having an active collaboration with the Mexican scientific community. The plenary topical sessions and parallel thematic sessions were given by active researchers both from abroad and working in México. The program included also a permanent poster session and the organizing committee awarded the best poster - a decision made by the three working groups - with a silver medal. On Sunday 23 October, we had an excursion to the ancient archaeological site of Plazuelas near Penjamo (Guanajuato). Plazuelas is a prehispanic archaeological site located just north of San Juan el Alto, some 2.7 kilometers north of federal highway 90 (Penjamo-Guadalajara), and about 11 kilometers west of the city of Penjamo in the state of Guanajuato, Mexico. The site has been recently opened to the public. This site is a very complex city, it was edified following the natural landscape surrounding it. This city was occupied between 600 and 900 a.C. After spending some time at this very interesting archaeological site, we went to Hacienda Corralejo, an hacienda where Tequila Corralejo is produced and we had a guided visit of the 'Tequilera' where the famous Corralejo blue bottle of Tequila is made. Hacienda Corralejo is very close to the orginal Hacienda where Miguel Hidalgo (a Mexican independence hero) was born which now

  17. "Ganando Confianza": Research Focus Groups with Immigrant Mexican Mothers

    Science.gov (United States)

    Hausmann-Stabile, Carolina; Zayas, Luis H.; Runes, Sandra; Abenis-Cintron, Anna; Calzada, Esther

    2011-01-01

    Immigrant families with children with developmental disabilities must be served using culturally sensitive approaches to service and research to maximize treatment benefits. In an effort to better understand cultural issues relevant to the provision of parenting programs for immigrant Mexican mothers of children with developmental disabilities, we…

  18. Determinants of Coping Responses among Mexican American Adolescents.

    Science.gov (United States)

    Guinn, Bobby; Vincent, Vern

    2002-01-01

    Examined the relationship of perceived stress, self-esteem, acculturation, and gender to the coping response of Mexican American adolescents. Data from self-report surveys indicated that adolescents had relatively high perceived stress levels, low acculturation, and a moderate self-esteem, with no significant gender differences. Self-esteem was…

  19. Interparental Relations, Maternal Employment, and Fathering in Mexican American Families

    Science.gov (United States)

    Formoso, Diana; Gonzales, Nancy A.; Barrera, Manuel, Jr.; Dumka, Larry E.

    2007-01-01

    This study examined independent and interactive relations between the interparental relationship and maternal employment in predicting fathering within low-income, Mexican American two-parent families (N = 115). Interparental conflict was negatively related to quality fathering, and these relations were noted only for single-earner families. The…

  20. Discrimination of citrus tristeza virus (CTV) strains using Mexican ...

    African Journals Online (AJOL)

    Two strains of citrus tristeza virus (CTV) were studied for six years in Yaounde in the forest zone of Cameroon. These strains, SNCL2 and SNCL4, were characterized on Lisbon lemon in Nyombe in the littoral zone of Cameroon. They were inoculated onto combinations of Mexican lime/citrange Troyer. The virulent strain ...

  1. Family Stress and Coping for Mexican Origin Adolescents

    Science.gov (United States)

    Liu, Freda F.; Gonzales, Nancy A.; Fernandez, Aida Cristina; Millsap, Roger E.; Dumka, Larry E.

    2011-01-01

    Family-related stressors pose special challenges for adolescents of Mexican origin, given traditional cultural norms that compel youths to get involved with family problems despite their limited ability to effect change. The current study examines the prospective effects of coping strategies (i.e., active, distraction, avoidance, support-seeking,…

  2. A Mexican American Woman Encounters Sociology: An Autobiographical Perspective.

    Science.gov (United States)

    Williams, Norma

    1988-01-01

    Describes the author's experience of teaching bilingual educators. Identifies the bureaucratic structure of the school and the Mexican American culture as the two problem areas focused upon during the course. Concludes that her major areas of research interest in sociology are a direct product of her ethnicity, work experience, and this…

  3. Detecting Diabetic Blindness in Low-Income Mexican Adults

    Centers for Disease Control (CDC) Podcasts

    This podcast features Kenny Mendoza-Herrera, a former graduate student at the National Institute of Public Health of Mexico and one of the winners of PCD's 2017 Student Research Paper Contest. Kenny answers questions about his winning research and what impact his study has on the prevention of diabetic blindness and public health, particularly for Mexican adults.

  4. Antibacterial and antifungal activities of some Mexican medicinal plants.

    Science.gov (United States)

    Ruiz-Bustos, E; Velazquez, C; Garibay-Escobar, A; García, Z; Plascencia-Jatomea, M; Cortez-Rocha, M O; Hernandez-Martínez, J; Robles-Zepeda, R E

    2009-12-01

    In Mexico about 4,000 plant species have some medicinal use. The aim of this work was to evaluate the antimicrobial activity of six Mexican medicinal plants against fungi and Gram-positive and Gram-negative bacteria. Methanolic extracts were prepared from the Mexican medicinal plants Amphypteringium adstrigens, Castella tortuosa, Coutarea latiflora, Ibervillea sonorae, Jatropha cuneata, and Selaginella lepidophylla. The antibacterial and antifungal activities of the plants were determined by the broth microdilution method and the radial growth inhibition assay, respectively. All Mexican plants tested showed antimicrobial activity. Among the six plant extracts analyzed, J. cuneata showed the highest growth-inhibitory activity against fungi, Gram-positive and Gram-negative bacteria (J. cuneata > A. adstrigens > C. latiflora > C. tortuosa > I. sonorae approximately S. lepidophylla). Shigella flexneri and Staphylococcus aureus were the most susceptible bacteria to plant extracts. Complete inhibition of S. flexneri growth was observed with J. cuneata methanolic extract at 90 microg/mL. This plant extract also showed the strongest antifungal activity against Fusarium verticillioides and Aspergillus niger. Our data suggest that the medicinal plants tested have important antimicrobial properties. This is the first report describing the antimicrobial activities of several of the Mexican medicinal plants used in this study.

  5. Production of both esters and biogas from Mexican poppy | Singh ...

    African Journals Online (AJOL)

    This paper details a dynamic evaluation of a procedure for extracting both, ester and biogas from seeds and waste of Mexican poppy (Argemone mexicana) using simple and inexpensive technique. Results showed that A. mexicana seed contains 30% oil. Through the process of transestrification, oil extracted from seed, ...

  6. Exploratory Talk, Argumentation and Reasoning in Mexican Primary School Children

    Science.gov (United States)

    Rojas-Drummond, Sylvia; Zapata, Margarita Peon

    2004-01-01

    The study analyses the effects of training primary school children in the use of a linguistic tool called "Exploratory Talk" (ET) on their capacity for argumentation. ET allows for reasoned confrontation and negotiation of points of view, making the reasoning visible in the talk. Eighty-eight Mexican children from the 5th and 6th grades…

  7. The Attitudes of Mexican Parents Toward School Discipline

    Science.gov (United States)

    Ogletree, Earl J.; Rodriquez, Margarita

    1978-01-01

    Surveys the attitudes of Mexican parents toward school discipline of primary-level children in terms of the following questions: 1) will parents accept the use of corporal punishment in schools?, 2) what form of disciplinary measure will they accept or recommend?, 3) if parents accept corporal punishment, who will be the school disciplinarian, and…

  8. Attitudes toward Suicide among Mexican American and Anglo Youth.

    Science.gov (United States)

    Domino, George

    1981-01-01

    There were statistically significant differences between answers of 76 Anglo and 76 Mexican American youth on 35 of 100 opinion questionnaire items. Items centered on religion, psychopathology, aggression-impulsivity, acceptability of suicide, the "cry for help" dimension, and emotional impact. (Author/CM)

  9. Optimal transmission planning under the Mexican new electricity market

    International Nuclear Information System (INIS)

    Zenón, Eric; Rosellón, Juan

    2017-01-01

    This paper addresses electricity transmission planning under the new industry and institutional structure of the Mexican electricity market, which has engaged in a deep reform process after decades of a state-owned-vertically-integrated-non-competitive-closed industry. Under this new structure, characterized by a nodal pricing system and an independent system operator (ISO), we analyze welfare-optimal network expansion with two modeling strategies. In a first model, we propose the use of an incentive price-cap mechanism to promote the expansion of Mexican networks. In a second model, we study centrally-planned grid expansion in Mexico by an ISO within a power-flow model. We carry out comparisons of these models which provide us with hints to evaluate the actual transmission planning process proposed by Mexican authorities (PRODESEN). We obtain that the PRODESEN plan appears to be a convergent welfare-optimal planning process. - Highlights: • We model transmission planning (PRODESEN) in the Mexican new electricity market. • We propose a first model with a price-cap mechanism to promote network expansion. • In a second power-flow model, we study centrally-planned grid expansions. • The PRODESEN appears to be a convergent welfare-optimal planning process. • Incentive regulation could further help to implement such an optimal process.

  10. Pandemics and networks : The case of the Mexican flu

    NARCIS (Netherlands)

    Omic, J.; Van Mieghem, P.

    2010-01-01

    The recent widespread of the new Mexican flu and SARS show the high dependency on contemporary traveling patterns. The air transport network is recognized as an important channel of epidemic propagation for different diseases. In order to predict epidemic spreading and the influence of protection

  11. Effects of Malathion Dust and Mexican Tea Powder ( Chenopodium ...

    African Journals Online (AJOL)

    The experiment was conducted in the laboratory at the Bako Agricultural Research Center, from January to July 2013. Combinations of different rates of Malathion and Mexican tea powder were evaluated against the maize weevil in no choice situations. The treatments were laid out in a randomized complete design with ...

  12. PROTEIN & SENSORY ANALYSIS TO CHARACTERIZE MEXICAN CHIHUAHUA CHEESES

    Science.gov (United States)

    It has been established that native microflora in raw milk cheeses, including Queso Chihuahua, a Mexican cheese variety, contributes to the development of unique flavors through degradation of milk proteins resulting in the release of free amino acids and short peptides that influence the taste and ...

  13. Neighborhood Contexts, Fathers, and Mexican American Young Adolescents' Internalizing Symptoms

    Science.gov (United States)

    White, Rebecca M. B.; Roosa, Mark W.

    2012-01-01

    The family stress model posits that contextual stressors, such as neighborhood danger, negatively influence youth adjustment, including internalizing symptoms, via disruptions in parenting and family processes. The current study examined a culturally and contextually modified family stress model in a diverse sample of Mexican-origin fathers and…

  14. Cultural and Contextual Influences on Parenting in Mexican American Families

    Science.gov (United States)

    White, Rebecca M. B.; Roosa, Mark W.; Weaver, Scott R.; Nair, Rajni L.

    2009-01-01

    Family stress theory can explain associations between contextual stressors and parenting. The theory, however, has not been tested among Mexican Americans or expanded to include cultural-contextual risks. This study examined associations between neighborhood, economic, and acculturative stressors and parenting behaviors in a sample of 570…

  15. Good Mathematics Teaching from Mexican High School Students' Perspective

    Science.gov (United States)

    Martinez-Sierra, Gustavo

    2014-01-01

    This paper reports a qualitative research that identifies the characteristics of good mathematics teaching from the perspective of Mexican high school students. For this purpose, the social representations of a good mathematics teacher and a good mathematics class were identified in a group of 67 students. In order to obtain information, a…

  16. Using Media Literacy to Explore Stereotypes of Mexican Immigrants.

    Science.gov (United States)

    Vargas, Lucila; dePyssler, Bruce

    1998-01-01

    Examines media portrayals of Mexican immigrants, and interplay between these images and portrayals of U.S.-born Latinos. Argues that examining media images is imperative because the influence of media saturation is almost overwhelming. Suggests a media-literacy framework for developing abilities for interpreting media and giving students control…

  17. Parental Agency in Educational Decision Making: A Mexican American Example

    Science.gov (United States)

    McClain, Margy

    2010-01-01

    Background/Context: This article explores the experiences of one Mexican American family as they make a key curriculum choice for their 9-year-old son. Relatively little attention has been paid to parents' beliefs, attitudes, and, in particular, experiences as they actively engage in--and sometimes affect--their children's schooling. Parents'…

  18. The Free Trade Agreement and the Mexican health sector.

    Science.gov (United States)

    Laurell, A C; Ortega, M E

    1992-01-01

    This article presents a discussion of the probable implications for the Mexican health sector of the Free Trade Agreement (FTA) between the United States, Canada, and Mexico. The authors argue that the FTA should be seen as part of neoliberal policies adopted by the Mexican government in 1983 that are based on large-scale privatization and deregulation of labor relations. In this general context the health sector, which traditionally has been dominated by public institutions, is undergoing a deep restructuring. The main trends are the decapitalization of the public sector and a selective process of privatization that tends to constitute the private health sector in a field of capital accumulation. The FTA is likely to force a change in Mexican health legislation, which includes health services in the public social security system and recognizes the right to health, and to accelerate selective privatization. The U.S. insurance industry and hospital corporations are interested in promoting these changes in order to gain access to the Mexican market, estimated at 20 to 25 million persons. This would lead to further deterioration of the public institutions, increasing inequalities in health and strengthening the private sector. The historical trend toward the integration of a National Health Service in Mexico would be interrupted in favor of formation of a dual private-public system.

  19. Evaluating the Success of Educational Policy in Mexican Higher Education

    Science.gov (United States)

    Sagarra, Marti; Mar-Molinero, Cecilio; Rodríguez-Regordosa, Herberto

    2015-01-01

    State support in higher education (HE) is often justified on the grounds that HE is important for the development of the country. However, little analysis is normally done in order to assess the impact of education quality initiatives. The Mexican government has been engaging in a policy of HE quality improvement that can be traced to 1989. In…

  20. Implicit Race/Ethnic Prejudice in Mexican Americans

    Science.gov (United States)

    Garza, Christelle Fabiola; Gasquoine, Philip Gerard

    2013-01-01

    Implicit race/ethnic prejudice was assessed using Spanish- and English-language versions of an Implicit Association Test that used Hispanic/Anglo first names and pleasant/unpleasant words as stimuli. This test was administered to a consecutive sample of Mexican American adults residing in the Rio Grande Valley region of Texas of whom about…