Showing papers by "Universidad Iberoamericana Ciudad de México published in 2004"
TL;DR: In this paper, the authors demonstrate that pyridine-type regions on the tube surface bind strongly to ammonia, acetone and OH groups, thus altering their density of states, and demonstrate that these regions could be used as fast responsive and reusable sensors.
183 citations
TL;DR: In this article, a traves de mecanismos de proteccion and conciliación, reducir the violación de los derechos humanos in la esfera de la vida domestica evitando la judicializacion and penalizacion de los conflictos, are presented.
Abstract: Colombia ha experimentado una creciente violencia, militarizacion y violacion de los derechos humanos. La construccion cultural de las identidades ha estado afectada por una amplia violencia en el campo de lo domestico, la cual se superpone con otras expresiones politicas y sociales de violencia. La respuesta reciente del Estado ha buscado, a traves de mecanismos de proteccion y conciliacion, reducir la violacion de los derechos humanos en la esfera de la vida domestica evitando la judicializacion y penalizacion de los conflictos. Este articulo presenta resultados de las dificultades de esta respuesta, no solo por extender la conciliacion a casos de violacion de derechos humanos, sino tambien por la escasa consideracion a los patrones culturales y las identidades de genero en el contexto de la violencia intrafamiliar. El estudio explora los discursos de agresores y victimas a traves de entrevistas separadas. Cualquier intervencion se encuentra limitada, no solo por la gran demanda y el modelo de atencion adoptado, sino tambien por los valores e imagenes culturales de las autoridades, que hacen problematica la intervencion, toda vez que se trata de violencia en la vida privada. La investigacion es llevada a cabo en Bogota por un grupo interdisciplinario de genero mixto, a traves de una amplia muestra de expedientes en comisarias de familia, y por medio de entrevistas personales, para valorar la efectividad de los procesos de conciliacion y proteccion en el marco de la Ley contra la Violencia Intrafamiliar.
41 citations
TL;DR: The results indicate that it is possible to substitute a live diet with a microencapsulated one (with a wall composition made up of a polysaccharide blend) in Litopenaeus vannamei mysis.
Abstract: An artificial diet for shrimp larvae was microencapsulated with a polysaccharide blend [66% gum arabic, 17% mesquite gum and 17% maltodextrin 10 dextrose equivalent (DE)]. Microencapsulated diet (MD) was fed to mysis alone, as a co-feed with the microalgae Chaetoceros cerastosporum and Tetraselmis chuii (mixed) and compared with a live diet (control) of C. cerastosporum, T. chuii and Artemia nauplii. No significant differences (P > 0.05) were detected in growth rates, development and quality indexes of larvae fed the three experimental diets. All diets supported survival percentages of >90%. Shrimp larvae fed MD and mixed diets had higher specific trypsin activity and soluble protein content than those fed live diet. Amylase activity decreased in larvae fed the mixed and MD apparently due to the carbohydrate composition of the diet. The results indicate that it is possible to substitute a live diet with a microencapsulated one (with a wall composition made up of a polysaccharide blend) in Litopenaeus vannamei mysis.
37 citations
TL;DR: In this paper, the authors analyzed how maternal returns to cognitive ability on children's height reflect contemporaneous endowments and childhood background of the mother, and found that maternal return to cognitive abilities on child height are less likely to reflect observed mother's childhood endOWments as measured by parental transmission of knowledge or school quality, but are more likely to be associated with learning to be a mother and with a better capacity to take advantage of household and community available resources.
Abstract: Little is known about the mechanisms through which mother's cognitive ability operates in enhancing her children's health. This paper analyzes how maternal returns to cognitive ability on children's height reflect contemporaneous endowments and childhood background of the mother. Results suggest that maternal returns to cognitive ability on child height are less likely to reflect observed mother's childhood endowments as measured by parental transmission of knowledge or school quality, but are more likely to be associated with learning to be a mother, and with a better capacity to take advantage of household and community available resources.
29 citations
TL;DR: The anthropologist Manuel Gamio as discussed by the authors examined the progress of the federal government's Valle Bajo Rio Bravo agricultural development project and conducted an anthropological survey of the region, which was used as a guide for settling repatriated Mexican workers from Texas as small farmers in this new irrigation district.
Abstract: In January 1939 the anthropologist Manuel Gamio toured the hinterlands of the Mexican border town of Matamoros, Tamaulipas, to examine the progress of the federal government's Valle Bajo Rio Bravo agricultural development project and to conduct an anthropological survey of the region. Over the previous four years the government of President Lazaro Cardenas had invested huge amounts of money in the construction of irrigation and flood control works in the Mexican half of the delta region of the Rio Bravo (known as the Rio Grande on the Texas side of the border) in an effort to create a cottonproducing agricultural zone that would replicate the economic growth of other cotton regions in the borderlands. The project had the goal of easing the social problems caused by the crisis of the 1930s, the most important of which was the massive re-immigration, or "repatriation," of Mexicans from the United States to the border region (Carreras de Velasco, 1973; Hoffman, 1974; Balderrama and Rodriguez, 1995). The report that Gamio produced was a regional study of the environmental and social conditions in Matamoros, to be used as a guide for settling repatriated Mexican workers from Texas as small farmers in this new irrigation district.' The anthropologist concluded:
26 citations
Journal Article•
TL;DR: In this paper, the authors assess the differences in the locus of control according to the level of poverty in a population of 900 persons classified under three groups: extreme poor, moderate poor and not poor.
Abstract: The aim of the present study was to assess the differences in the locus of control according to the level of poverty in a population of 900 persons classified under three groups: extreme poor, moderate poor and not poor. All subjects were self-supporting persons. We used a sociodemographic questionnaire and a locus of control scale. The results showed that the groups of highest familiar income, as well as the groups of not poor, and moderate poor, exhibit more an internal locus of control, whereas the group of extreme poor show mainly an external locus of control; on the other hand it was observed that the males, as well as the older people (36 to 72 years old) present a more internal locus of control than females and younger people (19 to 35 years old). Besides, people with a higher educational level (graduates and postgraduates) present a higher trend towards internality in comparison with people of lowest educational level (without education, primary, secondary and highschool). In turn, it was observed that the parent’s education influences the locus of control. In general terms, the variables that better predict the locus of control were the familiar income and the education of the subjects.
23 citations
Patent•
27 Jan 2004TL;DR: In this article, a process for chemical recycling of PET waste that comprises, among other stages, a saponification reaction stage, wherein PET waste particles are reacted with stoichiometric or excessive amounts of a strong base metal in an alcoholic reaction media, the reaction being brought to the boiling temperature of the alcoholic reaction medium, preferably at atmospheric pressure, thereby obtaining as reaction products a salt of terephthalic acid with the base metal and ethylene glycol, the latter being incorporated to the alcohol reaction media.
Abstract: The present invention relates to a process for chemical recycling of PET waste that comprises, among other stages, a saponification reaction stage, wherein PET waste particles are reacted with stoichiometric or excessive amounts of a strong base metal in an alcoholic reaction media, the reaction being brought to the boiling temperature of the alcoholic reaction media, preferably at atmospheric pressure, thereby obtaining as reaction products a salt of terephthalic acid with the base metal and ethylene glycol, the latter being incorporated to the alcoholic reaction media. From this reaction it is possible to afford ethylene glycol, terephthalic acid and salts thereof, which are products with a high commercial value.
20 citations
01 Jan 2004
TL;DR: In this article, a crisis global and a saldos de miseria y devastacion debe ser entendida como una oportunidad para transitar hacia otro modelo de relacion entre los hombres and su ambiente.
Abstract: El hombre del fin del milenio ha adquirido paulatinamente conciencia de que una epoca termina y por tanto se plantea dos opciones inequivocas: por un lado, continuar con modelos de desarrollo en los que los procesos economicos prevalecen y marcan las lineas de explotacion de los recursos y los habitos de consumo, o -en necesario contraste, entender que si alguna dictadura debe existir en el proximo siglo es la ambientalconsiderada como una dimension que trasciende su contexto ecologico e integra ambitos que tradicionalmente se han fragmentado, como lo politico, lo social y lo economico. La crisis global y sus saldos de miseria y devastacion debe ser entendida como una oportunidad para transitar hacia otro modelo de relacion entre los hombres y su ambiente.
19 citations
TL;DR: In this article, protein and gum-based edible films were prepared and their thermal diffusivity was determined by photoacoustics, and the results showed that mesquite gum was the highest thermal diffuser in single-component films.
Abstract: One of the most important factors in the preparation of edible films regards the choice of ingredients. Edible films are commonly prepared with single or mixed high-molecular-weight compounds like proteins and gums. In the present work, protein and gum-based edible films were prepared and their thermal diffusivity determined by photoacoustics. The films were prepared with different concentrations of four basic ingredients: whey protein concentrate, mesquite gum, sodium alginate, and κ-carrageenan. In single-component films, the highest thermal diffusivity was found in mesquite gum (1.97×10−7m2ċs−1), followed by sodium alginate, whey protein concentrate, and κ-carrageenan samples. In composed films, the highest thermal diffusivity was obtained in a ternary film made of mesquite gum, whey protein concentrate, and sodium alginate in identical parts (5.20×10−7m2ċs−1).
19 citations
TL;DR: In this article, the authors argue that while this situation has been characterized as an international "water war" stemming from a water crisis, it is more accurately described as a series of conflicts between regional, binational and national actors generated by a crisis of irrigated agriculture.
Abstract: Since 1992 water scarcity in the Rio Bravo/Rio Grande river basin has heightened tensions and conflicts among water users and politicians on both sides of the Mexico-U.S. border. This article argues that while this situation has been characterized as an international “water war” stemming from a “water crisis,” it is more accurately described as a series of conflicts between regional, binational and national actors generated by a “crisis of irrigated agriculture.” A close examination of the dynamics of these current water conflicts focused on the delta region of the Rio Bravo/Grande reveals a binational ecological consciousness among the agricultural users of the resource, the product of a long history of irrigated agricultural development in the borderlands. The article argues that these conflicts must be understood historically, and suggests that these binational, regional dynamics should be cultivated in the effort to negotiate the social dimensions of the crisis of irrigated agriculture in the borderlands, and to establish a more sustainable and democratic process of water management in the river basin. Key Words: Irrigation; Agriculture; Conflict; Borderlands; Water.
18 citations
TL;DR: In this article, the phase behavior of poly(2-ethyl-2-oxazoline) (PEOx)/poly(vinyl phenyl ketone hydrogenated) blends was studied for the entire range of compositions.
Abstract: The miscibility behavior of poly(2-ethyl-2-oxazoline) (PEOx)/poly(vinyl phenyl ketone hydrogenated) (PVPhKH) blends was studied for the entire range of compositions. Differential scanning calorimetry and thermomechanical analysis measurements showed that all the PEOx/PVPhKH blends studied had a single glass-transition temperature (Tg). The natural tendency of PVPhKH to self-associate through hydrogen bonding was modified by the presence of PEOx. Partial IR spectra of these blends suggested that amide groups in PEOx and hydroxyl groups in PVPhKH interacted through hydrogen bonding. This physical interaction had a positive influence on the phase behavior of PEOx/PVPhKH blends. The Kwei equation for Tg as a function of the blend composition was satisfactorily used to describe the experimental data. Pure-component pressure–volume–temperature data were also reported for both PEOx and PVPhKH. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 636–645, 2004
01 May 2004
TL;DR: The modelo maquilador haya llegado a su limite en Mexico en las currentes condiciones of los mercados internacionales, tanto en terminos de sus productos como de trabajo as discussed by the authors.
Abstract: Es posible que el ?modelo maquilador? haya llegado a su limite en Mexico en las actuales condiciones de los mercados internacionales, tanto en terminos de sus productos como de trabajo. Asimismo, la crisis actual de la maquila afecta su capacidad de incrementar la productividad, lo cual repercute en la caida de su tasa de ganancia. Lo anterior apunta a que el pais debe buscar un modelo de industrializacion diferente del maquilador, que no se base en la intensificacion del trabajo y en los bajos salarios. Los analisis de la informacion poco utilizada proveniente del Censo Nacional de Maquilas y de la Encuesta Nacional de Empleo, Salarios, Tecnologia y Capacitacion (ENESTYC) del INEGI, permiten dar una imagen global diferente de la maquila de aquella que se ha difundido a partir de estudios de casos exitosos.
TL;DR: The preservation of some control-oriented positive real properties in multi-input multi-output transfer functions is studied, when performing substitutions by a particular class of rational strictly positive real functions, the so-called SPR functions of zero relative degree (SPR0 functions).
Abstract: The preservation of some control-oriented positive real properties (passivity, positivity, bounded realness, as well as input-output behavior) in multi-input multi-output transfer functions is studied, when performing substitutions (of the complex Laplace variable s) by a particular class of rational strictly positive real (SPR) functions, the so-called SPR functions of zero relative degree (SPR0 functions). We also consider here the preservation of stability properties of a class of unforced linear time-invariant systems with memoryless (possibly time-varying nonlinear) input depending on the system output.
Journal Article•
TL;DR: In this article, the authors adapted DRASTIC and AVI to a local scale for land use in the southwest zone of Leon, Guanajuato, Mexico, and transformed the isoline maps to grid maps to be used by a Geographical Information System, GIS.
Abstract: Regional assessments of aquifer vulnerability, DRASTIC and AVI, are adapted to a local scale for land use in the southwest zone of Leon, Guanajuato, Mexico. The isoline maps were transformed to grid maps to be used by a Geographical Information System, GIS. The main potential sources of aquifer pollution were included in the territorial ordering analysis. The vulnerability tendencies and land uses were analyzed. The urban expansion tendencies were revised taking into account the aquifer vulnerability zoning. Vulnerability areas were restricted for urban development.
TL;DR: Ozone, a powerful oxidizing and disinfecting agent, is produced electrochemically in the undergraduate laboratory with simple equipment and under very mild conditions as discussed by the authors, and tests are given to characterize it, to observe its action in simulated environmental applications, and to measure its rate of production.
Abstract: Ozone, a powerful oxidizing and disinfecting agent, is produced electrochemically in the undergraduate laboratory with simple equipment and under very mild conditions. Tests are given to characterize it, to observe its action in simulated environmental applications, and to measure its rate of production.
01 Jan 2004
TL;DR: In this paper, the history of coffee production in Mexico is not only a background but also a framework to understand the adjustments peasants had to make through time to deal with risk, and some questions in the changes of different types of risks are basic for the understanding of contemporary coffee production and the impacts it has on the management of the relationship between nature, culture and socioeconomic forces.
Abstract: In this article, the history of coffee production in Mexico is not only a background but also a framework to understand the adjustments peasants had to make through time to deal with risk. Furthermore, some questions in the changes of different types of risks are basic for the understanding of contemporary coffee production and the impacts it has on the management of the relationship between nature, culture and socioeconomic forces. Dealing with risk is a continuous process acting in coffee production; but in the case of the small-scale cultivation it becomes basic to understand the decision making process involving land use, labor allocation, amount to harvest, time to sell, quantities to sell, other market crops options, and coffee monoculture or intermixing coffee with other plants (staples, natural vegetation, other commercial crops, and so on). Dealing with risk is the result of a series of environmental, social, cultural and ideological adjustments peasants have to make in order to produce food, reproduce their own families and obtain monetary resources to subsidize biological, economic, social and cultural necessities. Moreover, these adjustments change through time according to changes
TL;DR: In this paper, a simple control design for a class of single-output processes with at least two control inputs is proposed, where the process is factorized into a stable and non-minimum phase factor and a possible unstable minimum phase factor.
Journal Article•
TL;DR: In this article, the importance of diachronic studies in order to understand cultural mechanisms developed by several rural societies to take care of their natural resources was discussed, and Fantastic characters were chosen to show the ideological changes that have occurred as time passes as shown in two charts.
Abstract: This paper deals with the importance of diachronic studies in order to understand cultural mechanisms developed by several rural societies to take care of their natural resources. Fantastic characters invented by these societies to protect their natural resources were chosen to show the ideological changes that have occurred as time passes as shown in two charts. These beliefs and imaginary beings live in natural areas and keep vigil over their use, punishing those who abuse their exploitation. With this paper we have just scratched the surface of the relationship of culture and nature, and more case studies are needed.
Journal Article•
TL;DR: Indagar en la forma en la que el conocimiento se usa for la formulacion de politicas publicas resalta, inexorablemente, ciertos atributos que deben pre...
TL;DR: Meat surface fermentation has been reported as an efficient method to reduce undesirable microbial population of this food commodity in tropical areas with high ambient temperatures and humidity, however, in order to efficiently apply this method, growth of biopreservative strains and changes in the meat substrate should be studied.
TL;DR: In this paper, a mixture of bisphenol A, BPA, and 1,1 bi-2 naphthol, BN, diols has been synthesized and their gas permeability coefficients and selectivity separation factors for O2/N2 and CO2/CH4, at 5 atm and 35 °C, have been measured in a standard permeation cell.
Abstract: Polysulfone copolymers based on mixtures of bisphenol A, BPA, and 1,1 bi-2 naphthol, BN, diols have been synthesized and their gas permeability coefficients and selectivity separation factors for O2/N2 and CO2/CH4, at 5 atm and 35 °C, have been measured in a standard permeation cell. The polysulfone copolymers can form flexible thin films suitable for gas separation membranes. The gas selectivity for O2/N2 measured for the polysulfone copolymers synthesized with 50 and 70 mol % of BN, with the rest being BPA, in the initial mixture of diols are 6.4 and 6.8, respectively. The corresponding gas permeability coefficients for O2 are 1.24 and 1.09 Barrers. Compared to the corresponding selectivity and permeability balance reported for polysulfones based on pure BPA, BPA–PSF, the copolymers show a balance that moves in the direction of higher selectivity with small losses in the permeability of the fastest gas. From the glass transition temperature determinations, it is observed that the incorporation of BN in the repeating unit of BPA–PSF inhibits large-scale segmental motions that are reflected in reductions in the diffusivity coefficients for all gases. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 226–231, 2004
TL;DR: In this paper, an inventory of sexual experiences and response of disabled men and women in the Mexican Republic is presented, based on the properties of three scales which specifically identify the experiences that comprise part of the human sexual response; altogether 609 subjects, 464 women (76.2) and 145 men (23.8) between the ages of 14 and 87 (x = 37), 245 unmarried and 364 living as a couple, the frequency of motor disability taking first place (308 subjects = 50.6), followed by mental disability (113 subjects = 18.6) and
Abstract: Mexico has approximately 2300000 people who live with some severe disability. Disability is a health problem that has increased progressively and as such, has serious consequences for the person who experiences it, as well as for the family. The impact of the disability on sexuality is an undeniable aspect that frequently is reported in scientific literature; there is also a general consensus among clinical investigators of diverse countries with respect to the effects as much at the physiological as at the psychological level of sexuality. How these changes affect the Mexican population is unknown, due to the scant amount of research. The intent of the investigation was to construct and validate an inventory that made it possible to know what sexual experiences and response is of disabled men and women in the Mexican Republic. This study was aimed at validating the properties of three scales which specifically identify the experiences that comprise part of the study subjects’ human sexual response; altogether 609 subjects, 464 women (76.2) and 145 men (23.8) between the ages of 14 and 87 (x = 37), 245 unmarried and 364 living as a couple, the frequency of motor disability taking first place (308 subjects = 50.6), followed by mental disability (113 subjects = 18.6) and visual deficits (68 subjects = 11.2). This inventory consists of three areas: (1) sexual satisfaction in disability, (2) sexual response in disability, and (3) factors that interfere with sexuality in disability; the area of sexual response includes scales of desire, arousal and orgasm. The inventory was applied individually and the results were processed through statistical package SPSS, doing analysis of frequencies, t tests, variance, and chi-square test, as well as reliability tests. The results show in all cases, a greater tendency by men with some type of disability to search for and be involved in experiences of an affective and sexual type, which makes one suppose that gender roles have a big influence on sex following disability.
Posted Content•
TL;DR: The costo social de homicidios a nivel nacional para 1997, bajo distintos supuestos acerca del perfil de salarios, obtuvimos de.03 a.6 por ciento del PIB, dependiendo del factor de descuento utilizado.
Abstract: Realizamos mediciones del costo social del crimen. Primero estimamos el costo de los homicidios a nivel nacional para 1997, bajo distintos supuestos acerca del perfil de salarios, y obtuvimos de .03 a .6 por ciento del PIB, dependiendo del factor de descuento utilizado. Segundo, contemplamos otros tipos de violencia para estimar los costos sociales del crimen en la ciudad de Mexico, los cuales ascendieron a 3.6 por ciento del PIB de la ciudad, el cual consideramos subestima los verdaderos costos. Contar con informacion sobre no victimas seria muy valioso para continuar investigando sobre el tema.
Journal Article•
Journal Article•
TL;DR: In this article, the authors reflect on the future of university social service, as well as humanistic education as the keystone of cooperative plans for future projects, enriches t...
Abstract: This article reflects on the future of university social service. Humanistic education, as the keystone of cooperative plans for future projects, enriches t...
TL;DR: A woman gains 37% of her bone mass during adolescence, and when an adolescent experiences pregnancy and lactation, her metabolism is challenged to support her own growth.
Abstract: A woman gains 37% of her bone mass during adolescence. When an adolescent experiences pregnancy and lactation, her metabolism is challenged to support her own growth while providing the energy and nutrient requirements of fetal growth and milk synthesis.
01 Jan 2004
Journal Article•
Proceedings Article•
20 Jul 2004TL;DR: This paper concerns the characterization of positive real matrices generated by substitutions in scalar rational transfer function by matrix positive real functions and includes here a partial extension of both the Kalman-Yakubovich-Popov lemma and the circle criterion.
Abstract: This paper concerns the characterization of positive real matrices generated by substitutions (of the Laplace variable s) in scalar rational transfer function by matrix positive real functions. Our main results are restricted to both strongly strictly positive real matrices arid strictly bounded real matrices. As a way to illustrate our main results, we also include here a partial extension of both the Kalman-Yakubovich-Popov lemma (for strongly strictly positive real systems of zero relative degree) and the circle criterion (for strictly positive real systems of zero relative degree).