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Una de las consecuencias más importantes del cambio climático para México se relaciona con un menor acceso a cantidades y calidades de agua suficientes para los usos humanos y ambientales. El ahorro de agua doméstica se enmarca en este contexto como una medida de adaptación frente el cambio climático. El objetivo de este trabajo es explorar los factores que afectan el ahorro de agua en hogares mexicanos. Para ello se utilizan datos de más de 13 mil hogares de la Encuesta Nacional de los Hogares (ENH) desarrollada en 2017 y del Módulo de Hogares y Medio Ambiente aplicado ese año con la ENH. A través de análisis de regresión se prueba el efecto de factores sociodemográficos (edad, sexo, nivel educativo y tamaño de localidad), de gestión (forma de cobro del servicio) y climáticos (percepción de cambios en temperatura, precipitación y fenómenos extremos) como predictores de prácticas de ahorro de agua en hogares urbanos y rurales. Los hallazgos apuntan a un efecto estadísticamente significativo y positivo del cobro del agua a través de micromedición; así como efectos significativos, pero menores, de la percepción de mayor temperatura, cambios en la lluvia, e impactos de fenómenos climáticos en el hogar, como factores relacionados positivamente con prácticas de ahorro de agua doméstica.

Objetivo: evaluar las diferencias intraurbanas en las percepciones y respuestas a los riesgos asociados a contaminación del aire y olas de calor en la ciudad de Hermosillo, en el noroeste árido de México. Metodología: una muestra no aleatoria de 45 personas mayores de 18 años, habitantes de distintas zonas de la ciudad, respondió a una entrevista semiestructurada procesada en una base de datos para su análisis estadístico. Resultados: las personas identifican riesgos asociados tanto con la contaminación del aire como con las olas de calor; sin embargo, hay variaciones intraurbanas tanto en la percepción de dichos problemas, como en los mecanismos para prevenir los riesgos asociados con estos. Limitaciones: el estudio podría mejorar con una muestra aleatoria más amplia y utilizando otras fuentes de datos adicionales a las percepciones poblacionales sobre estos riesgos. Conclusiones: la percepción de riesgos ambientales urbanos constituye la base para el involucramiento ciudadano en la prevención, mitigación y adaptación frente a ellos en un contexto de cambio climático global y creciente urbanización.

Mexico is a global change hotspot highly integrated into international trade related to a petroleum, agro-export and tourism-based economy; human migration; and climate adaptation processes. Institutional and economic liberalization during the late twentieth century enhanced these dynamics, challenging human adaptation especially in rural settings. To date, there is a lack of systematic empirical analysis characterizing adaptation across the diverse rural communities of the country. In addressing this gap, this article reviews 50 empirical studies of adaptation in rural Mexico published between 1990 and 2019. The analysis identifies adaptive responses and contextual factors enabling or constraining adaptation at different scales and dimensions within rural social-ecological systems. Findings indicate: a) a decreasing frequency and variety of responses as they require more resources; b) an atomistic view of rural systems, excluding factors impacting adaptation, such as deagrarianization and water institutional centralization; and c) a gap in the evaluation of long-term sustainability of adaptation.

Water plays a central role in climate adaptation, economic development, poverty alleviation, food and energy security, and ecosystem processes. Addressing current and future global change, particularly for competing water-governance objectives, requires planning flexibility that may be constrained by physical water-resources infrastructure. This paper reviews infrastructure, the institutions for its management, and adaptive governance. We emphasize mechanisms that enhance adaptive capacity by accounting for: (1) uncertainties in supply, demand, and extreme conditions; (2) institutional inertia and means to overcome path dependence; and (3) flexibility in planning and operation of infrastructure. We define and discuss the ‘re-adaptation challenge,’ that is, accounting for infrastructure and institutions extant from past cycles of development while strengthening the capacity of planners, managers and other stakeholders to confront current complexities and future uncertainties. In so doing, we bring forward resilience as a water-governance goal, identifying infrastructure re-operations, other soft-path measures, and potentially, infrastructure removal as transformative adaptive pathways.

Women’s participation in large-scale mining (LSM) has been increasing in Mexico and worldwide; however, few comprehensive studies exist on the socioeconomic effects of mining on women depending on the specific roles they play in this activity. The objective of this study was to analyze, from a feminist political ecology perspective, the effects of mining on women in a rural community in Sonora State, in arid northwest Mexico, a region with important participation of LSM in the country. For this purpose, we developed a mixed methods approach combining literature review on gender and LSM, semistructured in-depth interviews, and analysis of secondary government data. Most literature on women and mining treats them conceptually as a homogeneous social group or focuses on only one role women play in mining. We address this gap by identifying several roles women can play in their interactions with the mining sector and then analyzing and comparing the effects of mining associated with these distinctive roles. In doing so, we unravel the gendered complexities of mining and highlight the socioecological contradictions embedded in these dynamics for individual women who are faced with significant trade-offs. Mining can provide economic and professional opportunities for women of varying educational and socioeconomic levels in otherwise impoverished and landless rural households. At the same time, women are unable to, as one interviewee phrased it, “break the glass ceiling even if using a miner’s helmet,” especially in managerial positions. Extraction of natural resources in the community is accompanied by the extraction of social capital and personal lives of miners. We give voice to the social–ecological contradictions lived by women in these multiple roles and offer potential insights both for addressing gender-based inequities in mining and for avenues toward collective action and empowerment.

Classification of deep (D), superficial (S) MCA territories and their junctional vascular area (the internal border zone, IBZ) can help to identify patients most likely to benefit from aggressive reperfusion therapy after stroke. We tested the prognostic value of an IBZ injury compared to DWI-ASPECTS and infarct volume.DW lesions of 168 patients with acute (4.2±6.5 h) MCA strokes were retrospectively examined and manually delineated. Patients with haemorrhagic transformation or other neurological diseases were excluded. Clinical data were recorded within 24 h following symptom onset and 48 h for patients who benefited from reperfusion therapy. The occurrence of an IBZ injury was determined using a standardized stereotaxic atlas. Performance to predict a good outcome (mRS3 at 3 months) was estimated through ROC curves for DWI-ASPECTS≤6, lesion volume≥100 mL and IBZ injury. Logistic regression models were performed to estimate independent outcomes for infarct volume and IBZ injury.Infarcts involving the IBZ were larger (94.9±98.8 mL vs. 30.2±31.3 mL), had higher NIHSS (13.8±7.2 vs. 7.2±5.7), more frequent MCA occlusions (64.9% vs. 28.3%), and worse outcomes (mRS 3.0±1.8 vs. 1.9±1.7), and were less responsive to IVtPA (34±47% vs. 55±48% of NIHSS improvement). The area under the ROC curves was comparable between the occurrence of IBZ injury (0.651), ASPECTS≤6 (0.657) and volume≥100 mL (0.629). Logistic regression analyses showed an independent effect of an IBZ injury, especially for superficial MCA strokes and for patients who benefited from reperfusion therapy.An IBZ injury is an early and independent marker of stroke severity, functional prognosis and treatment responsiveness.

Livelihoods in rural communities have become increasingly complex due to rapidly changing socio-economic and environmental forces, with differing impacts on and responses by female and male youth. This study contributes to feminist political ecology through an explicit focus on youth and an examination of the intersections of age and gender in educational choices, livelihood systems, and human–environment interactions. We undertake double exposures analysis to explore female and male youths’ livelihood-related decision-making in Rayón, a semi-arid rural community in Northwest Mexico, undergoing global environmental change and globalization-related shifts in agriculture, climate, water, and socio-economic conditions. Global environmental change exacerbates an already fragile, local ecological context. A focus on gender issues among youth in three age categories (14–15, 16–19, and youth in their 20s) with respect to their decision-making concerning the future is critical to gaining a better understanding of the roles women and men will play in linked agricultural and non-agricultural, rural to urban livelihood systems. Agricultural employment increasingly includes global agribusiness where local youth compete with people from other areas. Access to employment, education, as well as water and land resources varied by gender, age, and social class, and played significant roles in livelihood diversification and migration decisions and outcomes. Mothers’ access to government assistance for their natural resource-based livelihoods positively impacted daughters’ opportunities. Educational curricula failed to link environmental change with local livelihoods and to prepare students for urban careers. This study offers insights related to female and male youths’ needs associated with environmental education, technology access, job training, and child and sibling care in order for them to more successfully confront the future across village, town, and city spaces.

Transboundary waters are characterized by diverse and complex socio-politico-economic obstacles to effective water management. We examine five distinct cases in the arid Americas–in locations from the US–Mexico border to the Andes mountains–employing water security as a conceptual prism to unravel the multiple and varied attributes of transboundary water challenges. We describe how borders complicate water security in arid regions and explore how institutional arrangements and practices–within and across jurisdictions–respond to these challenges. We find that institutional capacity is needed on multiple levels for effective water management, and institutions must be responsive and flexible to change. Fil: Albrecht, Tamee R.. University of Arizona; Estados Unidos Fil: Varady, Robert G.. University of Arizona; Estados Unidos Fil: Zuniga Teran, Adriana A.. University of Arizona; Estados Unidos Fil: Gerlak, Andrea K.. University of Arizona; Estados Unidos Fil: Routson De Grenade, Rafael. University of Arizona; Estados Unidos Fil: Lutz Ley, América. El Colegio de Sonora; México Fil: Martin, Facundo Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentina Fil: Megdal, Sharon B.. University of Arizona; Estados Unidos Fil: Meza, Francisco. Pontificia Universidad Católica de Chile; Chile Fil: Ocampo Melgar, Diego. Pontificia Universidad Católica de Chile; Chile Fil: Pineda, Nicolás. Colegio de Sonora; México Fil: Rojas, Juan Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Taboada Hermoza, Rossi. Universidad Nacional Mayor de San Marcos; Perú Fil: Willems, Bram. Universidad Nacional Mayor de San Marcos; Perú

Rangelands are complex social-ecological systems (SES) commonly used to support ranching and other agrarian livelihoods. Common to Earth's drylands, rangelands are susceptible to drought, desertification, and land degradation from both climatic and human activities. In the arid Americas, ranching communities are often located in watersheds and rely on local riparian resources (e.g. surface- and ground-water) to support crop and animal cultivation. However, anthropogenic climate change in combination with intensified agriculture integrated into international markets degrade both landscape and water resources. In Sonora, Mexico's Rio San Miguel Watershed we find via an interdisciplinary set of methods that rangeland productivity, surface-water reaches, and aquifers are reduced to critical levels, agrarian livelihoods endangered, and within this dynamic, that downstream locations are less resilient and water secure than operations upstream. This spatio-temporal dynamic to water insecurity is due both to (a) latitudinal-based climatic changes and (b) upstream groundwater pumping activity. Participatory rapid rural appraisal, agro-ecosystem analysis, and remote sensing tell us how climate, landscape, water, and ranching operation dynamics are interrelated and affect SES morphology and resilience across time, operations, and sub-watersheds. Partnerships and cooperation among ranchers, sub-watersheds, and institutions are among the management and policy interventions available to prepare for or mitigate the developing social-ecological crisis in the watershed. Lessons from Mexico's Rio San Miguel Watershed are relevant for other drylands, agrarian systems, and groundwater-reliant economies, especially as the specter of long-term global climate change and water insecurity looms large for many of the Earth's social-ecological systems.

Climate change is posing emerging threats to people and the environment, particularly in arid regions. However, some groups are more vulnerable than others, depending on their levels of exposure, sensitivity and adaptive capacity, which are determined by climatic and non-climatic factors. In water-scarce environments, water policies become key non-climatic factors that affect vulnerability yet enable modifications if their impacts unintentionally exacerbate vulnerability. Therefore, it is necessary to analyze the impacts of water policies on vulnerability, particularly for disadvantaged groups. In this paper, we analyze four cases in the arid Americas that illustrate an array of challenges at different scales and across the rural-urban continuum: (1) irrigated oases in Mendoza, Argentina, where groundwater and surface water management are disconnected; (2) rural communities in central Sonora, Mexico, where local water rights have been transferred to large scale mining; (3) peri-urban marginalized neighborhoods in Hermosillo, Mexico, where competition for water is driving changes in land use; and (4) underserved communities in Tucson, Arizona, USA who are left behind in a rainwater harvesting movement. Our analysis shows that water policies in arid regions interact with land and neoliberal policies between sectors across different scales, exacerbating vulnerabilities disproportionately in less privileged groups and enhancing disparities. Here, we offer recommendations for more inclusive policymaking processes that can build capacity, protect the livelihoods of disadvantaged groups, and reduce their vulnerability to climate change.

Addressing wicked problems challenging water security requires participation from multiple stakeholders, often with conflicting visions, complicating the attainment of water-security goals and heightening the need for integrative and effective science-policy interfaces. Sustained multi-stakeholder dialogues within science-policy networks can improve adaptive governance and water system resilience. This paper describes what we define as “dialogic science-policy networks,” or interactions -- both in structural and procedural terms -- between scientists and policy-makers that are: 1) interdisciplinary, 2) international (here, inter-American), 3) cross-sectoral, 4) open, 5) continual and iterative in the long-term, and 6) flexible. By fostering these types of interactions, dialogic networks achieve what we call the 4-I criteria for effective science-policy dialogues: inclusivity, involvement, interaction, and influence. Here we present several water-security research and action projects where some of these attributes may be present. Among these, a more comprehensive form of a dialogic network was intentionally created via AQUASEC, a virtual center and network initially fostered by a series of grants from the Inter-American Institute for Global Change Research. Subsequently, AQUASEC has significantly expanded to other regions through direct linkages and additional program support for the International Water Security Network, supported by Lloyd's Register Foundation and other sources. This paper highlights major scientific and policy achievements of a notable suite of science-policy networks, shared practices, methods, and knowledge integrating science and policy, as well as the main barriers overcome in network development. An important gap that remains for future research is the assessment and evaluation of dialogic science-policy networks' long-term outcomes., Highlights • Current challenges in water access, use, and management constitute wicked problems. • Dialogic science-policy networks can help in addressing wicked water problems. • Eight study cases in the arid Americas exemplify science-policy network approaches. • Dialogic networks foster inclusivity, interaction, involvement, and influence. • Steady commitment and financial support are major challenges to dialogic networks.

Background and aims Previously, we determined that training with vibrotactile feedback (VTfb) of trunk sway improves MS patients' balance impairment. Here, we posed 5 questions: 1) How many weeks of VTfb training are required to obtain the best short-term carry over effect (CoE) with VTfb? 2) How long does the CoE last once VTfb training terminates? 3) Is the benefit similar for stance and gait? 4) Is position or velocity based VTfb more effective in reducing trunk sway? 5) Do patients' subjective assessments of balance control improve? Methods Balance control of 16 MS patients was measured with gyroscopes at the lower trunk. The gyroscopes drove directionally active VTfb in a head-band. Patients trained twice per week with VTfb for 4 weeks to determine when balance control with and without VTfb stopped improving. Thereafter, weekly assessments without VTfb over 4 weeks and at 6 months determined when CoEs ended. Results A 20% improvement in balance to normal levels occurred with VTfb. Short term CoEs improved from 15 to 20% (p ≤ 0.001). Medium term (1–4 weeks) CoEs were constant at 19% (p ≤ 0.001). At 6 months improvement was not significant, 9%. Most improvement was for lateral sway. Equal improvement occurred when angle position or velocity drove VTfb. Subjectively, balance improvements peaked after 3 weeks of training (32%, p ≤ 0.05). Conclusions 3–4 weeks VTfb training yields clinically relevant sway reductions and subjective improvements for MS patients during stance and gait. The CoEs lasted at least 1 month. Velocity-based VTfb was equally effective as position-based VTfb.

The United-States-Mexico food system, and in particular the section located in the Sonoran Desert, is an example of the detrimental effects that result from instensified food production to supply increased demand from regional, transboundary, and global areas. Impacts to freshwater and terrestrial ecosystems in addition to human livelihoods and institutions create serious management and policy challenges. Understanding the region as an integrated water-food system with institutional imbalances reveals the following consequences: (a) an increasing reliance on groundwater resources for the majority of agriculture and livestock production; (b) a net export of nonrenewable water; and (c) a virtual water imbalance that further threatens the region’s water and food security.

La adaptación de la ciudad de Hermosillo al medio natural que la rodea, caracterizado por la exposición periódica a altas temperaturas, implica contar con mecanismos de previsión y mitigación de los efectos de las temperaturas extremas sin menoscabo del desarrollo de las actividades económicas ni de la calidad de vida (Varady, Scott, Wilder, Morehouse, Pineda, & Garfin, 2013). En este reto, la población más vulnerable es la que habita en viviendas precarias que carecen de los medios para mitigar el calor o para evitar las deshidrataciones, golpes de calor, diarreas e incluso la muerte. Dentro de la población que habita en estas viviendas, los grupos más vulnerables son los niños, las personas de la tercera edad y las mujeres que permanecen la mayor parte del tiempo en dichas viviendas.

Este artículo analiza el papel de los dere - chos de agua en la gestión por cuenca. Esta es considerada como un recurso de uso común donde la intervención estatal y el registro de los derechos de agua pueden ser aprovechados para poner límites a las extracciones y evitar la sobreexplotación del recurso. Para el análisis, se hace un repaso de las ideas de la gestión por cuenca y se revisa el marco legal de los derechos del agua en México; después se revisa una base de datos de derechos de agua de la cuenca del río Sonora; y al final del trabajo se presentan los hallazgos. Entre ellos se encuentran las discrepancias entre los principios del marco legal y la operación concreta de los derechos de agua, así como el desaprovechamiento de estos últimos para ejecutar la gestión por cuencas.

PURPOSE: Noninvasive image-guided breast brachytherapy delivers conformal HDR (192)Ir brachytherapy treatments with the breast compressed, and treated in the cranial-caudal and medial-lateral directions. This technique subjects breast tissue to extreme deformations not observed for other disease sites. Given that, commercially-available software for deformable image registration cannot accurately co-register image sets obtained in these two states, a finite element analysis based on a biomechanical model was developed to deform dose distributions for each compression circumstance for dose summation. MATERIAL AND METHODS: The model assumed the breast was under planar stress with values of 30 kPa for Young's modulus and 0.3 for Poisson's ratio. Dose distributions from round and skin-dose optimized applicators in cranial-caudal and medial-lateral compressions were deformed using 0.1 cm planar resolution. Dose distributions, skin doses, and dose-volume histograms were generated. Results were examined as a function of breast thickness, applicator size, target size, and offset distance from the center. RESULTS: Over the range of examined thicknesses, target size increased several millimeters as compression thickness decreased. This trend increased with increasing offset distances. Applicator size minimally affected target coverage, until applicator size was less than the compressed target size. In all cases, with an applicator larger or equal to the compressed target size, > 90% of the target covered by > 90% of the prescription dose. In all cases, dose coverage became less uniform as offset distance increased and average dose increased. This effect was more pronounced for smaller target-applicator combinations. CONCLUSIONS: The model exhibited skin dose trends that matched MC-generated benchmarking results within 2% and clinical observations over a similar range of breast thicknesses and target sizes. The model provided quantitative insight on dosimetric treatment variables over a range of clinical circumstances. These findings highlight the need for careful target localization and accurate identification of compression thickness and target offset.

Climate variability and change exert disproportionate impacts on the water sector because water is a crosscutting resource for food production, energy generation, economic development, poverty alleviation, and ecosystem processes. Flexible surface water and groundwater storage together with adaptive water governance are increasingly recognized and deployed to strengthen climate resilience, specifically by buffering drought and flood extremes, bridging interannual variability, and providing for multiple uses of water, including environmental flows. Adaptation can be further enhanced by the following: (1) accounting for hydroclimatic and water-demand uncertainties; (2) strengthening institutional learning in relation to reservoirs (reoperations as well as mechanisms to address growing civil-society critiques of “hard-path dependence”); (3) increasing flexibility of policies for infrastructure (including readaptation to past cycles of infrastructure development); and (4) building on science-policy dialogues that link infrastructure and governance. An array of complementary adaptation tools will buttress climate resilience. Some emerging techniques include underground storage, distributed basin-wide enhancement of water retention, efficient water use (with limits on the expansion of new demands on saved water), and wastewater reclamation and reuse (with their own emerging storage and recovery techniques). Each of these techniques is directly linked to reservoirs in practical and operational terms. Conjunctive surface-water and groundwater storage must be further developed through infrastructure, institutional, and policy approaches including groundwater banking, trading and credit schemes, water swaps (substitutions and exchanges), and a robust approach to targeted water storage for climate resilience.

En este trabajo se analiza la eficiencia física, comercial y global de los organismos operadores de agua en las localidades urbanas de México entre 2002 y 2008. A partir de sus puntajes se forman cuatro grupos que se comparan atendiendo a las variables que podrían afectar su desempeño. Los resultados indican que no existen cambios significativos en las eficiencias en este periodo. La eficiencia física es mayor en las localidades grandes, con elevados niveles de consumo, de PlB per cápita y de costos de producción; en cambio la eficiencia comercial y la recaudación por metro cúbico son superiores en las localidades que cuentan con mayor cobertura de micromedición.

Resumen: en este estudio se investigan los factores asociados con el desempeno de los organismos operadores de agua en Mexico, mediante el analisis de la estructura de correlacion de los principales indicadores para una muestra de 106 de ellos. Se clasificaron a partir de un analisis de cluster sobre componentes mas importantes, para identificar patrones de eficiencia relacionados con variables contextuales. Los resultados indican que el volumen de agua no contabiliza-da es mayor en organismos con mas empleados, por cada mil tomas. Esto tambien se correlaciona con bajos costos de produccion y tasas elevadas de precipitacion. Las ciudades mas grandes y desarrolladas tienen mejor acceso a los ser-vicios de agua potable y alcantarillado; aunque la cobertura tiende a ser menor en las que crecen con mayor rapidez. El porcentaje de recaudacion y el ingreso promedio por me-tro cubico son mayores en localidades con micromedicion alta, donde tambien la relacion ingreso-costo es mejor. Palabras clave

Online analytical techniques were used to monitor fast and strong exothermic nitrations in microreactors. Mechanistic studies were conducted by using online FTIR microscopy to identify key intermediates in microchannels. IR spectroscopy, thermography and HPLC were used to investigate the influence of changing process conditions, to control the completeness of conversion and to monitor the stability of the entire microreaction process.

Resume Compte-tenu de l’importance des recits d’histoires dans le developpement psychologique, nous souhaiterions examiner l’influence des traumatismes vecus dans la petite enfance sur la capacite narrative des enfants. Une nouvelle methode permet le recueil standardise et l’evaluation de narrations d’histoires : c’est la methode de « debuts d’histoires » (“story stem”). Dans ce procede, des debuts d’histoires (”story stem”) standardises sont racontes aux enfants qui doivent ensuite, a l’aide de figurines raconter comment les histoires continuent. Deux exemples de recits d’enfants en periode de latence illustrent le fait que des traumatismes vecus peuvent conduire a un exces de pulsions destructrices et/ou a une restriction evitante, deux modes reactionnels diminuant l’un comme l’autre, la capacite narrative.

Studies comparing efficacy of fibre optic phototherapy to conventional phototherapy are performed mostly in term infants and give conflicting results. This randomized prospective study compares efficacy of fibre optic phototherapy using the Ohmeda Biliblanket device to conventional fluorescent phototherapy in preterm infants. A total of 124 preterm infants with a nonhaemolytic hyperbilirubinaemia were evaluated. Stratification at randomisation was performed according to birth weight (

The efficiency of XeCl excimer laser ablation of ceramics was increased by one order of magnitude due to special processing conditions. Increasing either the temperature of the material beyond 1000°C or using a water film on the workpiece surface enables ablation rates of more than 2 μm/pulse for Al2O3. The interaction phenomena are studied using process diagnostics.

Between June 1988 and September 1994, 100 girls and 32 boys 2 months to 15.5 years old (average 4.9 years) with 204 refluxing ureteral units were treated by endoscopic subureteral collagen injection. The collagen injected was of bovine origin and cross-linked with glutaraldehyde (Zyplast*). Followup ranged from 3 to 75 months (mean 33). Reflux was absent in 62.7% of cases 3 months after 1 endoscopic subureteral injection. Improvement to reflux grades I and II, generally not requiring further treatment, occurred in a further 15.2% of cases. A total of 66 ureters was injected twice. The overall cure rate after 1 or 2 injections was 79.4% 3 months after injection. There was no correlation between the risk of recurrent reflux and initial degree of reflux. Late recurrence of reflux following a reflux-free period occurred in 11.3% of the 204 units during the observation period, which varied from 3 months to 6 1/4 years. Reflux was absent after 1 or 2 injections, including late recurrence, in 70.6% of cases and in an additional 13.2% recurrent reflux was grade I or II, not necessitating any further treatment. Considering these results, subureteral collagen injection remains an adequate method of treatment for vesicoureteral reflux in children.

El acuífero de la Costa de Hermosillo es uno de los más sobreexplotados de México. A pesar de ello, se sigue utilizando para cultivos de bajo valor y alto consumo de agua. En el presente artículo se estimó, mediante cuatro modelos de programación lineal, la asignación óptima de cultivos con base en la restricción que impone la recarga del acuífero; y es posible generar 90 por ciento del valor de la producción agrícola actual con alrededor de una tercera parte del volumen extraído. Los resultados permiten indicar la importancia de la eliminación de subsidios, de la reconversión agrícola y del uso de técnicas de riego eficientes, como medidas para lograr el manejo sustentable del acuífero.

The physical-activity and sporting at the child and the teenager is probably, in these years 2000, in full change. In a paradoxical way, extremely sporting children or teenagers are living beside extremely sedentary school-boys, neglecting the majority of the physical-activities and preferring a home-lifestyle. In the evaluation of overload sporting lesion of at teenager, it is thus imperative to take into account not only the individual characteristics of the child: its sex, its age, its stage of growth, its psychology, the presence or not of preexistent pathologies or anatomical disorders. It is naturally necessary to wonder about the training methods of the activity, but it appears fundamental to me to evaluate the child from a sensitivo-motor point of view and this can be carried out by assessments physio-therapeutic or aptitude tests carried out by doctors of the sport.

El surgimiento de organizaciones civiles ambientalistas en Sonora ha ocurrido desde hace más de dos décadas, sin que haya investigaciones suficientes sobre sus características y estrategias. En el presente trabajo se analizan las relaciones de información, apoyo, recursos materiales y financieros que 11 de ellas en Hermosillo establecen entre sí y con otras de fuera del municipio, así como con instituciones académicas y organismos gubernamentales. Para cada tipo de relación se evaluó la densidad y jerarquización de la red interna y de las externas, y se detectaron las organizaciones más sobresalientes. Los resultados indican que entre mayores sean los costos de las ligas, su densidad o frecuencia disminuye. La red hermosillense tiene una estructura jerárquica y las mayores densidades en las relaciones de información, apoyo y materiales; mientras que para los recursos financieros, esta característica se observa en las ligas de organismos gubernamentales hacia los civiles.

A XeCl excimer laser ( λ = 308 nm) was used for investigating the possibilities of micromachining ceramic materials. The influence of the optical setup and laser parameters on the processing quality has been determined, as well as the behaviour of various ceramic materials during the machining process. The machining results and the structure quality are discussed concerning the shape of the holes, break-outs in the structure and the homogeneity of the hole depth and size. Optical microscopy and SEM investigations served as the main tools for the characterization. Strategies for large area micromachining were investigated to achieve a very large number of high quality microstructures.